Foliar uptake and metal(loid) bioaccessibility in vegetables exposed to particulate matter

At the global scale, high concentrations of particulate matter (PM) enriched with metal(loid)s are currently observed in the atmosphere of urban areas. Foliar lead uptake was demonstrated for vegetables exposed to airborne PM. Our main objective here was to highlight the health risk associated with the consumption of vegetables exposed to foliar deposits of PM enriched with the various metal(loid)s frequently observed in the atmosphere of urban areas (Cd, Sb, Zn and Pb). Leaves of mature cabbage and spinach were exposed to manufactured mono-metallic oxide particles (CdO, Sb₂O₃ and ZnO) or to complex process PM mainly enriched with lead. Total and bioaccessible metal(loid) concentrations were then measured for polluted vegetables and the various PM used as sources. Finally, scanning electronic microscopy coupled with energy dispersive X-ray microanalysis was used to study PM–phyllosphere interactions. High quantities of Cd, Sb, Zn and Pb were taken up by the plant leaves. These levels depended on both the plant species and nature of the PM, highlighting the interest of acquiring data for different plants and sources of exposure in order to better identify and manage health risks. A maximum of 2 % of the leaf surfaces were covered with the PM. However, particles appeared to be enriched in stomatal openings, with up to 12 % of their area occupied. Metal(loid) bioaccessibility was significantly higher for vegetables compared to PM sources, certainly due to chemical speciation changes. Taken together, these results confirm the importance of taking atmospheric PM into account when assessing the health risks associated with ingestion of vegetables grown in urban vegetable crops or kitchen gardens.     

Sustainability of urban drainage management: a perspective on infrastructure resilience and thresholds

Urban wastewater infrastructures have been threatened by natural and socioeconomic disturbances. This study investigates infrastructure resilience against the risks of long-term changes rather than natural disasters. Urban expansion that leads to an increased urban runoff and massive population movements that cause fluctuations in domestic emissions are considered in this study. Pollution permits for water bodies are adopted as constraints on wastewater infrastructures. A land use-based accounting method, combined with a grid-based database, is developed to map domestic discharge and urban runoff to service areas of wastewater treatment plants. The results of a case study on downtown Sanya, the most famous seashore tourist attraction in China, show that the average resilient values of three sub-catchment areas in 2010 were -0.57, 0.10 and 0.27, respectively, a significant spatial variation. The infrastructure in the Sanya River sub-region is the least flexible, and is more likely to fail due to unstable inflows. The resiliencies will increase to 0.59, 1.01 and 0.54, respectively, in 2020, a considerable improvement in robustness. The study suggests that infrastructure resilience needs to be taken into further consideration for urban planning and the related realm of urban governance to foster more robust wastewater management under various risks.     

Evaluating sustainable land use for the Değirmendere valley: A case study from northeastern Turkey

Regional land-use development projects are undertaken to protect water resources necessary for agriculture, energy and sustaining human life. The De?irmendere valley, in the province of Trabzon in the Black Sea region of Turkey, provides clean water to the city of Trabzon. The valley is part of the Silk Road from Asia to the Black Sea and contains historical monasteries such as Sumela, Kustul and Vazelon. However, over the years, misuse of the valley has caused freshwater, sea and environmental pollution. In an attempt to overcome these problems, a multilateral project, De?irmendere Vadisi Çevre Düzenlemesi (DEVAÇED), was launched in the region. This paper aims to provide information necessary for engineering projects within the region. Six villages, on both sides of the valley, were selected for this research and evaluated in terms of river basin utilization, topography, cadastral survey of property and ownership, and land readjustment improvements. The study found illegal and improper urbanization, including industrial facilities within the valley causing water pollution. Current cadastral base maps are not sufficiently accurate for engineering projects, and in some places buildings have been constructed on unstable soils that are susceptible to landslides. The research results have helped to generate important recommendations for rehabilitation of the river basin.     

不同硬度条件下Cd~(2+)和Cu~(2+)对稀有鮈鲫的急性毒性

为研究水体硬度对稀有鮈鲫Cd~(2+)和Cu~(2+)毒性效应的影响,开展了96 h急性毒性试验。试验结果发现,当水体硬度(以CaCO_3计,下同)为50 mg·L~(-1)、250 mg·L~(-1)、450 mg·L~(-1)时,Cd~(2+)对稀有鮈鲫的96 h半数致死浓度(96 h-LC50)分别为4.30 mg·L-1、12.06 mg·L~(-1)、19.99 mg·L~(-1),对应的安全浓度(SC)依次为0.430 mg·L~(-1)、1.206 mg·L~(-1)、1.999 mg·L~(-1);Cu~(2+)对稀有鮈鲫的96h-LC50分别为0.046 mg·L-1、0.148 mg·L~(-1)、0.228 mg·L~(-1),对应的SC依次为0.0046 mg·L~(-1)、0.0148 mg·L~(-1)、0.0228 mg·L~(-1)。计算得到Cd~(2+)对稀有鮈鲫急性毒性与水体硬度的拟合方程为ln 96 h-LC50=0.687 ln H~(-1).243(r=0.998);Cu~(2+)对稀有鮈鲫急性毒性与水体硬度的拟合方程为ln 96 h-LC50=0.727 ln H-5.923(r=0.999),Cd~(2+)和Cu~(2+)对稀有鮈鲫的硬度斜率分别为0.687和0.727。这些结果表明,水体硬度可有效降低Cd~(2+)和Cu~(2+)对稀有鮈鲫的急性毒性,且稀有鮈鲫的硬度斜率与其他物种差异较大。在评估不同硬度水体下Cd~(2+)和Cu~(2+)的生物毒性及其生态风险时,应根据测试物种特异的硬度斜率而定。     

