Compared with traditional aluminum salts, polyaluminum chloride （PACI） has better coagulation-flocculation performance in turbidity removal. However, it is still inferior to organic polymers in terms of bridging fun...Compared with traditional aluminum salts, polyaluminum chloride （PACI） has better coagulation-flocculation performance in turbidity removal. However, it is still inferior to organic polymers in terms of bridging function. In order to improve the aggregating property of PACl, different composite PACl flocculants were prepared with various organic polymers. The effect of organic polymer on the distribution or Al（Ⅲ） species in composite flocculants was studied using ^27TAl NMR and Al-ferron complexation methods. The charge neutralization and surface adsorption characteristics of composite flocculants were also investigated. Jar tests were conducted to evaluate the turbidity removal efficacy of organic polymer modified composite flocculants. The study shows that cationic polymer and anionic polymer have significant influences on the coagulation-flocculation behaviors of PACl. Both cationic and anionic polymers can improve the turbidity removal performancc of PACl but the mechanisms arc much different： cationic organic polymer mainly increases the charge neutralization ability, but anionic polymer mainly enhances the bridging function.展开更多
A new inorganic polymer flocculant-PZFSiC (zinc-iron-silicate polymer composite) is prepared by adding acid into a high modulus solution of water glass and introducing appropriate metallic ions(M) including Zn and Fe....A new inorganic polymer flocculant-PZFSiC (zinc-iron-silicate polymer composite) is prepared by adding acid into a high modulus solution of water glass and introducing appropriate metallic ions(M) including Zn and Fe. The influence on flocculability of factors such as the mole ratios of M to SiO2,stirring time and pH are discussed .And the optimal preparing technical parameters are obtained by orthogonal tests. The optimum technical conditions of flocculation are determined. The result shows that when less PZFSiC is added into troubled water or waste water, turbidity removal can hit 98%, COD removal can exceed 93%. The water sample treated is clear and of good quality. These results also indicate that PZFSiC is a highly effective, nontoxic and benign to the enviroment.展开更多
By using polyaluminum chloride (PAC), chitosan (CTS) and montmorillonite (MM) as the main raw materials, a novel tap water flocculant had been prepared. The optimal mass proportion of this flocculant was 1 g·L–1...By using polyaluminum chloride (PAC), chitosan (CTS) and montmorillonite (MM) as the main raw materials, a novel tap water flocculant had been prepared. The optimal mass proportion of this flocculant was 1 g·L–1 chitosan:50 g·L–1 PAC:3g·L–1 MM = 30:11:7. Compared with the traditional polyaluminum chloride (PAC), the concentration of aluminum ion (Al3+) and suspended solids (SS) in the exit dropped 66.19% and 5.80% respectively, moreover, the cost was decreased by 9.95%. This flocculant was not only cheaper, but also provided improved flocculating function compared with traditional flocculant. The concentration of Al3+ in exit water was decreased greatly so the drinking water would be much safer.展开更多
A kind of environmental friendly novel composite flocculants which are used to treat raw water is prepared. It is made with chitosan (CS), iron modified polyaluminium chloride (CF-PAC) and modified montmorillonite on ...A kind of environmental friendly novel composite flocculants which are used to treat raw water is prepared. It is made with chitosan (CS), iron modified polyaluminium chloride (CF-PAC) and modified montmorillonite on the principle of “the combination of organic and inorganic”. Under the optimum best compound formula and flocculation process, the turbidity of the waste water reduced by 0.62%, the chemical cost decreased by 12.43% and the content of aluminium ions dropped by 70.65%. There is an excellent characteristic and higher efficiency on the composite flocculant which can adsorb the organic matter in the water and chelate the heavy metal ions in the water.展开更多
