?1605064101167700
SAMARA UNIVERSITY
COLLEGE OF ENGINEERING AND TECHNOLOGY
Evaluation of Biogas Generation from waste effluents of Samara University’s Student Cafeteria: Report
Chala Diriba1 *, Mohammed Hussen1, Milky Ali1
1College of Engineering and Technology, Samara University (Samara, Ethiopia)
Email: – HYPERLINK “mailto:[email protected][email protected]
Phone: – HYPERLINK “mailto:[email protected]” 0929046900

Submitted to: Samara University Research and Community Service core vice president
April-2018
Samara-Afar, Ethiopia
Evaluation of Biogas Generation from waste effluents of Samara University’s Student Cafeteria
Chala Diriba1 *, Mohammed Hussen1, Milky Ali1
1College of Engineering and Technology, Samara University (Samara, Ethiopia)
Email: – HYPERLINK “mailto:[email protected][email protected]
Phone: – HYPERLINK “mailto:[email protected]” 0929046900
AbstractSustainable Energy and waste management are among the focus for researchers and government activities. The anaerobic digester is a device used to produce energy, methane gas, from organic wastes. In this paper, an evaluation of Biogas Generation from Food in effluent waste in Student Cafeteria of Samara University presented. An observation used to identify the waste used for this research at initial survey. Four different distinguishable waste categories were identified for sample taking. Point one is a place where leftover food is temporarily stored and locals take for animal feed. Point two is from first manholes where effluent food contains cooked oils. The third category is oil-free waste points. The fourth point contains stored water which is separated by overflow process through the manhole of the food waste. Since changes in pH, temperature and C/N ratio are major factors affecting Anaerobic digestion, these factors are determined experimentally. The solid waste sample was taken from point two and point three to analysis their moisture content, organic matter, total nitrogen and C/N. The C/N ratio of waste is much greater than the allowable range for both waste samples. An addition of nitrogen contained material is necessary to improve the ratio of C/N before feeding this waste to the biogas digester. Furthermore, the quality of wastewater at point four was also analyzed to determine a possibility of using it for irrigation purposes for our campus.

Keywords: Sustainable Energy, waste management, Anaerobic digestion, biogas, C/N ratio

Contents
TOC o “1-3” h z u HYPERLINK l “_Toc512207356” 1.Background PAGEREF _Toc512207356 h 1
HYPERLINK l “_Toc512207357” 2.Material and Methods PAGEREF _Toc512207357 h 8
HYPERLINK l “_Toc512207358” 2.1. Study area description PAGEREF _Toc512207358 h 8
HYPERLINK l “_Toc512207359” 3.Result PAGEREF _Toc512207359 h 11
HYPERLINK l “_Toc512207360” 3.1. Waste solid characterization PAGEREF _Toc512207360 h 11
HYPERLINK l “_Toc512207361” 3.1.2 Composition of food waste PAGEREF _Toc512207361 h 11
HYPERLINK l “_Toc512207362” 3.1.2. Carbon to Nitrogen ratio(C/N) Ratio PAGEREF _Toc512207362 h 11
HYPERLINK l “_Toc512207363” 3.1.3. Temperature and Ph PAGEREF _Toc512207363 h 11
HYPERLINK l “_Toc512207364” 4.Discussion PAGEREF _Toc512207364 h 13
HYPERLINK l “_Toc512207365” 4.1. Utilization of unavoidable food-waste for biogas generation PAGEREF _Toc512207365 h 13
HYPERLINK l “_Toc512207366” 4.1.1. Contain biodegradable organic matter PAGEREF _Toc512207366 h 13
HYPERLINK l “_Toc512207367” 4.1.2. pH between PAGEREF _Toc512207367 h 13
HYPERLINK l “_Toc512207368” 4.1.3. C/N ratio PAGEREF _Toc512207368 h 13
HYPERLINK l “_Toc512207369” 4.2. Utilization of wastewater for irrigation PAGEREF _Toc512207369 h 14
HYPERLINK l “_Toc512207370” 4.2.1. Total dissolved solid PAGEREF _Toc512207370 h 14
HYPERLINK l “_Toc512207371” 4.2.2. Total alkalinity PAGEREF _Toc512207371 h 14
HYPERLINK l “_Toc512207372” 4.2.3. Total phosphorus PAGEREF _Toc512207372 h 14
HYPERLINK l “_Toc512207373” 4.2.4. Total Nitrogen PAGEREF _Toc512207373 h 14
HYPERLINK l “_Toc512207374” 5.Conclusions PAGEREF _Toc512207374 h 15
HYPERLINK l “_Toc512207375” H. Competing interests PAGEREF _Toc512207375 h 15
HYPERLINK l “_Toc512207376” I. Authors’ contributions PAGEREF _Toc512207376 h 15
HYPERLINK l “_Toc512207377” Acknowledgments PAGEREF _Toc512207377 h 15
HYPERLINK l “_Toc512207378” References PAGEREF _Toc512207378 h 15
HYPERLINK l “_Toc512207379” J. Annex PAGEREF _Toc512207379 h 17

Background
In Ethiopia, over 50% has grid coverage even though only 30% of the population can directly access to electricity. More than 80 percent of the country’s energy comes from firewood and charcoal, largely responsible for greenhouse gas emissions and deforestation. Ethiopia seeks to attain a triple win of achieving middle-income country status, carbon neutrality and climate resilient economy by the year 2025CITATION Kid l 1033 (UNDP).

