从水中去除砷的特殊处理技术

砷是一种常见于地下水和地表水中的具有高毒性的非金属。饮用水的砷污染对人体健康有害。几种技术（混凝、吸附、离子交换、过滤膜处理等）被用于从饮用水中去除砷。本文评估了3种砷的去除技术。间歇式试验结果显示涂有铁的沙子（IOCS．2）能够从合成的水中去除〉90％的砷。试验在pH为3（6、7、8）的条件下进行，初始砷的浓度为260μg／L。     

改性柚子皮对水中Cr~（6＋）的吸附研究

通过异丙醇（20%）改性后的柚子皮对水中Cr6＋的吸附实验,研究pH值、吸附时间、吸附剂的投加量及Cr6＋初始浓度对吸附性能的影响。结果表明：当pH=5,Cr6＋初始浓度为35μg/mL,吸附时间为45min,吸附剂的投加量为6g/L时,吸附效果最佳,去除率达到99.88%。     

强化混凝与PAC吸附组合工艺去除百菌清效能研究

采用强化混凝与粉末活性炭吸附组合工艺去除饮用水中的百菌清。结果表明,针对原水中不同浓度百菌清（65．55、212．81、316．89、396．06、543．35μg／L）,调节PAC投量（10、20、30、40、50mg／L）,吸附30min后,再投加10mg／L聚合氯化铝,混凝沉淀出水中百菌清浓度分别为3．34、2．50、2．58、2．60、2．92μg／L,满足《生活饮用水卫生标准》（GB5749—2006）要求。此方法操作方便、经济有效,可作为水厂应急预案。     

改性活性炭滤芯对饮用水中砷离子吸附性能的研究

探究了改性活性炭滤芯对饮用水中砷离子的吸附能力。利用溶胶-凝胶法制备TiO₂溶胶并将其负载于活性炭粉末上，活性炭粉末与聚乙烯混合压制并烧结制备滤芯，测试其对饮用水中砷离子的吸附性能。采用动态吸附法，分别测试了进口流速、砷初始浓度、pH对吸附效果的影响。结果表明，流速从6 L/h升高到30 L/h时，三价砷离子去除率从95.8%降低到80.1%，五价砷离子去除率从96.3%降低到77.6%。初始砷浓度从200μg/L到350μg/L时，三价砷离子去除率从89.2%降低到78.9%，五价砷离子去除率从90.5%降低到89.3%。三价和五价砷离子分别在pH为9和4的条件下吸附效果最好。另外，Thomas模型能较好地描述改性活性炭滤芯对砷离子的动态吸附行为。改性活性炭滤芯相较于未改性的滤芯吸附效果显著提高，在流速为6 L/h，初始浓度为200μg/L时，砷离子出口浓度低于10μg/L，符合国家饮用水标准。     

UV/PS去除饮用水中亚硝基二丙胺的研究

采用紫外/过硫酸盐(UV/PS)高级氧化技术去除饮用水中含氮消毒副产物亚硝基二丙胺(NDPA),考察了PS投加量、NDPA初始浓度、pH值、共存阴离子对NDPA降解效率的影响,并拟合其动力学模型。结果表明,单独UV辐射以及单独PS氧化,去除效果均不显著;UV/PS联用有较高的降解效果,在反应温度为25℃、pH值为7.0、紫外光照强度为168μW/cm²下,最佳PS投加量和NDPA初始浓度分别为0.05 mmol/L和200μg/L时,UV/PS可在40 min内降解75%以上的NDPA。NDPA的降解速率随着PS投加量的增大而增大,随着NDPA初始浓度的增加而降低;随着pH值的增大而减小;共存阴离子NO2下,最佳PS投加量和NDPA初始浓度分别为0.05 mmol/L和200μg/L时,UV/PS可在40 min内降解75%以上的NDPA。NDPA的降解速率随着PS投加量的增大而增大,随着NDPA初始浓度的增加而降低;随着pH值的增大而减小;共存阴离子NO^-_3对NDPA的去除具有轻微的抑制作用,而HCO-_3对NDPA的去除具有轻微的抑制作用,而HCO^-_3、Cl-_3、Cl^-对NDPA的去除具有一定的促进作用。其降解均符合一级动力学。     

