Degradation and Removal of Suifadiazine from Waters by a Novel Polymer-supported Hydrous Manganese Dioxide(HMO)

以大孔强碱阴离子交换树脂D201为载体,采用离子交换和氧化还原方法制备了一种新型树脂基水合锰氧化物材料HMO-201.考察了不同pH、离子强度和溶解性有机质(DOM)含量条件下,该材料对水体中磺胺嘧啶(SD)的去除能力.HPLC-MS分析表明,SD的高效去除是通过HMO-201的降解而非吸附方式实现的.实验结果表明,pH为1.0时HMO-201在120 min内对0.01 mmol/L SD的去除效率为99.9％,反应符合表观一级动力学模型；体系的离子强度和DOM含量变化对SD的去除效率均无显著影响.模拟环境离子强度和DOM浓度,连续10批次实验中SD废水的去除效率在240 min内均大于99％；HMO-201的柱动态降解装置连续处理SD溶液2000床体积,依然未检出SD.表明HMO-201材料具有较稳定的重复利用性,对环境中普遍存在的磺胺类抗生素药物具有着高效的降解去除效果,具有广泛的应用前景.     

基于电镀废水中复合污染物高效去除的新型磁性树脂组合工艺研究

选用磁性丙烯酸系阳离子交换树脂(NDMC)、磁性丙烯酸系阴离子交换树脂(NDMP)对Cu(II)、Ni(II)和丹宁酸(TA)复合组分污染物进行了去除实验。通过改变树脂组合方式,优选出的最佳工艺为NDMC与NDMP混合吸附的NDMC+NDMP工艺。在最优条件下,该工艺能够同时高效去除Cu(II)、Ni(II)和丹宁酸复合污染物,三者去除率可分别达到84.3%、74.5%和93.0%。进一步对比分析了预负载实验与共去除实验的性能规律,推测出NDMC树脂共去除重金属离子和溶解性有机物(DOM)的作用机制,包括磁性颗粒对Metal-DOM络合物的吸附作用以及固相负载重金属离子与DOM的络合作用,且前者为主导作用方式。     

新型树脂基水合氧化铁对水体中微量砷的吸附性能研究

将水合氧化铁固载于凝胶型强碱阴离子树脂N201上并合成出新型除砷吸附剂N201-Fe.研究了不同实验条件下N201-Fe对去除水溶液As(V)的影响.实验结果表明,N201-Fe对砷的吸附受pH值的影响较小;N201-Fe对As(V)具有很高选择性,在Cl-、HCO3-、SO42-等竞争离子共存时,N201对As(V)的去除率不到2%,而N201-Fe却高达90%.N201-Fe对As(V)的高选择性归因于N201-Fe中水合氧化铁与As(V)之间的络合配位能力及树脂表面的Donnan膜效应.静态吸附实验表明N201-Fe吸附As(V)的等温线符合Freundlich模型,热力学结果显示,该吸附过程为吸热过程.动态穿透实验表明,模拟水中的As(V)经N201-Fe处理后可达到中国和美国的饮用水标准,且N201-Fe的吸附处理量较N201提高30多倍.     

聚苯胺@碳纳米纤维复合材料对放射性核素铀的高效去除

本文通过原位聚合方法成功制备了聚苯胺改性的碳纳米纤维(PANI@CNF)复合材料,并用于水溶液中放射性核素铀(U(VI))的高效去除.扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)、傅里叶红外光谱(FTIR)和X射线光电子能谱(XPS)等表征证明所制备的材料具有丰富的官能团和优良的物理化学性质.批实验方法系统研究了周围环境(pH、背景电解液、反应时间和温度)的变化对U(Ⅵ)去除结果的影响.结果表明,pH对于U(Ⅵ)去除影响很大,而离子强度没有影响,表明二者之间的作用机理为内层表面络合.吸附能够在30 min内快速达到平衡,且符合拟二级动力学模型.吸附等温线符合Langmuir等温线,表明U(Ⅵ)的去除是单分子层均匀吸附过程.在pH=5.0和T=298 K时, PANI@CNF对U(Ⅵ)的最大吸附量高达319.4 mg/g,远远高于单纯的CNF(133.9 mg/g). U(Ⅵ)主要与材料表面的含氮和含氧官能团形成了稳定的内层络合物,从而达到高效去除的目的.以上分析表明, PANI@CNF具有快速反应动力学和高效吸附能力,可以作为放射性核素高效去除的潜在储备材料,为我国核废料治理工作提供理论依据.     