Globally, about four billion tons of foods are produced for human consumption every year, of which 1.3 billion tones get lost or wasted CITATION FAO l 1033 (FAO). In Ethiopia, food waste is the single largest category of municipal solid waste which reported to have 80% of the theoretical methane yields ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “DOI” : “10.5755/j01.erem.63.1.2912”, “ISSN” : “2348-795X”, “abstract” : “Abstract: Now a day biogas production is one of the most promising renewable energy sources in Ethiopia. Anaerobic digestion is one of the effective ways of generating biogas. It is also a reliable method for treating food wastes such as cafeteria wastes, vegetable wastes etc. and cow dung and the digested slurry can be used as fertilizer to enhance the fertility of the soil. Co-digestion of food waste with cow dung or other feed stocks with low carbon content can improve process stability and methane production. Anaerobic co-digestion of food waste with cow dung is needed to enhance biogas production and very useful to treat these wastes. This review paper looks at the possibility of producing biogas from co- digestion of food waste with cow manure by optimizing the parameters that affect biogas production.”, “author” : { “dropping-particle” : “”, “family” : “Gashaw”, “given” : “Alemayehu”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Teshita”, “given” : “Abile”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “International Journal of Research (IJR)”, “id” : “ITEM-1”, “issue” : “7”, “issued” : { “date-parts” : “2014” }, “page” : “475-500”, “title” : “Co-Digestion of Ethiopian Food Waste with Cow Dung for Biogas Production”, “type” : “article-journal”, “volume” : “1” }, “uris” : “http://www.mendeley.com/documents/?uuid=d97e8de9-c23f-4848-91d6-afc64dba4f8b” } , “mendeley” : { “formattedCitation” : “(Gashaw and Teshita, 2014)”, “plainTextFormattedCitation” : “(Gashaw and Teshita, 2014)”, “previouslyFormattedCitation” : “(Gashaw and Teshita, 2014)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Gashaw and Teshita, 2014). Interest in use of small-scale biogas digesters in rural communities to treat and utilize organic wastes is increasing ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “DOI” : “10.3390/en5082911”, “ISBN” : “0098-1354”, “ISSN” : “0038092X”, “PMID” : “20832775”, “abstract” : “This review is a summary of different aspects of the design and operation of \nsmall-scale, household, biogas digesters. It covers different digester designs and materials used for construction, important operating parameters such as pH, temperature, substrate, and loading rate, applications of the biogas, the government policies concerning the use of household digesters, and the social and environmental effects of the digesters. Biogas is a value-added product of anaerobic digestion of organic compounds. Biogas production depends on different factors including: pH, temperature, substrate, loading rate, hydraulic retention time (HRT), C/N ratio, and mixing. Household digesters are cheap, easy to handle, and reduce the amount of organic household waste. The size of these digesters varies between 1 and 150 m3. The common designs include fixed dome, floating drum, and plug flow type. Biogas and fertilizer obtained at the end of anaerobic digestion could be used for cooking, lighting, and electricity.”, “author” : { “dropping-particle” : “”, “family” : “Smith”, “given” : “JU”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Balana”, “given” : “Bedru Babulo”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Black”, “given” : “Helaina”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Blottnitz”, “given” : “Harro”, “non-dropping-particle” : “von”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Casson”, “given” : “Emma”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Glenk”, “given” : “Klaus”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Langan”, “given” : “Simon”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Matthews”, “given” : “Robin”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Mugisha”, “given” : “Johnny”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Smith”, “given” : “Peter”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Walekhwa”, “given” : “Peter Nabusiu”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Yongabi”, “given” : “Kenneth Anchang”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Tumwesige”, “given” : “Vianney”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Joanne”, “given” : “S”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Avery”, “given” : “Lisa”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “AGAMA Energy (Pty) Ltd”, “given” : “”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Muriuki”, “given” : “John”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Rajendran”, “given” : “Karthik”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Aslanzadeh”, “given” : “Solmaz”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Taherzadeh”, “given” : “Mohammad J.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “enerpedia”, “given” : “”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Vinoth Kumar”, “given” : “K.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Kasturi Bai”, “given” : “R.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Programme”, “given” : “Scottish Biofuel”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Gracia Munganga”, “given” : “”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “1st World Sustain. Forum”, “id” : “ITEM-1”, “issue” : “10”, “issued” : { “date-parts” : “2013” }, “page” : “2911-2942”, “title” : “The potential of small-scale biogas digesters to alleviate poverty and improve Long term sustainability of ecosystem services in Sub-Saharan Africa”, “type” : “article-journal”, “volume” : “5” }, “uris” : “http://www.mendeley.com/documents/?uuid=f0040f14-470d-4895-a8ad-19d417194536” } , “mendeley” : { “formattedCitation” : “(Smith <i>et al.</i>, 2013)”, “plainTextFormattedCitation” : “(Smith et al., 2013)”, “previouslyFormattedCitation” : “(Smith <i>et al.</i>, 2013)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Smith et al., 2013) The higher institutions cafeteria wastes, in Ethiopia, such as leftover of Injera, which is made of teff, contains 15% protein, 3% fat and 82% carbohydrates and has high calorie content ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “DOI” : “10.5755/j01.erem.63.1.2912”, “ISSN” : “2348-795X”, “abstract” : “Abstract: Now a day biogas production is one of the most promising renewable energy sources in Ethiopia. Anaerobic digestion is one of the effective ways of generating biogas. It is also a reliable method for treating food wastes such as cafeteria wastes, vegetable wastes etc. and cow dung and the digested slurry can be used as fertilizer to enhance the fertility of the soil. Co-digestion of food waste with cow dung or other feed stocks with low carbon content can improve process stability and methane production. Anaerobic co-digestion of food waste with cow dung is needed to enhance biogas production and very useful to treat these wastes. This review paper looks at the possibility of producing biogas from co- digestion of food waste with cow manure by optimizing the parameters that affect biogas production.”, “author” : { “dropping-particle” : “”, “family” : “Gashaw”, “given” : “Alemayehu”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Teshita”, “given” : “Abile”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “International Journal of Research (IJR)”, “id” : “ITEM-1”, “issue” : “7”, “issued” : { “date-parts” : “2014” }, “page” : “475-500”, “title” : “Co-Digestion of Ethiopian Food Waste with Cow Dung for Biogas Production”, “type” : “article-journal”, “volume” : “1” }, “uris” : “http://www.mendeley.com/documents/?uuid=d97e8de9-c23f-4848-91d6-afc64dba4f8b” } , “mendeley” : { “formattedCitation” : “(Gashaw and Teshita, 2014)”, “plainTextFormattedCitation” : “(Gashaw and Teshita, 2014)”, “previouslyFormattedCitation” : “(Gashaw and Teshita, 2014)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Gashaw and Teshita, 2014). The depletion of the world petroleum reserves and the increased environmental threat and security concerns have stimulated the search for alternative sources of petroleum-based fuels. Biogas, a flammable gas (for cooking and lighting), obtained from biogenic sources is being viewed as one of the best alternatives to petroleum-based ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “DOI” : “10.5755/j01.erem.63.1.2912”, “ISSN” : “2348-795X”, “abstract” : “Abstract: Now a day biogas production is one of the most promising renewable energy sources in Ethiopia. Anaerobic digestion is one of the effective ways of generating biogas. It is also a reliable method for treating food wastes such as cafeteria wastes, vegetable wastes etc. and cow dung and the digested slurry can be used as fertilizer to enhance the fertility of the soil. Co-digestion of food waste with cow dung or other feed stocks with low carbon content can improve process stability and methane production. Anaerobic co-digestion of food waste with cow dung is needed to enhance biogas production and very useful to treat these wastes. This review paper looks at the possibility of producing biogas from co- digestion of food waste with cow manure by optimizing the parameters that affect biogas production.”, “author” : { “dropping-particle” : “”, “family” : “Gashaw”, “given” : “Alemayehu”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Teshita”, “given” : “Abile”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “International Journal of Research (IJR)”, “id” : “ITEM-1”, “issue” : “7”, “issued” : { “date-parts” : “2014” }, “page” : “475-500”, “title” : “Co-Digestion of Ethiopian Food Waste with Cow Dung for Biogas Production”, “type” : “article-journal”, “volume” : “1” }, “uris” : “http://www.mendeley.com/documents/?uuid=d97e8de9-c23f-4848-91d6-afc64dba4f8b” } , “mendeley” : { “formattedCitation” : “(Gashaw and Teshita, 2014)”, “plainTextFormattedCitation” : “(Gashaw and Teshita, 2014)”, “previouslyFormattedCitation” : “(Gashaw and Teshita, 2014)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Gashaw and Teshita, 2014)
Today, methane accounts for nearly 9% of domestic greenhouse gas emissions. Thirty-six percent of these emissions come from the agricultural sector, equivalent to over 200 million tons of carbon pollution. While methane’s lifetime in the atmosphere is much shorter than carbon dioxide, it is more efficient at trapping radiation. Pound for pound, the comparative impact of methane on climate change is over 20 times greater than carbon dioxide over a 100-year period.