UV／负载TiO2对微量磺胺甲恶唑的氧化降解效能

采用溶胶凝胶法,以玻璃纤维网为载体负载TiO2薄膜。利用小试试验研究了UV/负载TiO2体系对水中微量磺胺甲恶唑（SMX）的降解效能及影响因素。结果表明UV/负载TiO2体系对纯水中SMX有较好的去除效果,且降解过程很好地符合一级反应动力学模型;SMX的初始浓度和溶液pH值对体系的氧化性能均有一定的影响,较低的初始浓度和较低的pH值均有利于体系对SMX的降解;H2 O2的投加浓度存在最佳值（当SMX初始浓度为300μg/L时,最佳投加量为10μg/L）;此外,正丁醇和KI的存在均会降低体系对SMX的降解速率,原因在于正丁醇和KI会与SMX分子竞争＆#183;OH。通过对实际水样加标降解的试验可知,水源水中的SMX较污水生化池出水中的SMX更易去除。     

热改性铝污泥对水中磷的吸附性能

考察了接触时间、pH、投加量对热改性铝污泥吸附磷的影响,确定了其最佳吸附条件和影响因素顺序。结果表明,除磷影响因素依次为磷溶液初始浓度接触时间溶液pH投加量,改性铝污泥吸附除磷的最佳条件:初始磷浓度为60.00 mg/L,pH值为3.0,投加量为4 g/L,振荡反应时间为4 h,改性铝污泥对磷的最高去除率达77.2%。     

球磨载铝纤维素对水中砷离子的吸附性能研究

以木屑纤维素为基体,采用球磨法,制备负载铝氧化物的纤维素(C-Al),研究其对水中砷离子(As)的吸附行为。探讨不同吸附条件对C-Al的吸附影响,研究结果表明,C-Al对As有良好的去除效果,当溶液的pH为3～7,投加量为2 g/L,反应温度为25℃,As初始浓度为200 mg/L,C-Al对As的吸附容量高达62 mg/g。     

锰改性硅藻土对水中Cr~(6+)的吸附研究

用锰氧化物改性硅藻土制备吸附剂,考察pH值、吸附剂投加量、吸附时间和Cr6+初始浓度条件下,改性吸附剂对水中Cr6+去除的影响。结果表明,去除率随着吸附剂投加量的增高而上升,随pH值和Cr6+初始浓度升高而降低,吸附2h后达到吸附平衡。室温条件下,当pH值为1,吸附剂投加量为40g·L-1,吸附反应时间为2h,Cr6+的初始浓度为5mg·L-1,Cr6+去除效率能达到96%以上。锰改性硅藻土对Cr6+的等温吸附符合Langmuir和Freundlich方程。     

生物炭负载铁锰氧化物吸附去除Cr(Ⅵ)的试验研究

采用热解法制备负载铁锰氧化物的改性生物炭,并用于去除水中的Cr（Ⅵ）。通过SEM, XRD, FTIR等表征手段对材料进行分析,同时探究材料投加量、 Cr（Ⅵ）初始浓度、初始pH值对Cr（Ⅵ）去除的影响。在铁锰物质的量比为1∶3,香蒲质量为5 g的条件下,经600℃热解2 h制得改性生物炭F1M3BC5。改性后的香蒲草生物炭孔隙丰富,比表面积显著增大,更有利于材料对Cr（Ⅵ）的吸附。批量吸附试验结果表明,对于100 mL初始质量浓度为20 mg/L的含Cr（Ⅵ）废水,F1M3BC5的最佳吸附条件为pH值为3、投加量为0.15 g、温度为25℃、吸附时间为5 h。吸附过程与准二级动力学模型拟合,最大吸附量可达18.24 mg/g。     

