Research On Treating The Anaerobic Fermentation Liquor Of Large And Medium Scale Piggery Wastewater With Coagulate Beforehand

Piggery wastewater is heavy concentration organic wastewater, after anaerobic fermentation treatment, the most of organic pollutants in piggery wastewater has been removed, but it's difficult to be up to the discharge standard. The results of many studys by many researchers in this spect were not good.Thinking about the difficulties in anaerobic fermentation liquor of piggery wastewater treatement of current situation, the auther treated the fermentation of large and medium scale piggery wastewater by throwing flocculant and change the conditions of coagulate to find the effect of the effluent water results.When pH was 3.5-5.5, the results of the effluent water got better with the faster speed of coagulate, but more acid cost; the results of the effluent water became worse than the former and the floe size grown larger with high density when pH was 6.0-7.0.The single factor test of the optimum reaction conditions for flocculant indicated that, the optimum dosage of 5% inorganic coagulator Fe₂(SO₄)₃ is 55 mL, the optimum dosage of 3g/L nonionic PAM is 12mL; As the same time, when we disposed 1L large and medium scale piggery wastewater, we could find that the fine granularity of zeolite powder the better effect of effluent water we got. The optimum dosage of zeolite powder(725 mesh size) is 6511mg which got better effect than zeolite powder(325 mesh size) did.The hydrodynamic conditions and deposition time also have effects on the effect of coagulat. The removal efficiency of degree of turbidity was the highest when the G value of the velocity gradient was 110s^-1-120^-1, but the value of degree of turbidity went up by the G value increasing. If the value of Gt was larger, the value of the degree of turbidity would lower, and the removal efficiency of degree of turbidity is the highest when the value of Gt is 22500-25000. But the value of degree of turbidity would not change evidently when the value of Gt is larger than 25000. When deposition time was 20min²5min, the results of the effluent water was fine and the removal efficiency of degree of turbidity got the best.Designed orthogonal experimentation by the conditions above the frontal test, and...