A group function relation curve between flux(J) and bulk phase concentration of substrate(S) was set up. The biodegradation kinetic of organic compounds of acrylic fiber wastewater in biofilm is studied(the treatment ...A group function relation curve between flux(J) and bulk phase concentration of substrate(S) was set up. The biodegradation kinetic of organic compounds of acrylic fiber wastewater in biofilm is studied(the treatment technology is coagulation/sedimentation-anoxic/aerobic biofilm process), and the results showed that the concentration of non-degradation pollutants in effluent is 77 mg/L. In aerobic zone, the half-rate constant is 72.84 mg/L, the maximum removal rate of organic compounds at unit area filler is very low, 0.089 g/(m 2·d), which corresponds to the fact that there are some biorefractory compounds in the wastewater.展开更多
The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. ...The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. The silver ions were preferably coordinated with the free-NH2 groups and the -OH groups of secondary alcohol and carboxyl in CMCTS. TBZ preferably bonded to carboxyl group in CMCTS by electrostatic force and hydrogen bonding. Increase in silver ions content in the complex agent improved to some limited extent the antibacterial activity, but enhanced coloring and cost of the complex agent. Increase in TBZ content resulted in increase of antifungal activity, but decrease of water solubility of the complex agent. The antimicrobial MICs of the complex agent to Esherichia coil, Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor sp. were 20 -80, 15 -60, 20 - 55, 40 - 250, and 400 - 1700 mg/kg, respectively. Addition of 0.1% of this complex agent to acrylic emulsion paint made the paint without substantial change in color, luster, viscosity, odor or pH value, but with an excellent and chronically persisting broad-spectra antimicrobial activity.展开更多
Copolymer of maleic acid and acrylic acid （PMA-100）, combining with polyvinyl butyral （PVB） ultrafiltration membrane was used for the removal of Mn（II） from waste water by complexation-ultrafiltration. The carbo...Copolymer of maleic acid and acrylic acid （PMA-100）, combining with polyvinyl butyral （PVB） ultrafiltration membrane was used for the removal of Mn（II） from waste water by complexation-ultrafiltration. The carboxylic group content of PMA-100 and the rate of complexation reaction were measured. Effects of the mass ratio of PMA-100 to Mn（II） （n）, pH, background electrolyte, etc on the rejection rate （R） and permeate flux （J） were investigated. The results show that carboxylic group content of PMA-100 is 9.5 mmol/g. The complexation of Mn（II） with PMA-100 is rapid and completed within 5 min at pH 6.0. Both R and J increase with pH increasing in the range of 2.5-7.0, and R increases with the increase of n at pH 6.0 while J is little affected. The background electrolyte leads to the decrease of R, and CaCl2 has much greater effect on R than NaCl at the same ionic strength.展开更多
Graft copolymerization is one of the most attractive methods to modify natural polymers. In this study, graft copolymerization of acylic acid onto chitosan in aqueous media by ceric ammonium nitrate was investigated. ...Graft copolymerization is one of the most attractive methods to modify natural polymers. In this study, graft copolymerization of acylic acid onto chitosan in aqueous media by ceric ammonium nitrate was investigated. The graft copolymerization reaction was carried out in a three necked flask maintained at 70＋/-0.05 ℃ under nitrogen atmosphere in a homogeneous aqueous phase （containing a small potion of acetic acid） by using ceric ammonium nitrate as an initiator. Evidence of grafting was obtained. The synthetic conditions were systematically optimized through studying the influential factors on grafting. The effectiveness of each individual factor was investigated by calculating and monitoring the variations of the grafting parameters [like monomer conversation Cm, grafting efficiency （Ge） and viscosity]. Under optimum conditions monomer conversion of 100.5% and graft efficiency of 94% were obtained, at temperature of 70℃. Flocculating ability of the copolymerization product of chitosan was studied by using Kaolin suspension as the flocculating object. And the application of the product was applied in Huayue dyeing