大孔吸附树脂法去除淫羊藿多糖中蛋白的研究

从4种大孔吸附树脂中筛选出ADS-7, 考察了其对淫羊藿多糖中蛋白的去除作用, 并讨论了pH值、 鞣酸、 上样量等对树脂去蛋白效率的影响. 结果表明, 该方法对淫羊藿粗多糖中的蛋白具有较高的去除效率, 淫羊藿粗多糖中的蛋白含量由1.2%下降到0.035%.     

阴离子交换树脂回收水相中有机磷酸萃取剂

研究了阴离子交换树脂对水相中有机磷酸萃取剂的吸附。 通过比较不同的离子交换树脂对水相中2-乙基己基膦酸-单-2-乙基己基酯(P507)的去除率,发现大孔强碱性阴离子交换树脂(D201-OH)从水溶液中去除P507的能力最强,去除率可达99.24%。 而且当溶液在pH=1.0时,D201-OH对P507的吸附主要是分子吸附,其吸附等温线更适用于Langmuir模型;当溶液在pH=5.0时,阴离子交换反应占主导地位,其吸附等温线更适用于Freundlich模型。 研究还表明,D201-OH对P507的吸附在20 min内即达到吸附平衡时99.8%的吸附量。 通过动力学研究表明,拟一级动力学模型(R²>0.99)更适用于描述实验数据,并且吸附速率主要受膜扩散控制。 此外,吸附-解吸附循环8次后,D201-OH的吸附能力仍然保持在93%以上。 综上所述,D201-OH是有机磷酸类萃取剂的良好吸附剂,其吸附性能高效,循环过程稳定,因此可用于实际生产过程中回收有机磷酸萃取剂。     

大孔树脂去除炼油废水中酚的研究(英文)

论文对大孔树脂去除炼油废水中酚进行了研究。采用静态法实验研究了树脂用量、pH、温度、废水中酚的初始浓度等条件对H103和X-5树脂吸附和解吸酚的影响。实验结果表明,室温对吸附有利,随着树脂用量和初始浓度的增加,两种树脂对酚的吸附率增加。30min内吸附率可达80%以上,返洗率可达90%以上。用H103和X-5树脂对炼油厂废水处理厂排放的低含量含酚废水进行吸附处理后,酚的浓度能达到国家排放标准要求。     

活性碳纤维阴极电芬顿反应降解微囊藻毒素研究

以具有高比表面积的活性碳纤维作为阴极,通过电芬顿反应降解水中微囊藻毒素(MCRR,MCLR)的电化学方法系统考察了电流密度、pH值和Fe2+浓度等因素对微囊藻毒素降解效果的影响.实验结果表明,在Fe2+浓度为1.0mmol/L和电流密度为6.6mA/cm2条件下,电化学处理60min,MCRR(8.81mg/L)去除率为75%,MCLR(6.36mg/L)去除率为94%.证明过氧化氢可以通过电化学还原在活性碳纤维阴极表面高效产生,微囊藻毒素可被高效降解去除.     

响应面优化制备花生壳纤维素及其对罗丹明B的吸附性能

以废花生壳为原料制备了花生壳纤维素吸附剂并将其用于去除水中水中罗丹明B(Rhodamine B,RhB)染料。采用Box-Behnken Design(BBD)响应面法(RSM)法对制备条件进行了优化,筛选出获得吸附效果最佳的花生壳纤维素的制备条件。系统考察了溶液的pH值,初始浓度、吸附时间以及溶液离子强度对其吸附性能的影响。结果表明:pH=4时,花生壳纤维素对RhB的吸附效果最佳,饱和吸附容量q_m为166.7 mg·g~(-1);与RSM模型预测值吻合。吸附过程可在30 min内达到平衡,符合准二级动力学模型。吸附容量随着溶液离子强度的增大而减小,说明其吸附是以静电作用为主的吸附过程。10次循环使用后花生壳纤维素对RhB的吸附效率仍能保持91%以上,表明该材料可以多次循环使用,是潜在的高效吸附材料。     

