Treatability Studies of Pesticide Manufacturing Wastewaters: Glyphosate

摘要

The report gives results of subjecting various combinations of glyphosate production wastestreams to biological treatment following lime-pretreatment to reduce high levels of glyphosate. Bench-scale biological treatment demonstrated that glyphosate did not appear to interfere with biological degradation at concentrations up to 105 mg/L. Glyphosate itself showed only partial reduction with biological reduction (28-45%). The mechanism of this removal is not fully understood but may include sorption on sludge. No evidence for metabolism of glyphosate was generated in oxygen uptake studies. While the test does not provide any evidence for metabolic uptake of glyphosate, it is interesting to note that fairly high concentrations of the compound do not inhibit other microbial processes in acclimated sludge. Biological treatment significantly reduced the toxicity of these effluents to algae (Selenastrum capricarnutum) and invertebrates (Daphnia magna). Additional treatment options were investigated in an attempt to reduce glyphosate concentrations in the biologically treated effluents. These options included ozonation, adsorption, and ion exchange. These options only marginally reduced glyphosate concentrations in biologically treated effluents.