Degradation of antibiotics in water by non-thermal plasma treatment

The decomposition of three β-lactam antibiotics (amoxicillin, oxacillin and ampicillin) in aqueous solution was investigated using a dielectric barrier discharge (DBD) in coaxial configuration. Solutions of concentration 100 mg/L were made to flow as a film over the surface of the inner electrode of the plasma reactor, so the discharge was generated at the gas-liquid interface. The electrical discharge was operated in pulsed regime, at room temperature and atmospheric pressure, in oxygen. Amoxicillin was degraded after 10 min plasma treatment, while the other two antibiotics required about 30 min for decomposition. The evolution of the degradation process was continuously followed using liquid chromatography-mass spectrometry (LC-MS), total organic carbon (TOC) and chemical oxygen demand (COD) analyses.     

Relationship between persistent organic pollutants (POPs) and ranging patterns in common bottlenose dolphins (Tursiops truncatus) from coastal Georgia, USA

Bottlenose dolphins (Tursiops truncatus) are apex predators in coastal southeastern U.S. waters; as such they are indicators of persistent organic pollutants (POPs) in coastal ecosystems. POP concentrations measured in a dolphin's blubber are influenced by a number of factors, including the animal's sex and ranging pattern in relation to POP point sources. This study examined POP concentrations measured in bottlenose dolphin blubber samples (n = 102) from the Georgia, USA coast in relation to individual ranging patterns and specifically, distance of sightings from a polychlorinated biphenyl (PCB) point source near Brunswick, Georgia. Dolphin ranging patterns were determined based upon 5 years of photo-identification data from two field sites approximately 40 km apart: (1) the Brunswick field site, which included the Turtle/Brunswick River Estuary (TBRE), and (2) the Sapelo field site, which included the Sapelo Island National Estuarine Research Reserve (SINERR). Dolphins were categorized into one of three ranging patterns from photo-identification data. Individuals with sighting histories exclusively within one of the defined field sites were considered to have either Brunswick or Sapelo ranging patterns. Individuals sighted in both field sites were classified as having a Mixed ranging pattern. Brunswick males had the highest concentrations of PCBs reported for any marine mammal. The pattern of PCB congeners was consistent with Aroclor 1268, a highly chlorinated PCB mixture associated with a Superfund site in Brunswick. PCB levels in Sapelo males were lower than in Brunswick males, but comparable to the highest levels measured in other dolphin populations along the southeastern U.S. Female dolphins had higher Aroclor 1268 proportions than males, suggesting that the highly chlorinated congeners associated with Aroclor 1268 may not be offloaded through parturition and lactation, as easily as less halogenated POPs. Individuals sighted farther from the Superfund point source had lower Aroclor 1268 proportions.     

饮用水中动物性污染物及去除工艺的研究进展

通过收集整理国内外针对动物性污染物的报道及相关研究,总结了常见动物性污染物的分类、去除方法等内容,为今后此类问题的进一步研究奠定基础和提供借鉴。     

退役锂电池放电废水特征有机污染物解析

为研究退役锂电池盐水溶液放电产生的放电废水有机物的种类与来源,首先采用单因素优化方法对萃取剂类型、pH、萃取次数3个因素进行液-液萃取前处理优化实验,获得最佳萃取预处理条件。接着采用气相色谱与质谱联用(GC-MS)程序中分流比和升温模式对比实验,建立了放电废水有机成分定性分析方法,并对检出的有机污染物进行分类与来源判断。研究结果表明,选取乙酸乙酯为萃取剂,调节放电废水pH至9.38,以8000r/min离心5min (4℃),且采用间歇三次萃取时分离效果最优。对放电废水SIM定性扫描检测出10类有机污染物,其中酸酯类、酰胺类、烷烃类物质较多,且来源于反应衍生物与电解液添加剂的占比较大,分别为33.3%与20%,包括电解质增塑剂间苯二甲酸二(2-乙基己基)酯,电解液溶剂效应产物1,4-环己烷二羧酸二甲酯、磷酸三(2-氯乙基)酯,电解液添加剂硬脂酰胺、十六碳酰胺、十四酰胺、1,4-环己烷二甲醇二乙烯醚,退役锂电池塑料外壳中抗氧剂原料3,5-二叔丁基苯酚等。这些物质对水环境均具有不同程度的毒性危害,需进一步检测各有机物浓度并揭示其迁移转化规律,建立退役锂电池放电废水重点关注有机污染物清单。     

