东莞市大气亚微米粒子PM1及其中水溶性无机离子的污染特征

2011年8月—2012年7月期间,利用中流量(100 L·min-1)大气采样器对东莞市A和B两点(A:生活区,B:工业区)进行PM1、PM1~2.5、PM2.5~10采样,并定量分析颗粒物上F-、Cl-、NO-3、SO2-4、NH+4、Na+、K+、Ca2+、Mg2+等9种水溶性无机离子.分析结果显示,工业区B点的细粒子污染较生活区A点严重,B点PM1质量浓度年均值为48μg·m-3,其浓度是A点的1.2倍.A、B两点PM1对PM2.5和PM10的质量贡献率无明显差异,平均贡献率分别高达69%和45%.二次离子SO2-4、NO-3、NH+4及与燃烧行为有关的K+、Cl-等5种离子在细粒子PM1上富集,这5种离子对PM1质量的贡献率分别为18.82%~19.76%、4.98%~5.47%、3.98%~4.12%、2.03%~2.27%和3.39%~3.78%.而其他4种离子,Ca2+、Mg2+、F-和Na+积聚在粗粒子PM2.5~10上.PM10/PM2.5/PM1三种粒子中,PM1粒子酸性值AE/CE(阴离子当量浓度/阳离子当量浓度)比值和硫转化率SOR、氮转化率NOR值均是最高.     

成都市城区大气细颗粒物水溶性离子污染特征

为了解成都市城区大气细颗粒物水溶性离子污染特征,在成都市城区四季采集PM2.5有效样品共计102个,测得颗粒物质量浓度以及水溶性离子质量浓度(NH4+、Ca2+、Na+、Mg2+、K+、F-、NO3-、SO42-、Cl-),并分析其浓度变化特征,重点关注二次无机离子的污染特征及形成影响.结果表明,成都市城区水溶性离子与...     

硫化矿物中无机盐及重金属离子溶出的影响因素探讨

基于浸泡试验,在不同的时间、温度、酸碱度、固液比等条件下研究硫化矿物中无机盐和重金属离子的溶出反应,得到影响该溶出反应的重要因素,为实际矿业生产过程中硫化矿物的堆放和处理提供了理论依据.     

聚丙烯中空纤维膜萃取水溶液中铜离子的研究

研究了聚丙烯中空纤维膜萃取二(2-乙基己基)膦酸(D2EHPA)水溶液中铜离子的工艺条件.结果表明,两相流速、膜面积对萃取率基本无影响;而水溶液的pH值和有机相初始铜离子浓度的改变使萃取率在40%-99%之间变化.整个萃取过程的传质阻力主要来源于D2EHPA和 Cu2 的界面配位络合反应阻力,铜浓度比较高时,传质阻力与铜浓度无关;而当铜浓度降低时,传质阻力随着铜浓度的降低而增大.     

TiO_2/EP光催化降解水体中微污染磺胺嘧啶的研究

制备了膨胀珍珠岩(EP)为载体的TiO2催化剂(TiO2/EP),对使用较为广泛的抗生素磺胺嘧啶(SDZ)进行了光催化降解研究,探讨了TiO2的负载量、溶液的初始浓度、初始pH、无机离子(HCO3-、SO42-和Cl-)和腐殖酸(HA)对SDZ降解效果的影响。结果表明:SDZ的光催化降解符合一级反应动力学方程;当TiO2最佳负载量为20 wt%,SDZ浓度为5 mg/L,pH=6.7,紫外光照射强度为1 000μW/cm2,反应时间为45 min时,SDZ的降解率达到96%;HCO3-在低浓度时能促进SDZ的光催化降解,高浓度时促进作用不明显;SO42-和Cl-对SDZ的光催化降解有轻微的抑制作用;HA对SDZ光催化降解有显著的抑制作用,浓度越高,抑制作用越强。UV-TiO2/EP是一种去除水体中微污染SDZ的有效方法。     

磷酸活化-微波热解改性污泥对镉的吸附性能

以城市污水处理厂剩余污泥为原料,利用磷酸活化-微波热解制取改性污泥。以此污泥作为吸附剂,对含Cd2+废水进行了吸附实验研究。考察了溶液反应时间、Cd2+浓度、pH值和吸附剂用量对镉吸附去除效果的影响;利用等温吸附实验作出吸附等温线,并考察了改性污泥吸附剂吸附Cd2+的动力学方程。实验结果表明,改性污泥对Cd2+有良好的吸附性能,吸附最佳pH值为6.0,吸附较好地符合一级动力学吸附模型和Langmuir-Freundlich等温吸附方程,吸附为物理吸附,吸附反应发生12 h后达到吸附平衡。     

Cobalt-induced oxidative stress in brain, liver and kidney of goldfish Carassius auratus

