Abstract:
This research was to study the COD reduction of the antibiotic pharmaceuticalwastewaters by the method of Fentons reagent containing FeSO, and $0,. Three sources ofwastewaters used in this study were equalizing wastewater, still bottom wastewater and motherliquor wastewater. The experiments were devided into 2 parts: fust, study on the optimumconditions for the COD reduction of the original wastewater such as pH, doses and settling timeand second, study on the optimum conditions for COD reduction of the post treating wastewaterby coagulation.The results of the COD reduction of the original high strength wastewater (34,000 -191,000 mg/dm3 of COD) show that the optimum pH for all wastewaters were 4.00. Theoptimum FeSO, and H,O, doses were in range of 1,000 - 1,600 ppm and 1,400 - 3,400 ppm,respectively, The optimum settling time for equalizing wastewater and mother liquor wastewaterwere in range of 30 - 40 minutes and for still bottom wastewater was 10 minutes. The Iefficiencies of COD reduction were in range of 57 - 70%. The chemical cost for treatmentincluding final pH adjustment to pH 7.00 were in range of 120 - 290 baht per cubic meter,The results of the COD reduction of the antibiotic pharmaceutical wastewater aftertreated by coagulation which COD in range of 19,800 - 113,000 mg/dm3 show that the optimumpH for equalizing wastewater, still bottom wastewater and mother liquor wastewater were inrange of 4.00 - 9.00, 4.00 - 8.00 and 4.00 - 7.00, respectively. The optimum FeSO4 and H2O2doses were in range of 300 - 600 ppm and 700 - 1,200 ppm, respectively. The optimum settlingtime for all wastewaters were 40 minutes. The efficiencies of COD removal were 23 - 30%. Thechemical cost for treatment were in range of 70 - 140 baht per cubic meter. The total efficiencyof COD removal by coagulation combining with fentons reagent were in range of 55 - 60%. Thetotal chemical cost for treatment including final pH adjustment to pH 7.00 were in range of 1.50 -350 baht per cubic meter.The efficiency of COD removal by Fentons reagent method and coagulationcombined with Fentons reagent were similar. According to the chemical cost for treating ofmother liquor wastewater using Fentons reagent was higher than that of using coagulationfollowed by Fentons reagent. Whereas, chemical cost in treating of equalizing wastewater andstill bottom wastewater by Fentons reagent were cheaper.