Biogas systems have the potential to capture methane that would escape into the atmosphere and utilize it to create energy (e.g., electricity, heat, vehicle fuel). Other byproducts of biogas systems include non-energy products such as nutrient-rich soil amendments, pelletized and pumpable fertilizers, and even feedstock for plastics and chemicals. Successful biogas systems capture and use gas from landfills and/or the anaerobic digestion of wastewater biosolids, animal manure, and other organics for energy. Each system includes both the infrastructure to manage the organic wastes as well as the equipment to generate energy from the resulting biogas. These systems have been used on a commercial scale in the United States since the late 1970s when concerns over energy prices and U.S. dependence on oil spurred interest in the use of recovered biogas as a source of energyADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “ISBN” : “9781634825276”, “abstract” : “Methane is both a potent greenhouse gas and a valuable source of energy. In the Climate Action Plan, President Obama directed the Administration to develop a comprehensive, interagency strategy to reduce methane emissions. In March 2014, the White House released the Climate Action Plan – Strategy to Reduce Methane Emissions. As part of the Strategy, the U.S. Department of Agriculture (USDA), the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE) committed to work with industry leaders to formulate a biogas roadmap.”, “author” : { “dropping-particle” : “”, “family” : “USDA”, “given” : “”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “EPA”, “given” : “”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “DOE”, “given” : “”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “id” : “ITEM-1”, “issue” : “August”, “issued” : { “date-parts” : “2014” }, “page” : “28”, “title” : “Biogas Opportunities Roadmap: Voluntary Actions to Reduce Methane Emissions and Increase Energy Independence”, “type” : “article-journal” }, “uris” : “http://www.mendeley.com/documents/?uuid=48046a95-32c8-48ad-b014-57e3907ddfd3” } , “mendeley” : { “formattedCitation” : “(USDA, EPA and DOE, 2014)”, “plainTextFormattedCitation” : “(USDA, EPA and DOE, 2014)”, “previouslyFormattedCitation” : “(USDA, EPA and DOE, 2014)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(USDA, EPA, and DOE, 2014)

Anaerobic digestion (AD) is a proven technology for sewage sludge treatment and which allows generation of renewable energy from the same process. During AD, microorganisms break down the organic matter contained in the sludge and convert it into biogas, a mixture of main methane and carbon dioxide, which can be used for electricity, heat and biofuel production. At the same time, the sludge is stabilized and its dry matter content is reduced. The benefits of AD of sewage
sludge is widely recognized and the technology is well established in many countries. Today, a high proportion of biogas produced in AD plants is from those on municipal wastewater treatment sites (see Table 1) and there is still an enormous potential to exploit worldwide. ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “ISBN” : “9781910154229”, “author” : { “dropping-particle” : “”, “family” : “Bachmann”, “given” : “Nathalie”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Bachmann”, “given” : “Nathalie”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “editor” : { “dropping-particle” : “”, “family” : “BAxTER”, “given” : “David”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “id” : “ITEM-1”, “issued” : { “date-parts” : “2015” }, “publisher” : “IEA Bioenergy”, “publisher-place” : “massongex, switzerland”, “title” : “Sustainable biogas production in municipal wastewater treatment plants”, “type” : “paper-conference” }, “uris” : “http://www.mendeley.com/documents/?uuid=65c6887f-8d5e-4cef-9799-6c1959ec664e” } , “mendeley” : { “formattedCitation” : “(Bachmann and Bachmann, 2015)”, “plainTextFormattedCitation” : “(Bachmann and Bachmann, 2015)”, “previouslyFormattedCitation” : “(Bachmann and Bachmann, 2015)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Bachmann and Bachmann, 2015)
Energy production and environmental protection are the burning issues of the world. This is because, energy production and environmental protection are very important for satisfying basic needs, improving social welfare, and achieving economic development of a country. The accomplishment of civilization has largely been achieved through the increasingly efficient and extensive harnessing of various forms of energy to extend human capabilities and initiatives CITATION Har12 l 1033 (Harilal, 2012)The process of biogas generation

Anaerobic Digestion (AD) is a process which converts complex organic compounds such as carbohydrates, fats, and protein in the absence of oxygen and produces a mixture of methane, carbon dioxide and others (biogas). This mixture, biogas, is used for energy recovery and treats waste for environmental benefits. ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “DOI” : “10.4172/2157-7110.1000478”, “ISSN” : “21577110”, “abstract” : “Anaerobic digestion can be used to degrade food waste and recover energy. Methane is a biogas that can be efficiently converted in electricity. Organic loading rate, temperature, time, pH, carbon to nitrogen ratio are important factors to be operated in the bioreactors and still are challenges in this process to increase biogas production. It has been reviewed the single phase and two-stage bioreactors in the anaerobic digestion of food waste as well organic loading rates and the rate of methane produced.”, “author” : { “dropping-particle” : “”, “family” : “Doelle K”, “given” : “Oliveira F”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “Journal of Food Processing & Technology”, “id” : “ITEM-1”, “issue” : “08”, “issued” : { “date-parts” : “2015” }, “page” : “8-10”, “title” : “Anaerobic Digestion of Food Waste to Produce Biogas: A Comparison of Bioreactors to Increase Methane Contentu00c3u00a2u00c2€u00c2“A Review”, “type” : “article-journal”, “volume” : “06” }, “uris” : “http://www.mendeley.com/documents/?uuid=99b02cc9-72da-489c-947d-b894b4eb770e” } , “mendeley” : { “formattedCitation” : “(Doelle K, 2015)”, “plainTextFormattedCitation” : “(Doelle K, 2015)”, “previouslyFormattedCitation” : “(Doelle K, 2015)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Doelle K, 2015). The conversion of complex organic compounds into methane and carbon dioxide requires different groups of micro-organisms and is carried out in the sequence of four stages: Hydrolysis, Acidogenesis, Acetogenesis and Methanogenesis ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “abstract” : “The need to provide affordable energy for poor communities is of great importance world wide. This is just the same for poor communities in European countries. This study analyses the feasibility and potential production of biogas in these countries with emphasis on Romania, Kyrgyzstan, Georgia, Kazakhstan and Armenia. Comparison of the use of the biogas plants is done from India, China, Nepal and Bolivia and literature review is done as well before suggesting the same technology for the colder target communities. Suggestions are made on whether to use the plants on household or community level afterwards.”, “author” : { “dropping-particle” : “”, “family” : “Balasubramaniyam”, “given” : “Urmila”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Zisengwe”, “given” : “Llionel S”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Meriggi”, “given” : “Niccolo”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Buysman”, “given” : “Eric”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “id” : “ITEM-1”, “issue” : “May”, “issued” : { “date-parts” : “2008” }, “page” : “68”, “title” : “Biogas production in climates with long cold winters”, “type” : “article-journal” }, “uris” : “http://www.mendeley.com/documents/?uuid=b1de7e44-dd28-42aa-bb35-1b18000b0fc3” } , “mendeley” : { “formattedCitation” : “(Balasubramaniyam <i>et al.</i>, 2008)”, “plainTextFormattedCitation” : “(Balasubramaniyam et al., 2008)”, “previouslyFormattedCitation” : “(Balasubramaniyam <i>et al.</i>, 2008)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Balasubramaniyam et al., 2008) as shown in Figure 1.

