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91.
To investigate the fog chemistry along the Yangtze River basin, a field observation experiment was performed from Shanghai to Wuhan during November 2015. Fifteen fog water samples were collected by using a three-stage Caltech Active Strand Cloud water Collector(CASCC). The three-stage CASCC was mounted on the board of a ship. PH, electrical conductivity(EC), H_2O_2,HCHO, S(IV), ten inorganic ions, seven organicacids and sixteen trace metal elements were measured in this study. The p H of fog water samples ranged from weakly acidic(pH 4.3) to weakly alkaline(pH 7.05) and the EC ranged from 32.4 to 436.3 μS/cm. The main cations in fog water were NH+4 and Ca~(2+), accounting for 12.35% and 29.07% of those inorganic ions,respectively. In addition, SO_4~(2-) and NO_(-3) contributed to 25.52% and 12.93% to total anion concentrations respectively. Moreover, the dominant kinds of organicacids were formate and oxalate, occupying 45.28% and 28.03% of the total organicacids, respectively. For trace metal elements in fog samples, Al, Fe, Zn, and Ba revealed 34.6%, 16.4%, 19.3%, and 20.9%contributions to these sixteen trace element concentrations, respectively. The results indicated that pollutants were mainly from human activities, including fossil fuel combustion,biomass burning, steel-making, stone quarrying and sand digging. Besides, natural sources including natural background levels and long-range transport of sea salt particles also aggravated the pollution levels in the fog events along the Yangtze River.  相似文献   
92.
环渤海海冰弯曲强度影响因素分析   总被引:8,自引:2,他引:8  
本文根据多年环渤海海冰弯曲强度试验结果,分析了诸单因子对海冰弯曲强度的影响,并给出了各海区海冰弯曲强度设计值,海冰的弯曲强度随着应力速度的增加,经过延性,过渡和脆性三个阶段,在过渡区,海冰的弯曲强度达到最大值。随冰温的降低和冰中盐水体积减少,海冰的湾曲强度增大。  相似文献   
93.
This paper presents an overview of municipal solid waste (MSW) management in Beijing City. Beijing, the capital of China, has a land area of approximately 1368.32 km2 with an urban population of about 13.33 million in 2006. Over the past three decades, MSW generation in Beijing City has increased tremendously from 1.04 million tons in 1978 to 4.134 million tons in 2006. The average generation rate of MSW in 2006 was 0.85 kg/capita/day. Food waste comprised 63.39%, followed by paper (11.07%), plastics (12.7%) and dust (5.78%). While all other wastes including tiles, textiles, glass, metals and wood accounted for less than 3%. Currently, 90% of MSW generated in Beijing is landfilled, 8% is incinerated and 2% is composted. Source separation collection, as a waste reduction method, has been carried out in a total of 2255 demonstration residential and commercial areas (covering about 4.7 million people) up to the end of 2007. Demonstration districts should be promoted over a wider range instead of demonstration communities. The capacity of transfer stations and treatment plants is an urgent problem as these sites are seriously overloaded. These problems should first be solved by constructing more sites and converting to new treatment technologies. Improvements in legislation, public education and the management of waste pickers are problematic issues which need to be addressed.  相似文献   
94.
武汉东湖底泥释磷特点   总被引:90,自引:4,他引:86  
隋少峰  罗启芳 《环境科学》2001,22(1):102-105
为了探讨东湖底泥的释磷状况 ,采用实验室模拟法研究了环境条件变化对东湖底泥沉积物磷释放的影响以及底泥磷的形态分布与底泥释磷量的关系 .结果表明 :升高水温和扰动上覆水均能加速磷释放 .上覆水中性时(pH =7.4) ,底泥释磷量最低 ;在较高或较低 pH值时 ,底泥释磷量倍增 .厌氧条件下底泥释磷量是好氧条件下的30倍 .研究还显示 ,底泥中不同形态的磷与底泥磷释放量有不同程度的相关性 ,其中可溶性磷和铁磷与底泥磷释放量高度相关 (r>0 90 ,P<0.01) .  相似文献   
95.
