采用混合离子交换树脂提取钨酸根

本项目利用分光光度计和电感耦合等离子体-质谱联用仪(ICP-MS)测定钨酸根浓度,采用201x7、201x W和201x4阴离子交换树脂吸附钨矿提取液中的钨酸根离子,探究阴离子树脂混合比例对钨酸根离子的离子交换量,以及提取液中共存的杂质离子锡酸根、钼酸根对钨酸根吸附量和选择性的影响。结果表明:201x4树脂对钨酸根离子的吸附量最大,但选择性差;杂质离子对树脂吸附量和选择性影响较大。动态实验表明杂质离子可使钨酸根解吸附曲线后移,钨酸根吸附量减少。     

酸根离子对聚氯乙烯燃烧发烟的影响

本文讨论了各类酸根离子对聚氯乙烯燃烧发烟的影响，发现具有抑烟，吸收有毒气体及阻燃的多功能无机材料应具有类似硼酸根的酸根阴离子，类似锌，镁，铁的ｓ，ｄｓ区金属元素作为阳离子及含有适量结合水。     

胶原纤维负载锆对氟离子和磷酸根的吸附去除

将Zr(Ⅳ)负载在胶原纤维基质上制备吸附材料,研究了该吸附材料对水溶液中氟离子和磷酸根离子的吸附特性。结果表明,胶原纤维负载Zr(Ⅳ)(ZrCF)对氟离子和磷酸根离子均有较强的吸附能力,在pH=4～9,胶原纤维负载Zr(Ⅳ)对氟离子保持较高的吸附容量;ZrCF吸附磷酸根的适宜pH=3.0～6.0。胶原纤维负载Zr(Ⅳ)对氟离子和磷酸根离子的吸附等温线均符合Langmuir方程;吸附动力学研究表明,胶原纤维负载Zr(Ⅳ)对氟离子和磷酸根离子的吸附动力学可以用准二级速率方程来描述。水中常见的Cl-、NO3-、CO23-和SO24-对ZrCF吸附氟离子和磷酸根离子的影响不大,模拟地下水体系的动态实验结果表明,ZrCF对磷酸根的亲和力更强。     

水热法制备Mg-Fe类水滑石及对水中硫酸根离子吸附的研究

采用尿素分解水热合成法制备Mg-Fe类水滑石,并通过XRD,FF-IR表征.利用Mg-Fe类水滑石焙烧产物对水中硫酸根离子进行一定条件的吸附去除.结果表明,Mg-Fe类水滑石层间阴离子为碳酸根,结晶效果较好.焙烧后Mg-Fe类水滑石在pH =4～8,温度为35℃,对初始浓度500 mg/L硫酸根离子具有较好的吸附能力,90 min可快速达到吸附平衡,吸附数据表明该吸附符合准二级动力学方程,吸附等温线符合Langmuir吸附模型,最大吸附量为151.51 mg/g.     

锆改性蒙脱石作为除砷吸附剂的应用方法

本发明涉及将锆改性蒙脱石作为除砷吸附剂的应用方法。其主要技术特征是将以天然无害且价格低廉的蒙脱石矿物为原料，采用锆盐改性制备的材料作为水质除砷吸附剂，吸附后用碱液再生，该吸附剂清洁无害，耐酸碱。将待处理水样调节至中性及偏酸性可提高除砷能力，增加钙镁离子浓度可显著提高吸附剂吸附处理效果，吸附后的吸附剂采用氢氧化钠溶液进行再生。该吸附剂可作为废水和饮用水除砷材料。     

电容去离子过程电吸附行为与法拉第反应关系及去除水体硬度

采用活性炭涂层电极,研究了电容去离子过程中电吸附行为与法拉第反应之间的关系,同时以CaCl_2和MgCl_2溶液模拟硬度水体,探讨了电容去离子技术对硬度去除的可持续性。结果表明,随着电压的升高,电容去离子过程中有不同的法拉第反应发生,同时阴离子的电吸附行为促进了溶解氧和H_2O_2的还原;阳离子的电吸附行为促进了活性炭电极的氧化和水的电解,Cl~-的氧化不是出水pH变化的主要原因。电容去离子装置在去除钙镁离子时表现了很好的可持续性,钙镁离子不会对活性炭电极造成结垢问题。     

D301负载Fe(Ⅲ)去除饮用水中的As(Ⅴ)

