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51.
本文以锅炉“煤改气”项目为例,在项目施工期、运营期产生的环境影响进行评价,并提出相应的环境保护措施。为环保部门和企业管理提供理论依据,并为锅炉改造类项目污染预防治理提供实践经验,最大限度降低项目建设对周围环境的不利影响,推动“煤改气”项目的可持续发展。  相似文献   
52.
Airborne concentrations of PAH in the vicinity of the source region with open‐air burning of metal scraps were measured between February, 1992 and November, 1993. The activity of open‐air burning decreased significantly since 1993 due to prohibition regulation. Both gaseous phase and particle‐bound PAH were measured at five sampling sites, which included one reference sampling site far away from the source region. Both values of gaseous and particle‐bound PAH concentrations, which were measured in the vicinity of source region, decreased clearly during the two years monitoring period. It shows that the uncontrolled open‐air burning of metal scraps was a significant emission source of airborne PAH in the study area. The profiles of various species of PAH were also compared. A large decrease in benzo(a)pyrene was observed in the source region.  相似文献   
53.
生态文明是以人与自然协调发展为核心的观念。旅游业可持续发展中面临着“旅游景区”开发过程中的盲目性、生态旅游发展过程中的盲目性、文物古迹修缮过程中的盲目性,以及国民生态意识淡薄、旅游行为非生态化等问题。构建生态文明的旅游观,是旅游业摆脱困境,实现可持续发展的根本保证。  相似文献   
54.
连环湖阿木塔泡沉积物中重金属形态及其对环境影响分析   总被引:3,自引:0,他引:3  
采用了BCR三步提取法,对连环湖阿木塔泡AMT岩芯沉积物中的Mn、Cr、Cu、Fe、Ni、Pb和Zn等7种重金属元素的化学形态进行了分析。结果表明:Cr、Cu、Fe、Ni、Pb、zn元素以残渣态为主,Mn元素以可交换态及碳酸盐结合态为主。Cr、Cu、Ni、Pb的有机物及硫化物结合态、Fe—Mn氧化物结合态含量较高,Zn的有机物及硫化物含量较高。其中,Mn、Cr、Ni和Pb对环境产生危害的可能性最大,对这几元素应该予以足够的关注。  相似文献   
55.
以调查问卷的统计结果为参考,运用定性分析和定量分析两种方法,结合学生在学习过程中存在的课程内容繁杂、识记困难等问题,从课程的特点和高职学生的特征出发,提出课程在教学过程中可通过就业驱动、多媒体手段、现场展示、案例分析、校外实践、网络化教学等方法来提高学生的学习兴趣和应用能力。  相似文献   
56.
In this study, a cascade of anoxic and oxic fluidized bed biofilm reactors system was carried out to treat synthetic municipal wastewater. The parameters of the influent flow rates and C/N ratios were discussed. System performance was acceptable for chemical oxygen demand (COD), ammonia, and total nitrogen removal. A decrease of ammonia and total nitrogen removal efficiencies, however, was observed when the influent flow rates increased to 5.04 and 6.12 1 h(-1). Total nitrogen removal decreased at the influent C/N ratio of 3:1. The measured ratios of COD reduction in the anoxic column to nitrogen removal through nitrification-denitrification were 3.7, 3.5, 3.3, and 3.1 g COD/g(-1) N on average when the influent C/N ratios changed from 6:1 to 3:1. The observed sludge yield (Yobs) was 0.169 g VSS g COD(-1) because of perfect denitrification in the anoxic column and the relatively long solids retention time.  相似文献   
57.
The new Xicheng and new Dongcheng districts of Beijing in 2010 were chosen as the research object. Based on the analysis of the current municipal solid waste (MSW) logistics system, the transfer station’s processing capacity and the terminal treatment facilities' conditions of the two new districts and other districts, a MSW logistics system was built using geographic information system (GIS) and analytic network process methods considering transregional treatment. The new logistics (MSW from new Xicheng was collected for Majialou. MSW from old Dongcheng and Xuanwu was collected for Datun and Xiaowuji, respectively) proved to be an improvement with a 10 % less collection fee, 111 % output–input ratio after transfer station (include) and 0.8:4.6:4.6 I:C:L (incineration:compost:landfill). After Nangong, Gaoantun II and Asuwei incineration are established, the output–input ratio of the new logistics will reach 114 %, and I:C:L will reach 3.6:4.2:2.2 which is environmentally friendly and nearer to the 4:3:3 Beijing government target. For a full load of every transfer station, the complement schemes were also presented and contrasted based on GIS analysis. The results have great theoretical and practical significance in transregional treatment and improving resource management level of MSW.  相似文献   
58.
Fluoride (F) is a necessary trace element in the human body, which would lead to some diseases if human body lacks or accumulates it excessively (1–1.5 mg d−1). Fluoride contamination in sediments has become more and more serious, which has potential hazards to human body. In this paper, a novel sorbent (loess) was proposed to immobilize trace element F in sediment. The effectiveness of loess on F stabilization was evaluated by decreasing F bioavailability in contaminated sediment. The loess and the sediment were mixed at different proportions for stabilization. About 70 days after the application of loess, the soil column was subject to simulate acid rain leaching test to observe the leaching-migration of F, which can be used to predict the leaching migration of F in the study area. The results showed that when the loess dose was 5 kg, the loess converted highly effective fractions of F (i.e., water-soluble and exchangeable fractions) into a more stable state (i.e., residual state). After 30 days of leaching with HNO3 solution with pH at 3.0, the lowest concentration of F was found in the leachate of soil column with 2 kg loess application. Correlation analysis showed that the F concentration in soil column profile was affected by CaCO3, EC, pH, and OM, of which, pH and CaCO3 have greater influence than other factors.  相似文献   
59.
Journal of Material Cycles and Waste Management - The KW from Chaoyang District was mainly treated by incineration at present. The main purpose of this study was to analysis whether the properties...  相似文献   
60.
为进一步探索啶酰菌胺对水生生物的毒性,选择斑马鱼为供试生物,采用半静态法,研究了啶酰菌胺在斑马鱼体内的富集与消除规律及对其肝脏和鳃的毒性作用。结果表明,斑马鱼暴露于0.08、0.32 mg·L~(-1)中,14 d后均达到富集平衡,28 d生物富集系数(BCF_(28 d))分别为35.50和36.72。在0.16、0.32 mg·L~(-1)浓度下,斑马鱼的比肝重(HSI)和比鳃重(BSI)均明显高于对照组,而肝脏和鳃中琥珀酸脱氢酶(SDH)和线粒体呼吸链复合物II活性均明显低于对照组,浓度低于0.08 mg·L~(-1)时,对斑马鱼无明显影响。由此可知,啶酰菌胺对斑马鱼为中等富集性,并对其肝脏和鳃有一定毒性作用。  相似文献   
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