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551.
在温室中用砂培和水培方法种植紫花苜蓿和大麦,以此来研究SO_4~(2-)和SE(Ⅵ)对作物吸收Se的影响以及SO_4~(2-)和Se(Ⅵ)之间的相互作用。试验结果证明,紫花苜蓿和大麦体内都能累积Se(Ⅵ)并达到危害人类和动物健康的水平。Se(Ⅵ)对紫花苜蓿和大麦的干物质量都有不利的影响。当溶液含Se(Ⅵ)量超过0.1mg L~(-1)时,两者的干物质量减少25%—35%,含Se(Ⅵ)量超过lmg L~(-1)时,作物减产50%以上。SO_4~(2-)对植物吸收Se(Ⅵ)有明显的拮抗作用,能减少植物对Se(Ⅵ)的吸收,溶液中含SO_4~(2-)量超过2dS m~(-1),植物吸收Se(Ⅵ)减少99%,这是因为Se(Ⅵ)和SO_4~(2-)有相似的化学和物理性质,植物吸收Se(Ⅵ)和SO_4~(2-)的机理是极相似的。因此,当SO_4~(2-)在根的吸收基上成为主要离子时,植物组织中含Se(Ⅵ)量就会大大减少。含Se(Ⅵ)量较高的井水或农业排水是否可以用于灌溉,主要取决于水中的SO_4~(2-)含量。 相似文献
552.
利用原有的化粪池作厌氧池,并以射流曝气生物接触氧化处理工艺为主体,串联消毒杀菌装置,即采用厌氧—好氧—化学杀菌三级串联深度处理邛海宾馆污水取得良好效果。处理后的水质清澈透明,无异采,COD31mg/l,BOD_52.1mg/l,去除率均在95%以上。 相似文献
553.
554.
Coastal zones are among the planets most threatened ecosystems and effective management of these systems requires spatial
tools at appropriate spatial scales. Here we apply aerial photography with Geographic Information Systems (GIS), to map the
cumulative anthropogenic footprint of an industry in a spatially defined ecologically important region of the British Columbian
coast. Resolution required for such an analysis was made possible through highly detailed aerial photography of the region
taken at an elevation of 305 m, at a 1:3000 scale. The approach applied here was successful in accurately detailing the cumulative
extent of the anthropogenic activity on the foreshore which could have not been achieved at a coarser resolution. Such information
was then effectively applied to visualize and assess the potential impact of an industrial development of the foreshore on
bird distribution within the spatially identified region. The degree of overlap between the anthropogenic footprint and small
estuaries within the region was also successfully assessed. For ecologically important regions such as Marine Protected Areas,
and other such designated sensitive coastal regions, detailed mapping through aerial photography and GIS can aid in first
identifying the true extent of an anthropogenic activity and then secondly used to link to possible ecological consequences.
This in turn greatly enhances our ability to best manage the region of interest such that conservation priorities can be met. 相似文献
555.
Jen-ni Kuo Alicia Y. Soon Christine Garrett Michael T. K. Wan John P. Pasternak 《Journal of environmental science and health. Part. B》2013,48(4):250-261
The objectives of this study were to determine environmental occurrence and concentrations of selected currently-used-pesticides and some transformation products in agricultural farms in the Okanagan Valley (OKV), and to conduct a simple risk assessment of environmental pesticides levels detected in OKV on non-target aquatic organisms. The OKV is the tree fruit country of the Province of British Columbia where considerable amount of pesticides are applied annually. Water, sediment and soil samples were collected at eleven sites in early June and late September following rainfall events and/or extended periods of irrigation from drainage ditches and/or from small streams. Undisturbed reference sites were also sampled. Study results showed that forty of the eighty chemicals analyzed, including organochlorine, nitrogen-containing and organophosphate pesticides commonly used for OKV crops, were detected in runoff and small stream water samples. Among which, endosulfan-sulfate was the most frequently detected chemical. Also, azinophos-methyl (0.699–25.5 ng/L), diazinon (0.088–214 ng/L) exceeded, and α-, β- endosulfan, endosulfan sulphate approached the guidelines for the protection of aquatic life. 相似文献
556.
