湖泊沉积物中磷化氢的释放动力学初探

采用柱状芯样模拟法,研究了太湖沉积物-水界面磷化氢的释放动力学.结果表明:当沉积物-水界面磷化氢的释放达到动态平衡时,水界面中磷化氢的浓度基本不再增大,大约在0.34 pg·l-1左右,此时磷化氢的释放通量约为0.008 pg·dm-2·h-1.根据室内模拟结果,太湖沉积物每年的磷化氢释放量在13.81-49.62 g之间,从而使磷化氢在湖水中的平均浓度达到0.16 pmol·l-1.     

Effect of natural aquatic humic substances on the photodegradation of bisphenol A

The photochemical degradation of bisphenol A (BPA) was studied in the presence of natural humic substances from different origins under simulated solar irradiation. BPA underwent insignificant direct photolysis in neutral water, but rapid photosensitized degradation in four humic substances solutions via pseudo-first-order reaction occurred. The photo-degradation rate of BPA was insensitive to the different initial BPA concentrations and was inhibited in aerated solution compared with the deoxygenated medium. The reactive oxygen species (ROS) such as ·OH and ¹O₂ produced from excitation of humic substances under irradiation was determined from the quenching kinetic experiment using molecular probe. The five main intermediate photoproducts of BPA in Nordic lake fulvic acid (NOFA) were tentatively identified using gas chromatography/mass spectrometer (GC/MS). Based on the identification of ROS and the analysis of photoproduct formation, the possible phototransformation pathways of BPA were proposed, involving the direct photolysis due to the energy transfer from the triplet state humic substance (³HS*) to BPA molecules and hydroxyl radical addition and oxidation as well.     

The impact of urban planning on land use and land cover in Pudong of Shanghai,China

Functional zones in cities constitute the most conspicuous components of newly developed urban areas,and have been a hot spot for domestic and foreign investors in China,which not only show the expanse of urban space accompanied by the shifts both in landscape(from rural to urban)and land use(from less extensive to extensive),but also display the transformation of regional ecological functions.By using the theories and methods of landscape ecology,the structure of landscapes and landscape ecological planning can be analyzed and evaluated for studying the urban functional zones‘layout.In 1990,the Central Govermment of China declared to develop and open up Pudong New Area so as to promote economic development in Shanghai.Benefited from the advantages of Shanghai‘s location and economy,the government of Pudong New Area has successively built up 7 different functional zones over the past decade according to their functions and strategic goals.Based on the multi-spectral satellite imageries taken in 1990,1997and 2000,a landscape ecolgy analysis was carried out for Pudong New Area of Sanghai ,supported by GIS technology.Green space(including croplands )and built-up areas are the major factors considered in developing urban landscape.This paper was mainly concerned with the different spatial patterns and dynamics of green space,built-up areas and new buildings in different functional zones,as influenced by different spatial patterns and dynamics of green space,built-up areas and new buildings in different functional zones,as influenced by different functional layouts and development strategies.The rapid urbanization in Pudong New Area resulted in a more homogeneous landscape.Agricultural landscape and suburban landscape were gradually replaced by urban landscape as the degree of urbanization increased.As a consequence of urbanization in Pudong,not only built-up patches,but also newly-built patches and green patches merged into one large patch,which should be attributed to the construction policy of extensive green space as the urban development process in Pudong New Area.The shape of green area of 7 functional zones became more and more regular because of the horticultural needs in Shanghai urban planning.Some suggestions were finally made for the study of future urban planning and layout.     

粤北岩溶区的石漠化及其治理对策探讨

粤北岩溶石山地区分布有面积广泛的碳酸盐岩发育多种岩溶地貌。由于该地区的特殊地质、水文、气候等自然因子的影响，其岩溶生态环境脆弱，环境容量低，敏感度高，抗干扰能力弱。在不合理的人类活动和自然因素作用下，易引发出一系列的生态问题。岩溶生态环境开始恶化，植被走向逆向演替等，最后出现大面积的石山，发生石演化观象。     

光助Fenton氧化、化学絮凝法联合处理R盐废水的研究

采用光助Fenton氧化、化学絮凝法联合处理生物难降解的R盐废水,考察了不同反应条件对处理效果的影响.试验结果表明,光助Fenton氧化、化学絮凝法联合处理废水,两者之间存在协同作用,可以提高处理效果,降低处理成本.在最佳试验条件下,R盐废水经光助Fenton氧化、化学絮凝法联合处理后,COD去除率可达90%以上.     

