US/Zn~0体系降解水中的对硝基苯甲酸

为高效去除水体中的对硝基苯甲酸、开发新型水处理技术,提出以超声与单质锌联用降解水中的对硝基苯甲酸。考察了锌投加量、溶液初始pH、声功率及溶液初始浓度对拟一级反应速率常数(k0US/Zn)的影响,比较了US、Zn0和US/Zn03体系下的降解常数,并对US/Zn0体系的降解机理进行了初探。结果表明,以上4种因素对k0US/Zn均有很大影响,k0US/Zn分别在溶液初始pH为5、声功率为120 W、溶液初始浓度为0.04 mmol/L时达到最大值,且随着锌投加量的增加而增加。超声与单质锌在降解对硝基苯甲酸的过程中存在很好的协同作用,在最优条件下,k0US/Zn=0.052 min-1,分别是单独超声降解及单独锌降解的21.5倍和2.53倍。在联用体系中,主要是依靠OH·氧化及单质锌还原的相互加强来去除对硝基苯甲酸。     

深圳西丽水库水质研究

在西丽水库近8年水质监测(2005-2012年)的基础上,分析水库的主要污染物及其产生原因,研究西丽水库的水质变化规律,其水质状况为良好。铁、总氮、总磷、氨氮、粪大肠菌群、锰是西丽水库的主要污染物。     

中国沿海地区台风灾害损失评估研究

沿海地区作为人口积聚、国民经济和社会发展的重要区域和战略中心,在台风灾害中遭受的损失往往是惨重和致命的,所以亟待开展沿海地区台风灾害损失评估研究。根据1990-2007年的台风灾情资料,选取代表性指标尝试构建了台风灾情评估模型,并对沿海省市的台风灾害损失及其与致灾因子的关系进行分析评价。结果显示:除个别区域外,沿海地区台风灾害损失都呈下降趋势,但各区域下降的幅度不等,其中浙江省、江苏省和海南省下降幅度较低,均不足10%;浙江省、福建省和广东省18年间平均台风灾害损失较大;上海市以南各区域台风大风和暴雨的频次多、强度大,灾害损失大。     

The Potential Influence of Seasonal Climate Variables on the Net Primary Production of Forests in Eastern China

Knowledge of the effects of climate factors on net primary production (NPP) is pivotal to understanding ecosystem processes in the terrestrial carbon cycle. Our goal was to evaluate four different categories of effects (physical, climatic, NDVI, and all effects[global]) as predictors of forest NPP in eastern China. We developed regression models with data from 221 NPP in eastern China and identified the best model with each of the four categories of effects. Models explained a large part of the variability in NPP, ranging from 46.8% in global model to 36.5% in NDVI model. In the most supported global model, winter temperature and sunshine duration negatively affected NPP, while winter precipitation positively affected NPP. Thus, winter climate conditions play an important role in modulating forest NPP of eastern China. Spring temperature had a positive affect on NPP, which was likely because a favorable warm climate in the early growing season promotes forest growth. Forest NPP was also negatively affected by summer and autumn temperatures, possibly because these are related to temperature induced drought stress. In the NDVI model, forest NPP was affected by NDVI in spring (positive), summer (negative) and winter (negative) seasons. Our study provides insight into seasonal effects of climate and NPP of forest in China, as well as useful knowledge for the development of climate-vegetation models.     