The biopolymer flocculant （named PS-2） producing by Pseudomonas fluorescens was investigated. The PS-2 had high efficiency with small dosage, when dealing with kaolin suspension, formed larger floc, with big sedimen...The biopolymer flocculant （named PS-2） producing by Pseudomonas fluorescens was investigated. The PS-2 had high efficiency with small dosage, when dealing with kaolin suspension, formed larger floc, with big sedimentation rate, over a wide range of temperatures. Distributing of flocculating activity test showed that the biopolymer flocculant was an extracellular product. The composition analysis of purified biopolymer flocculant showed that it composed mainly of polysaccharide and nucleic acid. The content of polysaccharide was 86. 7%, which determined by using phenol-vitriol method, and the content of nucleic acid was 7.8%, which determined by UV absorption method. The biopolymer flocculant as a powder form showed much better stability than that as a supernatant. The character of biopolymer flocculant was stable even it was heated to 100℃ when it in acidic condition. The optimal conditions to flocculate kaolin suspension were as follows： pH 8-12, flocculant dosage lmL/L, and Ca^2＋ as the optimal cation.展开更多
A coagulation/flocculation process using the composite flocculant polyaluminum chloride-epichlorohydrin dimethylamine （PAC- EPI-DMA） was employed for the treatment of an anionic azo dye （Reactive Brilliant Red K-2B...A coagulation/flocculation process using the composite flocculant polyaluminum chloride-epichlorohydrin dimethylamine （PAC- EPI-DMA） was employed for the treatment of an anionic azo dye （Reactive Brilliant Red K-2BP dye）. The effect of viscosity 01）, basicity （B = [OH]/[Al]） and organic content （Wp） on the flocculation performance as well as the mechanism of PAC-EPI-DMA flocculant were investigated. The η was the key factor affecting the dye removal efficiency of PAC-EPI-DMA. PAC-EPI-DMA with an intermediate η （2400 mPa.sec） gave higher decolorization efficiency by adsorption bridging and charge neutralization due to the co-effect of PAC and EPI-DMA polymers. The Wp of the composite flocculant was a minor important factor for the flocculation. The adsorption bridging of PAC-EPI-DMA with η of 300 or 4300 mPa.sec played an important role with the increase of Wp, whereas the charge neutralization of them was weaker with the increase of Wp. There was interaction between Wp and B on the removal of reactive dye. The composite flocculant with intermediate viscosity and organic content was effective for the treatment of reactive dyeing wastewater, which could achieve high reactive dye removal efficiency with low organic dosage.展开更多
An inorganic-organic composite was prepared by poly（amidoamine） （PAMAM） dendrimer reacting with cobalt（Ⅱ）-monosubstituted polyoxometalates Na5Co^Ⅱ（H2O）PW11O39 （PW11CO） in an aqueous solution. The hybrid co...An inorganic-organic composite was prepared by poly（amidoamine） （PAMAM） dendrimer reacting with cobalt（Ⅱ）-monosubstituted polyoxometalates Na5Co^Ⅱ（H2O）PW11O39 （PW11CO） in an aqueous solution. The hybrid composite PW11Co/PAMAM was characterized by FT-IR, UV-Vis diffuse reflectance spectra （DR-UV-Vis）, XPS, XRD and TG/DTA, indicating that the PWI iCo was chemically anchored to PAMAM. The morphologies of the title composite were characterized by scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The catalytic activity was evaluated by oxidation of isobutyraldehyde （IBA） to isobutyric acid （IBAc） in MeCN under mild conditions （20 ℃, ambient pressure）, showing that the title compound is a more effective and recoverable catalyst than corresponding PW11Co.展开更多
This work investigates coag-flocculation optimization treatment of alum-brewery effluent system via response surface methodology (RSM). To minimize suspended and dissolved particles (SDP), experiments were carried out...This work investigates coag-flocculation optimization treatment of alum-brewery effluent system via response surface methodology (RSM). To minimize suspended and dissolved particles (SDP), experiments were carried out using nephelometric jar test and 23-factorial design with three star-points, six-center-points and two replications. A central composite design, which is the standard design of RSM, was used to evaluate the effects and interactions of three major factors (coagulation pH, coagulant dosage, settling time) on the treatment efficiency. Multivariable quadratic model developed for the response studied indicates the optimum conditions to be 9, 500mg/l and 20minutes for coagulation pH, coagulant dosage and settling time, respectively. At optimum, the SDP was reduced from 10831.490mg/l to 801.451mg/l, representing 92.601% removal efficiency. RSM has demonstrated to be appropriate approach for the optimization of the coag-flocculation process by statistical evaluation.展开更多
