Effects of composite microbial agents on the degradation of feces and sewage

In order to reduce the odor pollution of septic tanks, reduce the number of septic tank cleanings, and reduce the operating costs of septic tanks, a composite microbial agent was prepared and its degradation application effect was explored. The composite microbial agent（solid preparation and liquid preparation）prepared by the research group, which was made of Bacillus tequilensis YZS-C01, Bacillus safensis YZS-C03, Alcaligenes faecalis QQB-A05 and Pseudomonas putida ZTB-A29, was used as the research object. The in-situ reduction of fecal residue by the solid preparation and the odor removal rate of the liquid preparation were measured to evaluate its application effect. The results showed that the solid preparation of the composite microbial agent could make all the scum in the septic tank settle within 10 days, and the degradation rate of fecal residue was above 65%, which was more than 60% higher than the settlement rate and degradation rate of the control group. When the liquid preparation of composite microbial agent is sprayed to treat odor in septic tank, the immediate removal rate of ammonia and hydrogen sulfide is above 85%, and the removal rate of NH₃ and H₂S can still be maintained above 65% after 4 hours. It can also promote the degradation of scum in septic tank, with a degradation rate of 60%. The composite microbial agent prepared in the study can be used for in-situ reduction of fecal scum and removal of odor in septic tank at the same time, providing technical support for in-situ reduction of fecal scum in septic tank and bio-enhanced technology for odor treatment.