挥发性氯代烃在干燥土壤中的平衡吸附研究

吸附是挥发性氯代烃（volatile chlorinated hydrocarbons,VCHs）污染土壤的主要机制之一.采集长三角地区3类典型水稻土,用静态平衡吸附实验进行干燥土壤对6种VCHs的平衡吸附研究.结果表明,干燥土壤的平衡吸附等温线难以用Langmuir方程和BET方程描述,但用Dubinin-Astak...     

基于可达、可行、可接受的全面小康社会环境目标研究

基于2020年我国经济社会发展情景,开展环境目标与其他目标发展协调性分析,认为环境指标负向发展突出,是全面小康社会的短板和最大制约因素。从需求侧和供给侧分析小康社会环境目标的政治、公众需求与政府的供给条件、基础和能力,通过新常态资源环境压力分析与环境质量改善国际对标研究,认为我国在社会经济发展方式转型尚未完成、环境治理投入没有持续明显提升的情况下,大幅度、全面改善环境质量还存在很大障碍。提出全面小康的环境目标定位应以环境质量为核心,响应公众对环境质量改善的期待;合理看待小康社会的历史定位,制定阶段性目标;把握生态环境可达、经济技术可行、人民群众可接受的平衡,综合确定全面小康社会的环境底线。全面小康环境目标设置应体现保底线、全覆盖、诉民生、有标杆等原则。     

污染地下水的健康风险评估研究进展与启示

我国污染地下水的健康风险评估处于起步阶段,虽然已经发布了《污染场地风险评估技术导则》(HJ25.3-2014),但相关的理论和技术方法仍不成熟。根据国内外地下水健康风险评估的研究进展,同时总结了常用的评估模型(NAS四步法、RAGS模型、RBCA模型、多介质模型),为合理借鉴国外评估模型提供指导,并为我国进一步开展地下水健康风险评估提出建议:评估指南、标准以及模型的完善;地下水筛选值的制定;参数本地化。     

Impact of waterlogging on the uptake of arsenic by hyperaccumulator and tolerant plant

A significant proportion of arsenic (As)-contaminated sites are temporarily or permanently under reducing condition, which may affect phytoextraction efficiency using the As-hyperaccumulator Pteris vittata L. In this work, a pot experiment was conducted to investigate the solubility and redox species of As in soil. The uptake of As by two populations of P. vittata and As-tolerant grass Holcus lanatus under different water regimes was examined. Waterlogging decreased the redox potential from 350 to?50 mV, leading to an approximately 40% reduction of As(V) to As(III) and an increased dissolved As concentration by 150%–300%. The changes in the speciation and concentration of As influenced its uptake by plants. A population collected from a temporarily waterlogged riverside in Guangxi province (GX population) had ninefold higher shoot As concentration under the waterlogged condition than that under the non-waterlogged condition, indicating that it preferred taking up As in the form of As(III). By contrast, a population of P. vittata collected from a dry land in Yunnan province (YN population) and H. lanatus demonstrated a preference to As(V). The GX population was an appropriate species for the phytoextraction of waterlogged sites. These results implied the importance of habitat ecology on the extraction efficiency of hyperaccumulators.     

How water saving irrigation contributes to climate change resilience—a case study of practices in China

A warming climate system is now an indisputable fact. An effective response to climate change should include both mitigation and adaptation. Water is essential to human survival and social development. But the shortage of water resources is a worldwide problem, which in China has been exacerbated by climate change. In order to find out how to cope with climate change successfully, this study, on the basis of China statistical data 2007–2009, quantitatively analyzes the role of water saving irrigation (WSI) in addressing climate change. The study shows that water saving irrigation (WSI) can serve as a useful enabler in dealing with climate change. From the perspective of mitigation, the 3-year total CO₂ emission reduction stands at 34.67 (21.83 ~ 47.48) Mt, about per year 11.56(7.28 ~ 15.83)Mt. From the perspective of adaptation, the total water saved from 2007 to 2009 stands at 96.85 (61.81 ~ 129.66) Gm³. If per unit farmland irrigation takes a 3-year average of agricultural water consumption, the water saved in 2009 is enough to irrigate additional 5.70 (3.80 ~ 7.80) Mhm², or to increase the grain yield by 22.04 (14.68 ~ 30.15) Gt. In addition, WSI can reduce soil salinization and conserve soil to sustain land productivity and environmental benefits. So WSI can be a positive measure in coping with climate change when it is rightly deployed. However, the costs and local context of such practices call for further studies.     

湿法烟气脱硫吸收剂供应系统的应用分析与技术改进

作为湿法烟气脱硫的组成部分,吸收剂供应系统担负着供应二氧化硫吸收剂的重要任务。针对该系统在实际运行中存在的突出问题,进行了详细的原因分析,给出了预防措施和解决方法,并在此基础上提出了若干技术改进方案,供业内参考。     

氧化石墨烯电催化高效降解有机染料RBk5

电化学高级氧化技术是处理有机染料废水的有效技术方法之一，但其应用受传统贵金属电极成本高、易毒化失活等缺陷的限制.本研究采用廉价易得的石墨粉材料，制备氧化石墨烯（GO）催化剂，用于活性黑5（RBk5）染料废水的电催化氧化降解研究.利用透射电子显微镜、X射线光电子能谱、红外光谱、拉曼光谱、循环伏安法和电化学阻抗谱分析材料的结构特性及电化学性能.结果显示，氧化石墨烯具有较高的电子迁移速率，良好的亲水性和电催化活性.不同的RBk5浓度、外加电流、电解质、初始pH值等条件对RBk5的降解效率也有一定程度的影响.其中，电解质因素对材料性能影响最为显著.在RBk5浓度为10mg/L、外加电流为20mA、反应时间为35min、电解质为NaCl的条件下，电催化降解效率可以达到100%.     

Modelling Pesticide and Nutrient Transport in the Cameron Highlands, Malaysia Agro-Ecosystems

Cameron Highlands has a long history of intensive horticulture especially vegetable and flower cultivation. This industry uses large amounts of nutrients and pesticides. Several simulation models were used to assess the movement of pesticides and nutrients in relation to agronomic practices in farm plots cultivated with cabbage and chrysanthemum. It was shown that most of the pesticides are absorbed by the topsoils which are enriched by organic fertiliser, and are not leached beyond the top 10 cm layer. Methamidophos, dazomet, cyromazine, triforine and NO₃N were predicted to cause soil contamination. The application of high amounts of fertilisers can cause nitrate contamination to the groundwater in Cameron Highlands.