The Experimental Study On Domestic Wastewater Treatment By Bioflocculating Adsorption Process

In activated sludge process, the removal of organic pollutants mostly depended on solid/liquid separation, to which bioflocculation is critical. Good bioflocculation contributed to improve settling and dewatering properties of activated sludge. With wastewater being treated by bioflocculation, not only good effluent quality was obtained, but also subsequent sludge disposal costs were reduced. So bioflocculating adsorption process caused extensive attention. The research of bioflocculating adsorption process on wastewater treatment was investigated by micro-scale and semi-full-scale experiments.The study results showed that the sludge of bioflocculation matured in a week by simultaneous cultivation and domestication. Then good flocculation was obtained. And the optimum parameters were that air-water ratios, recycle ratio, aeration time, flocculating time and SRT were 10: 1, 30%, 2h, 30min, 6d, respectively.Good bioflocculation was obtained after steady operation of semi-full-scale experiment. The removal efficiency of COD and SCOD were preferable. It also had some removal efficiency to SCOD, NH₃-N and PO₄³-P. As influent quantity increased, the removal to contamination of bioflocculating adsorption process decreased. Bioflocculating adsorption process could endure lash load to some extent.The kinetics model of bioflocculating adsorption phase were investigated. The results showed that organic substance containing carbon was the main removing object of bioflocculating adsorption phase. The system was divided to nine groups. They were easy biodegrading dissolve substance, inertia dissolve organism, inertia dissolve metabolizing production, slow biodegrading undissolve substance, alive microorganism, dead microorganism, inertia undissolve metabolizing production, inertia undissolve organism and dissolve oxygen respectively. These groups in system transformed each other through five different processes which had different characters: l.microbial growth and metabolization of substance 2. undissolve organism hydrolyzing 3. microbial death 4.dead cell hydrolyzing 5.collection and adsorption. The model was stated with matrix expression. The forecasting result was close to measuring result.