Fractionation of rare earth and other trace elements in crabs, Ucides cordatus, from a subtropical mangrove affected by fertilizer industry

Fractionation of rare earth elements (REE) and other trace metal concentrations (Th, U, Cd, Cr, Cu, Ni, Pb, and Zn) between mangrove sediments and claw muscles and shells of male crabs (Ucides cordatus) from a subtropical estuary highly impacted by fertilizer industry activities was investigated. This is the first record of REE distribution in these organisms, and the results showed higher accumulations of these metals, U and Th in shells, probably related to the replacement of Ca during molting. Contents of Cd, Cr and Ni were similar in both tissues, but Cu, Zn and Pb were mostly accumulated in the claw muscle with concentrations above those considered safe for human consumption according to the Brazilian legislation. REE fractionation was different in the analyzed tissues being softer in the shells. The results provided evidences that the water absorbed during molting controls the chemistry of REE in shells. In contrast, the chemistry of REE in the claw muscle, in which was observed preferential absorption of light REE, is controlled by diet. REE fractionation obtained for the claw muscles was closely correlated to the observed in the contaminated substrate and in materials related to the production of phosphate fertilizers (contamination source), which supports their transference to this Ucides cordatus tissue without fractionation by the ingestion of sediments. Our results showed the potential use of crab tissues for monitoring REE and trace element sources in mangrove areas, with claw muscle exhibiting the contaminant source fingerprint.     

大连市地下水环境质量状况及污染防治对策

本文充分利用大连市已有地下水资料,通过对大连市地下水各项监测指标进行分析,利用Arc GIS反距离加权空间插值法将点状数据转化为面状数据,进行大连市地下水质量的区域评价。根据地下水水质8项监测指标的分析数据,利用Arc GIS空间分析平台,得到大连市地下水污染评价图,从而得出大连市各行政区域地下水存在不同程度污染的结论。最后通过对大连市地下水污染来源和防治现状的研究,提出大连市地下水污染防治对策及建议。     

淄博孝妇河流域孔隙水流酸盐污染特征及其形成

分析１９８９～１９９６年孔隙水的化学资料,总结出了研究区孔隙水硫酸盐污染的特点,借助原状土柱试验探明,孔隙水中污染组分来源于农业灌溉污水。农灌的频率与强度及大气降水的特点共同决定了本区孔隙水污染特征的形成。因此,停止或减少污灌量是改善地下水环境的有效且经济的方法。     

Transport of a non-volatile contaminant in unsaturated porous media in the presence of colloids

Stable colloidal particles can travel long distances in subsurface environments and carry particle-reactive contaminants with them to locations further than predicted by the conventional advective-dispersive transport equation. When such carriers exist in a saturated porous medium, the system can be idealized as consisting of three phases: an aqueous phase, a carrier phase, and a stationary solid matrix phase. However, when colloids are present in an unsaturated porous medium, the system representation should include one more phase, i.e. the air phase. In the work reported, a mathematical model was developed to describe the transport and fate of the colloidal particles and a non-volatile contaminant in unsaturated porous media. The model is based on mass balance equations in a four-phase porous medium. Colloid mass transfer mechanisms among aqueous, solid matrix, and air phases, and contaminant mass transfer between aqueous and colloid phases are represented by kinetic expressions. Governing equations are non-dimensionalized and solved to investigate colloid and contaminant transport in an unsaturated porous medium. A sensitivity analysis of the transport model was utilized to assess the effects of several parameters on model behavior. The colloid transport model matches successfully with experimental data of Wan and Wilson. The presence of air-water interface retards the colloid transport significantly counterbalancing the facilitating effect of colloids. However, the retardation of contaminant transport by colloids is highly dependent on the properties of the contaminant and the colloidal surface.     

Hepatic and immune biological effect assays in C57BL/6 mice to measure polycyclic aromatic hydrocarbon bioavailability under laboratory exposures with increasing environmental relevance

