非水相硝基苯在含水层中的迁移释放规律

通过室内模拟实验,探讨了在非水相硝基苯污染含水层的条件下,其在含水层中的迁移及释放规律。迁移规律表明,非水相硝基苯并非在含水层中直接进行垂向迁移,而是一方面在自身重力作用下向含水层下部迁移,另一方面在地下水流的作用下随地下水同向运移,整体表现为随地下水流的侧向运移,并最终迁移至含水层底部。释放规律表明,非水相硝基苯在含水层迁移的过程中会向地下水大量释放,释放出的硝基苯在水流的作用下随地下水同向运移,污染源及迁移至含水层底部的非水相硝基苯均存在再次释放。     

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。     

温拌沥青混合料摊铺节能减排效果的定量化研究

通过对温拌沥青混合料(WMA)和热拌沥青混合料(HMA)生产能耗值的测量和计算,对利用WMA替代HMA作为路面材料的节能效果进行了定量核算;并结合沥青路面摊铺的实际工程设计检测方案,通过实地检测,对WMA替代HWA进行路面摊铺这一重要环节的减排效果进行了定量化。测试和分析结果显示,采用适当的温拌技术,生产能耗可降低22.4%,但是提高生产环节的能源利用效率才是降耗的重要途径。对摊铺施工的实地测量表明,WMA替代HWA摊铺可使沥青烟排放降幅53.1%,一氧化碳排放降低35.4%,二氧化氮排放降低53%,二氧化硫排放降低63.1%,综合挥发性有机物化合物VOC排放降幅达56.2%。利用WMA代替HWA作为路面材料节能减排效果十分明显。     

An integrated approach to model the biomagnification of organic pollutants in aquatic food webs of the Yangtze Three Gorges Reservoir ecosystem using adapted pollution scenarios

The impounding of the Three Gorges Reservoir (TGR) at the Yangtze River caused large flooding of urban, industrial, and agricultural areas, and profound land use changes took place. Consequently, substantial amounts of organic and inorganic pollutants were released into the reservoir. Additionally, contaminants and nutrients are entering the reservoir by drift, drainage, and runoff from adjacent agricultural areas as well as from sewage of industry, aquacultures, and households. The main aim of the presented research project is a deeper understanding of the processes that determines the bioaccumulation and biomagnification of organic pollutants, i.e., mainly pesticides, in aquatic food webs under the newly developing conditions of the TGR. The project is part of the Yangtze-Hydro environmental program, financed by the German Ministry of Education and Science. In order to test combinations of environmental factors like nutrients and pollution, we use an integrated modeling approach to study the potential accumulation and biomagnification. We describe the integrative modeling approach and the consecutive adaption of the AQUATOX model, used as modeling framework for ecological risk assessment. As a starting point, pre-calibrated simulations were adapted to Yangtze-specific conditions (regionalization). Two exemplary food webs were developed by a thorough review of the pertinent literature. The first typical for the flowing conditions of the original Yangtze River and the Daning River near the city of Wushan, and the second for the stagnant reservoir characteristics of the aforementioned region that is marked by an intermediate between lake and large river communities of aquatic organisms. In close cooperation with German and Chinese partners of the Yangtze-Hydro Research Association, other site-specific parameters were estimated. The MINIBAT project contributed to the calibration of physicochemical and bathymetric parameters, and the TRANSMIC project delivered hydrodynamic models for water volume and flow velocity conditions. The research questions were firstly focused on the definition of scenarios that could depict representative situations regarding food webs, pollution, and flow conditions in the TGR. The food webs and the abiotic site conditions in the main study area near the city of Wushan that determine the environmental preconditions for the organisms were defined. In our conceptual approach, we used the pesticide propanil as a model substance.     

Kinetics and mechanism for omethoate degradation by catalytic ozonation with Fe(III)-loaded activated carbon in water

The kinetics and mechanism for degradation of omethoate (OMT) by catalytic ozonation with Fe(III)-loaded activated carbon (Fe@AC) were investigated in this study with focus on identification of degradation byproducts. The rate constants of OMT reacting with ozone and hydroxyl radical (OH) were determined to be 0.04 and 5.3 × 10⁸ M^?1 s^?1 at pH 7.5 and 20 °C, respectively. OMT was predominantly degraded by OH in the catalytic ozonation with Fe@AC. The high-molecular-weight degradation byproducts identified were O,O,O-trimethyl phosphoric ester (TMP), pyrrolidin-2-one, N-methyl-2-sulfanylacetamide, 2-(methylthio)acetamide, O,O,S-trimethylthiophosphate (STMP), and N-methyl-2-(methylthio)acetamide. Besides, low-molecular-weight organic acids and inorganic anions were also detected and quantified, including formic, acetic and oxalic acids as well as nitrate, sulfate and phosphate ions. In the catalytic ozonation, TMP and phosphate were two major P-containing byproducts resulting from OMT degradation. The toxicity of OMT solution gradually decreased during the catalytic ozonation, indicating that Fe@AC is a safe catalyst for OMT removal by ozone in water.     

