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971.
972.
半刚性路面基层环境影响评价研究 总被引:1,自引:0,他引:1
采用输人输出模型,通过清单分析和归一化处理对我国典型的路面基层材料水泥稳定粒料与石灰稳定粒料以及几种工业固体废弃物路面基层材料的环境影响进行了研究并和水泥混凝土进行了对比.结果表明,工业固体废弃物路面基层对资源能源消耗量少,生产过程中固体废弃物、温室气体、酸雨气体的排放量小.和我国目前广泛使用的水泥稳定粒料相比,其环境影响较小,而且可以被再循环用作水泥生产的混合材,是一类典型的生态建筑材料. 相似文献
973.
电子废物管理体系研究 总被引:1,自引:0,他引:1
分析了欧盟、日本、美国等国家的电子废物管理体系主要特点,并介绍我国电子废物管理现状和主要措施,在此基础上归纳总结了当前电子废物管理存在的主要问题并提出相关建议。 相似文献
974.
975.
轧钢污泥综合利用的技术研究 总被引:1,自引:0,他引:1
阐述了一种轧钢污泥的回收处理技术,该技术可把轧钢污泥有效地分离成氧化铁粉和混合油,实现综合利用,减少铁素资源浪费,有良好的经济效益和环境效益. 相似文献
976.
977.
Yao CHEN Jinhui LI Huabo DUAN Zhishi WANG 《Frontiers of Environmental Science & Engineering》2011,5(2):167-174
Mechanical waste-processing methods, which combine crushing and separation processes for the recovery of valuable materials, have been widely applied in waste printed wiring board (PWB) treatment. However, both the high impact toughness and the tensile and flexural strengths of whole PWB with a laminated structure result in great energy consumption and severe abrasion of the cutters during multi-level crushing. In addition, the high temperatures occurring in continual crushing probably cause the decomposition of the polymer matrix. A thermal-crack method using residual steam as the heating medium has been developed to pre-treat waste PWBs. This treatment reduces the mechanical strength in order to improve the recovery rate of valuable materials in subsequent mechanical recycling. The changes of the PWBs’ macro-mechanical properties were studied to evaluate thermal expansion impacts associated with changes in temperature, and the dynamic dislocation micro-structures were observed to identify the fracture mechanism. The results showed that thermal cracking with steam at the temperature of 500 K can effectively attenuate the mechanical properties of waste PWBs, by reducing the impact, tensile and flexural strengths respectively, by 59.2%, 49.3% and 51.4%, compared to untreated PWB. Thermal expansion can also facilitate the separation of copper from glass fiber by reducing peel resistance by 95.4% at 500 K. It was revealed that the flexural fracture was a transverse cracking caused by concentrated stress when the heating temperature was less than 500 K, and shifted to a vertical cracking after exceeding 500 K. 相似文献
978.
Leiyu FENG Yuanyuan YAN Yinguang CHEN 《Frontiers of Environmental Science & Engineering》2011,5(4):623-632
Effect of pH ranging from 4.0 to 11.0 on co-fermentation of waste activated sludge (WAS) with food waste for short-chain fatty acids (SCFAs) production at ambient temperature was investigated in this study. Experimental results showed that the addition of food waste significantly improved the performance of WAS fermentation system, which resulted in the increases of SCFAs production and substrate reduction. The SCFAs production at pH 6.0, 7.0, 8.0, and 9.0 and fermentation time of 4 d was respectively 5022.7, 6540.5, 8236.6, and 7911.7 mg COD·L-1, whereas in the blank tests (no pH adjustment, pH 8.0 (blank test 1), no food waste addition, pH 8.0 (blank test 2), and no WAS addition (blank test 3)) it was only 1006.9, 971.1, and 1468.5 mg COD·L-1, respectively. The composition of SCFAs at pH from 6.0 to 9.0 was also different from other conditions and propionic acid was the most prevalent SCFA, which was followed by acetic and n-butyric acids, while acetic acid was the top product under other conditions. At pH 8.0 a higher volatile suspended solids (VSS) reduction of 16.6% for the mixture of WAS and food waste than the sole WAS indicated a synergistic effect existing in fermentation system with WAS and food waste. The influence of pH on the variations of nutrient content was also studied during anaerobic fermentation of the mixture of WAS and food waste at different pH conditions. The release of N H 4 + - N increased with fermentation time at all pH values investigated except 4.0, 5.0 and in blank test one. The concentrations of soluble phosphorus at acidic pHs and in the blank test one were higher than those obtained at alkaline pHs. Ammonia and phosphorus need to be removed before the SCFAs-enriched fermentation liquid from WAS and food waste was used as the carbon source. 相似文献
979.
闫启平 《再生资源与循环经济》2012,5(2):4-9
废钢铁产业是我国再生资源产业的主体,其节能减排、低碳环保和不可替代的钢铁原料功效十分显著。阐述了我国废钢铁产业在经济转型中的主导地位、应用价值、投资环境及今后的发展战略。指出我国经济发展方式的转变,赋予了废钢铁产业良好的发展机遇和重大的历史使命,中国废钢产业具有良好的投资市场和巨大的发展空间。 相似文献
980.
通过电炉铜与转炉铜能耗对比,突显了电炉钢的节能与环保优势,同时介绍了国内外电炉钢应用现状。随着社会工业化的发展所带来的钢铁积蓄量的增加,以及电炉钢技术的不断完善和发展,加之迎合国家低碳经济政策的实施,国内电炉钢发展具有广阔前景。 相似文献