|
Now activated sludge process is a wide used biological treatment technology by sewage treatment plant in the world. It has many advantages such as matured, good treatment effect, stable operation, lower investment and operation cost. But with the economy, science and technology rapid development, it puts forward higher requirements based on activated sludge process. So, how to further improve treatment effect, decreased energy, lower investment and operation cost, reduce surplus sludge, wastewater reuse have become main developing direction.This paper wants to survey the pollutants removal effect and sludge reduction effect in wastewater treatment process by microbial agent. Through microbial agent combined with filler, activated sludge process and membrane bioreactor （MBR） treatment schoolyard domestic wastewater, it survey pollutants removal effect and sludge reduce effect by microbial agent, microbial agent combined with filler, respectively. The results showed that:（1） Microbial agent combined with filler treatment wastewater can produce very less sludge. The removal rate of COD、N、P can reach 99.84%, 60%, 85%, respectively. But the removal effect is unstable, operating condition and parameters wait to be further optimized.（2） Through comparison of mixed-agent, EM agent, bacillus combined with activated sludge process （SBR） to treat domestic sewage, it found mixed-agent has best effect. Selection mixed-agent combined with activated sludge process （SBR） treat domestic sewage, through orthogonal experiment survey influencing factors sludge reduce, the results showed that the influencing factors primary-secondary series arrangement is: hydraulic retention time, microbial agent addition amount, DO, COD concentration. On the optimal conditions, it can reduce sludge by 16%.（3） Though bacillus combined with MBR treatment schoolyard domestic wastewater, the result showed that after addition of predominant hybrid super bacteria into the MBR, the MLSS decreased from 9000 mg/L to 6000 mg/L, by 33.3%, the change of MLVSS is the same as MLSS; MLVSS/MLSS had little change compared with the system without addition of hybrid super bacteria. The average removal rate of COD, NH4+-N, TP were 96.03%, 88.25%, 84.79%, respectively. Both the ratio of MLVSS/MLSS and the average removal rate of contaminant increased a little to compare with the system without addition microbial agent.The result showed that using microbial agent can obviously reduce sludge production and also strengthen pollutants removal effect. When it is applied, it just direct addition microbial agent to reactor, needn’t increase special processing unit, and also needn’t change original treatment facilities. It has simple operation, high efficiency, and good application prospect. This study offered a new idea and method for our country wastewater treatment related problems.
|