源于钛白粉废料的含钛混凝剂效果及污泥特性

Coagulation Performance and Sludge Properties of A Coagulant Containing Titanium Derived from Titanium Dioxide Waste

以钛白粉生产中的废酸压滤饼(WAFC)为主要原料,制得聚合钛铁(M-PTF)混凝剂。利用SEM、XRD和FTIR考察了其微观特征,并采用荧光显微镜(FM)、烧杯实验对比了M-PTF与聚合铝(PAC)处理生活污水的效果及污泥特性。结果表明,M-PTF表面是由不规则样与晶状样组成的多形态结构的立体网状聚合物组成,表面积较大,且呈现粗糙状。当投药量均为2mmol/L时,M-PTF对有机物(耗氧量,CODCr)去除率比PAC高29%,污泥初期沉降速率(44 mL/min)远大于PAC(2 mL/min)。M-PTF污泥呈蓬松且紧密连接的棉花团状态,边界清晰,含水量较小,而PAC形成了边界不清晰且近乎透明的松散状絮团。M-PTF污泥体积远小于PAC,其含水率比PAC低1.11%～2.41%,对应的污泥体积下降了71.28%～84.38%,降低了浓缩和脱水的成本及难度。

A new coagulant,poly-Ti-Fe(M-PTF),was prepared using a kind of waste acid filter cake(WAFC)which was derived from production process of titanium dioxide as raw material.The microscopic characteristics of M-PTF were characterized by SEM,XRD and FTI.And coagulation performance and sludge properties of M-PTF in treating a domestic wastewater were studied using Jar test and fluorescence microscope(FM),compared with those of poly aluminum chloride(PAC).The results showed that the surface of M-PTF was composed of irregular and crystalline-like structures,and appeared to be rough and polymorphous networks having larger surface area.At a dosage of 2 mmol/L,M-PTF gave 29%higher organic matter(chemical oxygen demand,CODCr)removal than PAC,and had far greater sludge settling rate at starting point(44 m L/min)than PAC(2 m L/min).M-PTF sludge was a sort of fluffy and closely-connected catkins-like/cotton-like images with well-defined boundary and lower water content,while PAC sludge almost was a sort of transparent loose flocs without well-defined boundary.In addition,the sludge volume of M-PTF was much smaller than that of PAC,the water content of M-PTF sludge was lower 1.11%~2.41%than that of PAC sludge,corresponding to its sludge reduction of 71.28%~84.38%based on the sludge volume of PAC,which was largely beneficial to subsequent concentrating and dewatering.