Full Scale Treatment of Herbal Pharmaceutical Industry Wastewater

Herbal pharmaceutical industries generate moderately concentrated wastewater in huge volumes in terms of COD, BOD, and SS in the range of 21960-26000 mg/L, 12200-15660 mg/L and 5460-7370 mg/L respectively. It is not feasible to treat this wastewater in a single stage to meet the stipulated standards instead a combination of suitable treatments is required. Physicochemical treatment studies were carried out using various conventional coagulants individually and in combination with six polyelectrolytes of three different charges. Among ten combinations, Alum 300 mg/L + Oxyfloc-FL-11 was found to be the best combination with respect to COD, BOD, and SS removals of 6266 mg/L (64.00%), 2867 mg/L (69.40%) and 637 mg/L (80.82%) respectively. Further this treated effluent was selected for secondary biological Activated Sludge Process (ASP) using optimal parameters like organic / hydraulic loadings. Removals of organics in terms of absolute value of COD, BOD, and SS were found in the range with an absolute value of 896-944 mg/L, 156-174 mg/L and 66-74 mg/L respectively. Finally ASP treated effluent was subjected to tertiary Fenton’s oxidation process where the removals of COD, BOD, SS, and TOC were found to be efficient with 138 mg/L (85.19%), 20 mg/L (88.10%), 21 mg/L (70.00%), and 98 mg/L (78.22%) respectively on optimum conditions, which is well below the prescribed standards. This article discusses in details the results obtained on Primary physico-chemical, secondary biological and advanced oxidation treatment