大梯度磁滤法处理微污染水的试验研究

以受污染的湖水作为原水,采用大梯度磁滤取代传统的砂滤,对水中浊度、色度、藻类、有机物以及细菌、大肠杆菌等的去除进行了研究,结果表明,大梯度磁滤法对水中细菌、藻类和有机物具有很好的去除效果,在磁通密度为0.13T情况下藻类的去除率为96%,有机物去除率近60%,细菌去除率可达98%,大肠杆菌去除率可达96%,其它指标满足国家饮用水卫生标准。     

微磁絮凝沉淀工艺处理综合电镀废水

针对常规化学沉淀法处理综合电镀废水效率低、出水水质不稳定等问题,采用微磁絮凝沉淀工艺处理综合电镀废水。考察了磁种粒径、磁种用量和PAM(聚丙烯酰胺)用量对沉降速率及磁种回收率的影响。在pH为11.5,磁种粒径为37μm,磁种用量为0.8 g/L,0.2%PAM溶液用量为4 mL/L的优化条件下,微磁絮凝沉降速率为16.81 mm/s,是常规化学沉降速率的13.6倍,此时磁种回收率为98.5%,磁种运营成本约0.024元/t。     

电絮凝-膜分离反应器去除水中腐殖酸

考察了电絮凝-膜分离反应器(ECMR)去除水中腐殖酸(HA)的效果.研究了不同电化学参数对腐殖酸去除率的影响、ECMR平板陶瓷膜和EC-MF平板陶瓷膜抑制膜污染的作用机制,并进行了比较.结果表明,在电流密度为10 A/m2、初始电导率1000μS/cm、初始pH=6、电解时间30 min、初始HA质量浓度5 mg/L时...     

电絮凝技术与微滤技术在水处理及水净化中的应用

从电絮凝技术及微滤技术的概念出发,设计了一组实验进行了研究,并为其在新时期水处理剂净化中的应用进行了积极探讨,以期为广大行业同仁带来有益的参考。     

大梯度磁滤器对饮用水中有害物质的去除

介绍了大梯度磁滤处理饮用水的工作原理及工艺过程，分析了对水中污染物质的去除效果     

磁絮凝-膜过滤组合工艺处理微污染原水的实验研究

采用磁絮凝-陶瓷膜过滤组合工艺对微污染水进行处理,研究不同条件下的出水水质,分析PAC投加量、磁粉投加量以及磁化时间对出水水质的影响。通过正交实验确定其主要影响因素的最佳水平组合:PAC投加量为25 mg/L,磁粉投加量为8 mg/L,磁化时间为6 min。在此条件下对浑浊度、UV和COD的去除率可分别达到92.32%、58.50%和43.40%。     

微絮凝连续砂滤技术在矿区生活污水回用中的应用

采用微絮凝连续过滤技术深度处理矿区生活污水,当滤料粒径采用0．8～1．0mm,滤床厚度1．2m,滤速6～8m／h,砂循环速率在4mm／min,PAC投加量20mg／L,PAM投加量0.3mg／L时,出水SS小于5mg／L,去除率达到94．7％以上,其它各项指标达到并优于建设部《生活杂用水水质标准》（CJ25．1—89）要求,可以实现中水回用。     

磁絮凝法和高梯度磁流体萃取法集成处理含铬废水

将磁分离技术和化学絮凝法、溶剂萃取法相结合,提出磁絮凝法和高梯度磁流体萃取法集成处理高浓度含Cr电镀废水的新工艺。采用磁絮凝法对高浓度含Cr电镀废水进行一次处理,通过正交实验方法获得了最佳磁絮凝条件：pH 8,磁性Fe₃O₄颗粒用量4 g,搅拌速度80 r·min^-1,主絮凝剂PAFC用量6 ml,可使废水中Cr浓度由4325.13 mg·L^-1降为29.8 mg·L^-1;采用高梯度磁流体萃取法对磁絮凝后废水进行二次处理,将该废水流经两个串联的高梯度磁流体萃取装置,持续动态萃取7 h,在最佳萃取条件下,最高萃取率为99.40%,平均萃取率98.97%,总萃余液Cr浓度由29.8 mg·L^-1降为0.31 mg·L^-1,低于国家排放标准;碱性条件下磁流体萃取剂反萃率大于90%,再生磁流体萃取剂可重复使用。     

