Study On Solid Fluid Separation Technology And Processes Of Large-scale Piggery Wastewater In Shi Mahe Drainage Area

The solid-fluid separation effection in domestic and foreign large-scale piggery wastewater treatment was not ideal, created large pressure to the later biochemistry processes.First some static model experiments were made in the laboratory to find the best coagulant, best parameter etc. The organism dose, pH and a series of influence factors had also been detailedly researched and discussed. The results indicated that the optimum flocculant combination and concentration was PFAM( 300 mg.L^-1) which was a new product; The best hydrodynamic condition for quickly stirs stage G=878.8 s- ,GT=3.5×10⁴, slowly stirs stage G=33.9 s-, GT=3.05×10⁴; The best clarification time was 25min; Coagulation had good effective to different organic dose, but the treatment efficiency changed along with the influent COD_cr, the turbidity removed about 80%,COD_cr removed above 55% when COD_cr was higher than 8 000 mg.L^-1; Adjusted pH=6.2⁶.8 achieved even better effect; It was most advantageous to the coagulation that made the raw influent wastewater acidify 20 hours.According to parameters by the experimental study and theory basis, we designed a set of coagulation equipment in view of the Qingxi piggery wastewater solid-fluid separation. Locale coagulation experiments were made on large-scale piggery wastewater after the existing solid fluid separation technology in Shi Mahe drainage area in Dongguan city , Guangdong province. The results showed that, coagulation equipment functioned well. COD_cr and SS of the outflow was about 4 400-5 000 mg.L^-1 and 960 mg.L^-1, the insoluble COD percentage reduced up to 18.1-20.2%, B/C increased from 0.49 to 0.61,which indicated higher biotransformation. TS (total solid matter) reduced from 120 000 - 130 000 mg.L^-1 to 880 -980 mg.L^-1, the removal rate reached 99.1 - 99.3% by the improved solid fluid separation technics.It was not reported that pretreating the large-scale piggery wastewater through coagulation solid-fluid separation, the designed processes in this paper had certain superiority to the domestic and foreign existing methods, and also had certain scientific research value and application prospection.