The Effect of Dissolved Organic Matter on Zeta Potential During the Coagulation Process

During the municipal wastewater reclamation process, the Zeta potential presented significant difference between the particle in the surface water and in the secondary effluent of WWTP with the increasing of PAC. Dissolved organic matter(DOM) in effluent from conventional sewage treatment plant was isolated into five classes using adsorbent resins: hydrophobic bases(HoB), hydrophobic acids(HoA);hydrophilic bases(HiB), hydrophilic acids(HiA) and hydrophilic neutrals(HiN). The Zeta potential of different organic fractions was examined when PAC was injected. The results showed that the concentration and composition of DOM were main reasons for the Zeta potential difference between surface water and secondary effluent during the coagulation process. And, hydrophobic organic was the main component leading to the slow change on Zeta potential.