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741.
742.
“十二五”辽河流域沈阳段污染治理对策初探   总被引:1,自引:0,他引:1  
在研究分析“十二五”期间辽河流域沈阳段污染治理工作面临形势的基础上,总结了目前存在的主要问题,并有针对性地提出了解决对策。  相似文献   
743.
Microbial compositions showed high differences in two study areas. COD was the key anthropogenic indicator in the coastal wastewater disposal area. Distinctive microbes capable of degrading toxic pollutants were screened. Microbial communities in effluent-receiving areas followed “niche theory”. Microbial community structure is affected by both natural processes and human activities. In coastal area, anthropegenetic activity can usually lead to the discharge of the effluent from wastewater treatment plant (WWTP) to sea, and thus the water quality chronically turns worse and marine ecosystem becomes unhealthy. Microorganisms play key roles in pollutants degradation and ecological restoration; however, there are few studies about how the WWTP effluent disposal influences coastal microbial communities. In this study, sediment samples were collected from two WWTP effluent-receiving areas (abbreviated as JX and SY) in Hangzhou Bay. First, based on the high-throughput sequencing of 16S rRNA gene, microbial community structure was analyzed. Secondly, several statistical analyses were conducted to reveal the microbial community characteristics in response to the effluent disposal. Using PCoA, the significant difference of in microbial community structure was determined between JX and SY; using RDA, water COD and temperature, and sediment available phosphate and ammonia nitrogen were identified as the key environmental factors for the community difference; using LDA effect size analysis, the most distinctive microbes were found and their correlations with environmental factors were investigated; and according to detrended beta-nearest-taxon-index, the sediment microbial communities were found to follow “niche theory”. An interesting and important finding was that in SY that received more and toxic COD, many distinctive microbes were related to the groups that were capable of degrading toxic organic pollutants. This study provides a clear illustration of eco-environmental deterioration under the long-term human pressure from the view of microbial ecology.  相似文献   
744.
针对电厂循环冷却排污水的处理技术进行了中试研究.采用超滤、反渗透的工艺处理电厂循环冷却排污水,处理后的水能够满足低压锅炉补充水的要求.该工艺为循环冷却排污水的再利用开辟了一条新途径,既节约了水资源,又减少了环境污染.  相似文献   
745.
Xu F  Liang X  Lin B  Su F  Schramm KW  Kettrup A 《Chemosphere》2002,48(5):553-562
The capacity factors of a series of hydrophobic organic compounds (HOCs) were measured in soil leaching column chromatography (SLCC) on a soil column, and in reversed-phase liquid chromatography on a C18 column with different volumetric fractions (phi) of methanol in methanol-water mixtures. A general equation of linear solvation energy relationships, log(XYZ) XYZ0 + mV(I)/100 + spi + bbetam + aalpham, was applied to analyze capacity factors (k'), soil organic partition coefficients (Koc) and octanol-water partition coefficients (P). The analyses exhibited high accuracy. The chief solute factors that control logKoc, log P, and logk' (on soil and on C18) are the solute size (V(I)/100) and hydrogen-bond basicity (betam). Less important solute factors are the dipolarity/polarizability (pi*) and hydrogen-bond acidity (alpham). Log k' on soil and log Koc have similar signs in four fitting coefficients (m, s, b and a) and similar ratios (m:s:b:a), while log k' on C18 and logP have similar signs in coefficients (m, s, b and a) and similar ratios (m:s:b:a). Consequently, logk' values on C18 have good correlations with logP (r > 0.97), while logk' values on soil have good correlations with logKoc (r > 0.98). Two Koc estimation methods were developed, one through solute solvatochromic parameters, and the other through correlations with k' on soil. For HOCs, a linear relationship between logarithmic capacity factor and methanol composition in methanol-water mixtures could also be derived in SLCC.  相似文献   
746.