研究了用Fe(Ⅲ)改性的大孔弱碱性阴离子交换树脂D301在不同实验条件下对饮用水中As(Ⅴ)的吸附性能,包括pH、温度、吸附时间和共存离子的影响。研究结果表明:在pH<10时,D301-Fe对As(Ⅴ)具有较强的吸附性能,吸附方程符合Langmuir等温线,吸附过程分为自发、放热、熵推动过程;D301-Fe对砷的吸附遵循二级动力学方程;当含As(Ⅴ)与SO42-、Cl-、F-共存时,D301-Fe对砷仍具有较高的去除率,而与PO43-共存时其对砷的去除率明显下降,基本低于40%。     

阴离子交换纤维对磷酸根离子吸附性能及机理研究

以含偕胺肟基团的螯合纤维为原料,经Fe(NO3)3溶液处理,制得阴离子交换纤维,以其为吸附材料,对磷酸根离子进行吸附规律研究;并采用红外光谱仪(IR)和扫描电子显微镜(SEM)对样品进行了表征。实验结果表明,阴离子交换纤维对磷酸根离子的吸附反应符合Freundlich及Langmuir等温吸附模型,饱和吸附量为8.299 mmol/g。采用初始浓度法确定该反应为一级反应;在不同温度下对初始浓度为0.04994 mol/L的磷酸根离子进行吸附,测定了各温度下的反应速率常数,由速率常数与温度的关系得出反应的活化能Ea=22.55 kJ/mol,速率常数k=40.65 e-Ea/RT。     

Mg-Al-Fe类水滑石及其焙烧产物对活性艳红X-3B脱色性能研究

采用共沉淀法合成出一系列镁铝铁不同量的比的碳酸根型类水滑石(HTLCs),经500℃高温煅烧制备出镁铝铁复合氧化物HTLCs-500,并用X-射线、红外光谱对它们进行表征;考查了吸附剂投加量、反应时间、初始pH等因素对二者处理阴离子染料活性艳红X-3B模拟废水效果的影响,并对吸附机理进行了探讨.结果表明:以镁、铝、铁的量比为3:0.6:0.4时制得的类水滑石对活性艳红X-3B溶液的脱色效果最好;HTLCs及其焙烧产物HTLCs-500对活性艳红X-3B染料均具有较好的吸附性能,在较宽的pH范围内2者的脱色性能稳定,且HTLCs-500对该染料的吸附效果要优于HTLCs;HTLCs及HTLCs-500对活性艳红X-3B的吸附结果符合Langmuir吸附等温式,25°下饱和吸附量分别为362.9、889.2 mg·g-1;饱和吸附后的HTLCs-500用高温热解法再生,吸附性能良好,随再生次数增多,脱色率下降.     

镁钙锌铝四元类水滑石金属含量的测定研究

论述了镁-钙-锌-铝四元合成类水滑石中含量相差悬殊的4种金属元素含量的测定方法:第一份试液,以氟化铵掩蔽铝、镁、钙离子后,用乙二胺四乙酸二钠(EDTA)标准溶液滴定锌离子;第二份试液,用缓冲溶液调节pH为3.5,加过量EDTA煮沸处理,再调节pH为4.2,促使铝离子和锌离子全部与EDTA络合,以铜离子标准溶液滴定剩余的EDTA后,用取代络合滴定法测定铝离子;第三份试液,用小体积沉淀法处理,形成碳酸钙和氢氧化镁沉淀,与溶于水的偏锌酸根(ZnO2-2)和偏铝酸根(AlO-2)分离,再使碳酸钙与氢氧化镁溶于盐酸溶液,用EDTA滴定钙-镁总量;向第四份钙-镁溶液中加入乙二醇二乙醚二胺四乙酸钡(Ba-EGTA)-硫酸钠溶液掩蔽钙离子,用EDTA标准溶液滴定镁离子,以差减法计算钙离子含量.该法准确度和精密度均较高,能满足工业分析要求.     

水滑石焙烧产物对阴离子染料靛蓝胭脂红的吸附特性

碳酸根型水滑石焙烧产物对阴离子染料具有特异的吸附性能。该研究考察了两种具有不同镁铝摩尔比的镁铝复合氧化物对靛蓝胭脂红的吸附性能,并探讨了焙烧温度、投加量、初始染料浓度、溶液初始pH以及共存阴离子这几个因素的影响。结果表明经过500℃焙烧处理后的水滑石对染料的去除效果最好,去除率高达95%,平衡吸附量高达811.5 mg/g（1.74 mmol/g）;且吸附过程不受初始溶液pH和共存阴离子的影响。水滑石焙烧产物直接用于印染废水处理,脱色率达68%~84%。     

活性炭负载Fe(III)吸附剂去除饮用水中的As(V)

利用活性炭负载水合铁氧化物制备了复合吸附剂,并用于饮用水中As(V)的去除. 研究了活性炭种类、粒度、溶液pH值、Fe(III)盐浓度和干扰离子等对As(V)去除的影响. 结果表明,煤质活性炭作为基质负载水合铁氧化物比椰壳炭和果壳炭具有更好的除砷效果. 随着炭粒度降低,除砷效率显著增加. 在pH 3~9范围内,活性炭负载水合铁氧化物可有效吸附As(V). F-, Cl-, SO42-的加入对As(V)的去除效率基本无影响,而SiO32-和PO43-则明显抑制As(V)的去除. Langmuir模型比Freundlich模型能更好地描述复合吸附剂对As(V)的吸附平衡. 动力学研究表明,As(V)吸附反应可用二级速率方程描述.     

