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181.
用稀释接种法测定BOD5时,由于操作繁琐,全部实验时间需要5d,任一环节出现问题都会影响实验结果。在进行考核实验时,由于时间紧,样品量有限,因此每个实验操作步骤都要谨慎仔细。通过实践经验,就BOD,考核实验总结了一些注意点。 相似文献
182.
随着印染工艺不断更新,大量化学分子结构复杂的化工染料应用到印染行业,使得常规的水处理工艺难以降解印染废水中的染料。本文以活性黑(RB5)染料为研究对象,采用液相高压放电产生强氧化性自由基来降解染料废水,考察反应时间、初始浓度和气体流量对RB5降解的影响,研究结果表明:在外部功率相同的情况下,浓度高染料其降解率相对较低;通入氧气量增加,产生的活性自由基和活性物质数量也增加,RB5的降解率也增大,但气流量不宜过大;高压放电产生的各种活性物质容易破坏染料发色基团的分子链,使其脱色。 相似文献
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主要介绍了变压吸附气体分离技术治理PVC分馏尾气并回收其中有效组分的新工艺.此工艺相较传统处理方法具有回收率高,自动化程度高,尾气排放达标,社会、经济效益明显等优点. 相似文献
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Water supply is the primary element of an urban system. Due to rapid urbanization and water scarcity, maintaining a stable and safe water supply has become a challenge to many cities, whereas a large amount of water is lost from the pipes of distribution systems. Water leakage is not only a waste of water resources, but also incurs great socio-economic costs. This article presents a comprehensive review on the potential water leakage control approaches and specifically discusses the benefits of each to environmental conservation. It is concluded that water leakage could be further reduced by improving leakage detection capability through a combination of predictive modeling and monitoring instruments, optimizing pipe maintenance strategy, and developing an instant pressure regulation system. The environment could benefit from these actions because of water savings and the reduction of energy consumption as well as greenhouse gas emissions. 相似文献
188.
Higher concentrations of Hg can be emitted from coal pyrolysis or gasification than from coal combustion, especially elemental Hg. Highly efficient Hg removal technology from coal-derived fuel gas is thus of great importance. Based on the very excellent Hg removal ability of Pd and the high adsorption abilities of activated carbon(AC) for H2 S and Hg, a series of Pd/AC sorbents was prepared by using pore volume impregnation, and their performance in capturing Hg and H2 S from coal-derived fuel gas was investigated using a laboratory-scale fixed-bed reactor. The effects of loading amount, reaction temperature and reaction atmosphere on Hg removal from coal-derived fuel gas were studied. The sorbents were characterized by N2 adsorption, X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS). The results indicated that the efficiency of Hg removal increased with the increasing of Pd loading amount, but the effective utilization rate of the active component Pd decreased significantly at the same time. High temperature had a negative influence on the Hg removal. The efficiency of Hg removal in the N2-H2S-H2-CO-Hg atmosphere(simulated coal gas) was higher than that in N2-H2S-Hg and N2-Hg atmospheres, which showed that H2 and CO, with their reducing capacity, could benefit promote the removal of Hg. The XPS results suggested that there were two different ways of capturing Hg over sorbents in N2-H2S-Hg and N2-Hg atmospheres. 相似文献
189.
Characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China 总被引:1,自引:0,他引:1
Kai Zhang Fahe Chai Zilong Zheng Qing Yang Juansheng Li Jing Wang Yujie Zhang 《环境科学学报(英文版)》2014,26(1):147-153
To understand the pollution characteristics of atmospheric particles and heavy metals in winter in Chang-Zhu-Tan city clusters, China, total suspended particulate(TSP) and PM10samples were collected in cities of Changsha, Zhuzhou and Xiangtan from December 2011 to January 2012, and heavy metals of Cd, Pb, Cr, and As were analyzed. It shows that the average TSP concentration in Changsha, Zhuzhou and Xiangtan were(183 ± 73),(201 ± 84) and(190 ± 66) μg/m3respectively, and the average PM10 were(171 ± 82),(178 ± 65) and(179 ± 55) μg/m3respectively. The lowest TSP and PM10concentrations occurred at the background Shaping site of Changsha. The average ratio of ρ(PM10)/ρ(TSP) was 91.9%, ranging from 81.3% to 98.9%. Concerning heavy metals, in TSP samples, the concentration of Cr, As, Cd and Pb were 28.8–56.5, 18.1–76.3, 3.9–26.1 and 148.0–460.9 ng/m3, respectively, while in PM10samples, were 16.4–42.1, 15.5–67.9, 3.3–22.2 and 127.9–389.3 ng/m3, respectively. The enrichment factor of Cd was the highest, followed by Pb and As, while that of Cr was the lowest. 相似文献
190.
<正>对于任何国家而言,交通行业都是其主要温室气体排放来源之一,亦是各国控制温室气体排放的关键。本文主要介绍美国交通部门的减排政策法规及配套措施,以供我国借鉴。一、"双赢"的温室气体减排政策美国被誉为"车轮上的民族",其交通运输业的发达可想而知,因而其排放的温室气体亦影响较大。据测算,当前美国交通部门能耗占能源消费总量的28.1%,其温室气体排放量占总温室气体排放量的27%。 相似文献