INTEGRATING CHEMICAL AND BIOLOGICAL REMEDIATION OF ATRAZINE AND S-TRIAZINE-CONTAINING PESTICIDE WASTES

Fenton's reagent (FR) and the catabolic activity of Rhodococcus corall inus and Pseudomonas sp, strain D were combined to detoxify s-triazine s in pure solutions and mixed wastes. In solutions containing only atr azine, complete atrazine decomposition was accomplished with 2.69 mM F R. But FR treatment was not complete in a remediation context because stable, potentially carcinogenic chlorinated products accumulated as e nd products. Rhodococcus corallinus degraded these products in less th an or equal to 10 min and produced 47% (CO2)-C-14 from [2,4,6-C-14]atr azine in 7 d. Combining R. corallinus with Pseudomonas sp. strain D in creased (CO2)-C-14 production to 73%. When applied to a pesticide rins e water containing atrazine, cyanazine, alachlor, metolachlor, and EPT C, greater than or equal to 99% of the pesticides were degraded with 1 2.2 mM FR. Subsequent treatment with R. corallinus and Pseudomonas sp, strain D degraded all chlorinated s-triazine intermediates and releas ed 70% (CO2)-C-14 from a [2,4,6-C]atrazine tracer in 10 d. Use of R. c orallinus 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 t reatment for pesticide rinse water.