Removal of dicofol from water by immobilized cellulase and its reaction kinetics

Researches on the removal of dicofol catalyzed by immobilized cellulase were conducted. Factors, such as acidity, temperature, enzyme activity, and initial concentration of dicofol, which could influence the removal were studied. The optimal pH for dicofol removal by immobilized cellulase was approximately 4–7, broader than that for free enzymes. The removal efficiencies for immobilized and free cellulase both decreased with increasing initial concentration of dicofol. The K_m for immobilized cellulase was slightly lower than that of free cellulase, suggesting that substrate affinity may be enhanced by immobilization. The optimum temperatures for immobilized and free cellulase were 45 °C and 50 °C. The removal reaction for immobilized cellulase was found to be a first-order reaction. The activation energy was 64.3 kJ mol⁻¹. The continuous oxidation of dicofol carried out in the static system of immobilized cellulase showed that the removal efficiency of immobilized cellulase remained after six cycles of operation. Thus, the catalytic efficiency of cellulase was improved greatly. As evidenced by infrared and gas chromatography–mass spectrometry data, the mechanism of reaction might involve an attack by the OH free radical of cellulase at a weak location of the dicofol molecule, resulting in the removal of three chlorine atoms from dicofol, thus oxygenizing dicofol and producing 4,4′-dichloro-dibenzophenone.     

Size-dependent biological effect of copper oxide nanoparticles exposure on cucumber (Cucumis sativus)

Copper oxide nanoparticles (CuO NPs) have received considerable attention for their toxic effects on crops and potential application in agriculture. In order to investigate the biological effects of CuO NPs on plants, we exposed cucumber (Cucumis sativus) to two sizes of CuO NPs (510 nm, μCuO and 43 nm, nCuO). Results indicated that with concentration increased, the available Cu content in soil increased significantly. The addition of CuO NPs increased Cu content and other nutrient element (e.g., K, P, Mn, and Zn) content in plants. However, diverse particle sizes had different effects. The nCuO treatment had larger translocation factor, higher nutrient element content in fruits, and lower oxidative damage than μCuO treatment. Moreover, nCuO of 100 mg/kg could stimulate cucumber growth, while μCuO had no obvious effects on growth. Conclusively, CuO NPs could be used as copper fertilizer to supply copper to cucumber. The nCuO had better effects on improving the bioavailability of Cu and nutritional value of fruits. These results can help develop strategies for safe disposal of CuO NPs as agricultural fertilizer.

     

化学物质对室内空气的污染

随着国内人民生活水平的提高，百姓对居室内标准的要求越来越高。装修材料含有一定的有害化学物质，可使室内不同程度地受其污染，直接影响居民的身体健康，这已引起各发达国家和国内有关部门的重视。文章主要就室内化学物质的来源、种类、污染现状和对人体健康的影响作了简要概述，同时还介绍了室内空气中化学物质的简易测试方法。     

保护环境 共建我们的家园

随着人类社会的进步,经济文明的发展,全球的环境问题日益严重,建设绿色的家园成为全世界人民的迫切愿望和各国政府的责任。我国作为一个发展大国,如何保护环境,解决环境污染问题,笔者认为解决环境问题的基本思路是首先政府要转变观念,通过立法、税收等强制性手段来保护环境,通过技术创新来解决环保中的技术问题,将环境污染的程度降到最低。     

微生物絮凝剂产生菌的筛选及其絮凝除浊性能

采用某污水处理厂活性污泥富集的菌种 ,通过筛选获得了 1 0株絮凝除浊性能较强的菌株。以其中絮凝性能最优的菌株GS7为研究对象 ,探讨了影响其絮凝作用的主要因素。结果表明 ,GS7的最适生长条件为 :培养基pH值 6、培养时间 1 8h、培养温度 30℃。当废水pH值为 8左右时 ,GS7的絮凝效果最好。在废水中投加少量的二价金属离子Ca2 +可大大提高GS7的絮凝除浊率。GS7处理城市河涌污水等实际废水时浊度去除率可达 93.5%。     

铜、镉复合污染红壤对黑麦草生长和土壤酶活性的影响

采用石灰石调节红壤酸性后,利用对铜、镉具有一定耐性的高产牧草黑麦草修复铜、镉复合污染土壤。分析黑麦草的生长、生理生化指标以及土壤中酶活性的变化,探索在修复铜、镉复合污染红壤的同时又满足饲料作物安全种植的土地利用方式。结果表明,对于弱酸性红壤（pH 6.0左右）,土壤铜全量较低时（〈50 mg/kg）,黑麦草的生物量、叶...