การบำบัดน้ำเสียที่มีซัลเฟตและไนเตรทสูงโดยใช้ระบบยูเอเอสบี

Abstract

This research aims to study treatment of high sulfate and nitrate containing wastewater using 3 identical UASB reactors. The research was divided into 2 experiments, the first experiment used synthetic wastewater and the second experiment used  stainless industrial wastewater. For both experiments, calcium concentrations were varied to obtain  COD:calcium ratios of 10:0.85, 10:1.70 and 10:3.40. The COD, sulfate and nitrate concentrations were kept constant at 600, 90 and 60 mg/l, respectively. In both experiments, it was found that the COD:calcium ratio of 10:1.70 had the best  performance in terms of both treatment efficiency and size of  granule. The sludge granule having size larger than 1,200 µm, not found at the start-up period, was found to be 60.38 % after system operation. Consideration of  electron flow percentage using scanning electron microscope,  methanogenic bacteria, sulfate reducing bacteria and denitrifying bacteria were found to be 63.81, 22.41 and 13.78 %.   From this result,  the predominant microorganisms inside the granule were methanogens.