阴离子聚丙烯酰胺(APAM)和聚二甲基二烯丙基氯化铵(HCA)对给水厂污泥水分分布的影响及其与污泥颗粒的作用机制

The performance and mechanism of sludge dewatering with APAM and HCA in drinking water plant

为比较APAM和HCA对给水厂污泥调理的效果并探究其作用机制,测定了污泥调理前后的毛细吸水时间(CST)、污泥比阻(SRF)、溶解性有机污染物含量(DOC)、Zeta电位和絮体粒径的变化情况,并结合三维荧光谱图、液相-有机碳联用(LC-OCD)、热重差热法(TG-DTA)以及傅立叶红外(FTIR)的变化进行分析.结果表明,APAM和HCA的最佳投加量分别为0.05和0.10 g·L^(-1),与之对应的CST分别从71.0 s降到25.8 s和37.6 s,SRF从9.72×10^(12)m·kg^(-1)降到4.18×10^(12)m·kg^(-1)和5.70×10^(12)m·kg^(-1),APAM的调理效果占优.HCA仅可释放毛细水,而APAM可释放污泥的毛细水和表面吸附水.APAM通过氢键的吸附架桥形成大块絮体以改善污泥脱水性能,Zeta电位的升高和有机物的变化显示出电中和及去水化作用是HCA的主要调理机制.本研究结果可为给水厂污泥脱水有机药剂的选择提供数据基础.

The mechanism of sludge dewatering with APAM and HCA was explored by comparing its performance in a drinking water treatment plant,the capillary suction time(CST),specific resistance to filtration(SRF),dissolved organic carbon(DOC),Zeta potential and the floc size were measured,combined with the characterization with three-dimensional excitation-emission matrix(3 D-EEM),liquid chromatography-organic carbon detection(LC-OCD),thermo gravimetric-differential thermal analyzer(TG-DTA)and Fourier transform infrared(FTIR).The results showed that the optimal dosages of APAM and HCA were 0.05 and 0.10 g·L^(-1),where CST decreased from 71.0 s to 25.8 s and 37.6 s,SRF decreased from 9.72×10^(12)m·kg^(-1)to 4.18×10^(12)and 5.70×10^(12)m·kg^(-1),respectively.Meanwhile,APAM could release capillary water and surface adsorbed water from sludge,whereas HCA could only release capillary water.APAM improved sludge dewatering performance by adsorption and bridging through hydrogen bond.The increase of Zeta potential and the change of organic matter reflected that charge neutralization and dehydration are the main mechanism of HCA.In summary,this study can provide a data base for sludge dewatering conditioners in drinking water treatment plants.