焙烧态镁铝水滑石对刚果红的脱色性能研究

采用单滴法合成了n(Mg)/n(Al)=3的镁铝水滑石Mg3Al-LDH及其焙烧态产物Mg3Al-CLDH,并对刚果红溶液进行了吸附脱色试验。XRD分析结果说明合成的Mg3Al-LDH样品具有水滑石的典型结构,Mg3Al-CLDH在吸附刚果红阴离子后重新恢复为水滑石的层状结构。相同条件下Mg3Al-CLDH对刚果红的脱色率高于Mg3Al-LDH。对质量浓度为100mg/L的刚果红溶液,当Mg3Al-CLDH投加量为0.7g/L,pH值为5～10时,室温下反应40min,脱色率可达99%以上。Mg3Al-CLDH重复再生4次循环利用,刚果红脱色率仍在90%以上。表明Mg3Al-CLDH能够有效吸附溶液中的刚果红阴离子,可用于水体中阴离子染料的脱色处理。     

Removal of arsenic in water by an ion‐exchange fiber with amino groups

A new type of ion‐exchange fiber with amino groups, called RPFA‐I, was prepared. The amino modification and stretching resistance of RPFA‐I were characterized by FTIR spectrum, SEM test, and auto‐tensile test, respectively, and the removal of arsenite and arsenate in solution by RPFA‐I was investigated. The obtained experimental results show that RPFA‐I fibers have fine mechanical properties, and the amino functional groups have grafted to the surface of the matrix material. The adsorption results show that RPFA‐I has a high capacity and good adsorption kinetic property in removal of arsenate and arsenite at the trace level. The removal efficiency was 70% for arsenite and 93% arsenate, respectively, at the concentration of 5 mg/L. The isothermal adsorptions were correspondent to Langmiur/Frundlich adsorption equation, and the adsorption kinetics was fit to the Lagergren pseudosecond order rate equation. The adsorption of the used adsorbent could be efficiently regenerated by 0.1M NaOH in a simple way. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

柱撑蒙脱石对水中砷(Ⅴ)的吸附研究

采用羟基聚合Al-Fe为柱化剂对蒙脱石进行改性,将制得的柱撑蒙脱石作为吸附剂,研究了其对水溶液中砷的去除效果及其影响因素.结果表明:对蒙脱石柱撑改性后能显著提高其吸附性能.平衡吸附量与平衡质量浓度之间的关系符合Freundlich和Langmuir等温吸附方程所描述的规律.用Elovich方程和双常数方程可以较好地拟合柱撑蒙脱石对As(Ⅴ)的动力学吸附过程.     

Perchlorate Uptake from Aqueous Solutions by Calcined Mg-Al Layered Double Hydroxides

The calcined layered double hydroxides (CLDHs) with 3:1 Mg/Al molar ratio were observed to acquire a high removal efficiency of perchlorate. And they were applied into perchlorate adsorption process with the initial 100 mg/L perchlorate solution in order to analyze removal efficiencies of perchlorate on various influential factors. The results represented that 1.5 g/L CLDHs could achieve ideal adsorption efficiencies of perchlorate at the pH range of 7–9 and at the temperature of 25°C. The removal efficiencies of perchlorate increased up to a maximum efficiency with the increasing dose of CLDHs. Acidic or highly alkaline environment adversely affected perchlorate adsorption. The adsorption process was found to be endothermic due to the higher adsorption capacity in CLDHs with the increasing temperature. The removal of perchlorate was best represented by the pseudo second-order kinetics model and Langmuir isotherm model. Co-existing anions tests showed that the anions of higher valence had a more significant effect than the monovalent anions during the adsorption process. Finally, the adsorption process was further validated by the X-ray patterns and Fourier-transform Infrared spectra of CLDHs. Results demonstrated potential utility of CLDHs that could be developed into a viable technology for perchlorate removal from water.     

