Acidification Treatment of Woolscouring Effluent by Using Acidophilic thiobacillus
利用嗜酸性硫杆菌的生物产酸作用处理洗毛废水

Suspended solids dispersed in woolscouring effluent (WSE) could be flocculated and precipitated in low pH. The aim of this study is to decrease pH in WSE, result in liquid-solid separation and remove COD of WSE through bio-acidification of Acidophilic thiobacillus. Acidophilic thiobacillus TS6 and sulfur powder as energy substance were inoculated and added into WSE for incubation in shaker at 180 r/min and 30 degrees C for 12 d. The results showed that suspended solids in WSE would flocculate and precipitate spontaneously and rapidly when pH in WSE drops to 3.00 due to bio-acidification. As a result, 91.4% of COD could be removed through consequent liquid-solid separation. Throughout the experiment, the control without inoculated with Acidophilic thiobacillus only led to 20% of COD removed. Furthermore, dewaterability of the sediment or dreg in bio-acidification treatment was enhanced markedly, as indicated by the decline of its specific resistance from more than 9.81 x 10(13) m x kg(-1) to 5.60 x 10(11) m x kg(-1). It seemed that bio-acidification approach might be an attractive treatment method for the organic wastewater of high wax content or high suspended solids content.