絮凝-微滤处理洗煤废水及膜污染机理研究

采用聚合氯化铝铁(PAFC)预处理+微滤工艺处理电厂的洗煤废水,研究了混凝对水质的影响,考察了絮凝减缓膜污染的效果。结果表明,当PAFC的投加质量浓度为50 mg/L时,废水中COD、悬浮固体、浊度的去除率分别为68%、98%、95%。PAFC混凝处理将过滤过程中的总阻力降低了39.2%,其中滤饼层阻力降低了68.7%,膜孔阻塞阻力降低了59.1%,但是浓差极化阻力升高了138.4%。PAFC混凝处理减轻了膜孔阻塞和滤饼层污染。     

Cu-Zn合金滤料去除水中的氯和重金属

研究了自制的Cu-Zn合金滤料在除氯、除重金属方面的性能.结果表明具有高比表面积和接触表面的自制Cu-Zn合金滤料去除余氯的性能优于KDF55,对于高浓度Pb2 的去除率高于KDF55,而对Cd2 和Cr6 的去除率与KDF55相当.     

Removal of corrosion products from viscous aqueous suspensions by magnetic filtration

The removal of micron-sized corrosion products, which may occur during industrial processing by magnetic filtration, has been theoretically and experimentally investigated. The effect of alterations in rheological properties of suspensions carrying particles on magnetic filter performance was determined. Magnetic filter dimensions were 0.03×0.04×0.09 m. The filter was filled with 6.35×10⁻³ m diameter ferromagnetic spheres. Magnetic fields ranging from B=0 to B=1.4 T perpendicular to the flow direction were applied. The suspension flow rate through the magnetic filter was 0.4 m/s. It was determined that 85% of corrosion products show magnetic properties. The magnetic filtration of suspensions composed of water, corrosion products and glycerine at different concentrations was studied. The effects of initial concentration of corrosion products, viscosity of aqueous suspension, magnetic field intensity and the number of filtration cycles on magnetic filter performance were determined. Theoretical and experimental results were in good agreement.     

Removal of heavy metal ions by dithiocarbamate-anchored polymer/organosmectite composites

In this study, the dithiocarbamate-anchored polymer/organosmectite composites were prepared for the removal of heavy metal ions (lead, cadmium and chromium) from aqueous media containing different amounts of these ions (50–750 ppm) and at different pH values (2.0–8.0). Initially, the modification of the natural smectite minerals was performed by treatment with quartamin styrene and chloromethylstyrene. Then, modified smectite nanocomposites were reacted with carbondisulfide, in order to incorporate dithiocarbamate functional groups into the nanolayer of organoclay. The dithiocarbamate-anchored nano-composites have been characterized by FTIR and used in the adsorption–desorption process. The maximum adsorptions of heavy metal ions onto the dithiocarbamate-anchored polymer/organosmectite composites from their solution was 170.7 mg g^− 1 for Pb(II); 82.2 mg g^− 1 for Cd(II) and 71.1 mg g^− 1 for Cr(III). Competition between heavy metal ions (in the case of adsorption from mixture) yielded adsorption capacities of 70.4 mg g^− 1 for Pb(II); 31.8 mg g^− 1 for Cd(II) and 20.3 mg g^− 1 for Cr(III). Desorption of the heavy metal ions from composite was studied in 0.5 M NaCl and very high desorption rates, greater than 93%, were achieved in all cases. Adsorption–desorption cycles showed the feasibility of repeated uses of this nanocomposite.     