文摘Compared with traditional aluminum salts, polyaluminum chloride （PACI） has better coagulation-flocculation performance in turbidity removal. However, it is still inferior to organic polymers in terms of bridging function. In order to improve the aggregating property of PACl, different composite PACl flocculants were prepared with various organic polymers. The effect of organic polymer on the distribution or Al（Ⅲ） species in composite flocculants was studied using ^27TAl NMR and Al-ferron complexation methods. The charge neutralization and surface adsorption characteristics of composite flocculants were also investigated. Jar tests were conducted to evaluate the turbidity removal efficacy of organic polymer modified composite flocculants. The study shows that cationic polymer and anionic polymer have significant influences on the coagulation-flocculation behaviors of PACl. Both cationic and anionic polymers can improve the turbidity removal performancc of PACl but the mechanisms arc much different： cationic organic polymer mainly increases the charge neutralization ability, but anionic polymer mainly enhances the bridging function.
文摘A new inorganic polymer flocculant-PZFSiC (zinc-iron-silicate polymer composite) is prepared by adding acid into a high modulus solution of water glass and introducing appropriate metallic ions(M) including Zn and Fe. The influence on flocculability of factors such as the mole ratios of M to SiO2,stirring time and pH are discussed .And the optimal preparing technical parameters are obtained by orthogonal tests. The optimum technical conditions of flocculation are determined. The result shows that when less PZFSiC is added into troubled water or waste water, turbidity removal can hit 98%, COD removal can exceed 93%. The water sample treated is clear and of good quality. These results also indicate that PZFSiC is a highly effective, nontoxic and benign to the enviroment.
文摘By using polyaluminum chloride (PAC), chitosan (CTS) and montmorillonite (MM) as the main raw materials, a novel tap water flocculant had been prepared. The optimal mass proportion of this flocculant was 1 g·L–1 chitosan:50 g·L–1 PAC:3g·L–1 MM = 30:11:7. Compared with the traditional polyaluminum chloride (PAC), the concentration of aluminum ion (Al3+) and suspended solids (SS) in the exit dropped 66.19% and 5.80% respectively, moreover, the cost was decreased by 9.95%. This flocculant was not only cheaper, but also provided improved flocculating function compared with traditional flocculant. The concentration of Al3+ in exit water was decreased greatly so the drinking water would be much safer.
文摘A kind of environmental friendly novel composite flocculants which are used to treat raw water is prepared. It is made with chitosan (CS), iron modified polyaluminium chloride (CF-PAC) and modified montmorillonite on the principle of “the combination of organic and inorganic”. Under the optimum best compound formula and flocculation process, the turbidity of the waste water reduced by 0.62%, the chemical cost decreased by 12.43% and the content of aluminium ions dropped by 70.65%. There is an excellent characteristic and higher efficiency on the composite flocculant which can adsorb the organic matter in the water and chelate the heavy metal ions in the water.
文摘The biopolymer flocculant （named PS-2） producing by Pseudomonas fluorescens was investigated. The PS-2 had high efficiency with small dosage, when dealing with kaolin suspension, formed larger floc, with big sedimentation rate, over a wide range of temperatures. Distributing of flocculating activity test showed that the biopolymer flocculant was an extracellular product. The composition analysis of purified biopolymer flocculant showed that it composed mainly of polysaccharide and nucleic acid. The content of polysaccharide was 86. 7%, which determined by using phenol-vitriol method, and the content of nucleic acid was 7.8%, which determined by UV absorption method. The biopolymer flocculant as a powder form showed much better stability than that as a supernatant. The character of biopolymer flocculant was stable even it was heated to 100℃ when it in acidic condition. The optimal conditions to flocculate kaolin suspension were as follows： pH 8-12, flocculant dosage lmL/L, and Ca^2＋ as the optimal cation.
