The effects of mediator and granular activated carbon addition on degradation of trace organic contaminants by an enzymatic membrane reactor

• Published in: Bioresource technology Vol. 167; pp. 169 - 177
• Main Authors: Nguyen, Luong N., Hai, Faisal I., Price, William E., Leusch, Frederic D.L., Roddick, Felicity, Ngo, Hao H., Guo, Wenshan, Magram, Saleh F., Nghiem, Long D.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.09.2014; Elsevier
• Subjects: Batch Cell Culture Techniques; Biodegradation, Environmental - drug effects; Biofouling; Biological and medical sciences; Bioreactors; Charcoal - pharmacology; Enzymatic membrane reactor (EMR); Fundamental and applied biological sciences. Psychology; Granular activated carbon (GAC); Laccase; Laccase - metabolism; Membranes, Artificial; Organic Chemicals - isolation & purification; Pressure; Redox-mediator; Trace organic contaminants (TrOCs); Water Pollutants, Chemical - isolation & purification; Water Pollutants, Chemical - toxicity; Granular activated carbon (GAC); Redox-mediator; Enzymatic membrane reactor (EMR); Trace organic contaminants (TrOCs); Laccase; Oxidation reduction; Enzyme; Degradation; Membrane reactor; Carbon addition; Activated carbon; Oxidoreductases; Contaminant; Organic compounds
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2014.05.125

•Laccase degradation of non-phenolic persistent TrOCs was investigated by EMR.•TrOC loading greatly affected enzymatic degradation of the resistant TrOCs.•Redox-mediator notably improved TrOC degradation but increased effluent toxicity.•Simultaneous addition of a redox-mediator and GAC enhanced enzymatic degradation.•GAC addition to EMR reduced membrane fouling and toxicity of treated effluent. The removal of four recalcitrant trace organic contaminants (TrOCs), namely carbamazepine, diclofenac, sulfamethoxazole and atrazine by laccase in an enzymatic membrane reactor (EMR) was studied. Laccases are not effective for degrading non-phenolic compounds; nevertheless, 22–55% removal of these four TrOCs was achieved by the laccase EMR. Addition of the redox-mediator syringaldehyde (SA) to the EMR resulted in a notable dose-dependent improvement (15–45%) of TrOC removal affected by inherent TrOC properties and loading rates. However, SA addition resulted in a concomitant increase in the toxicity of the treated effluent. A further 14–25% improvement in aqueous phase removal of the TrOCs was consistently observed following a one-off dosing of 3g/L granular activated carbon (GAC). Mass balance analysis reveals that this improvement was not due solely to adsorption but also enhanced biodegradation. GAC addition also reduced membrane fouling and the SA-induced toxicity of the effluent.