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211.
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213.
紫外、臭氧复合对饮用水的杀菌除微污染实验 总被引:7,自引:1,他引:7
以可在线产生O3的反应器为依托 ,变换反应器中的不同工艺条件 ,分别对UV、O3、UV/O3、UV/在线O3等不同工艺条件对总细菌数、E .coli的杀灭和对微污染物 2 ,4 二氯酚的降解规律进行研究 .结果表明 ,UV/O3可以有效杀菌和降解微污染物 ;在循环实验中 ,反应器水流速在 40 0L·h- 1时 ,该反应器可有效产生在线O3,其在线O3对杀菌和除微污染均有一定的增效作用 .实验证明 ,UV/O3复合处理是一种很有前景的饮用水杀菌、除微污染的技术 . 相似文献
214.
Xiaomin Chen Qirong Shen Yangchun Xu 《Frontiers of Environmental Science & Engineering》2007,1(4):443-447
Every year about 1,500 ha of land is reclaimed from the sea along the coastline of Jiangsu Province, China. It is important to characterize the hydraulic properties of this reclaimed land to be able to predict and manage salt and water movement for amelioration of these saline soils. In this paper, we report hydraulic properties of these salt-affected soils. The pressure-plate method, constant head method, the crust method and Klute's method were used in this study. The saturated hydraulic conductivities of the soils ranged from 128.66 to 141.26 cm/day and decreased with increasing soil depth. The unsaturated hydraulic conductivities followed an exponential function of pressure head. The soil water retention curves were similar for three soil layers in the soil. The saturated water content, field capacity and wilting point decreased with increasing soil depth. Plant available water contents of the three layers in the soil profile were 0.21, 0.20 and 0.19 cm3/cm3, respectively. The unsaturated soil water diffusivity of the studied soils ranged from 0.07 to 10.46 cm2/min, and was related to the water content via an exponential relationship. 相似文献
215.
本研究以湖南省林业技术推广总站在湖南选育的17个耐寒桉树优良单株为试验材料,进行组培繁殖,有14个优良单株成功地诱导出了愈伤组织或芽。结果表明,以一年生扦插苗的当年生嫩枝作为外植体来源,污染率低且愈伤组织和芽的诱导率高;0.25%氯化汞消毒15—20分钟,可将污染率控制在70%以下,且对外植体的损害最小;按树最佳的诱导培养基为:1/2MS+BA_(1.0)+IBA_(0.25),最佳的继代培基为:MS+BA_(1.0)+KT_(1.0)+VB2_(10)。 相似文献
216.
砷在金属氧化物/水界面上的吸附机制Ⅰ.金属表面羟基的表征和作用 总被引:2,自引:1,他引:2
利用红外光谱对铁铈氧化物(Fe-Ce)吸附材料中的金属表面羟基(M-OH)进行了表征,并探讨了金属羟基在砷吸附中的作用.透射和原位温度漫反射-傅立叶变换红外光谱(FTIR)表征结果表明,Fe-Ce表面存在丰富的M-OH,但M-OH含量随制备温度升高而逐渐减少;Fe-Ce上的M-OH与一般金属氧化物的表面羟基特性存在显著不同,可能是一种特殊类型的结构性羟基.对砷吸附前后的Fe-Ce材料进行透射FTIR表征,发现砷饱和吸附后M-OH的摇摆振动消失,同时生成了新的As-O振动峰,表明M-OH在砷的去除中起着重要的作用;初始吸附pH由9.0降至5 0只引起了吸附剂上As-O键的伸缩振动向高频略微偏移;综合FTIR结果可以推测,M-OH和砷阴离子发生了直接的表面络合,在不同的pH条件下均与砷形成了内层络和物. 相似文献
217.
以渤海湾西岸天津段入海河流的径流量和输沙量数据为基础,采用Kendall秩相关检验法和Mann-Kendall法对近50年入海径流量和输沙量进行了趋势分析和突变性检验.结果表明,近50年来渤海湾西岸天津段入海径流量和输沙量均呈显著下降的趋势.近50年来华北地区降水量减少、天然径流偏低是导致入海径流量减少的自然因素,而流域人类活动如水库和防潮闸的建设,以及沿河取水取沙也是不可忽视的重要因素.该段海岸入海径流量和输沙量的减少已导致河口区盐度上升、水质恶化、沉积物污染等问题,最终会影响河口生态系统的结构和生物资源的可持续发展与利用. 相似文献
218.
219.
Seasonal changes in the concentrations of nitrogen and phosphorus in farmland drainage and groundwater of the Taihu Lake region of China 总被引:3,自引:0,他引:3
Xiaomin Chen Fei Wo Can Chen Kun Fang 《Environmental monitoring and assessment》2010,165(1-4):159-168
Monte Carlo simulations were performed using the GEANT4 code for the investigation of γ-ray absorption in water in different spherical geometries and of the efficiency of a NaI(Tl) detector for different radionuclides in the aquatic environment. In order to test the reliability of these simulations, experimental values of the NaI(Tl) detector efficiency were deduced and seem to be in good agreement with the simulated ones. In addition, using the simulated efficiency, an algorithm was developed to determine the minimum detectable activity in becquerels per cubic meter in situ as a function of energy for typical freshwater and seawater spectra. 相似文献
220.
Xiaomin Chen Qirong Shen Yangchun Xu 《Frontiers of Environmental Science & Engineering in China》2007,1(4):443-447
Every year about 1,500 ha of land is reclaimed from the sea along the coastline of Jiangsu Province, China. It is important
to characterize the hydraulic properties of this reclaimed land to be able to predict and manage salt and water movement for
amelioration of these saline soils. In this paper, we report hydraulic properties of these salt-affected soils. The pressure-plate
method, constant head method, the crust method and Klute's method were used in this study. The saturated hydraulic conductivities
of the soils ranged from 128.66 to 141.26 cm/day and decreased with increasing soil depth. The unsaturated hydraulic conductivities
followed an exponential function of pressure head. The soil water retention curves were similar for three soil layers in the
soil. The saturated water content, field capacity and wilting point decreased with increasing soil depth. Plant available
water contents of the three layers in the soil profile were 0.21, 0.20 and 0.19 cm3/cm3, respectively. The unsaturated soil water diffusivity of the studied soils ranged from 0.07 to 10.46 cm2/min, and was related to the water content via an exponential relationship. 相似文献