水体中4-叔丁基苯酚的去除研究进展

4-叔丁基苯酚是一种外源性酚类雌激素物质,它通过生物体内积累作用进入周围的环境以及人体,产生不可忽视的危害作用,目前我国饮用水水源已经严重受到烷基酚类、农药类等内分泌干扰物的污染。概述了4-叔丁基苯酚的性质、对环境以及人体的危害,水体中的检出情况。鉴于目前国内外对该物质的去除研究很少,根据其它烷基酚类内分泌干扰物质的去除研究情况,展望了4-叔丁基苯酚在水处理中可能的去除方法。     

科聚亚提供“更绿色”的亚磷酸醋稳定剂

在K2007会展上总部设在美国米德尔伯里的科聚亚公司推出了一个具有成本优势更绿色替代行业标准的辅助抗氧剂三（壬基苯）磷酸酯（TNPP）。Weston NPF 705亚磷酸酯稳定剂100％不含壬基苯酚,并且在降解过程中也不形成壬基苯酚。在欧洲联盟和其他一些国家,壬基酚及其衍生物正在被淘汰,因为它们在环境中的持久性和被怀疑干扰内分泌。     

双酚A的精制工艺

酚A为制备环氧树脂的原料。通常由丙酮和苯酚缩合制备双酚A——2,2-bis(4-hydroxyphenyl),要经过蒸馏精制工序。蒸馏后的釜底物,称之为焦油,一般都焚烧弃掉。这在产率上是个严重的损失,因焦油中含有大量双酚A的高缩物、双酚A的异构物及带色物质;用无水溴化氢处理这些釜底物和苯酚的加混物,则可使其中的大部副产物异构化为双酚A,使焦     

多种酚类污染物共存体系下光降解影响因素研究

水体中存在的酚类内分泌干扰物种类较多,其中大多是难降解有机污染物,可通过物理吸附、光降解和生物降解等方法处理。以苯酚(phenol)、双酚A(BPA)和2,4-二氯苯酚(2,4-DCP)为研究对象,将3种物质置于同一体系中研究水体中多种酚类污染物的光降解过程,探讨了光源、铁离子、氯离子和腐殖酸等外部因素对酚类光降解的影响。实验结果表明,酚类物质的光降解主要受光源波长的影响,紫外光降解效率最好,且相互间存在竞争关系。离子强度(Fe~(3+)和Cl~-)对双酚A的光降解产生促进作用,对2,4-二氯苯酚表现为抑制作用。阴阳离子的双重作用与酚类的结构稳定性和体系中的活性基团有关。腐殖酸(HA)对双酚A的光降解促进作用明显,对2,4-二氯苯酚有抑制作用,低浓度腐殖酸(≤1 mg/L)对苯酚有促进作用。可对水体中多种酚类的光降解研究提供基础数据。     

二氧化氯的产生、氧化和消毒作用

1　前言长期以来 ,自来水的消毒是采用氯和漂白粉作为消毒剂 ,其消毒效用是人们所公认的 ,但同时它对人类所产生的危害也越来越被人们所认识。 1974年荷兰 (ROOK)及美国(Beller)在自来水中检出了氯仿为主的三卤甲烷。到目前为止 ,人们已在水源中检测出2 2 2 1种有害人类健康的有机物 ,而饮用水中有 76 5种 ,其中致癌物有 2 0种 ,可疑致癌物2 3种 ,促癌物有 18种 ,致突变物有 5 6种 ,这些物质除致癌外 ,还会引起人们的肝中毒、神经中毒、代谢紊乱等危害 (见表 1)。表 1　水中氯化副产物对人类健康的影响试剂种类副产物毒理作用三卤甲烷氯仿…     

多种酚类污染物共存体系下光降解影响因素研究

水体中存在的酚类内分泌干扰物种类较多,其中大多是难降解有机污染物,可通过物理吸附、光降解和生物降解等方法处理。以苯酚(phenol)、双酚A(BPA)和2,4-二氯苯酚(2,4-DCP)为研究对象,将3种物质置于同一体系中研究水体中多种酚类污染物的光降解过程,探讨了光源、铁离子、氯离子和腐殖酸等外部因素对酚类光降解的影响。实验结果表明,酚类物质的光降解主要受光源波长的影响,紫外光降解效率最好,且相互间存在竞争关系。离子强度(Fe⁽³⁺⁾和Cl(3+)和Cl^-)对双酚A的光降解产生促进作用,对2,4-二氯苯酚表现为抑制作用。阴阳离子的双重作用与酚类的结构稳定性和体系中的活性基团有关。腐殖酸(HA)对双酚A的光降解促进作用明显,对2,4-二氯苯酚有抑制作用,低浓度腐殖酸(≤1 mg/L)对苯酚有促进作用。可对水体中多种酚类的光降解研究提供基础数据。     

