ANOAS시스템의 HRT와 COD부하변동에 따른 염색폐수 처리특성

초록

Textile wastewater treated by conventional activated sludge processes exhibits harsh characteristics, such as high chemical oxygen demand (COD), chromaticity, and salinity, and typically contains dyes, slurries, additives, oiling agents, acid-base substances, fiber impurities, and inorganic salts. This study aimed to evaluate the effect of hydraulic retention time (HRT) in an anaerobic/aerobic activated sludge (ANOAS) system coupled with a high-rate filter (HRF) as an alternative to conventional primary settler processes. The removalefficiencies of suspended solids (SS), color, biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were monitored to assess treatment performance. The HRF with a much shorter HRT of 0.3 hr demonstrated performance efficiency comparable to that of coagulation-sedimentation using a high coagulant dose and the conventional settler with a longer HRT of 3.0 hr. When an HRT of 4 hr was applied to each process in the ANOAS system, the anaerobic reactor exhibited the highest color removal efficiency at an HRT of 8 hr. On the other hand, the aerobic reactor achieved higher organic removal efficiency at HRTs exceeding 4 hr. At COD loading rates below 1.0 kgCOD/m3․d, the ANOAS system showed comparable efficiencies in removing COD, BOD, and color. These findings indicate that the most efficient configurations of the anaerobic–aerobic activated sludge process require a longer HRT for the anaerobic reactor and a shorter HRT for the aerobic reactor.

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