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251.
252.
低C/N条件下MUCT工艺的反硝化除磷特性 总被引:1,自引:0,他引:1
以C/N较低的污水为处理对象,重点研究和分析了MUCT工艺缺氧区的反硝化除磷特性.结果表明,①缺氧区1因为COD浓度相对较高,回流污泥中的硝酸盐氮优先被传统反硝化菌利用,不能作为DPB的电子受体,所以主要发生释磷反应;②缺氧区2内DPB利用厌氧段贮存大量PHB为碳源,以硝酸盐氮为电子受体进行吸磷,且吸磷量逐日提高,从最初的0 .93 mg/L增加至18 mg/L,缺氧吸磷率最终稳定在40%左右;③缺氧区3内,由于硝酸盐氮和COD浓度过低,进行无效释磷反应过程,释磷量在0 .27~3 mg/L之间;④系统对COD、TN、TP的去除率较高,出水TN和TP浓度分别在10 mg/L和0 .9 mg/L以下. 相似文献
253.
254.
太湖主要入湖河流排污控制量研究 总被引:3,自引:1,他引:3
利用2006—2008年的监测数据对太湖主要入湖河流的水环境状况进行了分析,通过对研究区工业污染源、农业污染源和城镇生活污水排污的分布以及入河情况的调查,对各种污染源的入河量进行了计算,根据确定的水质目标,分别计算出主要入湖河流以及区域水系的水环境容量和排污控制量。结果表明:15条主要入湖河流超标现象显著,近3a来污染程度有所波动,N、P污染最为严重。研究区内污染物入河量较大,未接管的生活源污染物入河量所占比重最大,各类污染物均在50%~60%之间;张家港市的污染物入河量最大,各类污染物所占比重达总入河量的18%~20%。研究区内河网密布,水环境容量分布不均匀,望虞河、直湖港、武进港等7条河流水环境容量较大,张家港市区域水环境容量较大。为保证水质达标,研究区内近期共须削减CODCr66554.38t/a、NH4-N8105.71t/a、TP1324.42t/a;远期共须削减CODCr96719.08t/a、NH4-N11541.45t/a、TP1788.71t/a。 相似文献
255.
几种工矿废渣改善土壤供硅能力的效果 总被引:1,自引:0,他引:1
施用硅肥可以改善土壤硅素肥力状况,提高水稻产量,改善稻米品质,增强水稻抗性,利用工矿废渣生产硅肥还能产生良好的生态环境效益。本研究采用室内模拟与盆栽试验的方法,研究了高炉渣、粉煤灰和金刚石矿渣作硅肥施用对水稻土供硅能力的影响。结果表明,在北方酸性水稻土上施用废渣使土壤硅素释累积放量显著增加,明显改善土壤的供硅能力,促进水稻对硅素养分的吸收,上述效果随废渣用量增加而更为明显,且高炉渣的效果要明显好于粉煤灰和金刚石矿渣。另外,五种废渣的不同施用量与植株含硅量增加率之间均满足对数正相关关系,对数项系数a与127d的硅素累积释放量之间存在极显著的线性正相关关系,说明土壤硅素累积释放量可以评价施用过废渣的土壤的供硅能力,能够反映废渣作硅肥的适宜性。 相似文献
256.
Given the amounts of end-of-life electrical and electronic equipment (EoL-EEE) being generated and their contents of both harmful and valuable materials, the EoL-EEE issue should be regarded not only as an emerging environmental problem but also as a resource management strategy in China. At present, in order to provide the basis for managing EoL-EEE at both product and substance levels in China, it is necessary to carry out a quantitative analysis on EoL-EEE and to determine how much of it will be generated and how much materials and substances it contains. In this study, the possession and obsolescence amounts of five types of household appliance (HA) including television (TV) sets and the amounts of substances contained in EoL TV sets were estimated using time-series product flow analysis (PFA) and substance flow analysis (SFA). The results of PFA indicated that the total possession amounts of those five types of HAs will exceed 3.1 billion units in 2030, which will be two times higher than those in 2010. In addition, it was estimated that cumulatively over 4.8–5.1 billion units of these five types of EoL HA would be obsoleted between 2010–2030. The results of SFA on TV sets indicated that the generated amounts of most of the less common metals and a part of common metals such as copper (Cu) would tend to decrease, whereas those of other common metals such as iron (Fe) as well as precious metals would tend to increase in EoL TV sets in 2015–2030. The results of this study provide a quantitative basis for helping decision makers develop strategic policies for the management of EoL-EEE considering both environmental and resource aspects. Moreover, a calculation scheme of obsolete HAs presented in this study can be applied to estimate other types of EoL durable good. Meanwhile, the frameworks of this study will help not only the policy decision makers in the Chinese government but also those in developing countries that are facing similar problems. 相似文献
257.
