给水污泥特性及混凝剂调理对其的影响研究

Study on Properties of Waterworks Sludge and Effect of Coagulants Conditioning on Dewatering Performance

为了研究给水厂污泥调质对其脱水性能的影响,针对不同水源水质特点(高浊、高有机物),对两个典型水厂进行了污泥特性研究及调理试验。结果表明:两种污泥的有机物种类、含量以及Zeta电位差别较大,深圳某水厂污泥的COD含量较高,且含有蛋白质,制约了污泥的脱水性能。在自然沉降条件下,上海水厂的污泥沉降性能明显优于深圳水厂;污泥比阻和毛细吸水时间的较大差异也说明深圳水厂污泥的脱水性能较上海水厂污泥差。对比二者的调理数据可以发现,深圳水厂污泥中较高含量的溶解性有机物直接影响到添加的混凝剂的水解过程,从而影响混凝效果。对于上海某水厂污泥,PAM对其脱水性能的改善作用最弱,并且极易增加TOC;而PAC和HPAC则表现出较理想的混凝效果,且电中和能力更强的HPAC具有较为明显的优势。深圳某水厂污泥的Zeta电位较高,阴离子型PAM不但可以中和污泥颗粒表面的正电荷,其较强的吸附架桥能力也能够有效地使污泥颗粒聚集沉降,表现出较优的污泥调理效果。

In order to study the influence of coagulants conditioning on dewatering performance of waterworks sludge, and according to different water quality characteristics （high turbidity and high organic matter concentration）, characteristics research and conditioning experiments of sludge from two typical waterworks were performed. The results indicated that there were significant differences between the two waterworks sludge in types and contents of organic matter and Zeta potential. The sludge from waterworks in Shenzhen had relatively high COD content and contained protein, which restricted the dewatering property. Under the condition of natural sedimentation, the sludge from Shanghai waterworks performed better than that from Shenzhen waterworks. The significant difference between the two types of sludge in specific resistance to filtration （SRF） and capillary suction time （CST） could also explain that dewatering per- formanee of the sludge form Shenzhen waterworks was poorer than that form Shanghai waterworks. Comparison of coagulants conditioning data between the two types of sludge showed that higher concentration of dissolved organic matter in the sludge form Shenzhen waterworks directly affected the hydrolysis process and reduced coagulation effect when coagulants were added. For the sludge from Shanghai waterworks, the effect of PAM on improvement of the dewatering performance was the weakest, and PAM could increase the TOC easily. However, PAC and HPAC showed the ideal coagulation effect, and HPAC had more obvious advantage due to its stronger charge neutralization capacity. Zeta potential of the sludge form Shenzhen waterworks was higher, anionic PAM could neutralize the positive charge on the surface of sludge particles, and its strong adsorption-bridging ability could also effectively concentrate and settle sludge particles, showing the optimal sludge conditioning effect.