557.
日光温室蔬菜中百菌清残留状况及不同处理对其的影响 总被引:9,自引:0,他引:9
近些年来,食品安全问题逐渐成为人们关注的热点,而农药残留由于其对食品安全和人类健康的影响,引起了广泛的关注.随着越来越多的温室蔬菜出现在人们的生活中,其农药残留势必会对人们的健康产生巨大的影响.本文应用气相色谱法研究两种常见温室蔬菜(黄瓜、番茄)的农药百菌清残留情况及不同处理对其的影响.结果表明,百菌清在这两种温室蔬菜中严重超标,而实验中所采取的类似家庭采用的流水洗净和去皮两种不同处理方式都可以有效降低百菌清的残留量,去皮的效果更为显著. 相似文献
558.
在试验的基础上,分析了声波助清灰技术对除尘效率的影响,并对各种清灰方式单独或组合使用的效果进行比较,最后对下一步的研究提出了一些建议。 相似文献
559.
C. K. Ngan U. B. Cheah W. Y. Wan Abdullah K. P. Lim B. S. Ismail 《Water, Air, & Soil Pollution: Focus》2005,5(1-2):125-136
The fate of chlorothalonil, chlorpyrifos and profenofos in sandy loam soil under tropical condition was studied in a vegetable
plot in the Cameron Highlands, Malaysia. The plot was treated with chlorothalonil, chlorpyrifos and profenofos according to
normal agricultural practices of the Cameron Highlands. Water (runoff and lysimeter), soil and bedload sediment samples were
taken according to a sampling schedule. Residues in water, soil and bedload sediment samples were laboratory analysed to determine
amount. Chlorothalonil residues were detected in the range of < 0.01–0.08 mg/kg in the soil, < 0.01–0.02 ng/mL in the leachate,
< 0.01–0.02 ng/mL in the runoff and < 0.01–0.11mg/kg in the sediment. Field studies of chlorpyrifos showed residue levels
of < 0.01–0.06 mg/kg in the soil, < 0.01–0.07 ng/mL in the leachate, < 0.01–0.08 ng/mL in the runoff and < 0.01–0.62 mg/kg
in the sediment. Residue levels of profenofos were detected in the range of < 0.01–0.02 mg/kg in the soil, < 0.01–0.87 ng/mL
in the leachate, < 0.01–0.08 ng/mL in the runoff and < 0.01–0.35 mg/kg in the sediment. The three pesticides dissipated rapidly,
with DT50 (time for 50% loss) of less than two days. The study showed that these pesticides dissipated rapidly under the climatic
conditions of the Cameron Highlands in Malaysia. 相似文献
560.
Removal of batteries from solid waste using trommel separation 总被引:4,自引:0,他引:4
Lau ST Cheung WH Kwong CK Wan CP Choy KK Leung CC Porter JF Hui CW Mc Kay G 《Waste management (New York, N.Y.)》2005,25(10):1004-1012
This paper describes the design and testing of a trommel for separation of batteries from solid waste. A trommel is a cylindrical separation device that rotates and performs size separation. It has also been used in areas such as municipal solid waste (MSW) processing, classifying construction and demolition debris, screening mass-burn incinerator ash and compost processing. A trommel has been designed based on size separation to separate household batteries from solid waste, which can then be used as feedstock for alternative applications of solid waste combustion, particularly where the metal content of the product is also a critical parameter, such as the Co-Co process for integrated cement and power production. This trommel has been tested with batches of university office and restaurant wastes against various factors. The recovery efficiency of batteries increases with decreasing inclination angle of the trommel and decreasing rotational speed. A physical characterization of the university solid waste has been performed with a 20-kg sample of the tested waste. It was found that there is a trend of decreasing recovery of batteries with increasing paper composition, and a trend of increasing recovery of batteries with increasing organic materials composition. 相似文献