Yu J  Sun L  Xiang J  Hu S  Su S  Qiu J 《Chemosphere》2012,86(11):1122-1126
This paper investigated the volatilization behavior of heavy metals during thermal treatment of model solid waste in a fluidized bed reactor. Four metal chlorides (Cd, Pb, Cu and Zn) were chosen as metal sources. The influence of redox conditions, water and mineral matrice on heavy metal volatilization was investigated. In general, Cd shows significant vaporization especially when HCl was injected, while Cu and Pb vaporize moderately and Zn vaporization is negligible. Increasing oxygen concentration can lower heavy metal vaporization. Heavy metal interactions with the mineral matter can result in the formation of stable metallic species thus playing a negative effect on their behavior. However, HCl can promote the heavy metal release by preventing the formation of stable metallic species. The chemical sorption (either physical or chemical) inside the pores, coupled with the internal diffusion of gaseous metal species, may also control the vaporization process. With SO2 injected, Cd and Pb show a higher volatility as a result of SO2 reducing characteristics. From the analysis, the subsequent order of heavy metal volatility can be found: Cd > Cu ? Pb ? Zn.  相似文献   
747.
污染减排是中国环境保护工作的中心任务。"十二五"污染减排必须基于污染源普查动态更新调查结果确定减排基数。根据2009年珠海高新区动态更新调查结果,从企业规模和行业规模的角度对珠海高新区工业源的主要污染物排放特点进行分析,为明确减排基数奠定基础。并从加强前期研究、发展循环经济、创新工作机制等三个方面对珠海高新区污染减排工作提出对策建议,促进污染减排工作可持续发展和产业结构优化升级,推进资源节约型、环境友好型社会建设。  相似文献   
748.
背角无齿蚌净化养殖水体中的重金属   总被引:1,自引:0,他引:1  
通过建立微型生态系统,研究不同养殖密度和处理时间的背角无齿蚌(Anodonta woodiana)对大宗淡水鱼养殖池塘水体中重金属的净化效果.结果显示,背角无齿蚌对重金属的净化效果受到处理时间和养殖密度的显著影响(PPP3和22.77 d、40 ind./m3和19.78 d时,对Cr和Zn的去除率可提升至80.3%和81.8%.本研究表明背角无齿蚌有潜力用于养鱼水体重金属的净化.  相似文献   
749.
对低温环境中乙醇汽油和普通汽油的冷凝水、CO、HC、NOx和CO2排放特性进行了研究,并对5种排放物的形成机理和排放趋势进行了分析。ECE工况(-20、-10和0 ℃)和怠速工况(-30、-20、-10和0 ℃)下,乙醇汽油和普通汽油的冷凝水排放量主要受含氢量、车辆构造和外界环境的共同影响。ECE工况中冷凝水的总体排放趋势是随着温度降低而增加,乙醇汽油的总排水量持平或略低于普通汽油。-10 ℃时乙醇汽油的高含氧量能促进燃烧速度和燃烧效率,减少CO和HC排放,增加NOx排放;0 ℃时低温环境和乙醇的高汽化潜热会影响可燃混合气形成和燃烧速度,降低缸壁温度,增加CO和HC排放。  相似文献   
750.
Atmospheric particulate pollution in China has attracted much public attention. Occasionally, the particle number concentration increases sharply in a short time period, which is defined as a “particulate matter explosive increase”. Heavy particulate matter pollution not only reduces visibility but also has an adverse effect on human health. Hence, there is an urgent need to discover the causes of particulate matter explosive increase. During this campaign, the particle number concentration and free radicals were measured at a tall building on the campus of Lanzhou University of Technology. Additionally, we examined a series of chemicals to reproduce the observed particulate matter explosive increase in a smog chamber to determine its potential factors. Then, we analyzed the mechanism of particulate matter explosive increase in the presence of free radicals. We found that, among the potential inorganic and organic sources analyzed, a mixture of organic and SO2 in the research region had a major effect on particulate matter explosive increase. Moreover, free radical oxidation has a large effect, especially in the formation of organic particulates.  相似文献   
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