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Zhu J.,Chongqing University | Zheng H.,Chongqing University | Zhang Z.,Chongqing University | Jiang Z.,Chongqing University | And 4 more authors.
Huagong Xuebao/CIESC Journal | Year: 2012

The composite flocculant was prepared by polymerizing CPAM (a cationic flocculant P: acrylamide-methacryloxyethyltrimethyl ammonium chloride-acryloxyethyltrimethyl ammonium chloride) and PFAS (polymeric aluminum ferric sulfate). The morphological distribution of Fe and Al was studied by using Ferron analysis, and the morphology of the copolymer was observed using scan electron microscopy. The Box-Behnken mathematical relational model between CODCr removal rate and affecting factors was established, and the technique composing PAFS-CPAM was optimized. The optimum synthesis conditions were: react temperature 61°C, react time 74 min, and Fe/CPAM mass ratio 28, respectively. At these optimized conditions and using 50 mg·L-1 PAFS-CPAM flocculant prepared, CODCr removal and turbidity removal rates were 80.86% and 97.50%, respectively. © All Rights Reserved. Source


Jiang Z.,Chongqing University | Zheng H.,Chongqing University | Tan M.,Jiangmen Wealth Water Purifying Agent Co. | Zhu J.,Chongqing University | And 3 more authors.
Tumu Jianzhu yu Huanjing Gongcheng/Journal of Civil, Architectural and Environmental Engineering | Year: 2013

A new composite coagulant polymeric aluminum ferric sulfate (PAFS) was synthesized using FeSO4·7H2O and Al2(SO4)3 (industrial) by the direct oxidation method. The optimization of preparation process of PAFS was investigated using single factor and response surface methodology based on Box-Behnken central design. Parameters affecting the coagulant performance, such as reaction temperature, time, SO4 2-/Fe, NO3 -/Fe, Al/Fe, PO4 3-/Fe, and OH/Fe molar ratios were examined. The results show that when temperature, time, SO4 2-/Fe, NO3 -/Fe, Al/Fe, PO4 3-/Fe, and OH/Fe molar ratios were 84°C, 48 min, 0.38, 0.47, 0.11, 0.14, 0.03, respectively, it is the optimum conditions for synthesis. In this condition TP removal was 98.67%, and the experimental results were in good agreement with the predicted values of the model equation with 0.38% deviation. Furthermore, COD (chemical oxygen demand) and turbidity removal efficiency were 79.13% and 98.12%, respectively. Source


Zheng H.,Chongqing University | Feng L.,Chongqing University | Jiang Z.,Chongqing University | Yin H.,Chongqing Water Investment Group Ltd. | And 3 more authors.
Tumu Jianzhu yu Huanjing Gongcheng/Journal of Civil, Architectural and Environmental Engineering | Year: 2013

Polymeric aluminum ferric sulfate (PFAS) was developed by Industrial Grade ferrous sulfate heptahydrate and industrial aluminum sulphate(16% Al2O3). PFAS was used for printing and dyeing wastewater treatment. The new synthetic Polymeric aluminum ferric sulfate (PFAS) with a unique spatial fold-like structure was discovered by scanning electron microscopy analysis(SEM). The treatment efficiency was evaluated by investigated sludge volume and the reduction of removal rate of COD and turbidity of printing and dyeing wastewater by using single factor. The results show that the removal rate of COD is achieved 83.0%, the removal rate of turbidity is achieved 95.0% and the sludge volume is 52.8 mL when the coagulant dosage is 0.3 g/L and pH is 8.5. Meanwhile, compared with the common coagulant (PFS, PAC and CPAM) in application of printing and dyeing wastewater treatment, the performance on the removal of COD and turbidity of self-make PFAS is better than those of PFS, PAC and CPAM. Source


Zheng H.L.,Chongqing University | Xiang X.Y.,Chongqing University | Xiang X.Y.,Southwest University | Tan M.Z.,Jiangmen Wealth Water Purifying Agent Co. | And 3 more authors.
Asian Journal of Chemistry | Year: 2013

In this research, the synthesis and property of N,N-dithiocarboxy diethylenetriamine ethyl polymer were investigated. The polymer was synthesized through one-step reaction of diethylenetriamine, carbon disulfide with 1,2-dichloroethane, with the reaction time and required temperature being reduced significantly compared with that of traditional two-step reaction. Such factors as addition of sodium-hydroxide and its adding procedure, adding procedure of carbon disulfide, addition of diethylenetriamine, reaction temperature and reaction time were studied in details. Physical and chemical characteristics of this polymer were determined taking advantage of IR, UV and melting point test. Heavy-metal-ion absorbing property of this polymer was studied intensively. The results showed that several kinds of heavy metal ions could be significantly absorbed with the produced polymer, among which Ag +, Cu2+ and Zn2+ could be absorbed most effectively. The absorption ability of this polymer was maximized when the pH value was controlled at 5. Copyright © 2013 Asian Journal of Chemistry. Source


Tshukudu T.,Chongqing University | Zheng H.,Chongqing University | Hua X.,Chongqing University | Yang J.,Chongqing University | And 4 more authors.
Korean Journal of Chemical Engineering | Year: 2013

Response surface method and experimental design were applied as alternatives to the conventional methods for optimization of the coagulation test. A central composite design was used to build models for predicting and optimizing the coagulation process. The model equations were derived using the least square method of the Minitab 16 software. In these equations, the removal efficiency of turbidity and COD were expressed as second-order functions of the coagulant dosage and coagulation pH. By applying RSM, the optimum condition using PFPD1 was coagulant dosage of 384 mg/L and coagulation pH of 7. 75. The optimum condition using PFPD2 was coagulant dosage of 390 mg/L and coagulation pH of 7. 48. Confirmation experiment demonstrated a good agreement between experimental values and model predicted. This demonstrates that RSM and CCD can be successfully applied for modeling and optimizing the coagulation process using PFPD1 and PFPD2. © 2012 Korean Institute of Chemical Engineers, Seoul, Korea. Source

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