Removals of phenolic compounds and phthalic acid esters in landfill leachate by microbial sludge of two-stage membrane bioreactor.

Removals of bisphenol A (BPA), 2,6-di-tert-butylphenol (2,6-DTBP), 2,6-di-tert-butyl-4methylphenol (BHT), di-ethyl phthalate (DEP), di-butyl phthalate (DBP) and bis (2-ethylhexyl) phthalate (DEHP) were monitored in two-stage membrane bioreactor (MBR) by operating under no sludge wastage condition for 500 days. Those emerging contaminants were removed by 99.5%, 99.0%, 99.5%, 97.9%, 96.8% and 95.7% under long term operation in MBR without reaching maximum adsorption capacity of sludge. Biodegradation was the main mechanism for their removals in MBR systems and the microbial activities were enhanced by long sludge age operating condition. The removals of those compounds by microbial sludge in MBR by adsorption and combined (adsorption & biodegradation) mechanisms were well explained by pseudo-second order and first order kinetics, respectively.