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排序方式: 共有849条查询结果,搜索用时 15 毫秒
751.
加强联合 振兴环保产业   总被引:1,自引:0,他引:1  
企业规模小 ,投资比较分散 ,规模效益不明显是我国环保产业发展、上水平的制约因素。要应付入关后的挑战 ,必须扶持、培植掌握高新技术 ,并能推动技术进步的环保骨干企业。  相似文献   
752.
磁化水抑垢的研究   总被引:2,自引:0,他引:2  
通过静态试验研究了Ca^2+、Mg^2+的总浓度、碱度、PH、SO^2-4对磁水抑垢效果的影响,得出了应用磁化水抑垢的适宜条件,为磁水器的实际应用提供了依据。  相似文献   
753.
ABSTRACT: We formally evaluated the relationship between landscape characteristics and surface water quality in the state of Pennsylvania (USA) by regressing two different types of pollutant responses on landscape variables that were measured for whole watersheds. One response was the monthly exported mass of nitrogen estimated from field measurements, while the other response was a GIS‐modeled pollution potential index. Regression models were built by the stepwise selection protocol, choosing an optimal set of landscape predictors. After factoring out the effect of physiography, the dominant predictors were the proportion of “annual herbaceous” land and “total herbaceous” land for the nitrogen loading and pollution potential index, respectively. The strength of these single predictors is encouraging because the marginal land cover proportions are the simplest landscape measurements to obtain once a land cover map is in hand; however, the optimal set of predictors also included several measurements of spatial pattern. Thus, for watersheds at this general hierarchical scale, gross landscape pattern may be an important influence on instream pollution loading. Overall, there is strong evidence that using landscape measurements alone, obtained solely from remotely sensed data, can explain most of the water quality variability (R2= approx. 0.75) within these watersheds.  相似文献   
754.
This paper deals with the procedure and methodology which can be used to select the optimal treatment and disposal technology of municipal solid waste (MSW), and to provide practical and effective technical support to policy-making, on the basis of study on solid waste management status and development trend in China and abroad. Focusing on various treatment and disposal technologies and processes of MSW, this study established a Monte-Carlo mathematical model of cost minimization for MSW handling subjected to environmental constraints. A new method of element stream (such as C, H, O, N, S) analysis in combination with economic stream analysis of MSW was developed. By following the streams of different treatment processes consisting of various techniques from generation, separation, transfer, transport, treatment, recycling and disposal of the wastes, the element constitution as well as its economic distribution in terms of possibility functions was identified. Every technique step was evaluated economically. The Mont-Carlo method was then conducted for model calibration. Sensitivity analysis was also carried out to identify the most sensitive factors. Model calibration indicated that landfill with power generation of landfill gas was economically the optimal technology at the present stage under the condition of more than 58% of C, H, O, N, S going to landfill. Whether or not to generate electricity was the most sensitive factor. If landfilling cost increases, MSW separation treatment was recommended by screening first followed with incinerating partially and composting partially with residue landfilling. The possibility of incineration model selection as the optimal technology was affected by the city scale. For big cities and metropolitans with large MSW generation, possibility for constructing large-scale incineration facilities increases, whereas, for middle and small cities, the effectiveness of incinerating waste decreases.  相似文献   
755.
Sludge granulation is considered to be the most critical parameter governing successful operation of an upflow anaerobic sludge blanket and expanded granular sludge bed (EGSB) reactors. Pre-granulated seeding sludge could greatly reduce the required start-up time. Two lab-scale and a pilot-scale EGSB reactors were operated to treat Shaoxing Wastewater Treatment Plant containing wastewater from real engineering printing and dyeing with high pH and sulfate concentration. The microbiological structure and the particle size distribution in aerobic excess sludge, sanitary landfill sludge digested for one year, and the granular sludge of EGSB reactor after 400 d of operation were analyzed through scanning electron microscopy (SEM) and sieves. The lab-scale EGSB reactor seeded with anaerobic sludge after digestion for one year in landfill showed obviously better total chemical oxygen demand (TCOD) removal efficiency than one seeded with aerobic excess sludge after cation polyacrylamide flocculation-concentration and dehydration. The TCOD removed was 470.8 mg/L in pilot scale EGSB reactor at short hydraulic retention time of 15 h. SEM of sludge granules showed that the microbiological structure of the sludge from different sources showed some differences. SEM demonstrated that Methanobacterium sp. was present in the granules of pilot-scale EGSB and the granular sludge produced by landfill contained a mixture of anaerobic/anoxic organisms in abundance. The particle size distribution in EGSB demonstrated that using anaerobic granular sludge produced by sanitary landfill as the seeding granular sludge was feasible.  相似文献   
756.
