Research and analysis of biogas produced from sewage sludge using a batch bioreactor

The examined equipment is a batch bioreactor intended to produce biogas from sewage sludge, vegetal and other organic wastes. The maintenance of an optimal temperature and oxygen concentration inside the devise, as well as the intensity of mixing a substrate, result in methane CH₄ actively generated by methanogenic bacterial colonies. Manufacturing biotechnologies and biogas deal with environmental protection, energy and economic problems. For research purposes, considering organic loading (hereinafter, VS/L), four different types of the packing material of sewage sludge, including VS/L = 3.5 g L^-1, VS/L = 5.0 g L^-1, VS/L = 10.0 g L^-1 and VS/L = 15.0 g L^-1, were used. The highest concentration of CH₄ (75.1%) and yield of biogas (36.78 L d^-1) were found using a packing material, the organic loading of which made 15.0 g L^-1. Throughout the experiment, the temperature of the mesophilic process reached 35-37°C, and the concentration of oxygen was 0.0-0.1%. The research carried out has disclosed the dependencies of the components of biogas on the number of the days of the performed experiment. With reference to experimental research conducted at the laboratory, a small-sized batch bioreactor can be designed and successfully used in a small farm.