澳大利亚饮用水中消毒副产物研究

自来水消毒对预防微生物疾病,确保饮用水安全卫生至关重要,但消毒过程中生成的各种副产物也威胁人体健康,目前,澳大利亚主要用氯和一氯胺消毒自来水。有些出厂水由于氯化而生成较高浓度的消毒副产物（DBPs),但除几家自来水公司并没有经常性地检测DBP浓度。由于这个原因,人们对澳大利亚饮用水的DBPs的性质、分布和含量等知之甚少。     

环境内分泌干扰物双酚A的吸附研究进展

双酚A是一种典型的环境内分泌干扰物,广泛存在于地表水、地下水及废水中,饮用水中也含有微量双酚A。其具有生物毒性和内分泌干扰作用,对生态环境安全和人类健康构成严重威胁。重点介绍了几种材料对双酚A的吸附效果和特性,通过化学改性可以明显提高吸附材料对双酚A的吸附效果,最后对环境水体中双酚A吸附研究的发展方向提出建议。     

双酚A毒理效应研究进展

环境激素双酚A(BPA)是一种外源性物质,能干扰生物体正常的内分泌,对生物体的生理过程产生较大的影响。文章对BPA的性质、毒理效应及作用机制的研究进行了综述。     

两种土壤对内分泌干扰物双酚A和类固醇的吸附性能

论文采用批量平衡法,研究两种土壤对于内分泌干扰物双酚A和类固醇（E1、E2、EE2、E3）的吸附特征,并探讨了温度和离子强度对吸附的影响。结果表明,五种物质在两种土壤中的吸附存在快速吸附和缓慢平衡的过程,Freundlich方程能够较好的拟合土壤对水中低浓度内分泌干扰物双酚A和类固醇的吸附等温线。土壤对五种物质的吸附是放热过程,温度升高会降低土壤的吸附容量。随着离子强度的增加,吸附容量增大。     

去除水环境中酚类内分泌干扰物的研究进展

就水环境中两种酚类内分泌干扰物——壬基酚和双酚A的来源、性质及污染情况进行综述,指出了开展内分泌干扰物研究的重要性,并着重对其降解去除方法进行了研究。提出了今后的研究方向,认为树脂吸附法是一种很有前途的去除酚类内分泌干扰物质的方法。     

Removal efficiencies of endocrine disrupting chemicals by coagulation/flocculation, ozonation, powdered/granular activated carbon adsorption, and chlorination

Removal efficiencies of endocrine disrupting chemicals (EDCs), bisphenol A and nonylphenol, during various types of water treatment processes were evaluated extensively using laboratory- and pilot-scale experiments. The specific processes of interest were coagulation/flocculation sedimentation/filtration (conventional water treatment process), powdered activated carbon (PAC), granular activated carbon (GAC), ozonation and chlorination. Batch sorption tests, coagulation tests, and ozone oxidation tests were also performed at higher concentrations with 14 EDCs including bisphenol A. The conventional water treatment process had very low removal efficiencies (0 to 7%) for all the EDCs except DEHP, DBP and DEP that were removed by 53%, 49%, and 46%, respectively. Ozonation at 1 mgO₃/ L removed 60% of bisphenol A and 89% of nonylphenol, while chlorination at 1 mg/L removed 58% and 5%, respectively. When ozone and chlorine doses were 4 and 5 mg/L, respectively, both EDCs were not detected. PAC removal efficiencies ranged from 15% to 40% at 3 to 10 mg/L of PAC with a contact time of 15 minutes. In the high concentration batch sorption tests, EDC removal efficiencies by PAC were closely related to octanol-water partition coefficient (K_ow). GAC adsorption was very effective water treatment process. The type and service time of GAC did not affect EDC removal efficiencies. The combination of ozonation and GAC in series appears to remove EDCs effectively to safe levels while conventional water treatment could not.     

Presence of Pharmaceuticals and Pesticides in Detroit River Water and the Effect of Ozone on Removal

Reports by different scientific groups indicate concern about traces of drugs that could make their way into tap water. Studies indicate that activated carbon and ozone are promising treatment methods to remove traces of pharmaceuticals and pesticides. The Windsor Utilities Commission (WUC), Windsor, Ontario, Canada, evaluated the occurrence of pharmaceuticals and endocrine disrupting chemicals in its raw water supply, and the effectiveness of ozone in removing these compounds. The analysis indicated that trace levels of compounds such as carbamazepine, caffeine, cotinine, and atrazine were detected in raw water and that treatment with ozone resulted in a greater removal versus conventional treatment.     

