Nghiên cứu các yếu tố ảnh hưởng đến hiệu xử lý Cod, Nitơ bằng quá trình bùn hoạt tính tăng trưởng dính bám cố định cho nước thải chợ đầu mối nông sản thực phẩm Bình Điền

Abstract

This study stimulates an attached growth process in which activated sludge fixes on the surface of random packs that is filled in the tank. The slime layer which develops on the media in the tank allows to form a biofilm of three zones, aerobic, anaerobic, and anoxic. The characteristic of Binh Dien Whole Sale Market‟s wastewater contains (1) CODt ranging from 700 – 1.120 mg/L; (2) CODs ranging from 800 – 1.160 mg/L; (3) BOD5 ranging from 782 – 1.216 mg/L with the BOD5/CODt ratio of 85 – 95%; (4) N_NH4+ ranging from 100 – 200 mg/L; (5) alkalinity of 400 – 600 mg CaCO3/L; (6) TDS of 4.120 – 5.110 mg CaCO3/L; (7) Cl- of 1.800 – 2.200 mg/L. The study on factors affecting the efficiency of substrate and nitrogen removal by applying attached growth process at the organic loading rate of 2.5 – 3.5 kgCOD/m3.day shows the CODt removal efficiency of 80 – 87% which accounted for the CODt decreases from 700 -1.120 mg/L to 144 – 96 mg/L, N_NH+4 removal efficiency of 56 – 75% which accounted for the N_NH+4 decreases from 100 - 200 mg/L to 82 - 52 mg/L; and N_NO-3 removal efficiency of 70 – 76% which accounted for the N_NO-3 decreases to 60 – 24 mg/L. At the ammonia loading rate of 0,2 – 0,4 kgN-NH+4/m3.day, ammonia removal efficiency reaches 85 – 95% which accounted for the N_NH+4 decreases from 100 - 200 mg/L to 19 – 6 mg/L, however, there is a need to control alkalinity by adding 130 mg NaHCO3 per liter of wastewater. At the DO of 3,0 – 4,0 mgO2/L, the removal efficiency of N_NH4+ and N_NO3- are 91 – 95% and 85 – 90%, respectively. In this technology, HRT must be reduced from 19hrs to 12hrs while alkalinity must be added to hasten the nitrification rate.