Synthesis And Flocculation Property Of EPI-DMA Flocculant Series

With the rapid development of industry, the ingredients of printing and dyeing wastewater have become more and more intricate. In order to treat printing and dying wastewater efficiently, it is urgent that higher efficiency coagulants should be exploited. In this paper, flocculants epichlorohydrin-dimethylamine polymers (EPI-DMA) were synthesized by polycondensation of dimethylamine and epichlorohydrin with modifying agents such as diaminoethane,.diethylenetriamine and triethylenetetramine. The influences of the amount of modifying agents on the characteristics of EPI-DMA were investigated. IR and TEM were used to test the structure of EPI-DMA. EPI-DMA flocculants were also used for decoloring waste water. A series of composite flocculants polyaluminum-epichlorohydrin -dimethylamine (PAC-EPI-DMA) were prepared by using PAC and EPI-DMA as raw materials. The electrical charge and the framework characteristic of PAC-EPI-DMA were studied by ZATESIZER 3000HSA tester and TEM respectively. The flocculating efficiency of PAC and PAC-EPI-DMA on treating dyeing waste water was preliminarily examined by Jar tests. The coagulating properties of EPI-DMA and PAC-EPI-DMA were contrasted by TEM and jar tests.The experimental results showed that: In the process of synthesis of EPI-DMA polymers, the addition of modifying agents changed the viscosity and the cationic degree of EPI-DMA. The IR spectrums of EPI-DMA polymers were analogical, but the morphology of the flocculants were different. When treating different type wastewater, EPI-DMA flocculants showed different flocculation mechanism. PAC-EPI-DMA was characterized by giving higher positive Zeta potential value than PAC. The η value of PAC and the content (P) of PDMDAAC in PAC-EPI-DMA had some effects on the Zeta potential, the structure of the flocculants and the efficiency of color removal. The contrast of the coagulating properties of EPI-DMA and PAC-EPI-DMA results showed PAC-EPI-DMA gave better coagulation results, and achieved higher charge-neutralizing and adsorption bridge building ability.