纳滤去除水中的有害离子

本文综述了纳滤去除饮用水和重金属废水中的有毒有害离子的应用研究,阐述了纳滤膜对无机盐的截留效果主要取决于膜对离子的电荷效应,表现在对多价离子的截留率高于单价离子。利用纳滤膜这种分离性能,可以去除部分饮用水中微量的有害单价离子（如NO2^-、NO3^-、F^-等）和大部分的有毒二价离子（如HAsO4^2-和重金属离子）,获取优质安全的饮用水;也可以用于处理重金属废水,能有效去除废水中的重金属离子。将纳滤和反渗透集成用于重金属废水处理,可以做到对有毒重金属离子的回收利用和出水回用,实现清洁生产,既具经济效益,又具环境效益,在工程实际中极具推广应用价值。     

珠江三角洲工业水污染负荷削减目标的探讨

节水减污是通过调控社会水循环过程的方式,实现珠江三角洲水环境状况改善的重要措施.珠江三角洲节水减污的战略目标为:①在2010年实现工业用水零增长,工业废水中COD排放量降至1990的水平;②在2020年使工业废水排放量降至1990的水平,工业废水中COD排放量降至1980的水平.基于上述目标,运用广东省环境统计数据和珠江流域水资源综合规划的调查数据,探讨了2010年和2020年珠江三角洲工业水环境负荷削减目标的定量方案.研究结论对于制定珠江三角洲水环境总体规划有着重要意义.     

钢铁行业烧结烟气多污染物协同净化技术研究进展

基于我国钢铁行业烧结烟气排放标准、排放特征和现行污染物控制技术,分析了国内外先进的多污染物协同控制技术——活性炭(焦)吸附工艺、湿法脱硫除尘+选择性催化还原协同净化技术、循环流化床多组分污染物协同净化工艺、高性能烧结废气净化工艺、新型密相半干法烟气集成治理技术等工艺的技术思路、特点和存在问题等,并针对钢铁行业的实际需求对多污染物协同控制技术的发展提出了建议.     

燃煤烟气中多环芳烃富集技术研究

介绍燃煤电厂排放烟气中多环芳烃(PAHs)污染物的富集方法,比较了各种富集技术的特点与使用情况。对多环芳烃富集过程中的质量控制与质量保证措施进行了分析,指出富集采样中的若干注意事项。     

Distribution and release of 2,4,5-trichlorobiphenyl in ice

The distribution of persistent organic pollutants(POPs) in ice and the release of POPs from ice during ice melting have an important influence on the eco-environment and water quality of a river. Through laboratory simulation experiments, the distribution and release of 2,4,5-trichlorobiphenyl(PCB29) in ice and the partition coefficients of PCB29 in ice water at different temperatures, concentrations, and p H levels were studied. The results showed that, at different temperatures and concentrations, the concentration of PCB29 in ice increased progressively with depth. The modes of release of different concentrations of PCB29 from ice were obtained. A large amount of PCB29 was released rapidly in the first melting period, and then the remaining PCB29 was released uniformly. The p H value dominated both the distribution and late release of PCB29 in ice. In ice water, at different temperatures, concentrations, and p H levels, the majority of PCB29 entered the water, and a lesser amount remained in the ice. Finally, laboratory experiment results were verified with field investigations. A theoretical framework is provided by this research of the behavior of POPs in ice under different environmental conditions, but a more quantitative understanding of the behavior of POPs in ice will need to be developed through further laboratory studies combined with field investigations.     

Effects of thermodynamics parameters on mass transfer of volatile pollutants at air-water interface

A transient three-dimensional coupling model based on the compressible volume of fluid(VOF) method was developed to simulate the transport of volatile pollutants at the air-water interface. VOF is a numerical technique for locating and tracking the free surface of water flow.The relationships between Henry's constant, thermodynamics parameters, and the enlarged topological index were proposed for nonstandard conditions. A series of experiments and numerical simulations were performed to study the transport of benzene and carbinol. The simulation results agreed with the experimental results. Temperature had no effect on mass transfer of pollutants with low transfer free energy and high Henry's constant. The temporal and spatial distribution of pollutants with high transfer free energy and low Henry's constant was affected by temperature. The total enthalpy and total transfer free energy increased significantly with temperature, with significant fluctuations at low temperatures. The total enthalpy and total transfer free energy increased steadily without fluctuation at high temperatures.