en تخصصي Special Systematic Review <div dir="ltr" style="text-align: justify;"><strong><em><span style="letter-spacing:.1pt;"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">Introduction:</span></span></span></em></strong> <span style="letter-spacing:.1pt;"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">The need for food produced from animal husbandry has made it a growing industry which result in increment of livestock waste. On the basis of environmental and economic considerations, these materials require treatment and management. Anaerobic digestion and creation of biogas are the most effective methods of waste management. Several parameters affect the anaerobic digestion of animal wastes which should be studied in order to optimize the biogas production of reactors.</span></span></span><br> <strong><em><span style="letter-spacing:.1pt;"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">Materials and Methods:</span></span></span></em></strong><span style="letter-spacing:.1pt;"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;"> The parameters affecting the performance of anaerobic processes in different scientific databases within 1984 -2016 were searched and related information were obtained.</span></span></span><br> <strong><em><span style="letter-spacing:.1pt;"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">Results:</span></span></span></em></strong><span style="letter-spacing:.1pt;"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;"> A wide range of reactors with retention times of 0.5 to 140 days and organic loading rates from 0.11 to 7.5 grams per liter of organic matter in a day were studied based on the Volatile Solid (VS) in different temperature range. Also, studies conducted on mixing, co-digestion, changes in pH and ammonia content of the substrate, C/N ratio, as well as the effect of chemical interference were investigated.</span></span></span><br> <strong><em><span style="letter-spacing:.1pt;"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;">Conclusion:</span></span></span></em></strong><span style="letter-spacing:.1pt;"><span style="font-family:times new roman,serif;"><span style="font-size:10.0pt;"> High COD removal decrease of VS were achieved in the range of 80-95 % and 65- 92 % respectively in bioreactors. The produced methane was also 48 mmol L^-1 to 4681.3 m³ per month for reactors with a volume of 120 ml to 1330 m³ achieved respectively at 37 and 55<span dir="RTL">˚</span>C from the Mesophilic and thermophilic temperatures. Results summarized on the physical and chemical conditions in this paper, can be used to study the effective parameters and optimize conditions used in biogas production.</span></span></span></div> Anaerobic Digestion,Biogas Yield,Cattle Manure,Physical and Chemical parameters. 235 247 http://jehsd.ssu.ac.ir/browse.php?a_code=A-10-1-50&slc_lang=en&sid=1 Saeed Samani Majd ssamnai@ut.ac.ir Yes Faculty of Environment, University of Tehran, Tehran, Iran. Mohammad Ali Abdoli No Faculty of Environment, University of Tehran, Tehran, Iran. Abdolreza Karbassi No Faculty of Environment, University of Tehran, Tehran, Iran. Hamid Reza Pourzamani No Environment Research Center, Isfahan University of Medical Sciences, Isfahan, Iran. Masoud Rezaee No Faculty of Environment, University of Tehran, Tehran, Iran.