Abstract

The existing methods for dewatering sewage sludge containing finely dispersed clay minerals can be applied with an initial moisture content of <75%. In the case of higher moisture content, it is necessary to treat preliminary such dispersions to provide their destabilization, sedimentation, and consolidation, that is, to obtain more concentrated precipitate, followed by the separation of the excess liquid phase. A decrease in the stability of clay disperse systems can be achieved by decreasing the electrostatic repulsion between particles with a decrease in their surface charge due to a change in the pH of the dispersed medium or adsorption of potential-determining cations, as well as due to the compression of the double electric layer with an increase in the total concentration of electrolyte. We studied the effect of the chemical composition of an aqueous dispersed medium on the ζ potential, the interaction and aggregation of dispersed particles in a model system based on kaolinite, sedimentation of aggregates, and consolidation of the sediment. The dependence of the obtained values of the ζ potential on the inhomogeneity of the surface charge of the particles and the polarization of the formed chain aggregates in an electric field is analyzed. The conditions for maximum sediment consolidation are determined, which ensure a further decrease in moisture content using methods combining pressure and electroosmosis.

中文翻译：

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黏土分散液的凝结，沉淀和固结

摘要

现有的将含细分散的粘土矿物的污泥脱水的方法，其初始含水量可<75％。在较高的水分含量的情况下，必须对这类分散体进行初步处理，以使其失稳，沉降和固结，即获得更浓的沉淀，然后分离出过量的液相。粘土分散体系稳定性的降低可通过降低颗粒之间的静电排斥力，以及由于分散介质的pH值变化或电势决定性阳离子的吸附而导致表面电荷降低而实现。随着电解质总浓度的增加，双电层受到压缩。在基于高岭石的模型系统中，我们研究了水性分散介质的化学组成对ζ势，分散颗粒的相互作用和聚集，聚集体的沉积以及沉积物固结的影响。分析了获得的ζ电势值与颗粒表面电荷的不均匀性以及在电场中形成的链聚集体的极化的关系。确定最大的沉积物固结条件，以确保使用压力和电渗合并方法进一步降低水分含量。分析了获得的ζ电势值与颗粒表面电荷的不均匀性以及在电场中形成的链聚集体的极化的关系。确定最大的沉积物固结条件，确保使用压力和电渗合并方法进一步降低水分含量。分析了获得的ζ电势值与颗粒表面电荷的不均匀性以及在电场中形成的链聚集体的极化的关系。确定最大沉积物固结的条件，以确保结合压力和电渗方法进一步降低水分含量。