Removal of a broad range of surfactants from municipal wastewater – Comparison between membrane bioreactor and conventional activated sludge treatment

摘要: Elimination of alkylphenol ethoxylates (APEO) and their degradation products (alkylphenols alkylphenoxy carboxylates), as well linear alkylbenzene sulfonates (LAS) coconut diethanol amides (CDEA), was studied in a pilot plant membrane bioreactor (MBR) working parallel to full-scale wastewater treatment (WWTP) using conventional activated sludge (CAS). In the CAS system 87% parent long ethoxy chain NPEOs were eliminated, but decomposition yielded persistent acidic neutral metabolites which poorly removed. The elimination short (NP1EO NP2EO) averaged 50%, whereas nonylphenoxy carboxylates (NPECs) showed an increase concentrations with respect ones measured influent samples. Nonylphenol (NP) only nonylphenolic compound efficiently removed (96%) treatment. On other hand, MBR good performance removing compounds overall 94% for total pool NPEO derived (in comparison 54%-overall CAS). individual follows: 97% parent, NPEOs, 90% 73% NPECs, 96% NP. Consequently, residual low μg/l level or below it. LAS CDEA similar both systems that investigated, no significant differences observed between two processes. Nevertheless, all effluent consistently lower independent concentrations. Additionally, quality terms chemical oxygen demand (COD), NH4+ concentration suspended solids (TSS) always superior also quality, demonstrates high potential MBRs municipal wastewaters.