Origin of raised maternal serum alpha-fetoprotein levels in second-trimester oligohydramnios

Concanavalin A (Con A) subtyping of alpha-fetoprotein (AFP) revealed higher concentrations of AFP non-reactive with Con A in sera of 12 pregnant women with second-trimester oligohydramnios and raised total serum AFP levels than in sera of 42 pregnant women with raised total serum AFP levels and a normal amniotic fluid volume. This suggests that in oligohydramnios the origin of excess AFP in the maternal compartment is amniotic fluid. It is proposed that oligohydramnios and the associated raised maternal serum AFP levels are caused by damage of the fetal membranes prior to 16 weeks of gestation resulting in leakage of amniotic fluid to the decidual tissue and resorption in the maternal circulation.     

膜分离技术在水处理中的应用研究

介绍了膜分离技术及其特点，对膜分离技术进行了分类，同时阐述了渗透、电渗析、反渗透、超滤、微滤和纳滤这些常规膜分离技术的研究和应用情况，在此基础上介绍了近年来发展起来的液膜、气态膜、双极膜、膜萃取和膜蒸馏这些新型膜分离技术。提出了膜分离技术存在的一些问题、研究方向、展示了膜分离技术的应用前景。     

DOM纳滤膜污染及对膜截留卡马西平性能的影响

研究了天然原水中溶解性有机物(DOM)对HL和ESNA1-K两种纳滤膜造成的膜污染及其对膜截留卡马西平(CBZ)性能的影响.结果表明,DOM的存在造成了严重的膜污染和通量衰减.膜污染对CBZ截留率的影响与膜本身的特性和污染物特性有关,DOM通过在膜表面形成污染滤饼层和进入膜孔内部造成的膜孔堵塞,影响弱疏水性的CBZ从水中的分离,青草沙水库原水中的DOM引起的膜污染提高了两种纳滤膜对CBZ的截留效果,而太湖DOM造成的膜污染会降低CBZ的截留效果.研究还发现,中等相对分子质量(1 500~10 000)有机物会紧密地黏附在膜表面形成滤饼层,从而改变膜表面的疏水性能,小分子主要通过进入膜孔导致膜孔径堵塞.滤饼层的疏水性和浓差极化作用以及膜孔径的堵塞造成膜通量衰减并影响CBZ去除率.应用XDLVO理论对DOM造成的膜污染的分析结果表明,太湖DOM的疏水性明显强于青草沙DOM,其分子间的聚合自由能更负,与膜的黏附自由能更负,因而造成的膜污染和通量衰减更严重.     

MBR＋纳滤＋反渗透工艺处理垃圾渗滤液实验研究

摘要：结合青岛市某生活垃圾处理场工程实例,介绍了MBR工艺处理垃圾渗滤液的工艺流程、原理等,分析了MBR工艺处理垃圾渗滤液的特点和优势。垃圾渗滤液经过MBR工艺处理,生化部分采用前置反硝化／硝化工艺,再经纳滤／反渗透等膜分离技术和其他方法处理,最终流出液水质可以达到《生活垃圾填埋场污染控制标准》（GB16889—2008）。     

纳米材料在水处理中的应用

纳米材料在水处理行业有着广阔的前景,文章主要介绍纳滤膜、光催化材料、纳米还原性材料及纳米吸附性材料在水处理中的应用现状及发展前景,并对纳米材料在水处理行业的应用提出了展望。     

钙钛矿型催化剂催化湿式氧化处理煤气化废水纳滤浓缩液

采用溶胶-凝胶法制备了Mn掺杂钙钛矿型催化剂LaFexMn1-xO3,并以其为催化剂催化湿式双氧水氧化处理煤气化废水纳滤浓缩液。采用XRD,SEM,FTIR技术对催化剂进行了表征。表征结果显示：制备的催化剂均具有标准的钙钛矿型结构,其中,LaFe0.9Mn0.1O3的结构稳定,比表面积大。实验结果表明：制备的催化剂中LaFe0.9Mn0.1O3的催化活性最高,且稳定性好,连续使用5次后催化活性未见明显减弱;在H2O2投加量3.0 g/L、n（H2O2）∶n（LaFe0.9Mn0.1O3）=12∶1、反应温度160 ℃、反应压力1 MPa、浓缩液pH 3、反应时间60 min的最优条件下,COD、UV254和TOC的去除率分别达到80.9%、95.2%和68.0%,BOD5/COD由0.02提升至0.40,可生化性大幅提高。     