超声-过氧化氢-氧化铜组合技术催化氧化水中苯酚

研究了超声-H2O2-CuO组合技术对苯酚的降解效果。考察了苯酚初始浓度、溶液温度及鼓入空气对苯酚去除率的影响。实验结果表明，与未鼓入空气时相比，连续鼓气时苯酚的降解效果较好；初始浓度低，苯酚去除率高；溶液温度从20％上升到55％时，苯酚去除率随温度升高而增大，温度对该过程的影响主要表现为对催化剂的影响而不是对超声作用的影响。高效液相色谱分析表明，苯酚降解的中间产物主要为对苯二酚、邻苯二酚及其他有机小分子物质，最终产物为草酸、二氧化碳和水。     

Genotoxicity of two novel pesticides for the earthworm, Eisenia fetida

In this paper, several studies were conducted to evaluate the genotoxicity of two pesticides, Imidacloprid and RH-5849, for earthworm (Eisenia fetida). Earthworms were exposed in different exposure systems to evaluate their acute toxicity and the genotoxicity of the two pesticides was evaluated by using the method of sperm deformity assessment, micronucleus test of root tip cells in Vicia faba, a mouse bone-marrow micronucleus test, and comet assay. LC(50) (interpolated concentration at which 50% mortality of test population occurs) for earthworms varied in different exposure systems. The results indicated that Imidacloprid was consistently more toxic than RH-5849 in all exposure systems. In this study, sperm deformity test was used to detect the potential adverse influences of pesticides on the reproduction of earthworms. The results demonstrated that significant induction of sperm deformity (p<0.01) and a dose-effect relationship displayed at Imidacloprid concentrations higher than 0.5 mg/kg dry soil. However, the sperm deformity frequency of groups exposed to RH-5849 did not show significant difference (p>0.05) from the control until the dose reached 100 mg/kg dry soil. The results of the V. faba micronucleus tests showed that micronuclei frequency of the exposed group did not show significant difference (p>0.05) from the control until the concentration of Imidacloprid and RH-5849 reached 100 mg/ml. The results of the mouse bone-marrow micronuclei test also indicate that two pesticides did not show significant effects (p>0.05) on the micronuclei frequency in mice bone-marrow cells until the dose reached 100 mg/kg for Imidacloprid and 300 mg/kg for RH-5849 (2/3 LD(50)). Although no genotoxicity was detected by using the micronucleus tests, the results of the comet assay showed that the two pesticides induce significant DNA damage (p<0.01) in earthworms and dose-effect relationships were displayed. The 'earthworm comet assay' is a rapid and sensitive way to screen chemicals or terrestrial environments for their DNA-damaging properties.     

村镇建设中农村污水处理设施的选择

有机废弃物是村镇环境的主要污染源,污水处理已成为村镇建设中亟待解决的问题。受经济发展水平限制,常规的污水处理设施在村镇难以实施,为此必须采用适合村镇经济水平和管理水平的污水处理方式。针对村镇的实施条件,在对几类小型简易污水处理设施特点进行分析的基础上,提出在村镇建设中易推行结构简单、费用低廉、便于管理、实施方便的沼气发酵池和地埋式无动力污水处理设施,以初步解决村镇污水问题。     

污水处理设施建设与运营模式浅析

详细介绍了国外污水处理设施建设与运营的管理经验,分析了英国、美国、法国和荷兰等典型管理模式的特点,阐述了中国污水处理事业的发展历程,调研了目前国内并存的事业体制、企业化管理、委托运营、DBO（设计-建设-运营）、特许经营、股权转让、合资合作、完全私有化、用户和社区资助等模式并逐一进行分析,指出了中国污水处理设施建设与运营的发展方向,认为应尽量慎重考虑涉及产权的特许经营模式,着力推广DBO模式。