Kinetic Modeling of Arsenic Removal from Water by Ferric Ion Loaded Red Mud

A laboratory study was conducted to investigate the ability of ferric ion loaded red mud (FRM) for the removal of arsenic species from water. The adsorbent material was characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. For an initial arsenic concentration lower than 0.3 mg/L, the FRM with a dosage of 1 g/L was able to reduce As(III) at pH 7 below 10 µg/L, the maximum contaminant level (MCL) of arsenic in drinking water set by the World Health Organization. In the case of As(V) removal, FRM was also particularly effective in reducing the initial arsenic concentration value of 1 mg/L at pH 2, below the MCL requirement of arsenic for drinking water. According to kinetic sorption data, the initial stage of adsorptions of As(III) and As(V) onto FRM were mainly governed by the external diffusion mechanism; however, upon saturation of the external adsorbent surface, the arsenic species were eventually adsorbed by intraparticle diffusion mechanism. The present results are promising for using the very inexpensive FRM as a low-cost material that is effective in remediating drinking waters contaminated with low concentrations of arsenic species. We report here the sorption kinetics and adsorption mechanisms of As(III) and As(V) on the FRM that has not been decsribed previously.     

MIEX—DOC离子交换树脂的饮用水除砷研究

对新型阴离子交换树脂MIEX—DOC@的除砷性能进行了研究,考察了该树脂除砷容量、对三价砷[As（m）]和五价砷[As（V）]的去除能力、不同离子和水体pH值对树脂除砷[包括As（Ⅲ）和As（V）]效率的影响。结果表明,MIEX-DOC~树脂对人工配制高砷水（O．1mg·L-1）的除砷容量约为0．0051mg·mL-1;对As（Ⅲ）和As（V）的去除能力相当;常见的共存离子对树脂除砷效率有抑制或促进影响;不同pH值下,MIEX—DOC@树脂除砷效率不同,但对0．1mg·L-1的高砷水的除砷效率均达到50％以上。对农村高砷水的实地中试研究表明,当源水砷浓度约为0．1mg·L-1时,出水砷浓度低于0．05mg·L-1达到《生活饮用水卫生标准》（GB5749—2006）的农村小型集中式供水和分散式供水水质指标。成本分析结果表明,采用国产MIEX-DOC净水设备的除砷效果与进口设备相当,但除砷成本较低（0．56元·t-1）,在我国农村高砷饮用水处理中有一定应用潜力。     

废煤渣的碱法改性对六价铬吸附的影响研究

利用氢氧化钠对废煤渣进行改性,实验探讨了吸附剂投加量,振荡时间,铬液初始浓度,pH等因素对六价铬的吸附性能影响。实验表明改性煤渣具有较好的吸附性能,在投加量为12 g,铬液初始浓度25 mg/L,pH=7,振荡240 min,改性煤渣的除铬率可达91.5%。     

水葫芦对水中Pb(Ⅱ)的吸附性能研究

通过静态吸附实验,研究了干体水葫芦对水中的重金属离子Pb(II)的吸附性能,考察了吸附剂投加量、重金属溶液起始浓度、溶液起始pH值及吸附时间对Pb(II)去除效果的影响。研究结果表明,水葫芦对Pb(II)吸附效果明显优于桔子皮、木屑和玉米芯屑,具有吸附时间短、投加量少、适应pH值范围广的特点。     

Response surface modeling,isotherm, thermodynamic and optimization study of arsenic (V) removal from aqueous solutions using modified bentonite-chitosan (MBC)

Arsenic contamination, a worldwide concern, has received a great deal of attention due to its toxicity and carcinogenicity. In the present study, we focused on the combined application of modified bentonite and chitosan (MBC) for the removal of As(V). Arsenic removal experiments were carried out to determine the amount of As(V) adsorbed as a function of pH (2-8), sorbent dosage (0.1-1.5 g/L), As(V) concentration (20-200mg/L) and time (60-240 min). The system was optimized by means of response surface methodology. The analysis of variance (ANOVA) of the quadratic model demonstrated that the model was highly significant (R²≈97.3%). Optimized values of pH, sorbent dosage, initial As(V) concentration and time were found to be 3.7, 1.40 g/L, 69mg/L, and 167min, respectively. The results reveal that the prepared adsorbent has a high adsorption capacity (122.23mg/g) for As(V) removal. Among the isotherm models used, the Langmuir isotherm model was the best fit for the obtained data. The adsorption kinetics following a pseudo-second-order kinetic model was involved in the adsorption process of As(V). Thermodynamic studies confirmed the spontaneous and endothermic character of adsorption process.     

