Integrating chemical and biological remediation of atrazine and S‐triazine‐containing pesticide wastes

Abstract

AbstractFenton's reagent (FR) and the catabolic activity of Rhodococcus corallinus and Pseudomonas sp. strain D were combined to detoxify s‐triazines in pure solutions and mixed wastes. In solutions containing only atrazine, complete atrazine decomposition was accomplished with 2.69 mM FR. But FR treatment was not complete in a remediation context because stable, potentially carcinogenic chlorinated products accumulated as end products. Rhodococcus corallinus degraded these products in ≤10 min and produced 47% 14CO2 from [2,4,6‐14C]atrazine in 7 d. Combining R. corallinus with Pseudomonas sp. strain D increased 14CO2 production to 73%. When applied to a pesticide rinse water containing atrazine, cyanazine, alachlor, metolachlor, and EPTC, ≥99% of the pesticides were degraded with 12.2 mM FR. Subsequent treatment with R. corallinus and Pseudomonas sp. strain D degraded all chlorinated s‐triazine intermediates and released 70% 14CO2 from a [2,4,6‐14C]atrazine tracer in 10 d. Use of R. corallinus obviated the need for additional chemical pretreatment, e.g., acidification or base hydrolysis, used in previous studies prior to microbial incubations. Thus, this method has potential as an on‐site treatment for pesticide rinse water.