河湖疏浚淤泥的表征、絮凝和脱水

以无锡锡山湿地公园河道淤泥及太湖贡湖湾疏浚底泥为研究对象,对比分析了两种淤泥的矿物组成、粒径分布及泥微粒表面基团、ζ电位等理化特性。以聚丙烯酰胺类聚合物(polyacrylamide,PAM)为絮凝剂,对比分析了其在2种底泥絮凝分离、真空抽滤脱水过程中的作用特征,并对相关影响因素进行了探讨。结果表明,两种淤泥样具有相近的主体矿物组分、有机基团及ζ电位值,但有机质含量稍高的淤泥样中大颗粒所占比例相对较高。相比阳离子型PAM,阴离子型PAM在较少用量下即可获得较大絮团,但上清液浊度较高。絮凝泥在抽滤过程受絮团尺寸影响较大, PAM不同类型基团间的差异对其影响较小,但对趋于平衡后的泥饼含水率略有影响。

Characterization, flocculation and dehydration of dredged sludge

The Wuxi Xishan wetland park river sediment and dredged sewage from Gonghu Bay of Tai Lake were chosen and studied. The characteristics such as particle size distribution, mineral composition, surface groups and zeta potentials were comparatively analyzed. The process of flocculating separation and vacuum filtration with the polyacrylamide (PAM) was discussed. The results showed that these two kinds of dredge sludge had similar mineral components, organic groups and ζ potential values, but the sludge sample with higher organic matter content had a relatively high large particle proportion. Compared with the cationic PAM, the anionic PAM could get larger flocculents with less doses, but the separated liquid turbidity value was bigger. The filtration rate of the flocculation sample was affected by the size of flocculate more than the difference between ionic groups of PAM, but the moisture content of mud cake after equilibrium was slightly affected.