Improvement strength is beneficial to the popularization of hollow fiber nanofiltration(NF) membrane.The tri-channel hollow fiber NF membrane was prepared by interfacial polymerization(IP).The high strength tri-channe...Improvement strength is beneficial to the popularization of hollow fiber nanofiltration(NF) membrane.The tri-channel hollow fiber NF membrane was prepared by interfacial polymerization(IP).The high strength tri-channel hollow fiber ultrafiltration(UF) membrane were used as the support membrane,m-phenylenedianline(m-PDA),and polyethylenimine(PEI) were used as aqueous phase monomer,and trimesoyl chloride(TMC) was used as organic phase monomer.Fourier transform infrared spectroscopy(FTIR),scanning electron microscope(SEM),and gas sorption analyzer(GSA) were applied in structural analysis of NF membrane.Polymer FTIR illustrates the IP occurrence between aqueous phase monomer and organic phase monomer.The SEM images of NF membrane show the formation of a thin dense layer on surface of support membrane after IP.The flux(J) of optimal NF membrane is 11.2 L·m-2· h-1 at the 0.35 MPa operating pressure.Its retention(R) for NaCl,Na2SO4,MgCl2,Xylenol orange,and Neutral red is 17.4%,30.2%,16.1%,94.3%,and 51.0%,respectively.The NF membrane is on negative charge and its pore radius distributes between 0.3-2.0 nm.展开更多
Landfill leachate treated with combined process of ＂pretreatment ＋biological treatment ＋advanced treatment （NF）＂ to produce nanofiltration concentrate, which bio-chemical ratio （B/C） is less than 0.1 and CODer...Landfill leachate treated with combined process of ＂pretreatment ＋biological treatment ＋advanced treatment （NF）＂ to produce nanofiltration concentrate, which bio-chemical ratio （B/C） is less than 0.1 and CODer concentration is 2 000-2 500 mg/L, high salt content. Which cannot be discharged under existing environ- mental standards. According to analysis based on electrochemical advanced oxidation mechanism, a two-step electrochemical tech- nique was recommended. In the first step, a pulse electrochemical technique was adopted. With Fe as consumption electrode and current density of 10 mA/cm2, the pollutants were removed by means of Fenton reaction, electroflotation and electrocoagulation. In the second step, a double function electrode was used to per- form electrocatalytic oxidation by means of titanium metallic oxi- dates. In the condition that current density being 12.5 mA/cm2, the pollutants were further removed by oxidation and electrolytic deposition. Result shows that the removing rate of CODer, NH3-N and CI were 70%-85%, 90% and 25%, respectively; average value of B/C ratio increased from 0.09 to 0.38 and conductivity reduced by 10%.展开更多
The current efficiency for NF3 formation was independent on the current density in the range of 200 to 1,000 mA·cm^2. The average values of NF3 current efficiencies on the BDD （boron-doped diamond） anode with t...The current efficiency for NF3 formation was independent on the current density in the range of 200 to 1,000 mA·cm^2. The average values of NF3 current efficiencies on the BDD （boron-doped diamond） anode with the boron-concentration of 2,500 ppm were 32.3% at 80℃, 63.3% at 100℃ and 59.7% at 120℃. The best current efficiencies for NF3 formation on the BDD anode with boron-concentrations of 2,500, 5,000 and 7,500 ppm were obtained at 100℃ and those were 63.3%, 73.3% and 56.2%, respectively. Although anode effect occurred on the BDD electrodes covered with a part of the surface of the spiculate structure, which had the boron-concentrations higher than 7,500 ppm, it did not take place on the BDD electrodes covered with the surface of diamond structure, even if the BDD electrode had the boron-concentration of 8,000 ppm.展开更多
基金National High Technology Research and Development Program of China (863 program) (No. 2008AA06Z330)National Technician Service Enterprise Action Program,China (No. 2009GJD00048)
文摘Improvement strength is beneficial to the popularization of hollow fiber nanofiltration(NF) membrane.The tri-channel hollow fiber NF membrane was prepared by interfacial polymerization(IP).The high strength tri-channel hollow fiber ultrafiltration(UF) membrane were used as the support membrane,m-phenylenedianline(m-PDA),and polyethylenimine(PEI) were used as aqueous phase monomer,and trimesoyl chloride(TMC) was used as organic phase monomer.Fourier transform infrared spectroscopy(FTIR),scanning electron microscope(SEM),and gas sorption analyzer(GSA) were applied in structural analysis of NF membrane.Polymer FTIR illustrates the IP occurrence between aqueous phase monomer and organic phase monomer.The SEM images of NF membrane show the formation of a thin dense layer on surface of support membrane after IP.The flux(J) of optimal NF membrane is 11.2 L·m-2· h-1 at the 0.35 MPa operating pressure.Its retention(R) for NaCl,Na2SO4,MgCl2,Xylenol orange,and Neutral red is 17.4%,30.2%,16.1%,94.3%,and 51.0%,respectively.The NF membrane is on negative charge and its pore radius distributes between 0.3-2.0 nm.
文摘Landfill leachate treated with combined process of ＂pretreatment ＋biological treatment ＋advanced treatment （NF）＂ to produce nanofiltration concentrate, which bio-chemical ratio （B/C） is less than 0.1 and CODer concentration is 2 000-2 500 mg/L, high salt content. Which cannot be discharged under existing environ- mental standards. According to analysis based on electrochemical advanced oxidation mechanism, a two-step electrochemical tech- nique was recommended. In the first step, a pulse electrochemical technique was adopted. With Fe as consumption electrode and current density of 10 mA/cm2, the pollutants were removed by means of Fenton reaction, electroflotation and electrocoagulation. In the second step, a double function electrode was used to per- form electrocatalytic oxidation by means of titanium metallic oxi- dates. In the condition that current density being 12.5 mA/cm2, the pollutants were further removed by oxidation and electrolytic deposition. Result shows that the removing rate of CODer, NH3-N and CI were 70%-85%, 90% and 25%, respectively; average value of B/C ratio increased from 0.09 to 0.38 and conductivity reduced by 10%.
文摘The current efficiency for NF3 formation was independent on the current density in the range of 200 to 1,000 mA·cm^2. The average values of NF3 current efficiencies on the BDD （boron-doped diamond） anode with the boron-concentration of 2,500 ppm were 32.3% at 80℃, 63.3% at 100℃ and 59.7% at 120℃. The best current efficiencies for NF3 formation on the BDD anode with boron-concentrations of 2,500, 5,000 and 7,500 ppm were obtained at 100℃ and those were 63.3%, 73.3% and 56.2%, respectively. Although anode effect occurred on the BDD electrodes covered with a part of the surface of the spiculate structure, which had the boron-concentrations higher than 7,500 ppm, it did not take place on the BDD electrodes covered with the surface of diamond structure, even if the BDD electrode had the boron-concentration of 8,000 ppm.