plant. The results indicate that the higher the viscosity is, the better the flocculating ability of the copolymerization product of chitosan will be. The flocculating percentage reaches 96.0%, when the concentration of the product is only 1.0 mg/L and pH fixed at 7.0. Suitable separating mixtures for the grafted copolymer were chosen and the investigation of flocculation ability of the grafted copolymer was carried out with the aim of developing a good flocculant for wastewater treatment. A test of treating dyeing wastewater with the grafted copolymer was carried out and showed that grafting of Acrylic Acid with chitosan has a high COD removal rate 75% to the dyeing wastewater when the concentration is only 6.0 mg/L.展开更多
A three-dimensional electrochemical oxidation （3D-EC） reactor with introduction of activated carbon （AC） as particle micro-electrodes was apphed for the advanced treatment of secondary wastewater effluent of a wet...A three-dimensional electrochemical oxidation （3D-EC） reactor with introduction of activated carbon （AC） as particle micro-electrodes was apphed for the advanced treatment of secondary wastewater effluent of a wet-spun acrylic fiber manufacturing plant. Under the optimized conditions （current density of 500 A/m2, circulation rate of 5 mL/min, AC dosage of 50 g, and chloride concentration of 1.0 g/L）, the average removal efficiencies of chemical oxygen demand （CODer）, NH3-N, total organic carbon （TOC）, and ultraviolet absorption at 254 nm （UV2s4） of the 3D-EC reactor were 64.5%, 60.8%, 46.4%, and 64.8%, respectively; while the corresponding effluent concentrations of CODcr, NH3-N, TOC, and UV2s4 were 76.6, 20.1, and 42.5 mg/L, and 0.08 Abs/cm, respectively. The effluent concentration of CODer was less than 100 mg/L, which showed that the treated wastewater satisfied the demand of the integrated wastewater discharge standard （GB 8978-1996）. The 3D-EC process remarkably improved the treatment efficiencies with synergistic effects for CODer, NH3-N, TOC, and UV2s4 during the stable stage of 44.5%, 38.8%, 27.2%, and 10.9%, respectively, as compared with the sum of the efficiencies of a two-dimensional electrochemical oxidation （2D-EC） reactor and an AC adsorption process, which was ascribed to the numerous micro-electrodes of AC in the 3D-EC reactor. Gas chromatography mass spectrometry （GC-MS） analysis revealed that electro- chemical treatment did not generate more toxic organics, and it was proved that the increase in acute biotoxicity was caused primarily by the production of free chlorine.展开更多
文摘A group function relation curve between flux(J) and bulk phase concentration of substrate(S) was set up. The biodegradation kinetic of organic compounds of acrylic fiber wastewater in biofilm is studied(the treatment technology is coagulation/sedimentation-anoxic/aerobic biofilm process), and the results showed that the concentration of non-degradation pollutants in effluent is 77 mg/L. In aerobic zone, the half-rate constant is 72.84 mg/L, the maximum removal rate of organic compounds at unit area filler is very low, 0.089 g/(m 2·d), which corresponds to the fact that there are some biorefractory compounds in the wastewater.
文摘The structure, properties and application to water-soluble coatings of a new complex antimicrobial agent Ag-carboxylmethyl citosan-thiabendazole （Ag-CMCTS-TBZ） prepared from different materiel ratios were reported. The silver ions were preferably coordinated with the free-NH2 groups and the -OH groups of secondary alcohol and carboxyl in CMCTS. TBZ preferably bonded to carboxyl group in CMCTS by electrostatic force and hydrogen bonding. Increase in silver ions content in the complex agent improved to some limited extent the antibacterial activity, but enhanced coloring and cost of the complex agent. Increase in TBZ content resulted in increase of antifungal activity, but decrease of water solubility of the complex agent. The antimicrobial MICs of the complex agent to Esherichia coil, Staphylococcus aureus, Candida albicans, Aspergillus niger, Mucor sp. were 20 -80, 15 -60, 20 - 55, 40 - 250, and 400 - 1700 mg/kg, respectively. Addition of 0.1% of this complex agent to acrylic emulsion paint made the paint without substantial change in color, luster, viscosity, odor or pH value, but with an excellent and chronically persisting broad-spectra antimicrobial activity.