进水中碳水化合物分子大小对污泥沉降性能的影响

为弄清楚碳水化合物分子大小和污泥沉降性能之间的影响关系,在3个序批式系统中,分别以颗粒型淀粉、溶解型淀粉和葡萄糖为碳源,考察了长期运行中系统的污泥沉降性能和处理能力.结果证明:碳水化合物分子越小,活性污泥对环境的变化越敏感,当运行条件不利时越容易引发污泥膨胀问题;大分子碳源吸附于絮体内部能够提高污泥的沉降性能;糖类作碳源时,活性污泥的PHA贮存量约为0.6mmol C/L,但系统SVI仍然能够维持在150mL/g以下;胞外聚合物中多糖与蛋白质(C/P)的比值与污泥的SVI呈正相关性,SVI从100mL/g增长到600mL/g,C/P比从0.248增长到1.201;以颗粒型淀粉、溶解型淀粉和葡萄糖为碳源时,系统的优势丝状菌分别为Type 0041、M. parvicella和S. natans;进水以葡萄糖作单一碳源时,系统的除磷能力能达到80%以上.     

活性炭颗粒对超细颗粒物的过滤性能

UFPs(超细颗粒物)对人体危害较大且难以脱除,但活性炭颗粒床利用多孔结构可以提高其过滤效率. 为探究试验条件对UFPs过滤效率的影响以及活性炭孔隙结构和UFPs过滤效率之间的关系,以实验室发生UFPs为研究对象,活性炭为过滤介质,对活性炭颗粒粒径、滤层厚度以及表观风速等条件对过滤UFPs的影响进行了研究,并通过对比过滤前后活性炭的孔径分布,分析活性炭多孔性与UFPs的关系. 结果表明:当活性炭颗粒平均粒径由2.50 mm减至0.45 mm、滤层厚度由20 mm增至100 mm、表观过滤风速由4.25 cm/s降至0.84 cm/s时,总过滤效率分别由41.87%、49.39%、68.24%升至86.27%、89.29%、83.04%;但从活性炭的单颗粒过滤效率和过滤质量角度来看,在活性炭颗粒粒径大、滤层厚度小、表观过滤风速低的条件下,更有利于单个活性炭颗粒的过滤作用的发挥;当UFPs粒径小于14.3 nm时,UFPs发生“热反弹”效应,并且主要过滤机理是扩散效应,但随着UFPs粒径增大,拦截和惯性碰撞对过滤效率的作用增强;活性炭500 nm以下的孔隙结构对脱除UFPs起着重要作用. 研究显示,选择含有更多500 nm以下孔隙的多孔材料更有利于过滤UFPs.      

UASB-曝气法应用于饮料废水中出现的问题及分析

UASB-曝气法应用在饮料废水处理的前期运行良好,但运行后期出现了出水不达标的异常现象,通过运行数据和UASB常见问题的分析,发现使系统出现异常的原因是UASB反应器内部腐蚀、三相分离器不完善等的常见问题。针对这些问题提出了相应的解决措施和二次启动厌氧池的建议,以使该系统恢复运行效果。     

滨海城市不同粒径大气颗粒物中水溶性离子的分布特征

选取东南滨海城市厦门的城区（厦门大学,仙岳小区）、郊区（集美大学城）、工业区（鹭联宾馆）和背景区（汀溪水库）5个站点为研究对象,于2008年10月至2009年9月对厦门市大气PM2.5、PM2.5-10和PM10-100分4个季节进行了采集工作,用离子色谱对其中的水溶性离子进行测定。研究结果表明,厦门市不同粒径颗粒物中水溶性离子具有明显的时空分布特征,且主要以富集在细颗粒物（PM2.5）上为主。SO42-、NO3-和NH4＋是PM2.5中主要的水溶性离子,占PM2.5中水溶性离子总质量浓度的64.59%～93.17%。PM2.5-10和PM10-100的水溶性离子则以Na＋、C1-和Ca2＋这些粒径较大的颗粒为主。滨海城市厦门PM2.5、PM10和TSP的SO2转化率（SOR）和NO2的转化率（NOR）年平均值分别为：0.35、0.39、0.41和0.04、0.08、0.09,较高的SOR和相对较低的NOR比值均说明厦门存在来自于SO2和NO2转化的二次污染物SO42-和NO3-。     

水解酸化预处理光学工业生产废水的效果研究

以水解酸化为预处理手段,利用自主设计的水解酸化柱为处理设备,处理光学工业生产废水。通过分析光学工业生产废水的水质了解到：该废水BOD5/CODCr〉0.3,可以采用生物的方法处理废水,但是考虑到BOD5/CODCr值较低,而该废水中又含有大量的高分子有机物,直接利用好氧生物降解的方法效果不明显,为提高其生物降解性能,使用水解酸化为前处理手段。通过近一个月的启动试验,水解酸化反应器出水稳定,CODCr去除率达到45%左右。以废水中CODCr去除率和酸化率为分析指标,确定水解酸化反应体系的最佳适用条件,试验结果表明：pH值为6.5～7.5,水力停留时间为8～10h时,废水CODCr去除率和酸化率较高。设定pH值为7、水力停留时间为8h的试验条件,比较进、出水BOD5/CODCr的试验结果变化可知：经水解酸化预处理后,该废水的可生化性提高了近一倍左右,水解酸化预处理效果明显,该预处理方法改善了光学工业生产废水的可生化降解性能。     

破坏性地震事件前后的紧急事务处理和震后紧急救援

根据我国目前的地震应急现状,提出了破坏性地震事件前后的紧急事务处理和震后紧急救援的有关问题以及二者之间的关系,论述了国际救援在大城市发生特大破坏性地震中的作用.