STAMP模型在危化品道路运输事故分析中的应用研究

为保障危化品道路运输行车安全,基于STAMP模型构建危化品道路运输的分层安全控制结构,将安全问题看作是控制问题,并将系统工程思想融入事故预防中。在此基础上,引入沪昆高速湖南邵阳段“7.19”特别重大道路交通危化品爆燃事故并对其进行实证分析,从物理层、基础层、运营层及监管层动态分析导致事故发生的控制缺失。结果表明:基于STAMP模型的安全分析方法不仅可考虑由组件失效引起的事故,还可发现组件之间的组织问题及决策背景,并对事故致因做出更为详细的解释,为类似事故的分析和预防提供思路与参考。     

河水可溶性有机物与Cu~(2+)络合常数的确定

分别采用单配位体、双配位体离散模型与连续分配模型对水体中可溶性有机物与金属铜离子的络合行为进行描述 .单配位体模型的使用中可采用不同拟合手段 ,对拟合结果有一定影响 .单纯以可决系数与误差平方和为判断依据 ,非线性拟合的拟合效果最佳 ,拟合结果为条件稳定常数logk =2 2 6 ,络合容量C =6 70mol·g-1.检测窗口的变化在极大程度上影响络合常数的计算结果 .双配位体模型的非线性拟合结果为logk1=7 2 9、logkn=1 90、C1=0 0 2 3mol·g-1、Cn=13 74 6mol·g-1,与单配位体模型相比没有明显改善 .连续分配模型可用来描述不同络合位饱和度下条件稳定常数的连续变化 ,并从曲线的外推计算出最强络合位的络合常数logkmax=4 71     

Air pollution and inhalation exposure to particulate matter of different sizes in rural households using improved stoves in central China

Household air pollution is considered to be among the top environmental risks in China.To examine the performance of improved stoves for reduction of indoor particulate matter(PM) emission and exposure in rural households, individual inhalation exposure to size-resolved PM was investigated using personal portable samplers carried by residents using wood gasifier stoves or improved coal stoves in a rural county in Central China.Concentrations of PM with different sizes in stationary indoor and outdoor air were also monitored at paired sites. The stationary concentrations of size-resolved PM in indoor air were greater than those in outdoor air, especially finer particles PM0.25. The daily averaged exposure concentrations of PM0.25, PM1.0, PM2.5 and total suspended particle for all the surveyed residents were 74.4 ± 41.1, 159.3 ± 74.3, 176.7 ± 78.1 and 217.9 ± 78.1 μg/m3,respectively. Even using the improved stoves, the individual exposure to indoor PM far exceeded the air quality guideline by WHO at 25 μg/m3. Submicron particles PM1.0 were the dominant PM fraction for personal exposure and indoor and outdoor air. Personal exposure exhibited a closer correlation with indoor PM concentrations than that for outdoor concentrations. Both inhalation exposure and indoor air PM concentrations in the rural households with gasifier firewood stoves were evidently lower than the reported results using traditional firewood stoves. However, local governments in the studied rural areas should exercise caution when widely and hastily promoting gasifier firewood stoves in place of improved coal stoves, due to the higher PM levels in indoor and outdoor air and personal inhaled exposure.     

广东乐昌铅锌尾矿的酸化潜力

利用净产酸试验(NAG)和净产酸潜力试验(NAPP)方法,研究了广东乐昌铅锌尾矿的产酸潜力.该尾矿的黄铁矿的硫和总硫含量分别为12.57%和18.68%,NAG和NAPP值分别为H₂SO₄ 220 kg·t^-1和326 kg·t^-1,NAG和NAPP的试验结果都表明该尾矿有着很高的产酸潜力.由于黄铁矿硫不会完全被氧化,NAG比NAPP可更为准确地预测尾矿的产酸潜力.2个剖面的分析表明,因氧化难以进入尾矿深部,酸化主要发生在尾矿表面0～20cm,且对下层尾矿的影响很小.尾矿的pH值与EC值显著负相关,表明酸化促进乐昌尾矿中盐分的溶解和重金属的迁移,在酸化的表层,有效态Pb、Zn、Cu和Cd含量显著高于未酸化的下层,而Pb、Zn、Cu和Cd的总量却显著低于未酸化的下层.     