基金Project (21176264) supported by the National Natural Science Foundation of ChinaProject (11JJ2010) supported by Hunan Provincial Natural Science Foundation of ChinaProject (LC13076) supported by Undergraduate Innovation Foundation of Central South University,China
文摘Copolymer of maleic acid and acrylic acid （PMA-100）, combining with polyvinyl butyral （PVB） ultrafiltration membrane was used for the removal of Mn（II） from waste water by complexation-ultrafiltration. The carboxylic group content of PMA-100 and the rate of complexation reaction were measured. Effects of the mass ratio of PMA-100 to Mn（II） （n）, pH, background electrolyte, etc on the rejection rate （R） and permeate flux （J） were investigated. The results show that carboxylic group content of PMA-100 is 9.5 mmol/g. The complexation of Mn（II） with PMA-100 is rapid and completed within 5 min at pH 6.0. Both R and J increase with pH increasing in the range of 2.5-7.0, and R increases with the increase of n at pH 6.0 while J is little affected. The background electrolyte leads to the decrease of R, and CaCl2 has much greater effect on R than NaCl at the same ionic strength.
文摘Graft copolymerization is one of the most attractive methods to modify natural polymers. In this study, graft copolymerization of acylic acid onto chitosan in aqueous media by ceric ammonium nitrate was investigated. The graft copolymerization reaction was carried out in a three necked flask maintained at 70＋/-0.05 ℃ under nitrogen atmosphere in a homogeneous aqueous phase （containing a small potion of acetic acid） by using ceric ammonium nitrate as an initiator. Evidence of grafting was obtained. The synthetic conditions were systematically optimized through studying the influential factors on grafting. The effectiveness of each individual factor was investigated by calculating and monitoring the variations of the grafting parameters [like monomer conversation Cm, grafting efficiency （Ge） and viscosity]. Under optimum conditions monomer conversion of 100.5% and graft efficiency of 94% were obtained, at temperature of 70℃. Flocculating ability of the copolymerization product of chitosan was studied by using Kaolin suspension as the flocculating object. And the application of the product was applied in Huayue dyeing plant. The results indicate that the higher the viscosity is, the better the flocculating ability of the copolymerization product of chitosan will be. The flocculating percentage reaches 96.0%, when the concentration of the product is only 1.0 mg/L and pH fixed at 7.0. Suitable separating mixtures for the grafted copolymer were chosen and the investigation of flocculation ability of the grafted copolymer was carried out with the aim of developing a good flocculant for wastewater treatment. A test of treating dyeing wastewater with the grafted copolymer was carried out and showed that grafting of Acrylic Acid with chitosan has a high COD removal rate 75% to the dyeing wastewater when the concentration is only 6.0 mg/L.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment (No. 2012ZX07201002-6)
文摘A three-dimensional electrochemical oxidation （3D-EC） reactor with introduction of activated carbon （AC） as particle micro-electrodes was apphed for the advanced treatment of secondary wastewater effluent of a wet-spun acrylic fiber manufacturing plant. Under the optimized conditions （current density of 500 A/m2, circulation rate of 5 mL/min, AC dosage of 50 g, and chloride concentration of 1.0 g/L）, the average removal efficiencies of chemical oxygen demand （CODer）, NH3-N, total organic carbon （TOC）, and ultraviolet absorption at 254 nm （UV2s4） of the 3D-EC reactor were 64.5%, 60.8%, 46.4%, and 64.8%, respectively; while the corresponding effluent concentrations of CODcr, NH3-N, TOC, and UV2s4 were 76.6, 20.1, and 42.5 mg/L, and 0.08 Abs/cm, respectively. The effluent concentration of CODer was less than 100 mg/L, which showed that the treated wastewater satisfied the demand of the integrated wastewater discharge standard （GB 8978-1996）. The 3D-EC process remarkably improved the treatment efficiencies with synergistic effects for CODer, NH3-N, TOC, and UV2s4 during the stable stage of 44.5%, 38.8%, 27.2%, and 10.9%, respectively, as compared with the sum of the efficiencies of a two-dimensional electrochemical oxidation （2D-EC） reactor and an AC adsorption process, which was ascribed to the numerous micro-electrodes of AC in the 3D-EC reactor. Gas chromatography mass spectrometry （GC-MS） analysis revealed that electro- chemical treatment did not generate more toxic organics, and it was proved that the increase in acute biotoxicity was caused primarily by the production of free chlorine.