饮用水中微量铬离子高效去除方法的研究

用腐殖酸包覆磁性四氧化三铁纳米材料吸附饮用水中的六价铬离子。结果表明,最佳吸附条件为:腐殖酸包覆四氧化三铁质量比为1∶1,反应温度90℃,分散剂与去离子水的比例为1∶5,反应时间60 min,Fe_3O_4/HA对Cr(Ⅵ)的吸附时间为30 min。在最佳条件下,Fe_3O_4/HA对Cr(Ⅵ)吸附量为25.83 mg/g,氨水(25%²8%)用量为10 m L;Fe_3O_4/HA对Cr(Ⅵ)的吸附符合Freundlich吸附等温方程。     

Removal of metal ions from an acidic leachate solution by nanofiltration membranes

This paper presents the feasibility of the application of two commercial nanofiltration (NF) membranes (Desal5 DK and NF-270) in the removal of metal ions from an acidic leachate solution generated from a contaminated soil using H₂SO₄ as a soil washing agent. The experimental results of soil washing indicated that H₂SO₄ is highly effective in removing metal ions from contaminated soil. Following this process, the treatment of this acidic solution by nanofiltration membranes showed good metal ion rejection (between 62% to 100%) where divalent ions were better rejected than monovalent ions. For characterization purposes, the membrane experiments were conducted using K₂SO₄ solutions at different pHs. Membrane performance criteria were evaluated according to membrane permeability and ionic retention in the tank and permeate, taking into account different operating conditions such as pressures, flow rate and pH. These results demonstrated the effectiveness and feasibility of the application of nanofiltration treatments in the cleaning-up of contaminated water residues generated during soil washing processes.     

Removal of metal ions by ultrafiltration of a micellar solution containing anionic surfactant

Heavy metals in wastewater were removed by ultrafiltration of a micellar solution containing surfactant such as sodium dodecyl sulfate. Experimental results showed that permeate flux was primarily controlled by the operating parameters such as transmembrane pressure difference, flow rate and feed concentration. The average permeate flux increased at a higher transmembrane pressure, feed velocity, and at a lower solution concentration. The transmembrane pressure had a relatively small effect on metal removal whereas the level of surfactant-to-metal ratio (S/M) had a substantial effect. The optimal ratio of S/M for a best removal of metal ions was measured around 5 and 8 in the presence of sodium dodecyl sulfate, and the affinity resulted in the order of Cr> Co> Ni> Mg.     

Removal of metal ions from electrochemical decontamination solution using organic acids

Applicability of the organic acids and cyclodextrin (CD) for the removal of Fe, Co and Ni from the spent electro-decontamination solution was investigated. Oxalic acid showed the highest removal efficiency: 90% for 0.89 M Fe and 95% for 0.0089 M Co and Ni, respectively. The metal–oxalate precipitates were characterized by differential scanning calorimetry/thermogravimetry analysis (DSC/TGA), Fourier transform infrared (FTIR) and X-ray fluorescence (XRF). After thermal decomposition at >300°C, the metal–oxalate precipitates were transformed into metal oxides (Fe₂O₃, FeO, CoO and NiO) and pure metals (Co and Ni). The results imply that organic acids have a high potential for the removal of heavy metals from electro-decontamination solutions.     

Removal of metal ions from aqueous solution by activated carbons obtained from different raw materials

The adsorption of Pb²⁺, Cu²⁺, Zn²⁺ and Cd²⁺ from aqueous solution at 293 K by activated carbons obtained from different raw materials was studied. These carbons were prepared by water vapour pyrolysis of the raw materials—apricot stones, coconut shells and lignite coal. The influence of the solution pH on the adsorption processes has been studied. The presence of other metal ions in the solution decreases the adsorption of each of the ions. The selective adsorption of the metal ions is observed but the ones preferentially adsorbed do not completely prevent the adsorption of other ions. The chemical nature of the carbon surface and metal ions have great significance for the adsorption process.     

Magnetic properties of metal layer deposited by reduction of metal ions contained in polymer with applying magnetic field

Metal layer was deposited by the reduction of NiCl₂ and CoCl₂ in polyacrylonitrile film after applying an external magnetic field in directions parallel and perpendicular to the surface of the film; the magnetic properties of the metal-deposited film were investigated. When the parallel magnetic field was applied, the values of coercivity (H_c), remanent flux density (B_r) and maximum flux density (B_s) increased regardless of the composition of the metal ions, compared with the case without the application of the magnetic field. From the scanning electron micrographs and X-ray diffraction analyses, it was shown that the growth of crystalline orientation in the deposited metals was enhanced by applying a parallel magnetic field.