Figure SEQ Figure * ARABIC 1: The conversion process of complex organic compounds into methane
During hydrolysis (addition of water) complex organic substrates converted into smaller components, Carbohydrates ? Sugars, Fats ? Fatty Acids and Protein ?Amino Acids. In step two of these smaller units (sugars, fatty acids, and amino acids) converted to volatile fatty acid, ethanol, CO2, and H2 by acidogenic bacteria. In the third step, Acetogenic bacteria convert these fermentation products into acetic acid, CO2, and H2. In the final step (4th step), methanogenic bacteria use hydrogen and acetate (most important substrate) and produce methane(most important final product) and carbon dioxide ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “abstract” : “The need to provide affordable energy for poor communities is of great importance world wide. This is just the same for poor communities in European countries. This study analyses the feasibility and potential production of biogas in these countries with emphasis on Romania, Kyrgyzstan, Georgia, Kazakhstan and Armenia. Comparison of the use of the biogas plants is done from India, China, Nepal and Bolivia and literature review is done as well before suggesting the same technology for the colder target communities. Suggestions are made on whether to use the plants on household or community level afterwards.”, “author” : { “dropping-particle” : “”, “family” : “Balasubramaniyam”, “given” : “Urmila”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Zisengwe”, “given” : “Llionel S”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Meriggi”, “given” : “Niccolo”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Buysman”, “given” : “Eric”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “id” : “ITEM-1”, “issue” : “May”, “issued” : { “date-parts” : “2008” }, “page” : “68”, “title” : “Biogas production in climates with long cold winters”, “type” : “article-journal” }, “uris” : “http://www.mendeley.com/documents/?uuid=b1de7e44-dd28-42aa-bb35-1b18000b0fc3” } , “mendeley” : { “formattedCitation” : “(Balasubramaniyam <i>et al.</i>, 2008)”, “plainTextFormattedCitation” : “(Balasubramaniyam et al., 2008)”, “previouslyFormattedCitation” : “(Balasubramaniyam <i>et al.</i>, 2008)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Balasubramaniyam et al., 2008). Biogas technology was introduced to Ethiopia as early as 1979 CITATION Get07 l 1033 (Esthete, 2007). Biogas is about 20% lighter than air and has an ignition temperature in the range of 6500C – 7500C. It has no odor, color, and burns with clear blue flame similar to that of Liquefied petroleum gas. Its caloric value is 20 MegaJoules /m3 and burns with 60 % efficiency in a conventional biogas stove. The gas is a mixture of different gases of different composition ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “abstract” : “BIOGAS 1”, “author” : { “dropping-particle” : “”, “family” : “By”, “given” : “Submitted”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “Dapartment of Biotechnology and Medical Engineering”, “id” : “ITEM-1”, “issued” : { “date-parts” : “2011” }, “page” : “1-48”, “title” : “BIOGAS PRODUCTION FROM KITCHEN WASTE A Seminar Report submitted in partial fulfillment of the requirements for Bachelor of Technology ( Biotechnology ) Prof . Krishna Parmanik Department of Biotechnology and Medical Engineering National Institute of Techn”, “type” : “article-journal” }, “uris” : “http://www.mendeley.com/documents/?uuid=35a0ccf0-00e8-4cd6-ac0f-c844812fb029” } , “mendeley” : { “formattedCitation” : “(By, 2011)”, “plainTextFormattedCitation” : “(By, 2011)”, “previouslyFormattedCitation” : “(By, 2011)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(By, 2011) as shown in table 1. Biogas technology is one of the integrated waste management systems that is a clean, renewable and naturally produced. It is one of the under-utilized sources of energy ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “DOI” : “10.3390/en5082911”, “ISBN” : “0098-1354”, “ISSN” : “0038092X”, “PMID” : “20832775”, “abstract” : “This review is a summary of different aspects of the design and operation of \nsmall-scale, household, biogas digesters. It covers different digester designs and materials used for construction, important operating parameters such as pH, temperature, substrate, and loading rate, applications of the biogas, the government policies concerning the use of household digesters, and the social and environmental effects of the digesters. Biogas is a value-added product of anaerobic digestion of organic compounds. Biogas production depends on different factors including: pH, temperature, substrate, loading rate, hydraulic retention time (HRT), C/N ratio, and mixing. Household digesters are cheap, easy to handle, and reduce the amount of organic household waste. The size of these digesters varies between 1 and 150 m3. The common designs include fixed dome, floating drum, and plug flow type. Biogas and fertilizer obtained at the end of anaerobic digestion could be used for cooking, lighting, and electricity.”, “author” : { “dropping-particle” : “”, “family” : “Smith”, “given” : “JU”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Balana”, “given” : “Bedru Babulo”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Black”, “given” : “Helaina”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Blottnitz”, “given” : “Harro”, “non-dropping-particle” : “von”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Casson”, “given” : “Emma”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Glenk”, “given” : “Klaus”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Langan”, “given” : “Simon”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Matthews”, “given” : “Robin”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Mugisha”, “given” : “Johnny”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Smith”, “given” : “Peter”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Walekhwa”, “given” : “Peter Nabusiu”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Yongabi”, “given” : “Kenneth Anchang”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Tumwesige”, “given” : “Vianney”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Joanne”, “given” : “S”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Avery”, “given” : “Lisa”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “AGAMA Energy (Pty) Ltd”, “given” : “”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Muriuki”, “given” : “John”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Rajendran”, “given” : “Karthik”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Aslanzadeh”, “given” : “Solmaz”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Taherzadeh”, “given” : “Mohammad J.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “enerpedia”, “given” : “”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Vinoth Kumar”, “given” : “K.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Kasturi Bai”, “given” : “R.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Programme”, “given” : “Scottish Biofuel”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Gracia Munganga”, “given” : “”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “1st World Sustain. Forum”, “id” : “ITEM-1”, “issue” : “10”, “issued” : { “date-parts” : “2013” }, “page” : “2911-2942”, “title” : “The potential of small-scale biogas digesters to alleviate poverty and improve Long term sustainability of ecosystem services in Sub-Saharan Africa”, “type” : “article-journal”, “volume” : “5” }, “uris” : “http://www.mendeley.com/documents/?uuid=f0040f14-470d-4895-a8ad-19d417194536” } , “mendeley” : { “formattedCitation” : “(Smith <i>et al.</i>, 2013)”, “plainTextFormattedCitation” : “(Smith et al., 2013)”, “previouslyFormattedCitation” : “(Smith <i>et al.</i>, 2013)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Smith et al., 2013)
Table SEQ Table * ARABIC 1: Biogas component and composition
S. No. Biogas composition % Composition
Methane 50-70
Carbon dioxide 30-40
Hydrogen 5-10
Nitrogen 1-2
Water vapor 0.3
Hydrogen sulfide Trace
Of these gas, methane is useful and is a substitute for firewood (reduce deforestation), dung, agricultural residues, petrol, diesel, and electricity, depending on the nature of the task, and local supply conditions and constraints. Biogas has a potential benefit to the household for improved food production; improved indoor air quality and sanitation; water reuse and recycling; reduction in odors and local job creation. Biogas systems also provide a residue of organic waste, after anaerobic digestion that has superior nutrient qualities over the usual organic fertilizer ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “abstract” : “BIOGAS 1”, “author” : { “dropping-particle” : “”, “family” : “By”, “given” : “Submitted”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “Dapartment of Biotechnology and Medical Engineering”, “id” : “ITEM-1”, “issued” : { “date-parts” : “2011” }, “page” : “1-48”, “title” : “BIOGAS PRODUCTION FROM KITCHEN WASTE A Seminar Report submitted in partial fulfillment of the requirements for Bachelor of Technology ( Biotechnology ) Prof . Krishna Parmanik Department of Biotechnology and Medical Engineering National Institute of Techn”, “type” : “article-journal” }, “uris” : “http://www.mendeley.com/documents/?uuid=35a0ccf0-00e8-4cd6-ac0f-c844812fb029” } , “mendeley” : { “formattedCitation” : “(By, 2011)”, “plainTextFormattedCitation” : “(By, 2011)”, “previouslyFormattedCitation” : “(By, 2011)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(By, 2011).
Factors to be considered
Many factors affect the design and performance of anaerobic digestion processes. In operation of biogas digestion process, different factors determine its productivity. The main factors are Sublayer composition, Temperature inside the digester, Retention time, Working pressure of the digester, Fermentation medium pH and Volatile fatty acids ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “author” : { “dropping-particle” : “”, “family” : “Letters”, “given” : “Romanian Biotechnological”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “id” : “ITEM-1”, “issue” : “3”, “issued” : { “date-parts” : “2014” }, “page” : “9283-9296”, “title” : “Main factors affecting biogas production – an overview”, “type” : “article-journal”, “volume” : “19” }, “uris” : “http://www.mendeley.com/documents/?uuid=6f84c9a1-06ff-486c-8d92-2b6aaae47fdb” } , “mendeley” : { “formattedCitation” : “(Letters, 2014)”, “plainTextFormattedCitation” : “(Letters, 2014)”, “previouslyFormattedCitation” : “(Letters, 2014)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Letters, 2014). The physical and chemical characteristics of the organic waste are important information for designing and operating anaerobic digesters. They include, but not limited to, moisture content, volatile solids content, nutrient contents, particle size, and biodegradability ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “DOI” : “10.1016/j.biortech.2006.02.039”, “ISBN” : “0960-8524”, “ISSN” : “09608524”, “PMID” : “16635571”, “abstract” : “Food waste collected in the City of San Francisco, California, was characterized for its potential for use as a feedstock for anaerobic digestion processes. The daily and weekly variations of food waste composition over a two-month period were measured. The anaerobic digestibility and biogas and methane yields of the food waste were evaluated using batch anaerobic digestion tests performed at 50 u00b0C. The daily average moisture content (MC) and the ratio of volatile solids to total solids (VS/TS) determined from a week-long sampling were 70% and 83%, respectively, while the weekly average MC and VS/TS were 74% and 87%, respectively. The nutrient content analysis showed that the food waste contained well balanced nutrients for anaerobic microorganisms. The methane yield was determined to be 348 and 435 mL/g VS, respectively, after 10 and 28 days of digestion. The average methane content of biogas was 73%. The average VS destruction was 81% at the end of the 28-day digestion test. The results of this study indicate that the food waste is a highly desirable substrate for anaerobic digesters with regards to its high biodegradability and methane yield. u00a9 2006 Elsevier Ltd. All rights reserved.”, “author” : { “dropping-particle” : “”, “family” : “Zhang”, “given” : “Ruihong”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “El-Mashad”, “given” : “Hamed M.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Hartman”, “given” : “Karl”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Wang”, “given” : “Fengyu”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Liu”, “given” : “Guangqing”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Choate”, “given” : “Chris”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Gamble”, “given” : “Paul”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “Bioresource Technology”, “id” : “ITEM-1”, “issue” : “4”, “issued” : { “date-parts” : “2007” }, “page” : “929-935”, “title” : “Characterization of food waste as feedstock for anaerobic digestion”, “type” : “article-journal”, “volume” : “98” }, “uris” : “http://www.mendeley.com/documents/?uuid=55fb4f8b-523c-48cb-a7f0-49d63effbeff” } , “mendeley” : { “formattedCitation” : “(Zhang <i>et al.</i>, 2007)”, “plainTextFormattedCitation” : “(Zhang et al., 2007)”, “previouslyFormattedCitation” : “(Zhang <i>et al.</i>, 2007)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Zhang et al., 2007)
In this study, the objectives were to characterize the unavoidable food waste and effluent wastewater from Samara University’s student cafeteria to evaluate biogas generation and utilization for irrigation purposes in the garden of the university. This study was mainly initiated to evaluate the feasibility of converting the food waste into biogas energy.