工业废水排放的影响因素量化分析   总被引:5,自引:0,他引:5  
工业废水排放量的大小受工业发展水平、产业结构、产品结构、技术工艺及设备水平、管理政策、环境法规等多因素的综合影响。选取长江三角洲典型地区的主要污染排放指标,重点分析工业经济规模、工业行业结构、工业技术进步以及环境治理投资等因素与工业水污染排放之间的相互关系。研究结果表明:随着长江三角洲地区产业结构的调整、工业技术进步、工业废水达标排放政策的实施,工业规模的扩大并没有引起工业废水的显著增加。从制造业结构看,有些行业的废水排放量对其结构调整比较敏感; 相反,有些行业的废水排放量对其结构的调整不敏感。工业技术进步和环境治理投资与工业废水排放量呈现负相关,说明工业技术进步、环境污染治理对于减少工业水污染排放起重要作用。  相似文献   
757.
降雨随历时变化标度性质的探讨   总被引:18,自引:0,他引:18  
降雨公式是水文计算的基本依据之一,也是工程师和水文学家十分关心的问题。长期以来水文中采用的降雨公式是基于大量降雨资料而建立起来的经验公式,多年的实践表明该公式能客观地反映降雨特性,计算结果符合实际,但是对该公式的理论基础却不太清楚。着眼于降雨在时间上的自相似性,将标度理论应用于降雨时间尺度问题,对降雨强度随历时变化的标度性质进行了研究,探讨了降雨公式的理论基础。由标度理论阐述了降雨标度性质(标度不变性)在时间尺度上的意义,并用此理论研究了成都望江楼站的降雨资料,计算了该站不同历时下降雨强度的各阶矩和变差系数,研究的结果表明,在一定的时间尺度范围内,降雨强度随历时变化确实具有多标度性质。最后由降雨强度随历时变化的标度性质推导出降雨公式,说明了降雨公式是降雨在时间尺度上标度特性的表示。  相似文献   
758.
基于水足迹的区域生态补偿标准及时空格局研究   总被引:1,自引:0,他引:1  
水资源是一种公共物品,其效益外部性使得水资源保护与开发利用成本应由相关的若干区域共同承担,因此,建立合理的区域生态补偿标准模型及区域内外共同补偿机制是当前生态经济领域的研究前沿。通过构建水足迹与生态补偿标准模型,对江西省及11地市水足迹与水生态补偿标准进行了估算。主要结果如下:2000~2013年,江西省总生产水足迹呈现先下降后增长的趋势,粮食、水产品、猪肉生产所占比重较大,水盈余呈波动下降趋势。11地市生产水足迹与水足迹效率呈上升趋势,除南昌市出现水赤字要支付生态补偿资金外,其余各市均有水盈余,应获得生态补偿资金。2000~2013年江西省水盈余共需补偿1 805.76亿元,平均每年128.98亿元。赣南的赣州市、赣中的吉安市、赣东北的上饶市、赣东的抚州市获得补偿额较高,将优先获得区域内外生态补偿额度。该研究结果可为生态文明先行示范区与区域生态补偿机制建立提供一定的科学依据。  相似文献   
759.
中国生态农业自80年代初提出,目前从理论到实践都取得很大发展。全国已有生态农业县100个,生态农业乡镇300个,生态农业村500个,提高了农业综合生产能力。经过3~5年试点建设,同未试点区相比,粮食增产15%左右,人均收入提高12%左右,光能利用率提高20%左右。作者认为,“发展生态良性循环的农业”,已成为中国农业发展方向。  相似文献   
760.
About half the world's households cook and/or heat daily with biomass fuels. At small scale, biomass combustion releases significant amounts of particulates, carbon monoxide, and hydrocarbons, the latter with significant concentrations of polycyclic aromatic hydrocarbons. Preliminary measurements in kitchens of developing-country villages have established airborne concentrations of these healthdamaging pollutants that are orders of magnitude above urban levels or relevant standards. Particle size measurements and dose calculations lead to significant concerns about potential health hazards. The few epidemiological studies are consistent with such effects although more work is clearly needed. These findings may have significant implications for the planning of rural energy development in a number of countries. In particular, they may relate directly to the question of the optimum balance between centralized and decentralized systems.  相似文献   
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