基于单颗粒电感耦合等离子体质谱法测定环境基质水样中纳米银颗粒

采用单颗粒电感耦合等离子体质谱法(SP-ICP-MS)同时测定环境水样中纳米银颗粒(AgNPs)的颗粒浓度、质量浓度和粒径分布,并考察了溶液的pH值、溶解性有机质(DOM)浓度以及离子强度等对AgNPs测定的影响。结果表明:SP-ICP-MS方法对60 nm AgNPs标准溶液的测定结果与标准值一致,准确性较好;pH值(5.0～7.0)、离子强度(≤1 mmol/L)和DOM浓度(≤30 mg/L)对测定结果影响较小;当溶液的pH值≤5.0或离子强度1 mmol/L时,AgNPs的颗粒浓度和粒径随pH值的下降或离子强度的增强而减小。采用SP-ICP-MS方法测定河水、染料废水、养殖废水3种水样中AgNPs的加标回收率分别为98.1%、83.3%和93.3%,表明该方法在合适的基质条件下可用于快速准确测定环境水样中AgNPs的颗粒浓度、质量浓度和粒径分布。     

Efficient removal of Cr(III)-carboxyl complex from neutral and high-salinity wastewater by nitrogen doped biomass-based composites

Heavy metals usually exist stably as the species of organic complexes in high-salinity wastewater. Therefore, their effective removal is challenging, especially when the initial pH is neutral. Herein, a novel nitrogen doped biomass-based composite (N-CMCS) was synthesized to remove the complexed heavy metal of Cr(III)-carboxyl. The maximum adsorption capacity of Cr(III)-Citrate (Cr-Cit) by N-CMCS under neutral pH (7.0) and high-salinity (200 mmol/L NaCl) condition was up to 2.50 mmol/g. And the removal performance remained stable after 6 times of regeneration. Combined with species and characterizations analysis, electrostatic attraction and hydrogen bonding were the main mechanisms for N-CMCS to remove Cr(III)-carboxyl complexes. Dynamic adsorption indicated N-CMCS column could treat about 1300 BV simulated wastewater and 350 BV actual wastewater with the concentration of effluent lower than 1.0 mg/L. Furthermore, N-CMCS could remove a variety of complexed heavy metal ions under neutral pH, indicating the great potential in practical application.     

Recyclable polymer-based nano-hydrous manganese dioxide for highly efficient Tl(I) removal from water

Tl(I)in water even at a trace level is fatal to human beings and the ecosystem.Here we fabricated a new polymer-supported nanocomposite(HMO-001)for efficient Tl(I)removal by encapsulating nanosized hydrous manganese dioxide(HMO)within a polystyrene cation exchanger(D-001).The resultant HMO-001 exhibited more preferable removal of Tl(I)than D-001 and IRC-748,an iminodiacetic chelating polymer,particularly in the presence of competing Ca(II)ions at greater levels in solution.Such preference was ascribed to the Donnan membrane effect caused by D-001 as well as the specific interaction between Tl(I)and HMO.The adsorbed Tl(I)was partially oxidized into insoluble Tl(III)by HMO at acidic pH,while negligible oxidation was observed at circumneutral pH.The exhausted HMO-001 was amenable to efficient regeneration by binary NaOH-NaClO solution for at least 10-cycle batch runs without any significant capacity loss.Fixed-bed column test of Tl(I)-contained industrial effluent and natural water further validated that Tl(I)retention on HMO-001 resulted in a conspicuous concentration drop from 1.3 mg/L to a value lower than 0.14 mg/L(maximum concentration level for industrial effluent regulated by US EPA)and from 1–4?g/L to a value lower than 0.1?g/L(drinking water standard regulated by China Health Ministry),respectively.     