Table SEQ Table * ARABIC 2: Characteristics of food wastes reported in the literature

Source Characteristics C/N Reference
MC% O.M% T.N% Dining hall 80 14.7 CITATION Han04 l 1033 (Han, 2004)Fruit and vegetable waste 17 371 This study
Unavoidable University’s cafeteria 85 36.4 CITATION Rao04 l 1033 (Rao, 2004)Opportunities and threats of biogas construction in the hot climate

Due to the generally warm climate in the study area, ambient temperature is sufficient to maintain the fermentation process and no additional heating is required.
The operational design of a biogas digester is generally classified according to operation temperature (psychrophilic ;20°C; mesophilic 30-42°C; or thermophilic (50-60°C); total solids content (wet 5-20% dry matter; dry ; 20% dry matter); the nature of feeding and output operations (continuous flow or batch systems); the number of digesters or separate phases (single, double or multiple); and the digester layout (vertical tank or horizontal plug flow) ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “DOI” : “10.3390/en5082911”, “ISBN” : “0098-1354”, “ISSN” : “0038092X”, “PMID” : “20832775”, “abstract” : “This review is a summary of different aspects of the design and operation of \nsmall-scale, household, biogas digesters. It covers different digester designs and materials used for construction, important operating parameters such as pH, temperature, substrate, and loading rate, applications of the biogas, the government policies concerning the use of household digesters, and the social and environmental effects of the digesters. Biogas is a value-added product of anaerobic digestion of organic compounds. Biogas production depends on different factors including: pH, temperature, substrate, loading rate, hydraulic retention time (HRT), C/N ratio, and mixing. Household digesters are cheap, easy to handle, and reduce the amount of organic household waste. The size of these digesters varies between 1 and 150 m3. The common designs include fixed dome, floating drum, and plug flow type. Biogas and fertilizer obtained at the end of anaerobic digestion could be used for cooking, lighting, and electricity.”, “author” : { “dropping-particle” : “”, “family” : “Smith”, “given” : “JU”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Balana”, “given” : “Bedru Babulo”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Black”, “given” : “Helaina”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Blottnitz”, “given” : “Harro”, “non-dropping-particle” : “von”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Casson”, “given” : “Emma”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Glenk”, “given” : “Klaus”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Langan”, “given” : “Simon”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Matthews”, “given” : “Robin”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Mugisha”, “given” : “Johnny”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Smith”, “given” : “Peter”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Walekhwa”, “given” : “Peter Nabusiu”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Yongabi”, “given” : “Kenneth Anchang”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Tumwesige”, “given” : “Vianney”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Joanne”, “given” : “S”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Avery”, “given” : “Lisa”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “AGAMA Energy (Pty) Ltd”, “given” : “”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Muriuki”, “given” : “John”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Rajendran”, “given” : “Karthik”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Aslanzadeh”, “given” : “Solmaz”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Taherzadeh”, “given” : “Mohammad J.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “enerpedia”, “given” : “”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Vinoth Kumar”, “given” : “K.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Kasturi Bai”, “given” : “R.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Programme”, “given” : “Scottish Biofuel”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” }, { “dropping-particle” : “”, “family” : “Gracia Munganga”, “given” : “”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “1st World Sustain. Forum”, “id” : “ITEM-1”, “issue” : “10”, “issued” : { “date-parts” : “2013” }, “page” : “2911-2942”, “title” : “The potential of small-scale biogas digesters to alleviate poverty and improve Long term sustainability of ecosystem services in Sub-Saharan Africa”, “type” : “article-journal”, “volume” : “5” }, “uris” : “http://www.mendeley.com/documents/?uuid=f0040f14-470d-4895-a8ad-19d417194536” } , “mendeley” : { “formattedCitation” : “(Smith <i>et al.</i>, 2013)”, “plainTextFormattedCitation” : “(Smith et al., 2013)”, “previouslyFormattedCitation” : “(Smith <i>et al.</i>, 2013)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Smith et al., 2013)
Available Nutrient
For growth bacteria need organic substances as a source of carbon, energy and certain mineral nutrients. Generation of bio-mass requires carbon, oxygen, and hydrogen an adequate supply of nitrogen, sulfur, phosphorous, potassium, calcium, magnesium and a number of trace elements which are usually available in municipal sewage and agricultural residues. Since the higher concentration of any individual substance usually has an inhibitory effects needs an analysis CITATION ene l 1033 (energypedia).

