Enhanced degradation of prometryn and other s-triazine herbicides in pure cultures and wastewater by polyvinyl alcohol-sodium alginate immobilized Leucobacter sp. JW-1.

The s-triazine herbicides, such as prometryn, have been widely used in agriculture and have raised much public concern over their contamination of water and soil. Leucobacter sp. JW-1 cells were immobilized in polyvinyl alcohol‑sodium alginate (PVA-SA) beads and then used to degrade prometryn. Orthogonal array experiments showed that the optimal immobilization conditions of PVA-SA immobilized Leucobacter sp. JW-1 beads (PSLBs) were 3% JW-1 cells (w/v, wet weight), 10-12% (w/v) PVA, 2-3% (w/v) calcium chloride, and an immobilization time of 24-36h. The PSLBs were more tolerance to pH, temperature and salinity changes than free JW-1 cells and were stable and effective for degrading prometryn through six reuse cycles without losing their degradation capacity. The half-life of prometryn degradation by PSLBs at 100mgL-1 in pesticide plant wastewaters were 1.1-6.9h. The rate constants of prometryn degradation by PSLBs in wastewaters ranged from 304 to 576mgL-1day-1, which were approximately 1.25-118 times those of degradation by free JW-1 cells. The PSLBs degraded 99.9% of atrazine, 99.9% of ametryn, 97.8% of propazine, 100.0% of simetryn, 77.9% of simazine, 98.9% of terbuthylazine, 95.2% of prometon, 98.9% of atraton, and 31.6% of terbumeton at an initial concentration of 50mgL-1 of each herbicide in 2days. This study indicates that PSLBs persistently biodegrade s-triazine herbicides better than JW-1 free cells, and can be an efficient, safe and reusable biomaterial for the removal of s-triazine herbicides from contaminated sites. Copyright © 2017 Elsevier B.V. All rights reserved.

Citation

Junwei Liu, Dandan Pan, Xiangwei Wu, Haiyan Chen, Haiqun Cao, Qing X Li, Rimao Hua. Enhanced degradation of prometryn and other s-triazine herbicides in pure cultures and wastewater by polyvinyl alcohol-sodium alginate immobilized Leucobacter sp. JW-1. The Science of the total environment. 2018 Feb 15;615:78-86

PMID: 28963898

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