ICP-MS法同时测定地表水中18种金属元素

以115In-103Rh为双内标校正系统,采用电感耦合等离子体质谱法同时测定地表水中铜、锌、硒、砷、汞、镉、铅、铁、锰、钼、钴、铍、锑、镍、钡、钒、钛、铊等18种金属元素,优化了测量同位素、内标元素等试验条件。18种金属元素在0μg/L～100μg/L范围内线性良好,检出限为0.006μg/L～0.123μg/L,标准样品的测定值均在保证值范围内,平行测定的RSD为1.7%～4.2%,实际水样加标回收率为89.0%～100%。     

进口含金属物料的固体废物鉴别方法研究

基于已完成的112例进口含金属物料的固体废物鉴别实践,系统地介绍了进口含金属物料的申报品名及各品名所占比例,种类及各种类的特征、固体废物鉴别关键方法和每种鉴别结果所占比例,其中申报品名主要为矿石(砂),所占比例为51.8%;鉴别结果主要为冶炼渣,所占比例为37.5%。提出对于进口的含金属物料,通过测量主要成分和含量、最主要金属元素及典型重金属元素的含量、物相组成、矿相组成,对于极细的粉末等特殊物料,还需要粒度分析等辅助试验,确定其产生来源。如果确定属于金属冶炼过程中产生的副产物、污染控制设施或环境治理过程中产生的物料、含金属废料简单加工处理产物、矿物采选过程中产生的废弃物,那么鉴别物料属于固体废物。     

Comparison of Four <Emphasis Type="Italic">Sesbania</Emphasis> Species to Remediate Pb/Zn and Cu Mine Tailings

A 6-month greenhouse pot trial was performed, aimed at screening appropriate Sesbania species for remediation of Pb/Zn and Cu mine tailings. Performances of young seedlings of four Sesbania species (S. cannabina, S. grandiflora, S. rostrata, and S. sesban) were compared with and without inoculation of rhizobia. Seedlings were planted in two types of tailings amended with garden soil or garden soil mixed with river sediment. The results indicated that inoculated plants generally produced a higher biomass than samples without inoculation. Pb/Zn mine tailings containing rather high concentrations of total and water-soluble Cu, Pb, and Zn were toxic to plant growth compared with Cu mine tailings, according to the growth performance of the four species. Sesbania sesban and S. rostrata showed superior growth performance, compared to the other two species. Thus, they can serve as pioneer species to modify the barren environment, by providing organic matter and essential nutrients such as nitrogen, upon decomposition, in a relatively short period of time. This is especially true for S. rostrata, which is an annual plant that forms both stem and root nodules. However, a longer-term field trial should be conducted to investigate if superior species can beneficially modify the habitat for the growth of subsequent plant communities.     

Persistent Impacts of Trace Metals from Mining on Floodplain Grass Communities Along Soda Butte Creek, Yellowstone National Park

Phleum pratense and Poa pratensis were significantly lower (P ≤ 0.001) on plots with more than 250 ppm copper. Above-ground biomass of Phleum pratense was also significantly lower on plots with copper levels above 250 ppm. Decreased mean grass density was found on plots with pH < 6.4, but the only statistically significant difference was for Juncus balticus, which had increased density on plots with pH < 6.4. In contrast to the clear impacts of trace metals and pH on vegetation, other site characteristics did not alter measured vegetation characteristics.     

Insights into metals in individual fine particles from municipal solid waste using synchrotron radiation-based micro-analytical techniques

Excessive inter-contamination with heavy metals hampers the application of biological treatment products derived from mixed or mechanically-sorted municipal solid waste (MSW). In this study, we investigated fine particles of < 2 mm, which are small fractions in MSW but constitute a significant component of the total heavy metal content, using bulk detection techniques. A total of 17 individual fine particles were evaluated using synchrotron radiation-based micro-X-ray fluorescence and micro-X-ray diffraction. We also discussed the association, speciation and source apportionment of heavy metals. Metals were found to exist in a diffuse distribution with heterogeneous intensities and intense hot-spots of < 10 μm within the fine particles. Zn-Cu, Pb-Fe and Fe-Mn-Cr had significant correlations in terms of spatial distribution. The overlapped enrichment, spatial association, and the mineral phases of metals revealed the potential sources of fine particles from size-reduced waste fractions (such as scraps of organic wastes or ceramics) or from the importation of other particles. The diverse sources of heavy metal pollutants within the fine particles suggested that separate collection and treatment of the biodegradable waste fraction (such as food waste) is a preferable means of facilitating the beneficial utilization of the stabilized products.     

