红色非硫光合细菌的生长特性研究

红色非硫光合细菌菌种从城市污水处理厂活性污泥中分离得到,对红色非硫光合细菌的生长规律及其影响因素进行研究,试验表明在进行污水处理时所用的红色非硫光合细菌的最佳培养条件为接种量2%,pH7～8,光照强度为1500lx,光照厌氧条件下培养3～5d。这为红色非硫光合细菌应用于染料有机化工废水处理的进一步研究提供了理论依据。     

Measuring water resource use efficiency of the Dong Nai River Basin (Vietnam): an application of the two-stage data envelopment analysis (DEA)

Environment, Development and Sustainability - The recent growth of agriculture, industry and urban areas in Vietnam requires a large amount of water consumption as a production factor. This paper...     

基于FDS仿真火灾温度下隧道衬砌安全评估

为了研究火灾下隧道衬砌的安全性,首先采用火灾模拟软件FDS4．0模拟不同规模的火灾：通过许多小的长方体堆砌建立隧道的实体模型,并采用FDS4．0中的多重网格技术（Multiple Meshes）进行网格划分;然后结合仿真得到横断面的温度场与相应温度下的材料参数,应用荷载一结构模式（即直刚法）对二次衬砌的安全性进行评估。结果表明：小规模火灾下（〈20MW）,衬砌的安全性能够得到满足,在较大火灾规模下（≥20MW）,拱顶的安全性得不到满足,而其余部位的安全性满足要求;随着火灾规模的增大,衬砌安全系数逐渐降低,拱顶的安全系数降低梯度最大。最后,对衬砌的耐火措施提出了一些建议。     

Zinc tolerance and accumulation in Pteris vittata L. and its potential for phytoremediation of Zn- and As-contaminated soil

A field investigation and pot experiments were conducted to determine the potential of arsenic (As) hyperaccumulator, Pteris vittata L., to remediate sites co-contaminated with zinc (Zn) and As. We found that P. vittata L. had a very high tolerance to Zn and grew normally at sites with high Zn concentrations. In addition, P. vittata L. could effectively take up Zn into its fronds, with a maximum of 737 mg kg(-1) under field conditions. In pot experiments, the accumulated Zn concentration increased significantly as the Zn treatment was raised from 0 to 2000 mg kg(-1), with a maximum Zn accumulation of 0.22 mg pot(-1). Although the concentration of As in P. vittata L. was reduced by the addition of Zn, total frond accumulation of As was elevated when the Zn treatment was increased from 0 to 1000 mg kg(-1), with a maximum As accumulation of 8.3 mg pot(-1) in the presence of 1000 mg kg(-1) Zn. The high Zn tolerance, relatively high ability to accumulate Zn, and great capacity to accumulate As under conditions of suppression by high Zn suggest that P. vittata L. could be useful for the remediation of sites co-contaminated with Zn and As.     

小型环境试验舱的研制及性能研究

自制小型环境试验舱的体积为0．17m^3，用产生甲醛的标准气体方法检验试验舱的稳定性、准确性及精密性。结果表明，试验舱稳定，无吸附，且有95％的精确性。通过测定试验舱内木板中甲醛释放量及释放规律检验试验舱的应用性能，测得甲醛释放规律与文献研究结果一致，表明该试验舱应用性能良好，因此该实验舱可用于检测室内装饰装修材料中污染物质释放量及释放规律的研究。     

Geotechnical and leaching properties of flowable fill incorporating waste foundry sand

Waste foundry sand (WFS) can be converted into flowable fill for geotechnical applications. In this study, WFS samples were obtained from 17 independent metal casting facilities with different casting processes, thus representing a good range of WFS properties. The laboratory studies include physical, geotechnical and leaching properties of flowable fills consisting of WFS, cement, and fly ash mixed to different water contents. The main properties measured include WFS physical properties (density, particle gradation, grain shape, and fine content), WFS flowable fill geotechnical properties (unconfined compressive strength, hydraulic conductivity, setting time, and bleeding), and the fill's leaching properties (heavy metals and organics in the bleed water and the leachate extracted from hardened WFS flowable fills). The test results indicate that in terms of the physical properties, most of the data fall within narrow ranges, although data from the copper/aluminum-based WFS samples might fall beyond the ranges. Geotechnical properties of WFS flowable fills in both fresh and hardened phases were verified conforming to the features of specified flowable fills. Material leaching analyses indicate that the toxicity of WFS flowable fills is below regulated criteria. A mix formulation range originated from this study is proposed for the design of WFS made flowable fill.     