Degradation of p-aminophenol wastewater using Ti-Si-Sn-Sb/GAC particle electrodes in a three-dimensional electrochemical oxidation reactor

In this study, Ti-Si-Sn-Sb/GAC particle electrodes were prepared by sol–gel method. The particle electrodes were characterized by SEM, XRD, EDX, and BET then used to carry out three-dimensional (3D) electrocatalytic oxidation degradation on simulated refractory p-aminophenol (PAP) wastewater. The effects of initial pH, cell voltage, aeration flow rate and initial PAP concentration on degradation experiments were investigated. Under the optimal conditions, the PAP and COD removal rates were 89.45% and 75.17% respectively. In addition, the possible degradation mechanism of PAP was further investigated by UV–Vis and HPLC. Finally, it was found that the Ti-Si-Sn-Sb/GAC particle electrodes with high catalytic activity and excellent stability could significantly improve the PAP wastewater removal efficiency.     

Renewable molybdate complexes encapsulated in anion exchange resin for selective and durable removal of phosphate

The existence of many anions in wastewater reduces the removal efficiency of phosphate by adsorbents under realistic conditions. Facing this challenge, the study reports on an insistent and stable composite adsorbent of molybdate complexes Fe-(MoO_x) embedded in a macroporous anion exchange resin (D-201). [Fe(MoO_x)]-D-201 shows 93.7% adsorption capacity (28.3 mg/g) for phosphate even when the molar concentration of coexisting ions is 5 times higher than phosphate. The capacity of adsorbent is maintained more than 84.2% after five regeneration cycles to remove phosphate in the wastewater containing coexisting ions. The ability of highly selective removal of phosphate is maintained during the regeneration cycles explained by the change of the binding of molybdate clusters with phosphate, which is due to the different structures of molybdate clusters depending on various pH. In general, this work puts forward a new idea for the development of phosphorus removal adsorbents for the treatment of wastewater containing coexisting ions.     

On-line microdialysis–high-performance liquid chromatographic determination of aniline and 2-chloroaniline in polymer industrial wastewater

Determination of aniline and 2-chloroaniline in polymer industrial wastewater was examined using high-performance liquid chromatography with on-line microdialysis. After dilution, aniline and 2-chloroaniline in the sample were diffused through a cellular dialysis membrane into the perfusion stream under controlled conditions. Conditions for obtaining optimum dialysis efficiency such as flow-rate and polarity modifier in the perfusion stream, pH and added salt in the sample solution, as well as chromatographic conditions were investigated. The results indicate that the dialysis achieved at a sample matrix pH value of 9.5 with 0.1 M NaCl addition, and the perfusate at 10-μl/min flow-rate offered optimum dialysis efficiency. The aniline and 2-chloroaniline were well separated in an acceptable time on a reversed-phase C₁₈ column eluted with 40% aqueous methanol solution at pH 7.0 and 1.0 ml/min flow-rate. The proposed method provided a very simple procedure to determine aniline and 2-chloroaniline in wastewater. Application was illustrated by the analysis of aniline and 2-chloroaniline in wastewater released from a polymer factory.     

HPLC-SEC: a new approach to characterise complex wastewater effluents

This work investigates the use of HPLC-SEC to characterise dissolved organic matter (DOM) of complex wastewater effluents. A silica-based column, sodium acetate eluent and multiple detections were employed: UV-254 absorbance for humictype, and tryptophan-like (Ex/Em = 270/355) and tyrosine-like (Ex/Em = 270/310) fluorescence for protein type compounds. Effects of eluent pH, eluent ionic strength and injection volume on separation efficiency were tested. Humic-type and protein-type fractions were clearly differentiated and eluted within and out of calibration range. Eluent ionic strength had the greatest influence on global resolution; the lowest eluent concentration of 0.01 M produced the best separation for all wastewater effluents tested at any detection. UV-254 absorbance was higher at neutral and basic eluent pH while tryptophan-like fluorescence depended on the sample composition rather than on the eluent pH or ionic strength. Tyrosine-like fluorescence decreased significantly with the increase of eluent ionic strength. Accurate molecular weight measurements could not be done, the separation being influenced by secondary interactions, but could be approximated using separate calibrations with sodium salts of polystyrene-sulfonates and protein standards. The results show that this method is suitable for determining DOM in wastewater at low eluent concentrations (up to 0.03 M), at neutral or slightly basic pH.     

