酸浸粉煤灰混凝法处理制革废水的研究

笔者研究了在热电厂粉煤灰中加入少量的鼓风炉铁泥和适量的助溶剂HS，在加热条件下用稀硫酸搅拌浸取2h后，制得集物理吸附和化学混凝为一体的混凝剂。这种混凝剂与聚硅酸铝铁(PSAF)絮凝剂配合处理COD为1500～2000mg/L制革废水，SS，COD，硫化物和铬的去除率分别为95%，93%，92%和88%。该法的显著特点是混凝沉降速度快，污泥体积小，处理废水费用低，此外还探讨了酸浸粉煤灰混凝剂对制革废水的混凝沉降机理。 

Study on Treatment of Tanning Wastewater by Coagulation Method with Fly Ash Treated by Acid

A kind of fly ash-based coagulant combining the capabilities of both physical adsorption and chemical coagulation has been prepared by adding a small amount of blast furnace iron sludge and an appropriate amount of helping solvent (HS) to fly ash in coal-fired thermal power plants and then the resulting mixture being stirred and extracted with a dilute H₂SO₄ for 2 h at 90℃. Combined with polysilicate aluminum and ferric (PSAF), this coagulant was thus used to treat tanning wastewater which COD value is 1 500～2 000 mg/L. The removal rates of SS, COD, sulfide and total chromium were 95%, 93%, 92% and 88% respectively. The remarkable characteristics of this method are a higher rate of settlement, a smaller volume of sludge, and a lower cost of treatment. The coagulation mechanism of fly ash coagulant in the treatment of tanning wastewater has been studied.