改性粉煤灰处理含铬（Ⅵ）废水的研究

文章对改性粉煤灰处理含铬（VI）废水进行了研究。通过实验考察了改性粉煤灰加入量、吸附时间、吸附温度和废水的pH对废水中铬（VI）去除率的影响。实验结果表明,改性粉煤灰处理含铬（Ⅵ）废水的最佳工艺条件为：改性粉煤灰加入量为1．5g,吸附时间为10min,吸附温度为25℃,废水的pH为6．0。在此条件下可使50mL模拟含铬废水中铬（VI）浓度由10mg／L降到0．47mg／L,铬（VI）去除率达95％以上,达到了国家《污水综合排放标准》。     

Fe2O3/凹凸棒土吸附-光催化法处理间氯甲苯工业废水研究

采用酸化法对凹凸棒土进行改性,考察改性条件、投加量、吸附时间以及废水pH值等因素对吸附效果的影响。在盐酸浓度为4mol/L,煅烧温度为200℃时,在最佳吸附条件（改性凹凸棒土投加量0.500g/25mL,废水pH=4,吸附时间1h）下,吸附法处理染料中间体间氯甲苯废水,COD的去除率由改性前的2.2%提高到14.1%。采用浸渍法制备纳米Fe2O3/凹凸棒土复合催化剂并对其表征,XRD分析结果表明,该复合物中光催化剂主要由α-Fe2O3构成;用凹凸棒土吸附-光催化氧化联合法处理间氯甲苯工业废水,在催化剂加入量为1.0g/L,pH=2,紫外光或太阳光照6h条件下,废水COD去除率分别达到59.2%和52.3%。复合催化剂的光催化活性要远大于纯纳米α-Fe2O3的光催化活性。     

Nanofiltration Membrane Process for the Removal of Arsenic from Drinking Water

The removal of arsenic from drinking water by nanofiltration membranes was investigated. Experiments were conducted with tap water to which arsenate and arsenite were added. Two types of nanofiltration membranes, i.e., NF‐90 and NF‐200, have been tested. The effect of various operating conditions, e.g., applied pressure, feed concentration, pH and temperature, were also investigated. The pH and arsenic concentration in the feed and the operating temperature are found to be decisive factors in determining the arsenic concentration remaining in the permeate. The level of removal of As(V) was higher than 98 % for both membranes, but that of As(III) was much lower. It can be concluded that by controlling the operating parameters, source water containing As(V) may be recovered as drinking water to EPA maximum contaminant level quality standards, but that water containing As(III) must undergo a pre‐oxidation treatment before passing through the nanofiltration membrane in order to maintain drinking water quality.     

改性粉煤灰处理低浓度含砷含氨氮废水

在冶金和采矿等行业里,排放废水中的砷和氨氮均存在不同程度的超标。本实验采用粉煤灰对砷和氨氮进行深度处理。考察了不同改性方法对粉煤灰除砷和氨氮的处理效果。实验结果表明： NaOH＋FeCl3复合改性的粉煤灰对两种污染物都有较好的去除效果,废水中含砷2 mg/L,含氨氮50 mg/L,复合改性粉煤灰的投加量为20 g/L,废水pH为6,搅拌1 h,砷和氨氮的去除率分别达到83.33%和82.48%,出水满足《污水综合排放标准》（GB8978-1996）中砷和氨氮的排放要求。     

高铁酸钾处理含砷废水

基于对K2FeO4氧化As(III)热力学平衡及As(III)氧化过程氧转移机理的研究,利用高铁酸钾氧化-絮凝一体化工艺处理100 mg/L模拟含砷废水,考察了Fe/As质量比、pH值、反应温度、反应时间等因素对砷去除效果的影响. 结果表明,最优工艺条件为Fe/As质量比3,pH值6,温度25℃,时间30 min,处理后出水的As浓度低于10 mg/L,达到《生活饮用水卫生标准》(GB5749-2006).