TREATABILITY OF 2,4-D PRODUCTION WASTEWATERS

This study evaluates the characterization and treatability of 2,4-D pr oduction wastewaters. Wastewaters contain 20000-40000 mg/l COD, 17000- 30000 mg/l chloride and pH is around 1.0. Chemical oxidation with hydr ogen peroxide provided almost complete COD removal. The optimum condit ions are 3:1 H2O2/COD oxidant dosage, 3000 mg/l Fe3+ as catalyst and p H 3. Partial oxidation at 0.5:1 H2O2/COD ratio is also effective provi ding 67% COD removal. A batch activated sludge system is used for biol ogical treatability. Dilution is needed to maintain a tolerable chlori de concentration which increases through COD removal. pH also increase d during COD removal. 85% COD removal is obtained for the 50% dilution at an organic loading of 0.3 day(-1) on a COD basis. Completely and p artially oxidized wastewaters are also treated in the activated sludge down to 30 mg/l BOD5.