Papers by Author: Cui Zhen Sun

Abstract: A new polymer of epichlorohydrin-ethylenediamine was obtained by suspension polycondensation of ethylenediamine with epichlorohydrin. The color removal performance and mechanism of the polymer in the treatment of synthetic reactive dyes wastewater was investigated, and in comparison with polymeric aluminum ferric chloride (PAFC) and polydimethyldiallylammonium chloride (PDMDAAC). The results showed that epichlorohydrin-ethylenediamine achieved higher color removal efficiency, and its adsorption-bridging and electric neutralization ability playedimportant roles in the flocculation process.

Abstract: The performance of sulfonamide and macrolide antibiotics in a spiked water removed by O₃ and O₃/H₂O₂ was evaluated uder different conditions such as ozone dosage, pH and H₂O₂/O₃ mole ratio. The results showed that O₃ and O₃/H₂O₂ were proved to be effective to oxdize sulfamethoxazole of sulfonamides containing the aromatic ring and erythromycin of macrolides, which were built of mostly saturated hydrocarbon structure, and O₃ was preferentially to oxidize sulfamethoxazole. With the reaction time of 30 min, when the ozone cocentrations were 2mg/L and 3mg/L, sulfamethoxazole and erythromycin removal efficiency was 93% and 91%, respectively. The sulfamethoxazole and erythromycin were removed completely within 30 min with ozone 6 mg/L. Degradation of sulfamethoxazole containing unsaturated C-C bonds occured easier at low pH only by O₃. Degradation of erythromycin with fully saturated structure was difficult, but the improved removal efficiency could be obtained at higher pH. The high concentratins of H₂O₂ to ozonation was favor to remove those antibiotics. At the 0.5 mole ratio of H₂O₂/O₃ ,the highest removal efficiency could be reached for all the antibiotics .

Abstract: A new composite coagulant, polymeric ferric aluminum chloride-polydimethyl diallylammonium chloride (PFAC-PD), was prepared by combing Polymeric ferric aluminum chloride (PFAC) with polydimethyl diallylammonium chloride (PDMDAAC). The turbidity, ultraviolet absorbance at 254 nm (UV254) and specific ultraviolet absorbance (SUVA) removal and flocculating mechanisms of the new composite coagulant and the traditional coagulants (PFAC, adding PFAC before adding PDMDAAC and adding PFAC after adding PDMDAAC) were investigated in treating surface water. The results indicated that the new composite coagulants exhibited better flocculation efficiency than PFAC and successive addition of PFAC and PDMDAAC. The neutralization ability of the coagulants was in the following order: PFAC-PD > PD+PFAC > PFAC+PD > PFAC.