Several Rules for Treating Phenol Wastewater via Oxidation by O3/UV-formed Radicals

IntroductionA large amount of phenol wastewater comes fromdifferent sources with potential severe impact to life andenvironment.Phenol is a prototype poison,which istoxic to all living creatures.Phenol can coagulate pro-tein and devitalize cells,especiall…     

The effect of recycling flux on the performance and microbial community composition of a biofilm hydrolytic-aerobic recycling process treating anthraquinone reactive dyes

Synthetic dyes are extensively used and rarely degraded. Microbial decomposition is a cost-effective alternative to chemical and physical degradation processes. In this study, the decomposition of simulated anthraquinone reactive dye (Reactive Blue 19; RB19) at a concentration of 400-mg/L in wastewater by a biofilm hydrolytic-aerobic recycling system was investigated over a range of recycling fluxes. The 16S rDNA-based fingerprint technique was also used to investigate the microbial community composition. Results indicated that the recycling flux was a key factor that influenced RB19 degradation. The RB19 and COD removal efficiency could reach values as high as 82.1% and 95.4%, respectively, with a recycling flux of 10 mL/min. Molecular analysis indicated that some strains were similar to Aeromonadales, Tolumonas, and some uncultured clones were assumed to be potential decolorization bacteria. However, the microbial community composition in the reactors remained relatively stable at different recycling fluxes. This study provided insights on the decolorization capability and the population dynamics during the decolorization process of anthraquinone dye wastewater.     

电化学氧化和臭氧化预处理酸性化工废水的效能研究

保持一定酸度条件下对比了电化学氧化和臭氧氧化预处理酸性化工废水的效能（废水原pH 0.85）. 结果表明,在废水中添加2 g·L^-1 NaCl电化学氧化预处理效果较佳,30 mA·cm^-2条件下电解20 min后水样的CODCr（化学需氧量）去除率达43.4%,BOD₅/COD_Cr（生化需氧量与化学需氧量的比值）值从原来的0.034上升至0.14,可生化性明显提高. 单独臭氧化仅在pH 7.0才能取得一定的预处理效能. Ti(Ⅳ)/O₃/H₂O₂高级氧化体系在pH 2.85条件下亦有较好的预处理效果,16 min后水样COD_Cr去除率达22.9%,BOD₅/COD_Cr值则提高至0.072.     

Adsorption of fluoride, phosphate, and arsenate ions on a new type of ion exchange fiber

A new type of ion exchange fiber for the removal of fluoride, phosphate, and arsenate ions has been developed. A batch adsorption technique for investigating adsorption kinetic and equilibrium parameters and determining pH adsorption edges is applied. It is shown that the adsorption properties of the ion exchange fiber for fluoride, phosphate, and arsenate ions depend on the pH value and anion concentration. The adsorption of arsenate on the sorbent reaches a maximum of 97.9% in the pH value range of 3.5 to 7.0. The adsorption percentage of phosphate is more than 99% in the pH range of 3.0 to 5.5. The adsorption of fluoride on the ion exchange fiber is found to be 90.4% at pH 3.0. The Freundlich model can describe the adsorption equilibrium data of fluoride, arsenate, and phosphate anions. The sorption of the three anions on the ion exchange fiber is a rapid process, and the adsorption kinetic data can be simulated very well by the pseudo-second-order rate equation. The column performance is carried out to assess the applicability of the ion exchange fiber for the removal of fluoride, phosphate, and arsenate ions from synthetic wastewaters with satisfactory removal efficiency. The desorption experiment shows that fluoride ion sorbed by the fiber column can be quantitatively desorbed with 5 mL of 0.50 mol/L NaOH at elution rate of 1 mL/min, and 30 mL of NaOH is necessary for the quantitative recovery of phosphate and arsenate ions.