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801.
Modeling vehicle emissions in different types of Chinese cities: importance of vehicle fleet and local features 总被引:3,自引:0,他引:3
Huo H Zhang Q He K Yao Z Wang X Zheng B Streets DG Wang Q Ding Y 《Environmental pollution (Barking, Essex : 1987)》2011,159(10):2954-2960
We propose a method to simulate vehicle emissions in Chinese cities of different sizes and development stages. Twenty two cities are examined in this study. The target year is 2007. Among the cities, the vehicle emission factors were remarkably different (the highest is 50-90% higher than the lowest) owing to their distinct local features and vehicle technology levels, and the major contributors to total vehicle emissions were also different. A substantial increase in vehicle emissions is foreseeable unless stronger measures are implemented because the benefit of current policies can be quickly offset by the vehicle growth. Major efforts should be focused on all cities, especially developing cities where the requirements are lenient. This work aims a better understanding of vehicle emissions in all types of Chinese cities. The proposed method could benefit national emission inventory studies in improving accuracy and help in designing national and local policies for vehicle emission control. 相似文献
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Chen J Chen TB Gao D Lei M Zheng GD Liu HT Guo SL Cai L 《Waste management (New York, N.Y.)》2011,31(1):65-70
Hydrogen sulfide (H2S) production patterns and the influence of oxygen (O2) concentration were studied based on a well operated composting plant. A real-time, online multi-gas detection system was applied to monitor the concentrations of H2S and O2 in the pile during composting. The results indicate that H2S was mainly produced during the early stage of composting, especially during the first 40 h. Lack of available O2 was the main reason for H2S production. Maintaining the O2 concentration higher than 14% in the pile could reduce H2S production. This study suggests that shortening the interval between aeration or aerating continuously to maintain a high O2 concentration in the pile was an effective strategy for restraining H2S production in sewage sludge composting. 相似文献
805.
Levels of PCDD/Fs and DL-PCBs in selected foods and estimated dietary intake for the local residents of Luqiao and Yuhang in Zhejiang, China 总被引:1,自引:0,他引:1
Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) were measured by high resolution gas chromatograph/high resolution mass spectrometer (HRGC/HRMS) in six food groups from Luqiao (LQ) where the e-waste has been recycled and from Yuhang (YH) where the agriculture dominates in Zhejiang Province in China. The total WHO-TEQ values of PCDD/Fs and DL-PCBs in selected foods from LQ were significantly much higher than those from YH. The highest level of the total WHO-TEQ was in crucian carp (10.87 pg g(-1) w.w.) followed by duck (3.77 pg g(-1) w.w.), hen eggs (2.80 pg g(-1) w.w.), chicken (2.43 pg g(-1) w.w.), rice (0.08 pg g(-1) w.w.) and vegetables (0.022 pg g(-1) w.w.) in LQ. By contrast, the highest levels were measured in duck (0.74 pg g(-1) w.w.) followed by hen eggs (0.69 pg g(-1) w.w.), crucian carp (0.55 pg g(-1) w.w.), chicken (0.44 pg g(-1) w.w.), vegetables (0.002 pg g(-1) w.w.) and rice (0.0002 pg g(-1) w.w.) in YH, respectively. The monthly intake of PCDD/Fs and DL-PCBs for the local residents was 401.75 pg WHO-TEQ g(-1) w.w. in LQ, which is above the provisional tolerable monthly intake (PTMI) set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). We determined a monthly intake of 37.13 pg WHO-TEQ g(-1)w.w. in YH, which is below the PTMI. Crucian carp was the predominant contributor to the estimated monthly intake (EMI), accounting for 67.74% and 36.51% in LQ and YH, respectively. High levels of PCDD/Fs and DL-PCBs in selected foods indicate severe contamination of these pollutants in the e-waste recycling site. 相似文献
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石油石化企业污染减排工作初探 总被引:4,自引:3,他引:1
污染减排是企业当前面临的一项重要而紧迫的任务。理顺污染减排工作机制体制,完善污染减排体系,落实污染减排措施,对于实现污染减排目标具有重要意义。文章根据国家相关规定和要求,结合石油石化行业特点及污染减排工作实践,系统提出了企业建立污染减排长效机制的对策建议。 相似文献
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809.
稳定性复合高铁酸盐的制备及其在水质净化中的应用 总被引:1,自引:0,他引:1
在复合高铁酸盐溶液的制备过程中投加Ca(ClO) 2,可以提高其稳定性能.通过对Ca(ClO) 2的投加量、Ca(ClO) 2的投加顺序、反应温度及反应时间的考察,确定其对复合高铁酸盐溶液的最佳稳定条件为:在生成复合高铁酸盐溶液后投加0.08 mol/L的Ca(ClO) 2,并在20℃条件下反应10 min.Ca(ClO) 2对复合高铁酸盐溶液的稳定作用,是ClO-缓慢释放的一级动力学反应过程.将复合高铁酸盐溶液与聚合氯化铝(PAC)联合投加,可净化城市生活污水和铜绿微囊藻配制水.研究表明,与PAC单独投加相比,复合高铁酸盐溶液与PAC联合投加对水体中的氨氯、COD、细菌、浊度、藻细胞等的去除效果更好,且达到同样处理效果所需药剂量少. 相似文献
810.
活性污泥总DNA提取方法的比较 总被引:1,自引:0,他引:1
从处理某制药废水的MBR反应器中采集活性污泥,评价不同DNA提取方法对其总DNA提取效率的影响。DNA提取分细胞裂解和DNA纯化2步,对细胞裂解比较了珠磨匀浆法、反复冻融法、十二烷基磺酸钠(sodium dodecyl sulfate,SDS)裂解法等7种方法;对DNA纯化比较了酚/氯仿纯化法和胶回收纯化法。结果表明,SDS裂解法、酚氯仿纯化法最优。通过条件优化实验,确定SDS裂解酚/氯仿纯化法在污泥量1.1 g,10 000 r/min离心5 min的操作条件下,获得的DNA产量(10 774 μg/g泥重)和纯度(OD260∶OD280=1.84)等综合指标最好。 相似文献