Toxicity of exogenous antimony to the soil-dwelling springtail Folsomia candida

Environmental Science and Pollution Research - Antimony (Sb) is a toxic pollutant, but data for Sb toxicity to springtails in soil are limited, and the effects of Sb speciation, soil physiochemical...     

Mercury transformation processes in nature: Critical knowledge gaps and perspectives for moving forward

The transformation of mercury (Hg) in the environment plays a vital role in the cycling of Hg and its risk to the ecosystem and human health. Of particular importance are Hg oxidation/reduction and methylation/demethylation processes driven or mediated by the dynamics of light, microorganisms, and organic carbon, among others. Advances in understanding those Hg transformation processes determine our capacity of projecting and mitigating Hg risk. Here, we provide a critical analysis of major knowledge gaps in our understanding of Hg transformation in nature, with perspectives on approaches moving forward. Our analysis focuses on Hg transformation processes in the environment, as well as emerging methodology in exploring these processes. Future avenues for improving the understanding of Hg transformation processes to protect ecosystem and human health are also explored.     

关于水体沉积物质量基准问题

本文综述了沉积物质量基准的最新进展。从底栖生物对沉积物中结合的污染物的敏感性讨论了沉积物质量基准的意义、数值型和响应型基准,以及建立沉积物质量基准的可能途径。重点讨论了沉积物/间隙水平衡分配法,并引入了基于该法建立的沉积物质量基准的初步值。     

化工园区应急管理能力评估研究

为了研究化工园区应急管理能力的影响指标,从控制事故致因角度出发,得到6个化工园区应急管理能力一级影响指标和32个二级影响指标。为了解决传统专家打分法和层次分析法存在的随意性大、计算结果不可预测的问题,通过考虑专家自然属性权重和采用模糊层次分析法对所得影响指标的权重进行研究,并运用模糊综合评价方法对某化学工业园区的应急管理能力进行评估。结果表明:采用的计算方法可快速计算各影响指标权重;一级影响因素中,人员组织建设和预案及制度建设最为重要,应急基础保障、应急技术支持和指挥协调建设其次,事后处置重要性最低;该化工园区的应急管理能力“较好”。研究成果可为管理者认识化工园区应急管理水平,有序开展化工园区应急管理能力建设提供参考。     

nZVI对亚硝化颗粒污泥性能的冲击性影响研究

本研究采用批次试验,考察了不同浓度纳米零价铁(n ZVI)对亚硝化颗粒污泥(NGS)性能的冲击性影响,并对氮形态转化规律、氨氧化菌比耗氧速率(SOUR-A)、胞外聚合物(EPS)与溶解性微生物产物(SMP)组成、铁元素分布情况进行了系统分析.结果表明,当n ZVI投加量从0mg·L~(-1)提高至10 mg·L~(-1)时,SOUR-A值显著提高,NGS对氨氮的去除率始终保持在95%以上,亚硝态氮比累积速率(μ(NO-2-N))由27.3mg·g~(-1)·h-1提高至30.7 mg·g~(-1)·h-1,EPS中多糖与蛋白质含量均明显上升.然而,当原水中n ZVI浓度高于25 mg·L~(-1)时,SOUR-A值大幅降低,EPS与SMP中的多糖组分出现此消彼长的现象.当n ZVI投加量达到700 mg·L~(-1)时,NGS对氨氮的去除率降至58.9%,μ(NO-2-N)值为17.5 mg·g~(-1)·h-1,仅相当于对照组的64.1%.此外,扫描电镜与能谱分析的结果表明,n ZVI在NGS表面的大量吸附不仅严重抑制了功能微生物的活性,也会显著改变污泥表面的微生态环境.     

持久性有机污染物在环境中相的划分及相平衡的泛逸度模型设想

鉴于持久性有机物在环境中的结合和承载机制,作者认为,对于持久性有机物,环境可以抽象为气相、水相、有机碳相和脂相等四个均质、同结合作用的环境相,为描述持久性有机物在环境相间的平衡分配行为,引入了“泛逸度”的概念,建立了环境相间相平衡酌泛逸度模型,并以DDT为例尝试了模型的应用。     

变压器长时感应耐压及局部放电试验参数估算

变压器长时感应耐压及局部放电试验受变压器容量、变比、联结方式等因素影响,试验频率及试验电流等参数相差较大。本文对变压器现场长时感应耐压及局部放电时的容性无功功率、试验频率、有功损耗及试验电流进行估算,简化出试验时变压器等效电容量计算公式, 对比集中电容法与分布电容法估算试验参数的准确性,为现场变压器长时感应耐压及局部放电试验提供参考。     

Speciation of methylmercury in rice grown from a mercury mining area

Monomethylmercury (CH₃Hg⁺ and its complexes; MeHg hereafter) is a known developmental neurotoxin. Recent studies have shown that rice (Oryza sativa L.) grain grown from mercury (Hg) mining areas may contain elevated MeHg concentrations, raising concerns over the health of local residents who consume rice on a daily basis. An analytical method employing high performance liquid chromatography (HPLC) - inductively coupled plasma mass spectrometry (ICP-MS) following enzymatic hydrolysis was developed to analyze the speciation of MeHg in uncooked and cooked white rice grain grown from the vicinity of a Hg mine in China. The results revealed that the MeHg in the uncooked rice is present almost exclusively as CH₃Hg-l-cysteinate (CH₃HgCys), a complex that is thought to be responsible for the transfer of MeHg across the blood-brain and placental barriers. Although cooking does not change the total Hg or total MeHg concentration in rice, no CH₃HgCys is measurable after cooking, suggesting that most, if not all, of the CH₃HgCys is converted to other forms of MeHg, the identity and toxicity of which remain elusive.     

Total suspended particulate matter and toxic elements indoors during cooking with yak dung

Many herders in the Tibetan Plateau still inherit the traditional lifestyle, including living in tents and burning yak dung for fuel. This short correspondence reports a pilot study on indoor air quality in the nomadic tents in the Nam Co region, inland Tibetan Plateau. The results showed very high concentrations of total suspended particles (TSP), averaging at 4.45 mg m^?3 during the cooking/heating period (with daily value of 3.16 mg m^?3). Elevated concentrations of toxic element Cd, As and Pb were also found within the tents, averaging 3.16 μg m^?3, 35.00 μg m^?3, and 81.39 μg m^?3 for a day, respectively, which were not only far higher than those of WHO indoor air quality guidelines, but also more than 10⁴–10⁶ times higher than the outdoor air level in the Nam Co area. The study raises serious concerns over the health of Tibetan herders following their long-term exposure to the tent air.     

秦淮河流域句容水库农业流域水体沉积物的反硝化作用

2007年5、8、11月和2008年2月,在秦淮河流域句容水库农业流域的河流和水库中,采用自行设计制作的无扰动采样器采集了沉积物柱样,使用乙炔抑制法进行培养试验,并测定了沉积物上覆水的温度(T)、铵态氮(NH4+-N)、硝态氮(NO-3-N)和总溶解性氮(TDN)的浓度,以及沉积物有机质(OM)和全氮(TN)含量,研究了沉积物反硝化潜势的季节变化及其影响因素.结果显示,水体沉积物反硝化潜势存在显著的季节差异,河流沉积物的反硝化潜势范围在8.85～64.04pμg·m-2·h-1之间、水库沉积物的反硝化潜势范围在5.01～28.18μg·m-2·h-1之间.沉积物反硝化潜势的季节变化与上覆水的温度、NH4+-N、NO-3-N和TDN的浓度,及沉积物的OM和TN含量的季节变化有关.