Background Monitoring biological responses that are mediated via the aryl-hydrocarbon receptor (AhR) in animals exposed to environmental contaminants can indicate both the presence to chemicals that act through this biochemical pathway and whether these chemicals are bioavailable. Objectives The use of an ex-situ method that incorporated biological responsiveness monitoring in mice for determining the presence of ‘biologically active’ hydrocarbons in contaminated soils was investigated. Methods The use of C57BL/6 as a test organism was validated by determining hepatic and immune responsiveness to two polyaromatic hydrocarbons (PAHs): 3,4 benz[a]pyrene (B[a]P) and 1,2 benz (a)anthracene (BA) administered via intraperitoneal (i.p.) injection. The responsiveness of mice exposed to soils spiked with hydrocarbons or ex situ exposures to soil removed from two contaminated sites was also investigated. Results and Discussion Mice that were exposed to B[a]P via i.p. injections showed a 14-fold increase in liver microsomal ethoxyresorufin O-deethylase (EROD) activity compared to the control group. In contrast EROD activity following BA exposure at the same level was not significantly enhanced. Mouse immune response was significantly inhibited in a dose-dependent manner by i.p. injections of B[a]P. No significant inhibition occurred with the same doses of BA. Following i.p. exposure, the retention of B[a]P in mouse carcasses was greater than BA. Mice exposed to clean soils spiked with environmentally relevant concentrations of B[a]P and BA failed to show any significantly different hepatic or immune responses. Carcass residue data indicated a limited uptake of PAH from the soil. In contrast, EROD activity in mice exposed (ex situ) to hydrocarbon-contaminated soils removed from a fuel-loading depot and decommissioned gas works was significantly enhanced (4- and 2-fold respectively). However, this increase in EROD activity did not appear to correlate with either soil or carcass PAH concentrations. Conclusions and Outlook These results support the assumption that B[a]P has a higher affinity for the aryl hydrocarbon receptor (AhR) compared to BA. Soil parameters such as organic carbon content, structure and particle size distribution can modulate the bioavailability of contaminants to biological receptors. These factors are implicated in the lack of responsiveness demonstrated in the spiked soil experiments. However the responsiveness of EROD activity in mice exposed (ex situ) to soil contaminated with complex mixtures of hydrocarbon compounds confirms the potential usefulness of this model to determine the presence of ‘biologically active’ compounds in aged soils removed from contaminated sites.     

无公害清洗剂的研制

研制了无公害清洗剂,该剂为弱碱性水基清洗剂,不含强酸,强碱,磷,铝等有害成分,能有效地清洗任何硬表面的油污,对人,畜基本无毒。     

我国土壤环境质量研究几个值得探讨的问题

针对当前我国土壤环境工作情况,讨论了土壤环境质量研究中3个值得探讨的问题:土壤污染定义、土壤环境质量标准修订和土壤污染防治法立法.关于土壤污染的定义,目前尚无一致的认识.笔者在综合国内外主要观点的基础上提出了土壤污染的定义,并建议建立基于风险评估的土壤环境质量标准体系,认为目前宜制订土壤环境质量目标值、土壤(分别有农业、居住、工业用地土壤)环境质量指导值和土壤污染危害临界值3类标准值,同时分别提出了初步的制订方法.制定土壤污染防治法是我国建立一套行之有效的土壤环境管理体系的需要,笔者在技术层面上讨论了土壤污染防治法的制定问题.     

用后处理装置减少DMDF发动机的有害排放

在一台增压中冷电控单体泵的四缸柴油机上采用柴油/甲醇双燃料（DMDF）燃烧方式进行台架实验,研究了甲醇替代率和不同后处理装置对有害气体、烟度和微粒排放特性的影响。结果表明：在排气管加装柴油机氧化催化转化器（DOC）耦合微粒催化转化器（POC）可以大幅降低双燃料燃烧产生的THC和CO,基本可以实现零排放;与催化前相比,微粒的总数量浓度和总质量浓度均有大幅度降低,平均降幅分别为91.7%和88.1%;烟度排放得到改善,平均降幅为21.9%;同时,该后处理装置对DMDF发动机的NOx排放无明显影响。与之不同,双DOC耦合的后处理装置对THC和CO的催化效率略优于DOC+POC,但在大部分工况下会导致NOx和烟度排放的同时增加。     

MFC产电辅助Fe,Ce-TiO2/Ti-Cu光催化处理染料废水

采用溶胶-凝胶法制备了Fe,Ce-TiO2/Ti膜电极,通过正交实验考察了该电极的最佳制备条件为550 ℃煅烧、掺杂摩尔比n(Fe:Ti）=6%和n(Ce:Ti）=3%。其X射线衍射(XRD)和紫外-可见漫反射(DRS)分析表明,催化剂晶型为锐钛矿,Fe、Ce掺杂抑制了晶粒的生长和金红石相的生成,使催化剂有明显的可见光响应。以Fe,Ce-TiO2/Ti为光阳极,Cu为阴极,并以微生物燃料电池(MFC)为外加电源,组装MFC电助Fe,Ce-TiO2/Ti-Cu光催化反应器,在可见光下光电催化(MPEC)处理活性艳红X-3B(RBR)。MPEC与自生电场光电催化(SPEC)和外加电场光电催化(PEC)的对比结果表明MPEC是可行的,它比SPEC的脱色率高9%,与PEC相当,但能耗更低。考察了MPEC的主要影响因素,得出最佳条件为2组MFC串联,废水流量80 mL·min-1,废水初始pH 2.56。在太阳光下,MPEC能使RBR有效脱色,处理100 min的脱色率可达87%。紫外-可见分光光谱分析表明,MPEC能使RBR的发色基团迅速遭到破坏。     

蛋壳、贝壳实现层烧炉脱硫脱硝

在4.2 MW链条锅炉使用蛋壳、贝壳粉平铺在煤层上部进行炉内脱硫脱硝后,通过风机的负压携带将燃烧形成的CaO随烟气带入湿法除尘设备,完成与NaOH的双碱法脱硫脱硝。结果表明,脱硫效率 > 80%,脱硝效率 > 50%。烟气排放指标优于国标。风机携带的CaO对水冷壁形成清扫作用,运行130 d节约煤炭20%。