代谢活化作用对多溴代联苯类污染物类/抗甲状腺激素活性的影响

选用大鼠肝匀浆(S9)和鼠肝癌细胞(H4ⅡE)两种体系代谢活化多溴代联苯醚混标(BDEs)和十溴联苯醚(BDE209),采用重组甲状腺激素受体基因酵母检测BDEs和BDE209母体及其代谢产物的类/抗甲状腺激素效应.结果表明,BDEs和BDE209母体均不表现甲状腺激素效应(p>0.05);但是经S9和H4ⅡE细胞代谢活化后,其代谢产物表现出明显的类甲状腺激素活性和抗甲状腺激素活性(p<0.05),BDEs和BDE209的干扰甲状腺激素效应需要经过代谢活化步骤.比较不同代谢活化体系,重组酵母细胞本身的代谢活化作用并不显著,而H4ⅡE细胞和S9代谢活化体系均能够导致活性中间体.     

Decolorization of synthetic Methyl Orange wastewater by electrocoagulation with periodic reversal of electrodes and optimization by RSM

Treatment of Methyl Orange (MO), an azo dye, synthetic wastewater by electrocoagulation with periodic reversal of the electrodes (PREC) was examined. Response Surface Methodology (RSM) was used to optimize the influence of experimental conditions for color removal (CR), energy consumption (ENC), electrode consumption (ELC) and sludge production (SP) per kg MO removed (kg(MO_r)) with optimal conditions being found to be pH 7.4, solution conductivity (к) 9.4 mS cm⁻¹, cell voltage (U) 4.4 V, current density (j) 185 mA cm⁻², electrocoagulation time (T) 14 min, cycle of periodic reversal of electrodes (t) 15 s, inter-electrode distance (d) 3.5 cm and initial MO concentration of 125 mg L⁻¹. Under these conditions, 97 ± 2% color was removed and ENC, ELC and SP were 44 ± 3 kWh kg(MO_r)⁻¹, 4.1 ± 0.2 kg(Al) kg(MO_r)⁻¹ and 17.2 ± 0.9 kg(sludge) kg(MO_r)⁻¹, respectively. With the enhanced electrochemical efficiency resulting from the periodic electrode reversal, the coefficients of increased resistance and decreased current density between the two electrodes in the PREC setup were 2.48 × 10⁻⁴ Ω cm⁻² min⁻¹ and 0.29 mA cm⁻² min⁻¹, respectively, as compared to 7.72 × 10⁻⁴ Ω cm⁻² min⁻¹ and 0.79 mA cm⁻² min⁻¹ as measured for the traditional electrocoagulation process. The rate constant of decolorization was also enhanced by 20.4% from 0.152 min⁻¹ in the traditional electrocoagulation process to 0.183 min⁻¹ in the PREC process. These performance characteristics indicate that the PREC approach may be more promising in terms of practical application, as a cost-effective treatment, than conventional electrocoagulation for textile dye removals.     

转鼓式内电解装置处理水中酸性橙Ⅱ染料

设计制作了转鼓式内电解反应装置,将铁屑与活性炭按体积比为1:1混匀后装填在转鼓内,对偶氮染料酸性橙Ⅱ(AOⅡ)进行降解实验,考察了溶液pH、转鼓转速和溶液浓度对AOⅡ降解过程的影响.结果表明,AOⅡ降解过程符合准一级动力学方程,酸性条件有利于AOⅡ的降解,转鼓转速过快和溶液浓度过高则不利于AOⅡ的降解.解决了铁炭床长时间运行板结结块的问题.AOⅡ分子在转鼓式内电解的作用下,其可见光和紫外光区的特征吸收峰逐渐降低直至消失,并新生成更容易生物降解的对氨基苯磺酸盐.     

铜掺杂钒酸铋光催化降解橙黄II废水及其机理

针对大多数半导体可见光催化剂光生载流子容易复合、光催化活性受限制的问题,制备了Cu元素掺杂BiVO₄可见光催化剂,对BiVO₄结构进行修饰以提高其光催化活性。通过X射线衍射(XRD),扫描电子显微镜(SEM),透射电子显微镜(TEM),X射线能谱(XPS)和紫外-可见漫反射光谱(UV-vis)对其进行了表征,对Cu掺杂BiVO₄光催化剂的光催化活性和稳定性进行了检测。结果表明,制备的样品纯度较高,Cu掺杂后并未改变BiVO₄的晶体结构,部分Bi³⁺离子被Cu²⁺取代,从而提高了BiVO₄的可见光催化活性。Cu掺杂BiVO₄催化剂能够在可见LED光照射下,活化过一硫酸盐(PMS)进行光催化降解染料橙黄Ⅱ。当催化剂投加量为0.5 g·L⁻¹、过一硫酸盐投加量为0.6 mmol·L⁻¹,反应60 min后,Cu掺杂BiVO₄催化剂对橙黄Ⅱ的降解率最高。经过Cu掺杂后,光生电子和空穴的分离效率有所提高,增强了BiVO₄的光催化活性。Cu-BiVO₄光催化剂经5次重复使用后,对橙黄Ⅱ的降解效率仍然可以达到78.3%以上,其展现出优异的催化稳定性。     

Practical performance and its efficiency of arsenic removal from groundwater using Fe-Mn binary oxide