The electrochemical selective reduction of NO using CoSe2@CNTs hybrid

Converting the NO from gaseous pollutant into NH₄ ⁺ through electrocatalytical reduction using cost-effective materials holds great promise for pollutant purifying and resources recycling. In this work, we developed a highly selective and stable catalyst CoSe₂ nanoparticle hybridized with carbon nanotubes (CoSe₂@CNTs). The CoSe₂@CNTs hybrid catalysts performed an extraordinary high selectivity for NH₄ ⁺ formation in NO electroreduction with minimal N₂O production and H₂ evolution. The specific spatial structure of CoSe₂ is conductive to the predominant formation of N-H bond between the N from adsorbed NO and H and inhibition of N-N formation from adjacent adsorbed NO. It was also the first time to convert the coordinated NO into NH₄ ⁺ using non-noble metal catalysis. Moreover, the original concept of employing CoSe₂ as eletrocatalyst for NO hydrogenation presented in this work can broaden horizons and provide new dimensions in the design of new highly efficient catalysts for NH₄ ⁺ synthesis in aqueous solution.

     

Selenium for the mitigation of toxicity induced by lead in chicken testes through regulating mRNA expressions of HSPs and selenoproteins

Lead (Pb) is a toxic element and environmental pollutant. Pb toxicity and antagonistic effect of selenium (Se) on Pb have been deeply studied in mammals. The testis is one of the target organs of Pb in birds. The aim of this study was to investigate the mitigating effect of Se on Pb toxicity in chicken testes by determining messenger RNA (mRNA) expressions of 5 heat shock proteins (HSPs) and 25 selenoproteins. Sixty male chickens (7-day-old) were randomly divided into the control group, the Se group, the Pb group, and the Pb + Se group, and were fed for 90 days. The feeding methods of chickens were as follows: The control group was fed drinking water and commercial diet (0.49 mg/kg Se). Lead acetate was added into the drinking water (350 mg/L Pb). Sodium selenite was added into the commercial diet (1 mg/kg Se). Multivariate correlation analysis and principal component analysis (PCA) were used to define the relationships among all the measured factors and the most important parameters that could be used as key factors, respectively. The results indicated that Se decreased the increase of mRNA expressions of all the HSPs and increased the decrease of mRNA expressions of all the selenoproteins induced by Pb in the chicken testes. HSP70 may be a biomarker of Pb poisoning in the chicken testes. Se alleviated Pb-induced toxicity in the chicken testes through regulating mRNA expressions of HSPs and selenoproteins.

     

Physical,chemical and biological process techniques and tools for pollution prevention and sustainability: an introduction

Environmental Science and Pollution Research -     

水中盐酸环丙沙星的超声降解

为研究超声波降解水中盐酸环丙沙星的机理,在不同超声波功率、不同盐酸环丙沙星初始浓度以及不同添加剂条件下,对盐酸环丙沙星进行超声降解研究.在实验条件下,当功率从180 W增至1 000 W时,10 mg/L盐酸环丙沙星降解率从55.2%提高到75.3%; 当功率为360 W,超声2 h时,未加添加剂时其降解率为62.5%,而加入FeSO4、NaCl、H2O2、CCl4、CuSO4、KI和N2后其降解率分别为85.3%、65.7%、70.1%、98.8%、43.6%、8.1%和51.2%.研究结果表明,FeSO4、NaCl、H2O2及CCl4的添加能促进盐酸环丙沙星的超声降解,而CuSO4、KI和N2却显著压抑其降解.盐酸环丙沙星的超声降解主要归因于·OH等活性自由基的氧化作用.     

Effects of aluminum substitution on the surface charge of colloidal goethite particles: experiments and MUSIC modeling

Environmental Science and Pollution Research - Proton adsorption behavior on the surface of Al-substituted goethites as a function of pH and ionic strength was investigated and simulated with the...