Experimental Study On Treatment Of Methanol Wastewater By Immobilized Microorganism

Immobilization of microorganisms has been widely used in the researches and applications as a new kind of technology in the engineering fields. As a type of wastewater treatment method, the immobilization of microorganisms has the characteristics of high removal efficiency, stability of operation, and less yield of sludge compared with mobilization of microorganisms.In this dissertation, wastewater with high methanol concentration is chosen to be treated with imbedded immobilization of microorganisms in the wastewater treatments experiments. With the imbedding material--sodium alginate and PVA, activated sludge is imbedded in the shape of ball and used in the orthogonal experiments of methanol wastewater treatments whose indicator is COD. Then the optimum imbedding conditions of sodium alginate and PVA are determined and performance if immobilized ball are enhanced under the optimum conditions.The imbedded ball made of sodium alginate is taken as an example to treat the methanol wastewater with fluidized-bed as the reactor. Through the researches of the impacts of biomass, HRT, temperature, pH, concentration of inflow on the COD removal efficiency and methanol degradation of immobilized activated sludge, the optimum experiments conditions are as following: imbedded ball/ wastewater=20/1000; temperature=30~40℃,pH=6.0~9.0, COD concentration in the inflow: less than 722.2 mg/L, which has the highest removal efficiency. After compared the treatment efficiency of immobilized microorganism and mobilized microorganism, the result shows that under the same conditions, HRT=6h, the former treatment method has a COD removal efficiency of 90.4% and methanol removal efficiency of 94.4%, while the same quantity of activated sludge only has the counterpart efficiency of 82.9% and 88.9%, whish demonstrates the advantages of immobilized microorganism treatment method in the methanol wastewater disposal.