Wastewater Characterization
Total Dissolved Solid(TDS)
Total Dissolved Solid is measured in (mg/l) or ppm. Water quality parameters for irrigation use are Class one (C1), Class Two(C2), Class Three (C3) and Class Four (C4). C1 has a threshold value of 0-160mg/l. Water with this range of TDS is appropriate to most plants when the land has little saltiness. C2 has a threshold value of 161mg/l – 480 mg/l and called a water with a moderate salt. This water is appropriate for irrigations that can undergo salts increase where there is moderate draining for the land. C3 a third class water for irrigation having a value of 481 mg/l – 1440 mg/l. A water in this range is a water of high salt and it is appropriate for plants when a land has a good draining system. The last category C4 has a TDS(mg/l) threshold value of 1441-3200. A water in this range of TDS is characterized as very high salt and appropriate for plants resistance to salts and on certain well-drained lands and deep washing for salts ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “DOI” : “10.2495/SDP-V9-N3-389-399”, “ISSN” : “1743761X”, “abstract” : “This study was conducted by analyzing data from satellite image and geographical information system (GIS) to classify water quality parameters of Euphrates River in Iraq for irrigation use. The main purpose of this research was to develop water quality classifi cation models for Euphrates River, Iraq, using remote sensing. The water quality parameters used in this study included total dissolved solids (TDS), chlorides (Cl-), electrical conductivity (EC), and sodium adsorption ratio (SAR). The classifi cation models were used for spatial prediction of these four parameters to determine the water’s suitability for irrigation use from the satellite image. GIS techniques were used in the beginning to project the coordinates of 16 stations along the River in LANDSAT satellite image for Iraq map. Positive strong correlations between digital numbers of the satellite image at Band 2 with the water quality parameters in December, 2009, helped to build four regression models between these two variables. These models could be used to predict these four water quality parameters (TDS, Cl-, EC, and SAR) at any point along the River in Iraq from the satellite image directly. The next stage depends on satellite image analyses for the sake of building water quality classifi cation models for Euphrates River on the satellite image to classify each of these water quality parameters according to irrigation use. These water quality classifi cation models can be used to manage the agriculture along the basin of the River and to discover the locations of pollution in the River. The general objective of this research is attaining a classifi cation model that supports the identifi cation, characterization and monitoring of water quality parameters that have an infl uence in irrigation. u00a9 2014 WIT Press.”, “author” : { “dropping-particle” : “”, “family” : “Al-Bahrani”, “given” : “H. S.”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “International Journal of Sustainable Development and Planning”, “id” : “ITEM-1”, “issue” : “3”, “issued” : { “date-parts” : “2014” }, “page” : “389-399”, “title” : “Spatial prediction and classification of water quality parameters for irrigation use in the euphrates river (iraq) using gis and satellite image analyses”, “type” : “article-journal”, “volume” : “9” }, “uris” : “http://www.mendeley.com/documents/?uuid=f403c4f2-9bd5-467b-bf10-7e333108bc66” } , “mendeley” : { “formattedCitation” : “(Al-Bahrani, 2014)”, “plainTextFormattedCitation” : “(Al-Bahrani, 2014)”, “previouslyFormattedCitation” : “(Al-Bahrani, 2014)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Al-Bahrani, 2014)
Total Nitrogen (as N)
Nitrogen is a plant nutrient and stimulates crop growth. Natural soil nitrogen or added fertilizers are the usual sources, but nitrogen in the irrigation water has much the same effect as soil-applied fertilizer nitrogen and an excess will cause problems, just as too much fertilizer would. If excessive quantities are present or applied, production of several commonly grown crops may be upset because of over-stimulation of growth, delayed maturity or poor quality. There are many ways of reporting nitrogen since it is combined in various organic and inorganic complexes. The most important factor for plants is the total amount of nitrogen (N) regardless of whether it is in the form of nitrate-nitrogen (NO3-N), ammonium-nitrogen (NH4-N) or organic-nitrogen (Org-N) CITATION FAO2 l 1033 (FAO). Wastewater category is Very low in total (N);18. Low (19-36), medium (37-54), high (55-90) and very high if total nitrogen is (;90) ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “author” : { “dropping-particle” : “”, “family” : “A. nalytic”, “given” : “Spectrum”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “id” : “ITEM-1”, “issue” : “740”, “issued” : { “date-parts” : “2012” }, “page” : “1-20”, “title” : “Guide To Interpreting Irrigation Water”, “type” : “article-journal”, “volume” : “1562” }, “uris” : “http://www.mendeley.com/documents/?uuid=226e09c0-2144-4198-927e-6034560782a2” } , “mendeley” : { “formattedCitation” : “(A. nalytic, 2012)”, “plainTextFormattedCitation” : “(A. nalytic, 2012)”, “previouslyFormattedCitation” : “(A. nalytic, 2012)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(A. nalytic, 2012).
Total phosphorus (As-P), mg/l
Its category is very low for total if p (mg/l) ;1. Low (1-1.9), medium (2-2.9), high (3-5) and very high if phosphorus is (;5) (A. nalytic, 2012).

Ph
A measure of the hydrogen ion concentration; pH of 7.0 indicates a neutral solution, pH values smaller than 7.0 indicate acidity, pH values larger than 7.0 indicate alkalinity.
Temperature
Temperature affects the usefulness of water for many purposes. Generally, users prefer water of uniformly low temperature.
The significance of the study

The implementation of these research findings in large scale can solve many environmental problems. Studies show that large compositions of wastes generated from student cafe and toilets are biodegradable. Moreover, the capturing of methane gas that is released from the decomposition of organic wastes in a biogas plant can protect the atmosphere from the substantial emission of greenhouse gases which strongly associated with global warming. Methane fermentation offers an effective means of pollution reduction, superior to that achieved via conventional aerobic processesCITATION FAO1 l 1033 (Miyamoto, 1997).
Material and Methods
2.1. Study area descriptionThe Sample for Evaluation of Biogas Generation of unavoidable food waste was taken from Samara University’s Student Cafeteria which is located in North-eastern Ethiopia at Samara town (11°47?32?N & 41°0?31?E).

Figure SEQ Figure * ARABIC 2: Study area description
At Samara University student cafeteria, the wash from the cafeteria floors and wash of different tools together with the wash from temporarily storage site of food leftover flow by gravity force has the following system shown in Figure 3.

Figure SEQ Figure * ARABIC 3: Simplified Effluent system description
At point-1 and point-2 leftover food can be taken from different uses. To avoid a competition with those stakeholders, unavoidable food waste sample was taken from point-3 (Sample1), Point-4 (Sample-3), point-5(sample-2) and point-6 (sample-4) on 10th-June-2017.
49625251468756b)
0

b)
24669751411605a)
00a)

Figure SEQ Figure * ARABIC 4: Leftover food a) at cafeteria outlet b) taking and floor cleaning
Measurement of solid waste properties
Sample preparation
Nonfood materials like the sponge, plastic bottles, wood materials were separated from food waste.

Mercury thermometer and portable ph-meter were used to measure temperature and Ph respectively sampling point during sample taking. The Sample was taken during daytime (1:00 PM) of 10th June. Assuming a homogeneous and well-mixed waste sample is obtained during this time. Sample 1 and Sample-2 taken and their moisture content, Organic matter, and total Nitrogen evaluated by AAEPA.

54387751478280b)
0b)
25336501455420a)
00a)

Figure SEQ Figure * ARABIC 5: Unavoidable food waste at a) initial manholes b) final holes
Measurement wastewater parameters
Sample-3 and Sample-4 were taken from sample point-4 and sample point-6 respectively to evaluate the wastewater quality parameters before deciding its use for irrigation purposes.

