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821.
湖长制是中国水环境治理进程中的重要制度创新,通过建立以党政领导负责制为核心的责任体系,落实属地管理责任,对实现湖泊水资源永续利用具有重要现实意义。使用2007~2017年武汉市环境状况公报和武汉统计年鉴数据,采用双重差分方法,探讨了湖长制对水环境治理效果的影响及其机制。结果表明:(1)湖长制显著改善了试点湖泊的综合水质,降低了污染物超标总值。上述结论在进行一系列稳健性检验后依然成立。(2)机制分析表明,环境治理投资和工业废水排放在湖长制与水环境治理效果之间起到部分中介作用,即湖长制通过促进环境治理投资和降低工业废水排放改善了水环境治理效果。(3)异质性分析表明,湖长制显著改善了高经济水平辖区和非跨辖区湖泊的水环境治理效果。研究结果为完善湖长制形成常态化和系统化的水资源管理制度,推进水环境治理体系和治理能力现代化提供了决策参考。 相似文献
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有机热载体锅炉安全选用及安装质量探讨 总被引:1,自引:0,他引:1
通过有机热载体炉的工作原理分析,介绍了锅炉及其系统中循环泵和膨胀器的选用及安装的要求,并对有机热载体炉安装过程中质量的控制提出了一些要求. 相似文献
824.
Chunhua XU Dandan CHENG Baoyu GAO Zhilei YIN Qinyan YUE Xian ZHAO 《Frontiers of Environmental Science & Engineering》2012,6(4):455
Batch adsorption experiments were conducted to explore the adsorption of Cr(VI) in aqueous solutions by β -FeOOH-coated sand. We investigated the key factors which affected the adsorption process such as adsorbent dosage, initial pH, initial Cr(VI) ion concentration, contact time and temperature. The uptake of Cr(VI) was very rapid and 44.3%, 51.6%, 58.9% of the adsorption happened during the first 180 minutes at 293K, 303K and 313K, respectively. The pseudo-second-order rate equation successfully described the adsorption kinetics. To study the adsorption isotherm, two equilibrium models, the Langmuir and Freundlich isotherms, were adopted. At 293K, 303K and 313K, the adsorption capacities obtained from the Langmuir isotherm were 0.060, 0.070 and 0.076 mg Cr(VI) per gram of the adsorbent, respectively. Thermodynamic parameters such as the change of energy, enthalpy and entropy were calculated using the equilibrium constants. The negative value of Δ G 0 and the positive value of Δ H 0 showed that the adsorption of Cr(VI) in aqueous solutions by β -FeOOH-coated sand was spontaneous, endothermic and occurred by physisorption. 相似文献
825.
Xiaowei ZHANG Qinyan YUE Dongting YUE Baoyu GAO Xiaojuan WANG 《Frontiers of Environmental Science & Engineering》2015,9(3):402
Dyes are common pollutants in textile wastewaters, and the treatment of the wastewater has now attracted much attention due to its wide application and low biodegradability. In this study, Fe0/C/Clay ceramics, a kind of novel micro-electrolysis filler, were sintered and employed in a dynamic micro-electrolysis reactor for synthetic Acid Red 73 (AR73) and Reactive Blue 4 (RB4) wastewater treatment. The effects of influent pH, hydraulic retention time (HRT), and aeration on the decoloration efficiencies of AR73 and RB4 were studied. The optimum conditions for wastewater treatment were: AR73, influent pH of 4, HRT of 2 h and aeration; RB4, influent pH of 5, HRT of 6 h and aeration. Under the optimum conditions, decoloration efficiency of AR73 and RB4 wastewater was 96% and 83%, respectively. Results of UV-vis spectrum scanning demonstrated that the chromophores were broken. Continuous running tests showed that improvement of micro-electrolysis system with Fe0/C/Clay ceramics for AR73 and RB4 synthetic wastewater treatment could avoid failure of micro-electrolysis reactor, which indicated great potential for the practical application of the ceramics in the field of actual industrial wastewater treatment. 相似文献
826.
A mine’s ventilation system is an important component of an underground mining system. It provides a sufficient quantity of air to maintain suitable working environment. Therefore, the status of mine ventilation should be tracked and monitored as a timely matter. Based on former findings and in-depth analysis of mine ventilation systems, a proper early warning model is proposed in this paper for such considerations to improve the mine ventilation safety. The model itself is comprised of two sub-models, and two data mining techniques are used to assist in building each sub-model. One is the optimal indexes selection model which applies the Rough Set theory (RS) to assist the selection of best ventilation indexes. The other is the risk evaluation model based on the Support Vector Machine (SVM) to classify the risk ranks for the mine ventilation system. Testing cases have been used to demonstrate the applicability of this integrated model. 相似文献
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829.
Jianwei Cheng Cheng Wang Shaoshuai Zhang 《Journal of Loss Prevention in the Process Industries》2012,25(3):425-435
Mine gas explosions present a serious safety threat in the worldwide mining industry. Since the beginning of mining, many coal miners have been killed due to the explosions. Accordingly, on a regular basis, mine operators should get air samples from the underground atmosphere. At the same time, monitoring and tracking the explosibility of the air sample should be done as a timely matter to avoid any potential explosions. All these works can provide very important information to assist the mine operators to well understand the mine atmospheric status and its trends. In additional, when facing the coal spontaneous combustion, mine fire events, or other chemical reactions related mine accidents, determination of explosibility is a definitely significant work for the safety of miners and mine rescue personnel especially when planning and implementing any mine rescue strategies. For many years, mining engineers and researchers have developed a number of methods for assessing the explosibility of the air–gas-mixture. Their research results provide a baseline for judgments of the mine gas explosibility and in determining the extent of change. In this paper, main popular and typical methods used in mining industry to determine the mine gas explosibility are introduced and reviewed. Case demonstrations for each method are also shown and can be used to instruct readers to understand how to apply them. Finally, a brief discussion about the current methods is presented and some preliminary suggestions are also listed for the further improvements in the future research. 相似文献
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