不同流量分配比对多级A/O工艺去除有机物及脱氮的影响

采用三级A/O工艺分段进水工艺处理低碳源生活污水,考察了进水流量分配比对系统去除有机物、硝化反硝化能力以及去除TN的影响。通过对水质指标沿程监测结果表明,不同流量分配比(4∶3∶3,5∶3∶2,6∶3∶1)对系统去除有机物及硝化效率影响不大,出水COD、氨氮分别均在30 mg/L、1 mg/L以下。但反硝化效果受流量分配比的影响较大,在流量比为5∶3∶2时,有效利用原水中碳源进行反硝化,反硝化效果最好。在流量比为5∶3∶2的情况下,TN出水为5.7 mg/L去除率为82.9%,优于流量分配比为6∶3∶1和4∶3∶3时的脱氮效果。总体而言,分段进水工艺在对碳源的有效利用及能耗节省方面优于单点进水。     

零价铁类Fenton试剂氧化降解废水中有机污染物的研究进展

综述了近年来国内外Fe0类Fenton试剂氧化反应降解废水中有机污染物的研究现状,介绍了Fe0-H2O2体系、紫外光-Fe0-H2O2体系和可见光-Fe0-H2O2体系处理有机污染物的机理、特点和效果,并对未来Fe0类Fenton试剂氧化反应体系处理有机污染物的发展前景进行了展望。     

Occurrence, sources, and inventory of hexabromocyclododecanes (HBCDs) in soils from Chongming Island, the Yangtze River Delta (YRD)

Hexabromocyclododecanes (HBCDs) is a concern due to their large usage combining with physico-chemical properties and toxicity to wildlife and human. However, very limited data were reported on HBCDs in soils, especially from rural area. In this study, 22 soil samples were collected from Chongming Island at estuary of the Yangtze River Delta, to investigate the level, diasteroisomer profile, potential sources, and mass inventory of HBCDs. The total concentrations ranged from not detected to 93.8 pg g⁻¹ dry weight (dw) with a mean of 23.3 pg g⁻¹ dw, which was at the low end of the global levels. The wide distribution of HBCDs in soils suggested that the local emissions of HBCD-containing materials and/or the inputs via atmospheric transport from other regions were two possible sources. Variation of HBCDs levels was observed in different types of soils. Woodland, tideland and road soils contained slightly higher HBCDs than those of farmland and grassland. Overall, γ-HBCD was the dominant diasteroisomer in soils, followed by α-HBCD and β-HBCD. Significant but weak correlations were only found between α-HBCD and β-HBCD versus TOC content in soils. Currently, the mass inventory of HBCDs in soils of Chongming Island was 5.3 kg. Based on these data, we gave perspective on human intake of HBCDs via soil ingestion by age. Local resident’s intakes ranged from 15.5 to 97.8 fg kg body weight⁻¹ d⁻¹, in which children are exposed more than adults.     

Spatial distribution of ciguateric fish in the Republic of Kiribati

Ciguatera is food poisoning caused by human consumption of reef fish contaminated with ciguatoxins (CTXs). The expanding international trade of tropical fish species from ciguatera-endemic regions has resulted in increased global incidence of ciguatera, and more than 50 000 people are estimated to suffer from ciguatera each year worldwide. The Republic of Kiribati is located in the Pacific Ocean; two of its islands, Marakei and Tarawa, have been suggested as high-risk areas for ciguatera. The toxicities of coral reef fish collected from these islands, including herbivorous, omnivorous and carnivorous fish (24% [n = 41], 8% [n = 13] and 68% [n = 117], respectively), were analyzed using the mouse neuroblastoma assay (MNA) after CTX extraction. The MNA results indicated that 156 fish specimens, or 91% of the fish samples, were ciguatoxic (CTX levels >0.01 ng g⁻¹). Groupers and moray eels were generally more toxic by an order of magnitude than other fish species. All of the collected individuals of eight species (n = 3-19) were toxic. Toxicity varied within species and among locations by up to 10 000-fold. Cephalapholis argus and Gymnothorax spp. collected from Tarawa Island were significantly less toxic than those from Marakei Island, although all individuals were toxic based on the 0.01 ng g⁻¹ threshold. CTX concentrations in the livers of individuals of two moray eel species (Gymnothorax spp., n = 6) were nine times greater than those in muscle, and toxicity in liver and muscle showed a strong positive correlation with body weight. The present study provides quantitative information on the ciguatoxicity and distribution of toxicity in fish for use in fisheries management and public health.     

杂多酸水溶液脱除烟气中SO2的性能研究

合成了H3PMo12O40、H4SiW12O40、H3PW12O40、H4PMo11VO40、H5PMo10V2O40和H6PMo9V3O406种杂多酸,分别采用红外光谱（FT-IR）和X射线衍射（XRD）表征杂多酸的结构,并采用气相色谱仪对6种杂多酸水溶液进行脱硫实验测试。实验结果表明：制备的6种杂多酸具有良好的Keggin型结构;H3PMo12O40、H3PW12O40和H4SiW12O40的3种水溶液中,磷钼杂多酸的脱硫性能最好,脱硫率在120 min时可达到16.38%;不同比例的多原子也会使杂多酸有不同的脱硫性能,脱硫性能顺序为：H6PMo9V3O40〉H5PMo10V2O40〉H4PMo11VO40;且6种杂多酸的脱硫稳定性的顺序为：H4PMo11VO40〉H6PMo9V3O40〉H3PMo12O40〉H5PMo10V2O40〉H4SiW12O40≈H3PW12O40。