A treatment unit packed by granular adsorbent of Fe-Mn binary oxide incorporated into diatomite (FMBO(1:1)-diatomite) was studied to remove arsenic from anaerobic groundwater without any pre-treatment or post-treatment. The raw anaerobic groundwater containing 35-45 μg/L of arsenic was collected from suburb of Beijing. Arsenic(III) constituted roughly 60%-80% of the total arsenic content. Approximately 7,000 bed volumes (ratio of efluent volume to adsorbent volume) treated water with arsenic concentration below 10 μg/L were produced in the operation period of four months. The regeneration of FMBO(1:1)-diatomite had been operated for 15 times. In the first stage, the regeneration process significantly improved the adsorption capacity of FMBO(1:1)-diatomite. With increased loading amount of Fe-Mn binary oxide, the adsorption capacity for arsenic decreased 20%-40%. Iron and manganese in anaerobic groundwater were oxidized and adsorptive filtrated by FMBO(1:1)-diatomite efficiently. The final concentrations of iron and manganese in efluents were nearly zero. The continued safe performance of the treatment units proved that adsorbent FMBO(1:1)-diatomite had high oxidation ability and exhibited strong adsorptive filtration.     

磁性离子印迹聚合物的制备及其对水中Pb(Ⅱ)的吸附

以铅离子为模板离子、乙二醇二甲基丙烯酸酯和偶氮二异丁腈为交联剂和引发剂、稀盐酸为洗脱剂,采用微波辅助反相乳液悬浮聚合法,制备了磁性离子印迹聚合物(MIIP),通过SEM、FTIR、XRD和BET技术对其进行了表征,并将其用于水中Pb(Ⅱ)的吸附.在初始质量浓度60 mg/L、溶液pH 6、吸附温度303 K、吸附时间6...     

铁酸锌纳米晶的合成及其催化脱色性能研究

采用改进的共沉淀法与溶剂热法相结合制备了ZnFe2O4纳米晶,利用X射线衍射(XRD)、透射电镜(TEM)对ZnFe2O4的晶型和形貌进行了表征,讨论了其表面的光伏效应,以酸性橙Ⅱ的光催化脱色性能作为探针反应,详细地考察了催化剂的用量、底物浓度及溶液pH等因素对其脱色效果的影响.结果表明,制备的ZnFe2O4为正尖晶石型结构,平均粒径为7 nm左右,样品具有一定的捕获电子能力,在外加电场下光伏响应变化明显,在正电场下有最佳响应值,而当负电场达到一定值时,外电场的光伏响应占据主导地位.在酸性橙Ⅱ为20 mg/L、催化剂用量为1.0 g/L的中性条件下,其脱色效率达95%左右,而且经过4次重复使用后催化剂仍然具有一定的脱色性能.     

CNTs-CeO2/H2O2复合光催化氧化体系降解水中酸性橙Ⅱ

运用"化学沉淀法",将CeO2负载到碳纳米管(CNTs)上制备复合光催化剂,采用"单因素实验法"优化了制备条件。运用透射电镜和X射线衍射仪对复合光催化剂进行了表征。结果表明,负载到CNTs上的CeO2为多晶面心立方结构,尺寸大小在6~10 nm之间,其在CNTs上分散效果好,负载均匀且负载率高。在溶液pH为5,CNTs-CeO2用量为0.50 g/L并光照2 h后,酸性橙Ⅱ的光脱色率和TOC去除率分别达到64.71%和44.25%;加入0.02 mmol/L H2O2后,CNTs-CeO2/H2O2复合体系对酸性橙Ⅱ的光脱色率和TOC去除率分别提高至91.35%和82.40%。这预示着CNTs-CeO2/H2O2复合光催化氧化体系在对水中偶氮染料的光催化处理方面具有潜在的应用价值。     

草酸改性柚子皮对废水中镉离子的吸附性能

以粗柚子皮(PP)为吸附剂原材料,以草酸为改性剂制备出了改性柚子皮吸附剂(MPP)。采用批量实验研究了改性吸附剂对水中Cd(Ⅱ)吸附的影响因素(如溶液pH、吸附剂用量、接触时间和Cd(Ⅱ)初始浓度)、吸附动力学、吸附等温线和吸附热力学等,并讨论了其吸附机理。在溶液初始pH为5.0、吸附剂投加量为5 g/L、Cd(Ⅱ)初始浓度为50 mg/L条件下,吸附剂MPP对Cd(Ⅱ)的吸附平衡时间为120 min,其吸附率可维持在95.63%以上。吸附过程可以很好地用准二级动力学方程和Langmuir吸附等温模型描述。热力学分析结果显示,吸附剂(MPP)对Cd(Ⅱ)的吸附是吸热反应,且能自发进行。     

白云石矿物对水溶液中Cu2+、Pb2+吸附的动力学和热力学

采用静态实验方法研究了白云石对水溶液中Cu2+、Pb2+的吸附特性,通过批实验考察了反应时间、溶液初始浓度、pH值、离子强度、温度以及固液比等因素对吸附的影响,探讨了白云石对Cu2+、Pb2+的吸附动力学、热力学规律及其反应机制。实验结果显示:白云石对Cu2+、Pb2+的吸附在24 h达到平衡,对Pb2+的吸附量大于Cu2+,伪二级和双常数动力学方程分别能较好地拟合白云石对Cu2+、Pb2+的吸附;在一定条件下,白云石对Cu2+、Pb2+的去除率与溶液初始浓度呈反比,与固液比呈正比;吸附等温方程符合Langmuir模型,为单分子层吸附;溶液pH值对吸附行为影响显著,在溶液pH=6~7时,吸附效果最好,离子强度对吸附影响甚微;白云石对Cu2+、Pb2+的吸附属于吸热反应,反应自发进行,高温促进白云石的吸附行为。