超声降解有机污染物的研究概况

本文介绍了超声降解有机污染物的原理、效果以及对降解有影响的主要声学因素,并对存在的问题和发展方向提出见解.     

CWPO处理含酚废水催化材料与反应机理研究进展

酚类污染物是常见的有机污染物之一,含酚废水处理难度大、毒性强,对自然环境与人类健康具有严重危害。催化湿式过氧化氢氧化技术(CWPO)以H₂O₂为氧化剂,利用催化剂催化产生·OH强氧化性自由基,可去除水中难降解有机污染物。介绍了CWPO非负载与负载型催化剂在含酚废水中的应用情况,负载型催化剂更具应用前景。利用密度泛函理论(DFT)分析了苯酚、间甲酚污染物主要降解途径,降解含酚废水是通过体系中·OH逐步改变苯环稳定结构形成苯醌类中间体,该中间体C-C断裂开环形成短链羧酸,最终完全矿化为CO₂和H₂O。未来可从制备稳定环保催化剂、分析实际废水降解机制方面展开研究,以发挥CWPO在含酚废水中的应用潜力。     

混合型表面活性剂液膜法处理含酚废水研究

研究了兰－１１３Ｂ＝Ｓｐａｎ－８０－－煤油ＮａＯＨ液膜体系处理苯酚废水的最佳操作工用于对高浓度含酚废水进行处理，实验结果表明，混合型表面活性剂各项指标均较好，除酚效率可达９９％以上，对内相ＮａＯＨ的最佳浓度的确定给出了估算方法。     

Cu-Bi2WO6的制备及应用于光催化氧化含酚废水的研究

以Bi(NO3)3·5H2O和Na3WO4·2H2O为原料,采用水热法合成了掺杂型可见光催化剂CuBi2WO6,并对其进行X射线粉末衍射(XRD)、紫外-可见漫反射(UV-Vis DRS)、扫描电子显微镜(SEM)表征.结果表明,Cu-Bi2 WO6在不同合成条件下呈现多孔微球和纳米片状结构.以苯酚水溶液为目标降解物,研究了在可见光催化作用下Cu-Bi2WO6的催化性能,实验结果表明掺杂型Cu-Bi2WO6具有比纯Bi2 WO6更高的催化活性.     

电极材料对含酚废水处理效果的影响

含酚废水是难降解有机废水,电化学方法处理工业废水具有高效、快速、无二次污染及适应性强的特点.该法是基于电极上的直接氧化和产生的自由基的间接氧化除去废水中的污染物.电极材料是电化学处理方法的核心,在很大程度上决定了废水处理效率.着重概述了不同电极材料对酚类降解效果的影响,认为该方法处理含酚废水应选择高过电位、性能稳定、活性高、成本低的电极材料.     

金属复合氧化物BiVO4的制备及其光催化降解含酚废水的研究

以Bi(NO3)3.5H2O和NH4VO3为原料,采用水热法合成了金属复合氧化物BiVO4,并对其进行扫描电子显微镜(SEM)、X射线粉末衍射(XRD)、紫外-可见漫反射(UV-Vis DRS)以及N2的吸附-脱附表征,探讨了合成条件(温度、时间、pH值)对BiVO4的结构、晶型、形貌、孔性质等方面的影响。以苯酚水溶液为目标降解物,研究了在可见光照射作用下BiVO4的光催化性能,结果表明BiVO4具有良好的可见光催化活性。     

超声降解有机污染物的研究概况

本文介绍了超声降解有机污染物的原理、效果以及对降解有影响的主要声学因素，并对存在的问题和发展方向提出见解。     

固体超强酸SO_4~(2-)/TiO_2-Fe_2O_3光催化降解含酚废水

采用固体超强酸SO42-/TiO2-Fe2O3为光催化剂,苯酚的光催化降解为模型反应,考察了pH值、苯酚初始浓度、催化剂投加量、光照距离、光照时间、助催化剂H2O2对光催化降解过程的影响。结果表明,苯酚初始浓度为50mg/L,催化剂投加量5g/L,光照距离11cm,光照时间为150min,降解率达61.29%,添加助催化剂H2O2后,反应60min,苯酚降解率达到85.12%。     

含钛高炉渣光催化降解邻硝基酚的实验研究

研究了用处理过的含钛高炉渣作为光催化材料光催化降解邻硝基酚溶液,并探讨了影响其光催化性的多种影响因素,以寻求含钛高炉渣综合利用的新途径.实验结果表明:含钛高炉渣作为光催化材料对邻硝基酚溶液有降解作用;邻硝基酚溶液的浓度越低,降解率越高.本实验中,用负载于玻璃片的含钛高炉渣降解邻硝基酚溶液时,最佳溶液浓度为15mg/L;邻硝基酚溶液的pH值为3.0时降解率最大;对邻硝基酚溶液施加电压可提高光催化效率,降解率随电压的增大而增大.     