一步法制备Mg改性玉米芯生物炭吸附磷酸盐研究

研究通过MgCl₂溶液浸泡玉米芯后在450℃下慢速热解1 h一步法制备获得Mg改性生物炭(Mg-BC),探究其对磷酸盐的吸附和影响因素。结果表明,Mg-BC吸附磷符合准1级、准2级动力学模型,说明吸附过程主要受物理、化学作用控制。Mg-BC对磷的等温吸附符合Langmuir方程,吸附类型为单分子层吸附,最大吸附量为56.54 mg/g。溶液中共存无机阴离子会显著抑制Mg-BC吸附PO₄^3-,其顺序为HCO₃^-> SO₄^2-> NO₃^->Cl^-;NaOH溶液解吸可使Mg-BC有效的再生利用,且循环4次后,其去除率仍高于60%。Mg-BC可有效去除P有高吸附量,为P去除提供了一种新型环保材料。     

Reusable high performance of calcined Mg/Al hydrotalcite for the removal of Navy Blue and Yellow F3G dyes

Water pollution with dye chemicals from apparel industries is a serious problem in the world.Since most of dyes are potentially have toxic and carcinogenic effects on human,it is important to remove them before they are discharged to the environment.Among many methods available for dyes removal in water,adsorption is the easiest and economically feasible that has no major obstacle for practical appli-cations.In the present study,we tested calcined Mg/Al hydrotalcite (Mg/Al CHT) prepared by co-precipitation technique as an adsorbent for the removal of Navy Blue (NB) and Yellow F3G (YF3G) dyes.Mg/Al CHT was characterized by using a Fourier transform infrared (FTIR) spectrometer,an X-ray diffrac-tometer (XRD) and a scanning electron microscope (SEM).The results showed that Mg/Al CHT was highly effective as an adsorbent for the removal of NB and YF3G under mild-acidic condition (pH 4) with removal capacities (b) according to Langmuir isotherm model were 7.97 × 10-4 and 5.80 × 10-4 mol·g-1,respectively.Kinetics study showed that the adsorption of NB and YF3D on Mg/Al CHT followed pseudo-second order with rate constant (kp2) 11.57 × 103 and 11.75 × 103 g·mol-1·min-1,respectively.The spent adsorbent can be easily regenerated by simply calcining it at 450 ℃ for 3 h.Adsorption test on the mix-ture of NB and YF3G showed that the adsorption capacity of Mg/Al CHT was eightfold higher than that of Mg/Al HT and the value was maintained with repeated use.     

Synthesis of As(V)-Cr(III) Co-Imprinted Polymer and Its Adsorption Performance for Arsenate Species

A novel mixed As(V)-Cr(III) ions co-imprinted polymer (MICIP) was synthesized with two functional monomers, 1,12-dodecanediol-O,O’-diphenyl-phosphonic acid (DDDPA) and 4-vinylpyridine (4-VP), by W/O/W polymerization. Arsenate and Cr(III) ions were simultaneously chosen as templates while Cr(III) ions played a role of the synergetic ions to improve the imprinting of arsenate on the ion-imprinted polymer. The adsorption performance of the MICIP has been investigated by adsorption experiments. The results showed that the MICIP was efficient for the simultaneous removal of Cr(III) and arsenate ions when pH was 4 to 5. It was found that Cr(III) ions had a significant synergetic effect on the selective adsorption of arsenate onto the MICIP in a mixed As(V) and Cr(III) solution and the MICIP showed little adsorption ability on arsenate without Cr(III) ions in solutions. The adsorption isotherm of arsenate ions on the MICIP was well described by the Freundlich model (R² > 0.99). The adsorption process obeyed the pseudo second-order kinetics and reached the equilibrium after 24 hours. The MICIP had high selectivity for arsenate anions in the presence of competitive ions with selectivity coefficients of 22.0 and 3.17 for k(As/Cd) and k(As/Ni), respectively.     

Removal of Hazardous Anions from Aqueous Solutions by La(lll)- and Y(lll)-lmpregnated Alumina

Abstract

New adsorbents, La(III)- and Y(III)-impregnated alumina, were prepared for the removal of hazardous anions from aqueous solutions. A commercially available alumina was impregnated with La(III) or Y(III) ions by the adsorption process. The change in the surface charge due to the impregnation was measured by acid/base titration. The adsorption rate and the capacity of the alumina for La(III) and Y(III) ions were determined. The adsorption characteristics of the La(III)- and Y(III)-impregnated alumina and the original alumina for fluoride, phosphate, arsenate and selenite ions were analyzed under various conditions. The pH effect, dose effect, and kinetics were studied. The removal selectivity by the impregnated alumina was in the order fluoride > phosphate > arsenate > selenite. The impregnated alumina has been successfully applied for the removal of hazardous anions from synthetic and high-tech industrial wastewaters.