排序方式: 共有67条查询结果,搜索用时 15 毫秒
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根据技术的复杂程度和系统性,经济效益,削减废弃物的潜力、环境效益、实施难易程度等5个方面,以权重打分综合的方法进行方案筛选,筛选出5个备选方案作经济、技术和环境评估。在此基础上,推存主要工段联合改造方案,并对此方案作出一步经济分析,表明该方案的实施是可行的。 相似文献
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小流域N、P污染负荷的构成比重研究 总被引:8,自引:0,他引:8
对浙江省宁海县颜公河流域N、P污染物负荷的构成比重进行了研究,提出了农业非点源污染造成水体污染的严重性。采用美国农业部的AnnAGNPS模型模拟计算流域中农业面源污染的N、P负荷,并对模型模拟计算的可靠性进行了验证。 相似文献
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纳米TiO2薄膜光催化降解2,4-二氯酚的动力学研究 总被引:11,自引:0,他引:11
以主波长为365nm的紫外光灯为光源,纳米TiO2薄膜为光催化剂,研究了2,4-二氯酚光催化降解的产物及Cl^-对2,4-二氯酚光催化反应动力学的影响,并进一步探讨了Cl对2,4-二氯酚光解影响的机理,2,4-二氯酚可以经光催化氧化被彻底矿化,结合外加Cl^-对2,4-二氯酚光催化降解的影响和L-H反应动力学分析,可以认为Cl^-对2,4-二氯酚光催化降解的抑制作用,是由于Cl^-与2,4-二氯酚在TiO2表面竞争同一活性位点所致。因此,当光催化反应进行到Cl^-在TiO2表面竞争性吸附较强时,在反应动力学方程中必须考虑Cl^-的竞争性作用。 相似文献
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生命周期评价研究进展 总被引:15,自引:2,他引:13
生命周期评价作为一种评价产品、工艺过程或活动在整个生命周期中环境影响的工具,在国际上广受关注。现对它的概念、发展历程、技术框架、特征及存在问题作简单的介绍,并对其未来发展作了展望。 相似文献
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Liu J Liang X Yang J Ye Y Su M Nie Z Chen Y 《Journal of environmental monitoring : JEM》2011,13(10):2844-2850
The environmental risk of aquatic phosphorus (P) critically depends on its mobility and bioavailability, both of which are greatly affected by the size distribution and composition of P. The size distribution (particulate, colloidal and truly dissolved phase) of P, composed of molybdate reactive P (MRP) and molybdate unreactive P (MUP), was determined at twenty-three typical sections of the East Tiao River, China in the plum rain season. Results indicated particulate P was dominant followed by the truly dissolved P, while colloidal P was quantitatively the lowest in the whole river. From upstream to downstream, particulate P sharply increased, along with a slight decrease of truly dissolved P. However, colloidal P remained at a relatively stable level in the whole river, ranging from below detection limit to 0.025 mg L(-1), 0 to 13.4% of total P (TP). Furthermore, colloidal MRP exhibited a rising trend downriver as compared to upriver, with the notable transfer of MRP from the truly dissolved phase to particulate and colloidal phases. Particle concentration effect for colloids, observed in the study of MRP distribution, further corroborated the role of colloids in MRP solid/liquid partitioning. These observations, in this large-scale field investigation, fitted the "colloidal pumping" hypothesis. It may be concluded that colloids act as the intermediate and buffer in the dynamically balanced transfer of P from truly dissolved phase to large particulate phase, having a significant role in size distribution of P. 相似文献
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This study investigated the toxicity extent of phenanthrene and pyrene to two cultivars (CM-72 and Gairdner) of barley (Hordeum vulgare). Germination of barley seeds was evaluated in 69-d aged soil, separately spiked with phenanthrene at extractable concentrations of 0.95, 6.3, 59, and 300 mg kg?1 (dry soil) and pyrene at 1.0, 9.0, 73, and 400 mg kg?1 (dry soil). Although germination was not inhibited, significant (P < 0.05) reduction in root and shoot length occurred at concentrations of phenanthrene ≥6.3 mg kg?1 and pyrene ≥9.0 mg kg?1 after both 72 and 240 h. Fresh and dry biomass of both cultivars reduced with increasing concentrations of both polycyclic aromatic hydrocarbons (PAHs). Barley cultivar CM-72 was more sensitive than Gairdner, and it can be considered suitable for toxicity assessment of PAH-contaminated soils. 相似文献
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More and more sewage sludge is being produced in China. Safe and economical methods for sewage sludge disposal should be found considering the increase in sewage treatment. In order to verify the feasibility of sludge disposal on newly built highway embankments, five treatments (0, 15, 30, 60 and 120 tons ha−1) of sewage sludge compost (SSC) were added to a silty-clay embankment soil on the Xi-Huang highway. The results showed that amendment with SSC increased soil available N, available P, organic matter, cation exchange capacity, and water content, and decreased soil bulk density. Application of SSC enhanced ryegrass growth and reduced runoff and soil erosion. Heavy metal losses from sediments in runoff remained constant or decreased relative to the control until a rate of 60 tons ha−1 was exceeded, when heavy metal losses appeared to increase. 相似文献
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