Quaternary ammonium compounds (QACs) are active ingredients of many disinfectant formulations and widely used as additives in personal care products. As a result of high consumption, QACs are released into the environment thus they are emerging pollutants. QACs are toxic and play a significant role in development and dissemination of antimicrobial resistance in the environment. Although QACs are biocides, microorganisms that can degrade QACs are present but rare. In this study, we immobilized cells of Pseudomonas sp. BIOMIG1BDMA which converts benzalkonium chlorides (BACs), a group of QACs, to benzyl dimethyl amine (BDMA) in to Ca-alginate by entrapment. 3-mm beads containing 107 cells were synthesized. BAC biotransformation rate of beads were determined as 0.46 µM-BACs/hr. A bench-scale plug-flow reactor was prepared by packing the beads into a glass column with 1.5 cm diameter and 15 cm height. The reactor was fed with a synthetic wastewater containing 20 µM BACs and operated at 4.7, 2.3, 1.2 or 0.6 hrs hydraulic residence times (HRT) for 30 days. Above 90% BAC removal was achieved at and above 1.2 hrs HRT. The reactor was also fed with synthetic wastewater containing 2 µM BACs or with secondary effluent containing BACs at 1.2 hrs HRT where 102±11% and 95±5% BAC removal was reported, respectively. In conclusion, a reactor composed of immobilized cells of Pseudomonas sp. BIOMIG1BDMA can efficiently be utilized for the treatment of QACs bearing wastewater and alleviate the environmental and human health impacts of QACs by converting them to non-toxic tertiary amines.

Biotransformation of benzalkonium chlorides by immobilized cells of Pseudomonas sp. biomig1 in a packed bed reactor

251st National Meeting (2016)

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