纳污湿地上覆水中重金属的监测及评价

以武河湿地为研究区域采集上覆水水样,采用ICP-AES法测定湿地水体中重金属的含量,参照有关标准用水质标准级别法对水中重金属污染情况进行了评价。结果表明:武河湿地中重金属Hg污染十分严重,各采样点均有分布且水质属劣Ⅴ类。重金属元素Cd污染并不严重,总体水质较好。重金属元素As、Cr、Cu、Pb在武河湿地中污染较轻近乎无污染,水质为Ⅰ类。由于重金属Hg的污染十分严重所以研究区内综合质量等级在4以上,水质为Ⅴ类和劣Ⅴ类,污染严重。     

电镀污染区植物重金属积累特征研究

采用野外采样室内分析方法,对泰州某电镀污染区12种优势植物和对应土壤中的Cu、Cr、Cd、Pb和Ni5种重金属含量进行测定,揭示了优势植物对复合污染重金属的富集和转运特征。结果表明,该电镀污染区土壤中Cd平均含量为4.10 mg/kg,是GB15618—2008《土壤环境质量标准》中二级标准9.1倍。植物吸收重金属的富集滞留在地上部较多,香樟对Cd,双穗雀稗、野艾篙、牛筋草对Cu,双穗雀稗对Cr,三叶草、蒲公英对Pb,双穗雀稗、苣荬菜对Ni表现出重金属植物修复的潜力,它们是修复Cd污染土壤的理想植物。     

The NICE-Whyco technologies partnership: saving energy, dollars, and the environment in the metal plating industry

In partnership with the US Department of Energy’s Office of Industrial Technology, Whyco Technologies, Inc., has developed an innovative perforated plating barrel used in the plating of metal parts. This new technology employs a thin-walled construction, differing from the traditional thick-wall design required to provide adequate structural integrity. The thicker walls lowered the efficiency of transferring plating solution into and out of the barrel and diminished the electrical current pushed through the holes and onto the parts being plated. By machining pockets out of the traditional thick-walled perforated structure, Whyco produced a ‘honeycomb’ of staggered cells, allowing for the greatest number of holes per open area while maintaining structural integrity. Hydrodynamic pumping occurs during barrel rotation to create greater solution transfer than in traditional barrels. The Whyco barrel has higher current density plating, which leads to faster plating cycles, reduced bath concentration, and better plating of difficult chemistries such as in alloys. This new technology has helped the company reduce energy use by 16%, eliminate more than 480 tons/year of solid waste, and reduce wastewater by more than 17 000 gallons/day. The resulting cost savings total more than $500 000 annually. The company has manufactured and sold more than 275 of these barrels to other electroplating companies that are reporting up to a 40% increase in plating productivity and similar energy and environmental impacts.     

Response of the sediment geochemistry of the Changjiang River (Yangtze River) to the impoundment of the Three Gorges Dam

Based on the measurement of major and trace elements in suspended sediments in the low reaches of the Changjiang River during throughout a whole hydrologic year, the origins, seasonal variations, and fluxes of multielements and the human impacts on multielements transport processes have been analyzed along with the influence of weathering in the Changjiang River basin. The results show that most element contents were high in both autumn and winter and low in summer, which was largely caused by the dilution of discharge. Weathering detritus in the Changjiang River basin is the main source of most elements in suspended sediments. However, riverine pollution could bring more loadings of Cd, Pb, As and Zn into river water than it did a few decades ago. The annual average fluxes of Cd, Pb and Zn, which are major contamination elements, to the sea were 179 ± 21 tons/year, 7810 ± 675 tons/year, and 12,000 ± 1320 tons/year,respectively, in which approximately 8.7%, 11.9% and 2.7% of their loadings, respectively,were contributed by pollution inputs. Element exports mainly occurred in the summer(44.4%–57.4%) in the lower part of the Changjiang River. A general relationship between sediment retention and element content suggests a positive feedback mechanism for the decreased number of particles, in which element riverine loadings are reduced due to the enhanced trapping effect by the Three Gorges Dam(TGD). Compared to those in 1980,current element shares of the Changjiang River compared to the global budget have declined due to the construction of the TGD.     

Treatment of metal-chloride-enriched wastewater by simulated constructed wetlands

The ability of surface flow and subsurface flow simulated wetlands to remove heavy metals from a NaCI-enriched wastewater was examined, employing bulrush (Scirpus validus) and cattail (Typha angustifolia) plants, and two organically amended substrates (mixtures of mushroom compost and leaf litter,with topsoil) with a limestone liner. A simulated wastewater solution containing Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn as chloride salts was added to the wetlands at a rate of 0.3 l h^–1. During 12 weeks of surface flow, Fe was retained most efficiently (74%), and Mn the least (24%). Most metal retention occurred in residual forms, primarily in the upper 5 cm of the substrate. A subsequent 10 week subsurface flow treatment exhibited greater removal efficiencies for all metals, probably due to increased contact with the highly buffered lower substrate. During both treatments, bioaccumulation occurred in plants, but accounted for a very small portion of the total metal removal. Plant species did not significantly influence wetland performance with respect to metal retention. Substrate type did not affect removal efficiency for most metals, but did influence the forms of the metals retained in the wetland.To whom correspondence should be addressed.