高效微生物絮凝剂对造纸废水的应用研究

APPLICATION OF HIGH-EFFICIENCY BIOFLOCCULANT IN PAPERMAKING WASTEWATER

从活性污泥中筛选出絮凝剂产生菌,以M-3为例进行絮凝特性研究,结果表明,M-3产生的絮凝剂属于胞外絮凝剂,对发酵液进行粗品提纯和成分分析,鉴定其主要成分为多糖,质量分数为75.38%。利用粗品对造纸污水进行处理,结果表明,在pH=12、生物絮凝剂加入量为7mL、加入5mL质量分数1%的CaCl2时,絮凝率可达98%,COD去除率为59.30%,氨氮去除率大于96%。研究了联合使用微生物絮凝剂和传统絮凝剂聚合氯化铝(PAC)对造纸废水的处理,在PAC的投加量为0.3mL、生物絮凝剂加入量为4mL、加入6mL质量分数1%的CaCl2、pH=11时,絮凝率可达97%,COD去除率为67.10%,氨氮去除率为95.18%。

Flocculant-producing bacteria were isolated mainly from the activated sludge, and flocculation characteristics of the flocculant-producing bacteria named M-3 was investigated. The results showed that the flocculant from M-3 belonged to extracellular biopolymeric flocculants. The crude was purified from the culture broth and its major components was identified as polysaccharide ,the content of which was 75.38%. The crude was studied in the papermaking wastewater. The best treatment conditions were determined by ortbogonal test including some factors, such as hydraulic mixing time, flocculant dosage, the CaCl2 solution dosage and pH values. Some water quality indexes under orthogonal test were monitored to evaluate the flocculant in the papermaking wastewater treatment. Under the pH value of 12, the volume offlocculants adding to 7mL, the volume of CaCl2 solution （1%） adding to 5mL, the flocculation rate was 98%.the COD removing rate was 59.30% ,and the removal ammonia-nitrogen reached above 96%. Combination of biofloeculant and traditional flocculants was also researched in the text, and it achieved good results by taking Polyaluminium Chloride （PAC） as traditional floceulants. The results showed that the flocculation rate was 97%,the COD removing rate was 67.1% ,and the removal ammonia-nitrogen reached 95.81% ,tinder the volume of PAC adding to 0.3mL, the volume of flocculants adding to 4mL ,the volume of CaCl2 solution （1%） adding to 6mL and the oH value of 11.