Abstract:
A comparative study of biogas production from poultry droppings, cow dung, and wastewater was conducted under the same operating conditions by subjecting each substrate to both conventional and electrolysed digester. Twenty kilogrammes of each waste was mixed with 20 litres of water which is approximately 20 kilogrammes and loaded into five waste reactors labeled 1a (ordinary digester containing cow dung), 1b (electrolysed digester containing cowdung), 2a (ordinary digester containing poultry droppings), 2b (electrolysed digester containing poultry droppings), and 3 (electrolysed digester containing wastewater) respectively. Three of the digesters were electrolysis-induced and the other two digesters in their ordinary form. The digestion period was monitored for 40days at an ambient temperature ranging from 24 to 35 oC. In all the digesters, biogas production started on the 2nd day, and attained maximum value on the 14th-17th day. Biogas production ended on the 34th and 35th day in digester 1a, 1b, 2a and 2b with production ending earliest in digester 3 containing wastewater on the 19th day. The highest biogas was produced in digester 2b (i.e electrolysed digester loaded with poultry droppings) with a cumulative volume percentage of 91.41 as compared to its conventional state with a cumulative volume percentage of 85.19 and both states of the cow dung waste with cumulative volume percentages of 77.26 and 71.64 respectively. The least production occured in digester 3 with a cumulative volume percentage of 4.59. Although previous studies have shown that electrolysis can be applied to wastewater and its treatment, the outcome of this study confirmed that electrolysis can also be applied to solid waste to enhance the production of biogas. It is concluded that poultry droppings has great potentials for the generation of biogas as compared to cow dung both in an ordinary and electrolysed state.