Green energy generation by pressure retarded osmosis: State of the art and technical advancement—review

Pressure-retarded osmosis (PRO) is a method for converting salinity gradients to power by allowing water to flow through a semi-permeable membrane against an applied hydraulic pressure. PRO already has a long history, starting from the middle of the last century, and has rapidly improved in recent years. In this paper, we present a historical development of PRO since its inception: the development of this renewable energy process has gone through several stages, depending on technological developments, worldwide energy demands, and environmental concerns. The technological progress of the process is also studied, as well as its cost viability and environmental impact. Finally, some ideas to further develop the PRO process and mitigate its detrimental effects are discussed.     

Uptake of cadmium into cells in culture∗

Cadmium has been recognized as pollutant of the environment for many years and numerous studies on its toxic effects have been carried out. Little, however, is known about its metabolic behaviour e.g. why the metal is accumulated so extremely rapidly into the organs of men and animals. Since the study of the individual metabolic steps is very difficult in vivo cell cultures may be used to obtain first indications of what happens in the whole animal.

We used CHO cells in monolayer culture to study the conditions under which the uptake of cadmium occurs. From serumfree medium the metal is accumulated rapidly in the cells. The uptake is inhibited very strongly by the presence of serum or albumin. Accumulation occurs against a concentration gradient and is dependent on the incubation temperature. Below 10°C no cadmium uptake is seen. Several substances which are known to affect cell metabolism have been used to influence cadmium accumulation. Neither inhibitors of energy production nor microtubule or microfilament disruptors showed any substantial effect. In contrast SH‐group blocking agents markedly reduced cadmium uptake.

The results show that cadmium uptake does not occur by passive diffusion but by some active mechanism.     

用纳滤膜分离技术处理发电厂循环冷却水

简要介绍了纳滤膜的定义和原理，并且对用纳滤膜处理厂循环冷却水进行工艺和经济技术分析。     

Ion exchange membrane-assisted electro-activation of aqueous solutions: Effect of the operating parameters on solutions properties and system electric resistance

The properties of electro-activated (EA) aqueous solutions as well as the dynamics of their changes were considered in the current study using aqueous solutions of NaCl and NaHCO₃. The concentrations of the salt solutions were 0.5, 0.25, 0.125 and 0.05 M. The tests were performed at the DC current densities of 25, 37.5, and 50 Å/m². The electro-activation reactor consisted of three individual cells assembled together and separated by anion-exchange (AEM) and cation-exchange (CEM) membranes. During the experiments, four configurations of the membrane placements and solutions concentrations were studied. The obtained results showed the dynamics of the electro-activation process that allows obtaining electro-activated solutions with targeted properties such as pH and oxydo-reduction potential (ORP). It was possible to obtain electro-activated solutions at the anodic side (acid anolyte) with pH of 3.0, 3.5, and 4.0 and ORP of +1100 ± 15 mV when NaCl solution was used as electrolyte. Furthermore, several types of electro-activated solutions with high redox potential (ORP = +921 ± 12 mV) and neutral pH (6.48 ± 0.05) were obtained on the anode side when sodium carbonate was used. At the same time, two types of solutions, one with acid pH (2.14 ± 0.14) and the other one with alkaline pH (10.46 ± 0.03) with ORP = +689 ± 10 and 110 ± 21 mV, respectively, were obtained in the central compartment which considered as electro-activated solutions obtained by means of noncontact electro-activation.