混凝-微滤膜工艺处理含铬废水

采用混凝-微滤膜工艺处理含铬废水，流程简单、工作压力低、停留时间短、处理效果好．当进水含六价铬质量浓度为50mg／L时，出水总铬质量浓度低于0．5mg／L，六价铬质量浓度低于0．1mg／L，浊度低于0．5NTU，pH值在6～8，并且装置有良好的抗冲击负荷能力．运行中发现当温度较高时，反应器中有铁氧体形成．     

天然有机高分子及其改性产品在污水处理中的应用

天然有机高分子及其改性产品以其来源广、价廉、残留毒性小的独特优势在污水处理中广泛用作絮凝剂、重金属吸附剂。文章着重介绍了近年来研究较多的淀粉类、甲壳素 /壳聚糖类在污水处理中的应用 ,同时还介绍了其他天然有机高分子及其改性产品在该行业中的应用。     

PDMS中空纤维渗透汽化膜处理含盐有机废水

本文以聚二甲基硅氧烷(PDMS)为膜材料,乙烯基三乙氧基硅烷(VTES)为交联剂,在聚偏氟乙烯(PVDF)中空纤维支撑膜表面通过交联反应制备出PDMS/PVDF中空纤维渗透汽化复合膜。采用扫描电子显微镜和全反射傅里叶红外光谱仪表征复合膜的形貌和结构变化。研究了膜对正丁醇-水、异丙醇-水及丙酮-水三种模拟含盐有机废水的分离效果,并考察了温度对膜性能的影响。结果表明:PDMS/PVDF中空纤维膜对这三种模拟含盐有机废水有较好的分离效果,操作温度为40 oC时,膜的渗透通量分别为275.95 g/(m2.h)、322.16 g/(m2.h)、489.76 g/(m2.h),分离因子为37.82、12.60、33.12。     

废水处理中膜生物反应器的研究进展

膜生物反应器作为一种新型高效的生物处理技术和绿色技术,在水处理领域中得到了广泛的应用.综述了膜生物反应器在全世界的研究现状,膜生物反应器的构型、好氧膜生物反应器和厌氧膜生物反应器及应用情况,膜污染控制技术.探讨和展望了膜生物反应器的应用前景,指出了今后的研究方向.     

Inhibitory effects of toxic compounds on nitrification process for cokes wastewater treatment

Cokes wastewater is one of the most toxic industrial effluents since it contains high concentrations of toxic compounds such as phenols, cyanides and thiocyanate. Although activated sludge process has been adapted to treat this wastewater, nitrification process has been occasionally upset by serious inhibitory effects of toxic compounds. In this study, therefore, we examined inhibitory effects of ammonia, thiocyanate, free cyanide, ferric cyanide, phenol and p-cresol on nitrification in an activated sludge system, and then correlated their threshold concentrations with the full-scale pre-denitrification process for treating cokes wastewater. Ammonia below 350 mg/L did not cause substrate inhibition for nitrifying bacteria. Thiocyanate above 200mg/L seemed to inhibit nitrification, but it was due to the increased loading of ammonia produced from its biodegradation. Free cyanide above 0.2mg/L seriously inhibited nitrification, but ferric cyanide below 100mg/L did not. Phenol and p-cresol significantly inhibited nitrification above 200 mg/L and 100mg/L, respectively. Meantime, activated carbon was added to reduce inhibitory effects of phenol and free cyanide.     

Nano-magnetically modified activated carbon prepared by oak shell for treatment of wastewater containing fluoride ion

In this study, the adsorption of fluoride ion (F^-) from synthetic wastewater was performed using activated carbon/Fe₃O₄ nanocomposite in a batch system. To prepare activated carbon (AC), oak shell was used. Also, several analyses such as BET, SEM, EDX, FTIR, XRD, VSM and DLS analyzes were used to study the structure and morphology of the AC/Fe₃O₄ nanocomposite. BET analysis indicated that the specific surface area of Fe₃O₄ and AC/Fe₃O₄ were 65.44 and 226.78 m²/g, respectively, which shows the surface area of the AC/Fe₃O₄ composite was significantly increased compared to Fe₃O₄. Also, the particle size of the AC/Fe₃O₄ composite was obtained 75 nm by the DLS analysis. The sorption tests indicated that the highest sorption efficiency of fluoride ion using the Fe₃O₄/AC nanocomposite was obtained 97.4%. Moreover, the experimental results were well fitted with the Freundlich model. The maximum monolayer uptake capacity using the AC/Fe₃O₄ was obtained as 454.54 mg/g and showed a remarkable adsorption capacity, whichever achieved for fluoride ion sorption. Also, zero-point charge of pH (pHzpc) was obtained 5. Furthermore, the kinetic data were described by the quasi-second-order model. Besides, the thermodynamic parameters showed that the uptake of fluoride ion with the AC/Fe₃O₄ nanocomposite was spontaneous, practical, and endothermic. The outcomes suggest that AC/Fe₃O₄ nanocomposite can be effectively applied for the F^- ion removal from synthetic wastewater.     

球形氧化镁的合成及氧化降解含酚废水应用

以硫酸镁及氨水为原料,经静态反应制备出花球状氢氧化镁前驱体。然后经氢氧化钠溶液处理后,球形颗粒表面变得光滑,得到纯度较高的球形氢氧化镁产物,再经煅烧得到产物球形MgO。实验过程采用XRD、SEM等分析手段对所得产品进行表征,并进行柠檬酸活性测试及氧化降解含酚废水应用。结果表明,600℃下煅烧2 h能够得到较高活性的单分散性良好的球形MgO,且在臭氧氧化降解含酚废水实验中能够明显促进苯酚的降解。     

Experimental investigation of phenolic wastewater treatment using combined activated carbon and UV processes

Experimental investigation shows that UV/hydrogen peroxide (H₂O₂) oxidation of a more concentrated phenolic wastewater can lead to economical savings. The savings can be achieved by the lower amount of H₂O₂ required and time needed to treat the wastewater. Phenolic wastewater can be concentrated by treating the bulk wastewater with activated carbon. The concentrated wastewater that is generated from activated carbon regeneration (assumed to be fully regenerated by steam) can then be treated with UV/H₂O₂. Experimental results show that H₂O₂ concentration goes through an optimum value where adding any more H₂O₂ will result in less effective removal of contaminants. Conductivity of treated wastewater increases sharply then drops down. This could be attributed to the presence of high molecular compounds, inorganic acids, and OH radicals.