13716001702435a)
0a)
44577001695450b)
0b)

Figure SEQ Figure * ARABIC 6: Wastewater at a) final discharge site b) final storage site
Wastewater measurement quality parameters: total dissolved solid, turbidity, total alkalinity, total hardness, total phosphorus (as-P), Total nitrogen (as N), Total organic carbon (TOC), mg/l was chosen and evaluated by AAEPA.

Result3.1. Waste solid characterization3.1.2 Composition of food waste Figure SEQ Figure * ARABIC 7: Compositions of food waste at study Point 1 and Point 2.

3.1.2. Carbon to Nitrogen ratio(C/N) Ratio
Carbon to nitrogen ratio is an expression of Organic material (mg/l) to Total nitrogen (mg/l). Therefore, the result of C/N ratio for foods waste for the sample from point 1 and point two are 641 and 101.
3.1.3. Temperature and PhMercury thermometer and portable ph-meter were used to measure temperature and Ph respectively sampling point during sample taking on the field.

Figure SEQ Figure * ARABIC 8: Characteristics of wastewater at flow (point-4) and storage site (point-6)
Discussion
4.1. Utilization of unavoidable food-waste for biogas generationThe feedstock used to produce biogas by anaerobic digestion should ensure a favorable condition. These conditions are the following as listed in ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “author” : { “dropping-particle” : “”, “family” : “Letters”, “given” : “Romanian Biotechnological”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “id” : “ITEM-1”, “issue” : “3”, “issued” : { “date-parts” : “2014” }, “page” : “9283-9296”, “title” : “Main factors affecting biogas production – an overview”, “type” : “article-journal”, “volume” : “19” }, “uris” : “http://www.mendeley.com/documents/?uuid=6f84c9a1-06ff-486c-8d92-2b6aaae47fdb” } , “mendeley” : { “formattedCitation” : “(Letters, 2014)”, “plainTextFormattedCitation” : “(Letters, 2014)”, “previouslyFormattedCitation” : “(Letters, 2014)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Letters, 2014).

4.1.1. Contain biodegradable organic matterFood waste is biodegradable. The unavoidable food waste studied has an organic matter of 76 percent, which is a major part of the waste.
4.1.2. pH between
The best pH range is between (6.8 – 7.3). The waste sample has a pH of 7.0 which is in range, as a result, there is no need to adjust the pH of this feedstock.

4.1.3. C/N ratio
The increase in carbon content (increase in C/N ratio) will give rise to more carbon dioxide formation and lower pH value, while high value of nitrogen (decrease in C/N ratio) will enhance production of ammonia gas that could increase the pH to the detriment of the micro-organisms ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “author” : { “dropping-particle” : “”, “family” : “I. J. Dioha”, “given” : “Etal”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “id” : “ITEM-1”, “issue” : “3”, “issued” : { “date-parts” : “2013” }, “page” : “1-10”, “title” : “EFFECT OF CARBON TO NITROGEN RATIO ON BIOGAS PRODUCTION I. J. Dioha, C.H. Ikeme, T. Nafiu2019u, N. I. Soba and Yusuf M.B.S. Energy Commission of Nigeria, Plot 701c, PMB 358, Central Area, Garki, Abuja, Nigeria”, “type” : “article-journal”, “volume” : “1” }, “uris” : “http://www.mendeley.com/documents/?uuid=9003c883-ccf8-4a1b-8714-fbacb659b12d” } , “mendeley” : { “formattedCitation” : “(I. J. Dioha, 2013)”, “plainTextFormattedCitation” : “(I. J. Dioha, 2013)”, “previouslyFormattedCitation” : “(I. J. Dioha, 2013)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(I. J. Dioha, 2013). The research conducted on the effect of C/N ratio on biogas yields showed the C/N ratio affects the biogas production. When the C/N ratio of feedstock is higher the biogas production was higher hydraulic retention time and lower withdrawal frequency ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “author” : { “dropping-particle” : “”, “family” : “Oghenero W.O, Ejiroghene K.O”, “given” : “Patrick O.E”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “International Journal of Innovative Science, Engineering & Technology”, “id” : “ITEM-1”, “issue” : “5”, “issued” : { “date-parts” : “2016” }, “page” : “119-126”, “title” : “Analysis of the Effect of Carbon / Nitrogen ( C / N ) Ratio on the Performance of Biogas Yields For Non-Uniform Multiple Feed Stock Availability and Composition in Nigeria”, “type” : “article-journal”, “volume” : “3” }, “uris” : “http://www.mendeley.com/documents/?uuid=a1b84002-bdce-4a1f-8f11-f20b97c818cc” } , “mendeley” : { “formattedCitation” : “(Oghenero W.O, Ejiroghene K.O, 2016)”, “plainTextFormattedCitation” : “(Oghenero W.O, Ejiroghene K.O, 2016)”, “previouslyFormattedCitation” : “(Oghenero W.O, Ejiroghene K.O, 2016)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Oghenero W.O, Ejiroghene K.O, 2016). For this study, an average C/N ratio was 371. This is as high as a C/N ratio of Sawdust (C/N ratio of 142-625:1) and cardboard (C/N ratio of 368:1) CITATION Car l 1033 (Home and Community Composting ). This waste is a kind of waste materials containing high amounts of carbon and considered as browns CITATION Pla l 1033 (Planet Natural). As a result, for better achievement of biogas generation combination of both low and high C/N ratio substrates is required ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “author” : { “dropping-particle” : “”, “family” : “Oghenero W.O, Ejiroghene K.O”, “given” : “Patrick O.E”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “container-title” : “International Journal of Innovative Science, Engineering & Technology”, “id” : “ITEM-1”, “issue” : “5”, “issued” : { “date-parts” : “2016” }, “page” : “119-126”, “title” : “Analysis of the Effect of Carbon / Nitrogen ( C / N ) Ratio on the Performance of Biogas Yields For Non-Uniform Multiple Feed Stock Availability and Composition in Nigeria”, “type” : “article-journal”, “volume” : “3” }, “uris” : “http://www.mendeley.com/documents/?uuid=a1b84002-bdce-4a1f-8f11-f20b97c818cc” } , “mendeley” : { “formattedCitation” : “(Oghenero W.O, Ejiroghene K.O, 2016)”, “plainTextFormattedCitation” : “(Oghenero W.O, Ejiroghene K.O, 2016)”, “previouslyFormattedCitation” : “(Oghenero W.O, Ejiroghene K.O, 2016)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Oghenero W.O, Ejiroghene K.O, 2016). The addition of sewage sludge provides stabilized and safe compost in a shorter period of time ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “author” : { “dropping-particle” : “”, “family” : “Mollazadeh”, “given” : “Nastaran”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “id” : “ITEM-1”, “issue” : “3”, “issued” : { “date-parts” : “2014” }, “page” : “311-317”, “title” : “Composting : a new method for reduction of solid waste and wastewater”, “type” : “article-journal”, “volume” : “8” }, “uris” : “http://www.mendeley.com/documents/?uuid=fdf68219-7dcd-4fdc-a7d4-6b37e46f506a” } , “mendeley” : { “formattedCitation” : “(Mollazadeh, 2014)”, “plainTextFormattedCitation” : “(Mollazadeh, 2014)”, “previouslyFormattedCitation” : “(Mollazadeh, 2014)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(Mollazadeh, 2014) solving the limitation of the digestion of high C/N ratio. Total nitrogen composition in the waste effluent in this study was 93mg/l and can improve C/N ratio of unavoidable food waste.