云南省是我国面向东南亚、南亚的重要陆路通道,要打造国际型现代物流中心,必定需要一支高素质的物流人才队伍。未来10年,云南省的物流人才缺口将在30万人以上,物流业成为最大的紧俏职业之一。分析云南物流人力资源供给的特征以及影响供给的因子,对云南省物流人力资源的开发和配置具有现实指导意义。 相似文献
258.
As in many sectors in emerging economies, the concept of corporate social responsibility (CSR) has become important for exporting agri‐food firms in view of their integration in global supply chains. The purpose of this research was to assess the implementation by Chilean fruit exporters of CSR practices that go beyond minimum legal requirements. The principal results are that, although socio‐economic components of CSR such as poverty reduction and socially just working conditions receive much attention, firms consider comprehensive environmental practices as less important. The results also indicate a slightly higher implementation of comprehensive CSR practices by large firms as compared to small and medium sized enterprises (SMEs). The main conclusion is that, although CSR is increasingly considered by Chilean firms, among SMEs in particular, more attention needs to be paid to raising awareness among managers about CSR practices and to providing assistance in their implementation. This supports findings on CSR implementation in other emerging economies that an active role of civil society and industry organizations is key and that targeted support strategies are needed to install a holistic awareness of CSR and help firms to improve on those aspects of CSR that are relatively underdeveloped. 相似文献
259.
Pete Campana John Knox Andrew Grundstein John Dowd 《Journal of the American Water Resources Association》2012,48(2):379-390
Campana, Pete, John Knox, Andrew Grundstein, and John Dowd, 2012. The 2007‐2009 Drought in Athens, Georgia, United States: A Climatological Analysis and an Assessment of Future Water Availability. Journal of the American Water Resources Association (JAWRA) 48(2): 379‐390. DOI: 10.1111/j.1752‐1688.2011.00619.x Abstract: Population growth and development in many regions of the world increase the demand for water and vulnerability to water shortages. Our research provides a case study of how population growth can augment the severity of a drought. During 2007‐2009, a drought event that caused extreme societal impacts occurred in the Athens, Georgia region (defined as Clarke, Barrow, Oconee, and Jackson counties). An examination of drought indices and precipitation records indicates that conditions were severe, but not worse than during the 1925‐1927, 1954‐1956, and 1985‐1987 drought events. A drought of similar length to the 2007‐2009 drought would be expected to occur approximately every 25 years. Streamflow analysis shows that discharge levels in area streams were at a record low during 2007 before water restrictions were implemented, because of greater water usage caused by recent population increases. These population increases, combined with a lack of water conservation, led to severe water shortages in the Athens region during late 2007. Only after per capita usage decreased did water resources last despite continuing drought conditions through 2009. Retaining mitigation strategies and withdrawal levels such as seen during the height of the drought will be an essential strategy to prevent water shortages during future extreme drought events. The key mitigation strategy, independent local action to restrict water use in advance of state‐level restrictions, is now prohibited by Georgia State Law. 相似文献
260.
Brian J. Harshburger Von P. Walden Karen S. Humes Brandon C. Moore Troy R. Blandford Albert Rango 《Journal of the American Water Resources Association》2012,48(4):643-655
Harshburger, Brian J., Von P. Walden, Karen S. Humes, Brandon C. Moore, Troy R. Blandford, and Albert Rango, 2012. Generation of Ensemble Streamflow Forecasts Using an Enhanced Version of the Snowmelt Runoff Model. Journal of the American Water Resources Association (JAWRA) 48(4): 643‐655. DOI: 10.1111/j.1752‐1688.2012.00642.x Abstract: As water demand increases in the western United States, so does the need for accurate streamflow forecasts. We describe a method for generating ensemble streamflow forecasts (1‐15 days) using an enhanced version of the snowmelt runoff model (SRM). Forecasts are produced for three snowmelt‐dominated basins in Idaho. Model inputs are derived from meteorological forecasts, snow cover imagery, and surface observations from Snowpack Telemetry stations. The model performed well at lead times up to 7 days, but has significant predictability out to 15 days. The timing of peak flow and the streamflow volume are captured well by the model, but the peak‐flow value is typically low. The model performance was assessed by computing the coefficient of determination (R2), percentage of volume difference (Dv%), and a skill score that quantifies the usefulness of the forecasts relative to climatology. The average R2 value for the mean ensemble is >0.8 for all three basins for lead times up to seven days. The Dv% is fairly unbiased (within ±10%) out to seven days in two of the basins, but the model underpredicts Dv% in the third. The average skill scores for all basins are >0.6 for lead times up to seven days, indicating that the ensemble model outperforms climatology. These results validate the usefulness of the ensemble forecasting approach for basins of this type, suggesting that the ensemble version of SRM might be applied successfully to other basins in the Intermountain West. 相似文献