Rapid and long-effective removal of broad-spectrum pollutants from aqueous system by ZVI/oxidants

• The coupling of oxidants with ZVI overcome the impedance of ZVI passive layer. • ZVI/oxidants system achieved fast and long-effective removal of contaminants. • Multiple mechanisms are involved in contaminants removal by ZVI/oxidant system. • ZVI/Oxidants did not change the reducing property of ORP in the fixed-bed system. Zero-valent iron (ZVI) technology has recently gained significant interest in the efficient sequestration of a wide variety of contaminants. However, surface passivation of ZVI because of its intrinsic passive layer would lead to the inferior reactivity of ZVI and its lower efficacy in contaminant removal. Therefore, to activate the ZVI surface cheaply, continuously, and efficiently is an important challenge that ZVI technology must overcome before its wide-scale application. To date, several physical and chemical approaches have been extensively applied to increase the reactivity of the ZVI surface toward the elimination of broad-spectrum pollutants. Nevertheless, these techniques have several limitations such as low efficacy, narrow working pH, eco-toxicity, and high installation cost. The objective of this mini-review paper is to identify the critical role of oxygen in determining the reactivity of ZVI toward contaminant removal. Subsequently, the effect of three typical oxidants (H₂O₂, KMnO₄, and NaClO) on broad-spectrum contaminants removal by ZVI has been documented and discussed. The reaction mechanism and sequestration efficacies of the ZVI/oxidant system were evaluated and reviewed. The technical basis of the ZVI/oxidant approach is based on the half-reaction of the cathodic reduction of the oxidants. The oxidants commonly used in the water treatment industry, i.e., NaClO, O₃, and H₂O₂, can be served as an ideal coupling electron receptor. With the combination of these oxidants, the surface corrosion of ZVI can be continuously driven. The ZVI/oxidants technology has been compared with other conventional technologies and conclusions have been drawn.     

MSBR 7池工艺除磷影响因素的试验研究

在正交试验确定的相对最佳操作条件的基础上,对MSBR7池工艺除磷影响因素进行了研究,结果表明:在本试验选定的因素中,对系统除磷影响的主次顺序为COD/P>R>MLSS>COD/N;工艺要求COD/P>60,COD/N>7,但是过高的COD/P也会导致TP去除率下降;在R为0.6时系统除磷效果最好;进水COD浓度过低或过高都会导致系统除磷效果下降.     

Persulfate activation by ferrocene-based metal–organic framework microspheres for efficient oxidation of orange acid 7

Environmental Science and Pollution Research - Ferrocene-based metal–organic framework with different transition metals (M-Fc-MOFs, M?=?Fe, Mn, Co) was synthesized by a simple...     

济南市地下水硝酸盐污染研究

调查了济南市东郊工业区浅层地下水、南部山区补给区地下水及市区饮用水中硝酸盐现状及发展趋势。结果表明，工业区浅层地下水硝酸盐含量超出国家饮用水卫生标准；补给区地下水及市区饮用水硝酸盐也受到人类活动的影响，污染呈逐年上升趋势。分析了造成地下水硝酸盐污染的原因，提出了相应的防治措施与对策。     

Stable oligonucleotide-functionalized gold nanosensors for environmental biocontaminant monitoring

The global propagation of environmental biocontaminants such as antibiotic resistant pathogens and their antibiotic resistance genes(ARGs) is a public health concern that highlights the need for improved monitoring strategies. Here, we demonstrate the environmental stability and applicability of an oligonucleotide-functionalized gold nanosensor. The mec A ARG was targeted as model biocontaminant due to its presence in clinically-relevant pathogens and to its emergence as an environmental contaminant.mec A-specific nanosensors were tested for antibiotic resistance gene(ARG) detection in ARG-spiked effluent from four wastewater treatment plants(WWTPs). The mec A-specific nanosensors showed stability in environmental conditions and in high ionic strength([MgCl_2] 50 m M), and high selectivity against mismatched targets. Spectrophotometric detection was reproducible with an LOD of 70 pM(≈ 4 × 10~7 genes/μL), even in the presence of interferences associated with non-target genomic DNA and complex WWTP effluent. This contribution supports the environmental applicability of a new line of cost-effective, field-deployable tools needed for wide-scale biocontaminant monitoring.     

简述二噁英降解方法的研究进展

二噁英是一类剧毒的持久性有机污染物和一级致癌物质。脱氯降解是降低二噁英毒性的有效途径之一。本文首先介绍了二噁英的种类、来源和危害，其次对二噁英的降解方法包括光降解、光-Fenton降解、生物降解、热降解、化学降解脱氯作了简要评述，比较了各种降解方法的优劣。     

国际RETScreenTM:一种评估潜在的可再生能源计划的决策支持和能力培养工具

大多数国家都有丰富的可再生能源可以利用,比如太阳、风、水、生物质和/或热.可再生能源技术(RET)行到了充分的发展,能够满足世界能源需求增长部分的需要,实际上,目前在许多应用中可再生能源项目是有成本效率的.     

故障树法和改进PSO-PNN网络的电梯故障诊断模型

针对电梯故障问题,提出一种将故障树分析法、改进的粒子群优化算法和概率神经网络相结合的方法用于电梯的故障诊断。以电梯的安全回路系统为例,用故障树法对回路进行分析,获得训练样本与故障类型;使用粒子群算法对概率神经网络的平滑因子进行优化,在优化过程中,针对粒子群算法存在易陷入局部最优的缺陷,提出对惯性权重的改进策略;采用相对误差对诊断效果做出评估,并与传统的概率神经网络和基本粒子群算法优化的概率神经网络在各种故障类型输出和最大相对误差等方面进行比较,结果表明:该模型能够有效诊断电梯故障。     

赤潮及其影响

近年来在我国沿海海域多次出现赤潮，其发生原因主要有两方面：一方面是自然条件，包括气候因素、海温、盐度、海水交换等；另一方面是人为因素，包括海水养殖和海洋环境污染等。赤潮形成后，对海洋生态系统造成严重危害，甚至危及人类健康。但由于赤潮的发生目前还难以及时准确的预报，科学的治理方法仍然是以防为主，防治结合。