阳离子絮凝剂HTCC与PAC复配对黄河兰州段水除浊性能研究

STUDY ON THE PERFORMANCES OF TURBIDITY REMOVAL FOR LANZHOU SECTION OF THE YELLOW RIVER BY CATIONIC FLOCCULANT HTCC COMBINED WITH PAC

通过正交实验制备了阳离子絮凝剂壳聚糖季铵盐(HTCC),研究了壳聚糖季铵盐与聚合氯化铝(PAC)复配对黄河兰州段水的除浊效果,确定最佳复配比为m(HTCC)∶m(PAC)=1∶3。按该复配比,且在最佳投加量(1.25 mg/LHTCC+3.75 mg/L PAC)下,原浊为27.85～33.28 NTU的黄河水经处理后余浊<3 NTU。实验结果表明:pH对HTCC/PAC的除浊效果影响较大,当pH为7～9时,除浊效果均良好;而当pH为5～7时,投药范围内的最佳投药量提前,而除浊效率有所降低;沉降时间对HTCC/PAC的除浊效果无明显影响;HTCC/PAC以固-固方式复配的除浊效果比液-液方式复配的较差。

Cationic 2-hydroxypropyltrimethyl ammonium chloride chitosan（HTCC） was prepared by orthogonal experiment,the removal rate of the turbidity about Lanzhou section of the Yellow River water sample by composite flocculants HTCC/PAC was investigated,and its best composite ratio was determined to be m（HTCC）∶m（PAC）=1∶3.For water of original turbidity about 27.85～33.28 NTU,the residual turbidity reaches under 3 NTU by the optimum dosage of HTCC/PAC with this composite ratio.The experiment result shows that pH has great influence on the turbidity removal efficiency of HTCC/PAC,and it reaches a good flocculation performance when pH is between 7 and 9;and the turbidity removal rate is slowing gradually when pH is from 5 to 7,but the optimum dosage of HTCC/PAC become smaller;The influence of settling time on turbidity removal is not obvious.The flocculation effect of HTCC/PAC compounded by the solid-solid way is less than that of the liquid-liquid way.