源于钛白粉废料的含钛混凝剂的效果及污泥特性

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

摘要:

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2 mmol/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(4 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。

Abstract:

A new coagulant, poly-Ti-Fe (M-PTF), was prepared using a solid “waste acid filter cake (WAFC)” derived from production process of titanium dioxide. The microscopic characteristics of M-PTF were characterized with SEM, XRD and FTIR, respectively. And coagulation performance and sludge properties of M-PTF in treating a domestic wastewater was studied using Jar tests and Fluorescence Microscope (FM), compared with that of Poly Aluminum Chloride (PAC). The results showed that M-PTF surface morphology was composed of irregular and crystalline-like structures, and appeared to be rough and polymorphous networks having larger surface area. M-PTF gave higher 29% organic matter (Chemical Oxygen Demmand, CODCr) removal than PAC at dosage 2 mmol/L, and had far greater sludge settling rate at starting point (44 mL/min) than PAC (4 mL/min). M-PTF sludge was a sort of fluffy and close-ly-connected catkins-like/cotton-like images with well-defined boundary and lower water content, while PAC almost appeared to be a sort of transparent loose flocs without well-defined boundary. M-PTF sludge volume was much smaller than PAC and the water content of M-PTF sludge was lower 1.11%~2.41% than that of PAC, corresponding to its sludge reduction of 71.28%~84.38% based on the sludge volume of PAC, largely beneficial to subsequent concentrating and dewatering.