Study and application of biological-aerated filter (BAF) in soybean protein advanced wastewater treatment

Abstract

Laboratory study and practical application of biological-aerated filter were investigated for soybean protein advanced wastewater treatment. The influences of media height, hydraulic retention time (HRT), and air–liquid ratio (A/L) on chemical oxygen demand (COD_Cr), biochemical oxygen demand (BOD₅), ammonium (–N), suspended solid (SS), and chromaticity of effluent were investigated in laboratory study and practical application. The results indicated that media height of 80 cm, HRT of 4 h, and A/L of 15:1 were the optimum conditions in laboratory study, and the mean effluent concentration of COD_Cr, BOD_5, –N, SS, and chromaticity was 39, 5.8, 2.5, 13.6 mg L⁻¹, and 16, respectively. When the optimum conditions of laboratory study were applied in practical project, the mean effluent concentration of COD_Cr, BOD₅, –N, SS, and chromaticity was 50, 7.9, 3.2, 18.8 mg L⁻¹, and 24, respectively. All the indicators was lower than the limits of the discharge standards of Shandong Province (, , –, , ).

Keywords:

• Laboratory study
• Practical application
• BAF
• Soybean protein wastewater
• Advanced treatment