基金supported by the National Natural Science Foundation of China (No. 50578089,21077066)the Key Projects in the National Science & Technology Pillar Program in the Eleventh Five-year Plan Period (No. 2006BAJ08B05-2)+2 种基金the Scientific Technology Research and Development Program of Shandong of China (No. 2009GG10006003 2010GZX20605)the Natural Science Foundation of Shandong Province of China (No. ZR2010BM014)
文摘A coagulation/flocculation process using the composite flocculant polyaluminum chloride-epichlorohydrin dimethylamine （PAC- EPI-DMA） was employed for the treatment of an anionic azo dye （Reactive Brilliant Red K-2BP dye）. The effect of viscosity 01）, basicity （B = [OH]/[Al]） and organic content （Wp） on the flocculation performance as well as the mechanism of PAC-EPI-DMA flocculant were investigated. The η was the key factor affecting the dye removal efficiency of PAC-EPI-DMA. PAC-EPI-DMA with an intermediate η （2400 mPa.sec） gave higher decolorization efficiency by adsorption bridging and charge neutralization due to the co-effect of PAC and EPI-DMA polymers. The Wp of the composite flocculant was a minor important factor for the flocculation. The adsorption bridging of PAC-EPI-DMA with η of 300 or 4300 mPa.sec played an important role with the increase of Wp, whereas the charge neutralization of them was weaker with the increase of Wp. There was interaction between Wp and B on the removal of reactive dye. The composite flocculant with intermediate viscosity and organic content was effective for the treatment of reactive dyeing wastewater, which could achieve high reactive dye removal efficiency with low organic dosage.
基金Project supported by the Natural Science Foundation of Fujian Province （No. E0510012） and a key item of Education Department of Fujian Province （No. JA04167）.Acknowledgements The authors thank professor Luo Yunjun and Li Guoping, School of Chemical Engineering and Materials Science, Beijing Institute of Technology for the support of PAMAM dendrimer compound.
文摘An inorganic-organic composite was prepared by poly（amidoamine） （PAMAM） dendrimer reacting with cobalt（Ⅱ）-monosubstituted polyoxometalates Na5Co^Ⅱ（H2O）PW11O39 （PW11CO） in an aqueous solution. The hybrid composite PW11Co/PAMAM was characterized by FT-IR, UV-Vis diffuse reflectance spectra （DR-UV-Vis）, XPS, XRD and TG/DTA, indicating that the PWI iCo was chemically anchored to PAMAM. The morphologies of the title composite were characterized by scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. The catalytic activity was evaluated by oxidation of isobutyraldehyde （IBA） to isobutyric acid （IBAc） in MeCN under mild conditions （20 ℃, ambient pressure）, showing that the title compound is a more effective and recoverable catalyst than corresponding PW11Co.
文摘This work investigates coag-flocculation optimization treatment of alum-brewery effluent system via response surface methodology (RSM). To minimize suspended and dissolved particles (SDP), experiments were carried out using nephelometric jar test and 23-factorial design with three star-points, six-center-points and two replications. A central composite design, which is the standard design of RSM, was used to evaluate the effects and interactions of three major factors (coagulation pH, coagulant dosage, settling time) on the treatment efficiency. Multivariable quadratic model developed for the response studied indicates the optimum conditions to be 9, 500mg/l and 20minutes for coagulation pH, coagulant dosage and settling time, respectively. At optimum, the SDP was reduced from 10831.490mg/l to 801.451mg/l, representing 92.601% removal efficiency. RSM has demonstrated to be appropriate approach for the optimization of the coag-flocculation process by statistical evaluation.