With economic development in China, human-induced pressures on aquatic environments have grown and created an urgent need for tools measuring the ecological condition of aquatic systems. However, biological indicators for wadeable streams in China were poorly developed. This study developed and validated a multi-metric index of fish assemblages for wadeable streams of southern China to meet the requirement of the water project which has been carried on in China in recent years. Fifty-seven stream sites were sampled in April–May and November–December 2010 to develop an index of biotic integrity. A set of 45 candidate metrics were evaluated for range, responsiveness and redundancy, resulting in the selection of six metrics for the index: number of native species, number of rheophilic species, proportion of benthic riffle individuals, number of lithophilic species, number of omnivore species, and number of fish per hour sampling. The publicly available census data were used as independent data set to validate our method. Twenty-three sites were assessed as subject to significant (SP) or non-significant pressures (NSP) based on anthropogenic pressure evaluation. Our index performed well in discriminating NSP and SP sites, which suggested that our method could provide an accurate measure for wadeable streams ecosystem condition. We believe this integrated approach would meet the requirements for the water projects of China, and the process of developing the method could be used as reference for managing the subtropical streams in other areas of China or other states.  相似文献   
96.
Environmental Science and Pollution Research - Macrolide antibiotics (MAs), as a typical emerging pollutant, are widely detected in environmental media. When entering the environment, MAs can...  相似文献   
97.
含油污水处理工艺中的污泥及污油回收技术改进措施   总被引:1,自引:0,他引:1  
针对油田含油污水处理工艺中油水分离设备及缓冲罐等,长期运行积累的污泥若不及时排出,将导致污水中的悬浮固体含量上升和过滤负荷增大、缩短污水处理时间、影响处理效果及水质的问题。寻找合适的工艺技术,去除系统中产生的污油,以提高处理效率、改善最终处理水质。通过采用污泥回收、污油回收等措施,实现了污泥的有效排出,污油的有效回收,改善了处理水质,满足油田的生产需要。  相似文献   
98.
A seasonal field campaign by passive sampling was conducted from February 2008 to February 2009, aiming to measure air concentrations of organochlorine pesticides (OCPs) in the urban and suburban areas in Dalian. At the urban site, similar annual average concentrations of α-endosulfan and α-HCH were found, both being approximately 4 times as high as those of p,p'-DDT and p,p'-DDE, while at the suburban site, the annual average concentration of α-endosulfan was 2.9 times as high as the average concentrations of α-HCH, p,p'-DDT and p,p'-DDE; concentrations of α-endosulfan, α-HCH and p,p'-DDE achieved annual peaks in summer. Back trajectory analysis revealed that the air concentration of α-endosulfan increased with the input of air masses from the land whereas decreasing air concentration of α-endosulfan at the urban site was associated with air masses from the sea. Pesticides used in local agriculture were identified to be major sources of α-endosulfan at both the urban and suburban sites, though long-range atmospheric transport from other sources might also contribute to atmospheric levels of this chemical over this coastal city. α-endosulfan, α-HCH, p,p'-DDT and p,p'-DDE in the air in Dalian might result from the atmospheric transport of the air masses from northeast area, Shandong peninsula and Korean peninsula. Emission due to "aged" DDT and HCH in contaminated local soils as well as atmospheric long-range transport were likely to be major sources of α-HCH, p,p'-DDT and p,p'-DDE at the suburban site. In addition, a fresh input of α-HCH and p,p'-DDT in the atmosphere could not be excluded in the urban area.  相似文献   
99.
本文通过对中国人口产业结构现状的分析,全面讨论了人口产业结构优化对经济科技发展的影响和作用,进而提出了人口产业结构转变对促进经济科技发展的若干结论。  相似文献   
100.
广州与香港的环境经济能值分析   总被引:13,自引:0,他引:13  
利用国际生态学最新发展的能值分析理论方法及各种能值指标,从资源基础、能值福利、对外贸易和环境压力四个角度对广州和香港的各种生态流进行比较研究。结果表明广州在自然资源和社会资源方面明显优于香港,具有较大的经济发展潜力。从能值理论和宏观角度分析,广州应将内地丰富的土地资源和科技力量与香港充裕的资金、信息和管理能力融合,充分发挥两地的分散生产要素和资源优势。本研究为促进广州和香港的共同繁荣和优化组合提供理论依据和科学指导。  相似文献   
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