Metabolic uncoupler, 3,3′,4′,5-tetrachlorosalicylanilide addition for sludge reduction and fouling control in a gravity-driven membrane bioreactor

摘要: The gravity-driven membrane bioreactor (MBR) system is promising for decentralized sewage treatment because of its low energy consumption and maintenance requirements. However, the growing sludge not only increases fouling, but also augments operational complexities (sludge discharge). We added metabolic uncoupler 3,3′,4′,5-tetrachlorosalicylanilide (TCS) to deal with mentioned issues. Based on results, TCS addition effectively decreased ATP yield (reduced by 50%). Extracellular polymeric substances (EPS; proteins polysaccharides) were transformed into dissolved soluble microbial products (SMPs) in bulk solution, leading break flocs small fragments. Permeability was increased more than two times, reaching 60–70 L/m2/h bar when 10–30 mg/L added, reduced suspended formation a thin cake layer EPS levels. Resistance analyses confirmed that appropriate dosages primarily hydraulically reversible resistances. at high dosage (50 mg/L) due release excess fragments SMP supernatant, compact fouling bioactivity developing surface, causing higher pore blocking Our study provides fundamental understanding how affects bio-fouling layers different dosages, practical relevance situ reduction alleviation MBR systems.