4.2. Utilization of wastewater for irrigation
4.2.1. Total dissolved solidWastewater in this study is a C3 (third class) of water for irrigation having a value of between 481 mg/l – 1440 mg/l) having an average TDS of 950mg/l. A water in this range is known as water of high salt and it is appropriate for plants when a land has a good draining system as described earlier.

4.2.2. Total alkalinity
Alkalinity is a combined effect of bicarbonates and the carbonates. High alkalinity indicates that the water will tend to increase the pH of the soil possibly to a point that is detrimental to plant growth ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “author” : { “dropping-particle” : “”, “family” : “A. nalytic”, “given” : “Spectrum”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “id” : “ITEM-1”, “issue” : “740”, “issued” : { “date-parts” : “2012” }, “page” : “1-20”, “title” : “Guide To Interpreting Irrigation Water”, “type” : “article-journal”, “volume” : “1562” }, “uris” : “http://www.mendeley.com/documents/?uuid=226e09c0-2144-4198-927e-6034560782a2” } , “mendeley” : { “formattedCitation” : “(A. nalytic, 2012)”, “plainTextFormattedCitation” : “(A. nalytic, 2012)”, “previouslyFormattedCitation” : “(A. nalytic, 2012)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(A. nalytic, 2012). The total alkalinity of wastewater for this study was 1619mg/l which is much higher than 200mg/l as described in ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “author” : { “dropping-particle” : “”, “family” : “A. nalytic”, “given” : “Spectrum”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “id” : “ITEM-1”, “issue” : “740”, “issued” : { “date-parts” : “2012” }, “page” : “1-20”, “title” : “Guide To Interpreting Irrigation Water”, “type” : “article-journal”, “volume” : “1562” }, “uris” : “http://www.mendeley.com/documents/?uuid=226e09c0-2144-4198-927e-6034560782a2” } , “mendeley” : { “formattedCitation” : “(A. nalytic, 2012)”, “plainTextFormattedCitation” : “(A. nalytic, 2012)”, “previouslyFormattedCitation” : “(A. nalytic, 2012)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(A. nalytic, 2012).

4.2.3. Total phosphorus
A total phosphorous composition is 41.4ppm which is (>5) is called high (A. nalytic, 2012).

4.2.4. Total NitrogenTotal nitrogen (as N) of sample analyzed was 93mg/l and category of high nitrogen (>90) ADDIN CSL_CITATION { “citationItems” : { “id” : “ITEM-1”, “itemData” : { “author” : { “dropping-particle” : “”, “family” : “A. nalytic”, “given” : “Spectrum”, “non-dropping-particle” : “”, “parse-names” : false, “suffix” : “” } , “id” : “ITEM-1”, “issue” : “740”, “issued” : { “date-parts” : “2012” }, “page” : “1-20”, “title” : “Guide To Interpreting Irrigation Water”, “type” : “article-journal”, “volume” : “1562” }, “uris” : “http://www.mendeley.com/documents/?uuid=226e09c0-2144-4198-927e-6034560782a2” } , “mendeley” : { “formattedCitation” : “(A. nalytic, 2012)”, “plainTextFormattedCitation” : “(A. nalytic, 2012)”, “previouslyFormattedCitation” : “(A. nalytic, 2012)” }, “properties” : { }, “schema” : “https://github.com/citation-style-language/schema/raw/master/csl-citation.json” }(A. nalytic, 2012).
Conclusions
Unavoidable food waste has a high source of carbon. Its C/N ratio is about 371 and needs an adjustment of its C/N ratio below 30:1 before using as feedstock for biogas digestion. Due to contaminants in effluent water, it needs a treatment before using them in irrigation.

H. Competing interestsAuthors should disclose any financial competing interests but also any non-financial competing interests that may cause them embarrassment were they to become public after the publication of the manuscript. Authors are required to complete a declaration of competing interests.

I. Authors’ contributionsIn order to give appropriate credit to each author of a paper, the individual contributions of authors to the manuscript should be specified in this section.

Acknowledgments

Major contributors and funding agencies shall be acknowledged.

ReferencesADDIN Mendeley Bibliography CSL_BIBLIOGRAPHY A. nalytic, S. (2012) ‘Guide To Interpreting Irrigation Water’, 1562(740), pp. 1–20.

Al-Bahrani, H. S. (2014) ‘Spatial prediction and classification of water quality parameters for irrigation use in the euphrates river (iraq) using gis and satellite image analyses’, International Journal of Sustainable Development and Planning, 9(3), pp. 389–399. doi: 10.2495/SDP-V9-N3-389-399.

Bachmann, N. and Bachmann, N. (2015) ‘Sustainable biogas production in municipal wastewater treatment plants’, in BAxTER, D. (ed.). massongex, switzerland: IEA Bioenergy.

Balasubramaniyam, U. et al. (2008) ‘Biogas production in climates with long cold winters’, (May), p. 68.

By, S. (2011) ‘BIOGAS PRODUCTION FROM KITCHEN WASTE A Seminar Report submitted in partial fulfillment of the requirements for Bachelor of Technology ( Biotechnology ) Prof . Krishna Parmanik Department of Biotechnology and Medical Engineering National Institute of Techn’, Dapartment of Biotechnology and Medical Engineering, pp. 1–48.

Doelle K, O. F. (2015) ‘Anaerobic Digestion of Food Waste to Produce Biogas: A Comparison of Bioreactors to Increase Methane Content–A Review’, Journal of Food Processing ; Technology, 6(8), pp. 8–10. doi: 10.4172/2157-7110.1000478.

Gashaw, A. and Teshita, A. (2014) ‘Co-Digestion of Ethiopian Food Waste with Cow Dung for Biogas Production’, International Journal of Research (IJR), 1(7), pp. 475–500. doi: 10.5755/j01.erem.63.1.2912.

I. J. Dioha, E. (2013) ‘EFFECT OF CARBON TO NITROGEN RATIO ON BIOGAS PRODUCTION I. J. Dioha, C.H. Ikeme, T. Nafi’u, N. I. Soba and Yusuf M.B.S. Energy Commission of Nigeria, Plot 701c, PMB 358, Central Area, Garki, Abuja, Nigeria’, 1(3), pp. 1–10.

Letters, R. B. (2014) ‘Main factors affecting biogas production – an overview’, 19(3), pp. 9283–9296.

Mollazadeh, N. (2014) ‘Composting?: a new method for reduction of solid waste and wastewater’, 8(3), pp. 311–317.

Oghenero W.O, Ejiroghene K.O, P. O. . (2016) ‘Analysis of the Effect of Carbon / Nitrogen ( C / N ) Ratio on the Performance of Biogas Yields For Non-Uniform Multiple Feed Stock Availability and Composition in Nigeria’, International Journal of Innovative Science, Engineering & Technology, 3(5), pp. 119–126.

Smith, J. et al. (2013) ‘The potential of small-scale biogas digesters to alleviate poverty and improve Long term sustainability of ecosystem services in Sub-Saharan Africa’, 1st World Sustain. Forum, 5(10), pp. 2911–2942. doi: 10.3390/en5082911.

USDA, EPA and DOE (2014) ‘Biogas Opportunities Roadmap: Voluntary Actions to Reduce Methane Emissions and Increase Energy Independence’, (August), p. 28. Available at: http://www.usda.gov/oce/reports/energy/Biogas_Opportunities_Roadmap_8-1-14.pdf.

Zhang, R. et al. (2007) ‘Characterization of food waste as feedstock for anaerobic digestion’, Bioresource Technology, 98(4), pp. 929–935. doi: 10.1016/j.biortech.2006.02.039.

J. AnnexTables and graphs shall be provided in the annex. Tables should be numbered sequentially.