Analysis of spatial and temporal changes of vegetation cover and its driving forces in the Huainan mining area

Environmental Science and Pollution Research - The Huainan mining area is rich in coal resources and has sparse vegetation and many collapsed waterways. Large-scale and long-term underground coal...     

基于主成分分析和神经网络的事故预测方法及应用

为解决人工神经网络(ANN)对复杂系统进行事故预测建模时,易导致网络复杂,降低网络性能和增大预测误差的问题,提出一种基于主成分分析法(PCA)的ANN事故预测方法。介绍PCA法和ANN的基本理论,阐述基于PCA法的ANN事故预测模型及其预测步骤,即在利用ANN预测之前,先用PCA法分析事故影响指标,将多个指标转化为少数几个能反映原始信息的互不相关的综合变量(主成分),然后以这些变量作为输入进行ANN建模,从而达到简化模型,提高网络性能和计算精度的目的。以煤矿事故预测为例,进行应用和对比研究。结果表明:基于PCA的ANN事故预测相对误差小于3%,而直接运用ANN方法预测的相对误差达到5%。这说明,对复杂安全系统进行事故预测时,基于PCA法的ANN预测方法是更可行的。     

碳中和背景下欧盟碳边境调节机制对我国的影响及对策分析

在全球碳中和的新形势下,欧盟委员会于2021年7月正式提出“碳边境调节机制”（CBAM）立法提案,并计划于2023年起实施。本文在总结立法提案关键要素的基础上,着重分析欧盟CBAM的合法性与合理性,研判可能对我国产生的潜在影响,并从国际国内层面提出对策建议。分析发现,欧盟采取“名义”碳市场的形式,初期将覆盖水泥、电力、化肥、钢铁和铝等5个行业,只核算产品生产过程的直接排放,暂不考虑间接排放,2023—2025年是过渡期,2026年开始正式实施。欧盟CBAM的合法性与合理性面临诸多挑战：不符合世界贸易组织国民待遇原则和最惠国待遇原则,但存在满足关税与贸易总协定例外条款的可能性;违反国际气候治理的共同但有区别的责任原则、公平原则和各自能力原则,也不符合公约关于国际贸易歧视或变相限制的条款;对解决碳泄漏问题和保护本土竞争力的作用有限;产品隐含碳核算和碳价确定是技术难点问题。影响评估发现,欧盟CBAM将使我国受影响部门的对欧出口总额降低11%～13%,出口成本增加1亿～3.05亿美元,其中约四分之三的成本将由钢铁行业承担,对贸易隐含碳的下降作用有待进一步考量;此外,欧盟CBAM将会影响多边国际...     

Risk assessment of Giardia from a full scale MBR sewage treatment plant caused by membrane integrity failure

Membrane bioreactors (MBR) are highly efficient at intercepting particles and microbes and have become an important technology for wastewater reclamation. However, many pathogens can accumulate in activated sludge due to the long residence time usually adopted in MBR, and thus may pose health risks when membrane integrity problems occur. This study presents data from a survey on the occurrence of water-borne Giardia pathogens in reclaimed water from a full-scale wastewater treatment plant with MBR experiencing membrane integrity failure, and assessed the associated risk for green space irrigation. Due to membrane integrity failure, the MBR effluent turbidity varied between 0.23 and 1.90 NTU over a period of eight months. Though this turbidity level still met reclaimed water quality standards (≤5 NTU), Giardia were detected at concentrations of 0.3 to 95 cysts/10 L, with a close correlation between effluent turbidity and Giardia concentration. All β-giardin gene sequences of Giardia in the WWTP influents were genotyped as Assemblages A and B, both of which are known to infect humans. An exponential dose-response model was applied to assess the risk of infection by Giardia. The risk in the MBR effluent with chlorination was 9.83 × 10^-3, higher than the acceptable annual risk of 1.0 × 10^-4. This study suggested that membrane integrity is very important for keeping a low pathogen level, and multiple barriers are needed to ensure the biological safety of MBR effluent.