Cobalt is an essential element, but at high concentrations it is toxic. In addition to its well-known function as an integral part of cobalamin (vitamin B₁₂), cobalt has recently been shown to be a mimetic of hypoxia and a stimulator of the production of reactive oxygen species. The present study investigated the responses of goldfish, Carassius auratus, to 96 h exposure to 50, 100 or 150 mg L⁻¹ Co²⁺ in aquarium water (administered as CoCl₂). The concentrations of cobalt in aquaria did not change during fish exposure. Exposure to cobalt resulted in increased levels of lipid peroxides in brain (a 111% increase after exposure to 150 mg L⁻¹ Co²⁺) and liver (30-66% increases after exposure to 50-150 mg L⁻¹ Co²⁺), whereas the content of protein carbonyls rose only in kidney (by 112%) after exposure to 150 mg L⁻¹ cobalt. Low molecular mass thiols were depleted by 24-41% in brain in response to cobalt treatment. The activities of primary antioxidant enzymes, superoxide dismutase (SOD) and catalase, were substantially suppressed in brain and liver as a result of Co²⁺ exposure, whereas in kidney catalase activity was unchanged and SOD activity increased. The activities of glutathione-related enzymes, glutathione peroxidase and glutathione-S-transferase, did not change as a result of cobalt exposure, but glutathione reductase activity increased by ∼40% and ∼70% in brain and kidney, respectively. Taken together, these data show that exposure of fish to Co²⁺ ions results in the development of oxidative stress and the activation of defense systems in different goldfish tissues.     

PVA降解混合菌系生长和产酶的营养条件分析

研究碳源、氮源以及不同金属离子对PVA降解混合菌系生长和产酶的影响。结果表明,混合菌系生长过程中无机氮源优于有机氮源;补充碳源可促进混合菌系的生长,但酶活比不添加时稍有降低。金属离子对酶活影响的正交实验表明Mg2＋浓度影响最大,其次是Fe2＋和K＋浓度,Ca2＋、Mn2＋、Zn2＋和Cu2＋浓度影响较小;最佳浓度分别为Mg2＋0.05 g/L、Fe2＋0.04 g/L、K＋2 g/L和Ca2＋0.05 g/L。     

The role of sorption and bacteria in mercury partitioning and bioavailability in artificial sediments

This study compared the relative importance of three types of sorption (organic matter-particle, mercury-organic matter and mercury-particle) in controlling the overall mercury partitioning and bioavailability in sediments. We found that all three types of sorption were important for both inorganic mercury (Hg) and methylated mercury (MeHg). Mercury-particle sorption was more important than mercury-fulvic acid (FA) sorption in increasing the mercury concentrations with increasing aging. Bioavailability (quantified by gut juice extraction from sipunculans) was mainly controlled by mercury-particle sorption, while FA-particle and mercury-FA sorption were not as important, especially for MeHg. Bacterial activity also increased the partitioning of Hg or MeHg in the sediments and was further facilitated by the presence of organic matter. The bioavailability of Hg or MeHg from sediments was only slightly influenced by bacterial activity. This study highlights the importance of sorption from various sources (especially mercury-particle sorption) as well as bacteria in controlling the partitioning and bioavailability of Hg or MeHg in sediments.     

Part V—sorption of pharmaceuticals and personal care products

Background, aim, and scope  Pharmaceuticals and personal care products (PPCPs) including antibiotics, endocrine-disrupting chemicals, and veterinary pharmaceuticals are emerging pollutants, and their environmental risk was not emphasized until a decade ago. These compounds have been reported to cause adverse impacts on wildlife and human. However, compared to the studies on hydrophobic organic contaminants (HOCs) whose sorption characteristics is reviewed in Part IV of this review series, information on PPCPs is very limited. Thus, a summary of recent research progress on PPCP sorption in soils or sediments is necessary to clarify research requirements and directions. Main features  We reviewed the research progress on PPCP sorption in soils or sediments highlighting PPCP sorption different from that of HOCs. Special function of humic substances (HSs) on PPCP behavior is summarized according to several features of PPCP–soil or sediment interaction. In addition, we discussed the behavior of xenobiotic chemicals in a three-phase system (dissolved organic matter (DOM)–mineral–water). The complexity of three-phase systems was also discussed. Results  Nonideal sorption of PPCPs in soils or sediments is generally reported, and PPCP sorption behavior is relatively a more complicated process compared to HOC sorption, such as the contribution of inorganic fractions, fast degradation and metabolite sorption, and species-specific sorption mechanism. Thus, mechanistic studies are urgently needed for a better understanding of their environmental risk and for pollution control. Discussion  Recent research progress on nonideal sorption has not been incorporated into fate modeling of xenobiotic chemicals. A major reason is the complexity of the three-phase system. First of all, lack of knowledge in describing DOM fractionation after adsorption by mineral particles is one of the major restrictions for an accurate prediction of xenobiotic chemical behavior in the presence of DOM. Secondly, no explicit mathematical relationship between HS chemical–physical properties, and their sorption characteristics has been proposed. Last but not least, nonlinear interactions could exponentially increase the complexity and uncertainties of environmental fate models for xenobiotics. Discussion on proper simplification of fate modeling in the framework of nonlinear interactions is still unavailable. Conclusions  Although the methodologies and concepts for studying HOC environmental fate could be adopted for PPCP study, their differences should be highly understood. Prediction of PPCP environmental behavior needs to combine contributions from various fractions of soils or sediments and the sorption of their metabolites and different species. Recommendations and perspectives  More detailed studies on PPCP sorption in separated soil or sediment fractions are needed in order to propose a model predicting PPCP sorption in soils or sediments based on soil or sediment properties. The information on sorption of PPCP metabolites and species and the competition between them is still not enough to be incorporated into any predictive models.