居住小区管网系统二次给水污染的研究

对西安市部分住宅楼二次供水系统进行分析,对比了4种不同供水方式及不同管材和水力停留时间对用户水质的影响。结果表明,以水箱供水的影响较大,气压给水二次污染较小;室内供水系统中钢塑复合管优于镀锌管;停留时间以不超过6h为宜。针对小区管网系统二次污染状况,提出管网系统二次污染的防治改造对策。     

管网叠压供水设备组件对系统运行的影响探讨

对管网叠压供水设备准入条件及其组件气压罐、稳流罐、倒流防止器进行探讨,认为系统中是否要设置气压罐应根据计算分析而定。当供水管网正常运行,设备进水管的补水能力大于系统的设计流量时,可不设置稳流罐;叠压供水设备直接由市政管网吸水为住宅小区、公共建筑增压时,水泵前应安装低阻力倒流防止器。     

供水增压泵站改造的优化计算

城乡一体化供水布局中,中途增压泵站对保证乡镇供水管网的水压具有重要作用。目前,多数供水增压泵站采用传统水池增压方式,上游进水管网余压难以充分利用,运行成本较高。基于水池增压改造的余压利用系统为水池和管道联合增压方式,在下游用水量低时,可使水流不经水池,直接由管道泵输水;在用水高峰期,可以通过切换到水池泵运行,以满足用户的高用水量和水压需求。借助供水管网水力模型和遗传算法,以供水能耗最低为目标函数,得到管道泵和水池泵的最佳运行方案。该方案根据不同的用水流量和市政管网压力值,合理切换管道泵和水池泵,计算及工程实践结果显示优化增压方式后能耗明显降低。     

Ozone: A Means of Stimulating Biological Activated Carbon Reactors

To reduce the formation of chlorination byproducts in drinking water, the European strategy consists in developing techniques for the removal of organic matter. No chlorine is added to the water until the end of the treatment line, allowing a great reduction of the chlorine dose applied. Delaying the chlorination also improves the biological assimilation of organics within the filters. Identification of the basic properties (i.e., molecular weight, biodegradability) of the molecules which react with chlorine shows that the combination of ozone and biological activated carbon (BAC) filtration is an efficient and economical technique for the removal of these undesirable byproducts. More and more, drinking water suppliers are faced with the worrisome problem of chlorinated byproducts. This concern was prompted largely by the degradation of raw waters. Chlorinated byproducts are caused by the effect of chlorine on organic matter dissolved in water.     

Potential toxicity and implication of halogenated byproducts generated in MBR online-cleaning with hypochlorite

Online chemical cleaning of membrane bioreactor (MBR) with sodium hypochlorite (NaClO) has been extensively applied for membrane fouling mitigation. However, it was recently revealed that residual NaClO from the online cleaning of MBR caused serious microbial lysis with the subsequent formation of dissolved organic matter (DOM), in which a substantial level of halogenated byproducts was detected. Different from those generated in potable water chlorination, most of the halogenated byproducts generated during MBR online cleaning with hypochlorite belonged to the haloaromatic family, which were apparently more toxic than aliphatic compounds. It was shown that a substantial amount of the generated halogenated byproducts passed through the microfiltration membrane and entered the surface waters through the discharge of MBR permeate. As such, the concentration of halogenated byproducts might likely reach an alarming level via bioaccumulation in the aquatic environment. This emerging situation indeed poses serious concerns for the aquatic environment, water supply and public health due to significantly high toxicity of haloaromatic compounds produced. Unfortunately, the potential halogenated byproducts-associated environmental risks have not been carefully and systematically assessed towards the establishment of relevant regulations. Therefore, this review attempted to fill up such a gap by providing the insights into the potential environmental impacts of halogenated byproducts in the MBR permeate. © 2019 Society of Chemical Industry     

自来水深度处理超滤膜的选择

试验设计、运行了聚砜中空纤维超滤(UF)膜,直接将未经预处理的某自来水管网输出水,处理成优质供水。结果表明,随着UF膜的切割分子量从0.6万增大到5万,产水量提高,对主要水质指标的去除率下降,净化水的水质优良,即使原水的水质突然恶化,UF膜能有效地将被严重污染的高浊度和色度的异常自来水转化成为符合饮用水水质指标的卫生洁净水。     

生活饮用水中的余氯检测

利用DPD分光光度法测定生活饮用自来水的余氯含量。研究了不同浓度标准溶液吸光度随测定时间和温度的变化关系,从而确定了适宜的测定条件:测定时间10min以内,温度20℃。