Application of hybrid modified UASB - MBBR technology for wastewater treatment of Sao Thai Duong Pharmaceuticals and Cosmetics Factory

Abstract

Wastewater of Sao Thai Duong Pharmaceuticals & Cosmetics Factory contains high concentration (more than 1000 mg/l) COD and BOD. Besides, some persistent substances are also found such as surfactants, emulsion oil and ammonium. Especially, the quite low BOD/COD ratio of 0.3 makes the treatment process of organic matters more complicated. Furthermore, the troublesome settlement of oil emulsions inhibits the wastewater biological treatment process which results in difficulties for selection of a stable and sustainable technology. For these reasons, it is recommended to use the Upflow Anaerobic Sludge Blanket Filtration (UASB) technique combined with the use of the bio-logical named carriers DHY-01 and DHY-02 (produced by Vinse Company). DHY carriers have a high porosity (92-96%), large surface area (10000-12000 m2) and apparent specific weight of 33 g/l. The anaerobic treatment tank (Upflow Blanket Filter - UBF) has a retention time of 10-12 hours. Influent COD concentration is about 1000-2000 mg/l, reduced by 65-70% after treatment. Influent BOD concentration is 200-600mg/l, reduced by about 60-65% after treatment. Aerobic tank (moving bed biofilm reactor - MBBR) has a retention time of 4-6 hours. COD and ammonium removal efficiency is about 85-90%.