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841.
TiO2光催化-微滤膜分离深度净化亚甲基蓝印染废水 总被引:1,自引:1,他引:0
采用悬浮式TiO2光催化膜反应器深度净化纺织工业园区含亚甲基蓝印染废水经生物处理二级出水,利用中空纤维微滤膜进行催化剂截留分离,研究催化剂投加量、运行时间、溶解氧、搅拌方式对出水水质及膜通量的影响。结果表明:光催化会消耗体系溶解氧,鼓风曝气搅拌可同时为系统供氧,优于机械搅拌;该耦合体系的催化剂最佳投加量为1 g/L,经光催化氧化-膜组合工艺处理后水质优于GB 4287-1992《纺织染整工业污染物排放标准》的I级标准,符合建设部颁布的《生活杂用水水质标准》(CJ/T 48-1999)。 相似文献
842.
固定化菌藻系统对污水处理厂出水的深度处理 总被引:4,自引:1,他引:3
将海藻酸钠固定化活性污泥和小球藻制成颗粒小球,以自制的流化床反应器对重庆市某污水处理厂出水进行深度处理,探讨了系统对氨氮、TP、COD的去除效果,实验结果表明:在HRT=12 h,溶解氧浓度为3.0 mg/L左右,pH值为6.2至8.0之间,环境室温条件下,系统对氨氮、TP、COD均有较好的去除效果,系统稳定运行后对氨氮、TP、COD去除率基本维持在60%、60%和30%以上,出水氨氮、TP、COD浓度基本维持在8、0.5和40 mg/L以下,出水浓度达到了《城镇污水处理厂污染物排放标准》(GB 18918-2002)的一级A标准。这项研究显示固定化菌藻胶球系统在污水处理厂出水的深度处理中具有潜在的应用前景。 相似文献
843.
高层建筑典型外墙保温材料火蔓延特性数值模拟研究 总被引:1,自引:0,他引:1
有机保温材料被广泛应用于高层建筑外墙保温体系的同时,也可能增加高层建筑的火灾风险。本文通过计算机模拟,着重研究了保温材料之一的聚苯乙烯泡沫塑料(EPS)的火蔓延速率、失重速率及温度场分布等特性。研究结果发现:发生火灾后,外墙保温材料可以在很短的时间内自下而上蔓延至整个材料表面,并有表皮着火的现象。在火焰到达材料顶部之前,向上火蔓延占主导地位,材料中部区域明显燃烧脱落,火焰在材料两端上部继续燃烧,有向下加速蔓延的趋势;之后,火焰沿着材料中部内侧向下剧烈燃烧,材料呈V字型燃烧直至熄灭。在高层建筑外墙外保温材料火蔓延中,不同着火点情况下的燃烧速率随时间变化的趋势相似,且会形成两个波峰。 相似文献
844.
845.
In the context of water treatment, the ferrate ([FeO(4)](2-)) ion has long been known for its strong oxidizing power and for producing a coagulant from its reduced form [i.e., Fe(III)]. However, it has not been widely applied in water treatment, because of preparation difficulties and high cost. This article describes a low-cost procedure for producing solid potassium ferrate. In this synthetic procedure, NaClO was used in place of chlorine generation; and 10?M KOH was used in place of saturated KOH in the previous procedures. In addition, this study investigated the reactions of potassium ferrate with tetracycline hydrochloride (TC) at different pH and molar ratios. Results showed that the optimal pH range for TC degradation was pH 9-10, and TC could be mostly removed by Fe(VI) in 60?s. However, results showed >70% of TC degraded and <15% of dissolved organic carbon (DOC) reduction at molar ratio of 1:20. The main degradation pathway of TC is proposed based on the experimental data. 相似文献
846.
Gao Ling Shi Lai Qing Lou Shuai Zhang Xue Wei Xia Qing Sheng Cai 《Environmental science and pollution research international》2013,20(12):8435-8445
Field studies were conducted to investigate arsenic (As), copper (Cu), and zinc (Zn) contamination in agricultural soils and wheat crops at two areas in Huaibei, China. Area A is in the proximity of Shuoli coal mine. In area B, three coal mines and a coal cleaning plant were distributed. The potential health risk of As, Cu, and Zn exposure to the local inhabitants through consumption of wheat grains was also estimated. The results showed that significantly higher (p?<?0.05) concentrations of As, Cu, and Zn were found in soils collected from area B than in those from area A. Arsenic concentrations in wheat sampled from area A were negatively correlated with the distance from the coal mine (p?<?0.001). Concentrations of Cu and Zn in wheat seedlings and grains collected from area B were significantly higher (p?<?0.05) than in those collected from area A, with the exception of Zn in wheat seedlings. Concentrations of Cu and Zn in most wheat grain samples were above the permissible limits of Cu and Zn in edible plants set by the Food and Agriculture Organization/World Health Organization. The hazard index of aggregate risk through consumption of wheat grains was 2.3–2.4 for rural inhabitants and 1.4–1.5 for urban inhabitants. The average intake of inorganic As for rural inhabitants in Huaibei was above 10 μg day?1. These findings indicated that the inhabitants around the coal mine are experiencing a significant potential health risk due to the consumption of locally grown wheat. 相似文献
847.
自燃煤矸石山表面构建覆盖层,需要具备一定的低渗透性能以有效阻隔空气,防止煤矸石山内部发生自燃。本研究通过室内实验,测定煤矸石山构建覆盖层涉及的碾压材料包括黄土、粉煤灰及掺有粉煤灰的混合土样的界限含水率、一维压缩特性及压实特性,揭示和分析7种覆盖材料配方的压缩压实特性,表明覆盖材料通过碾压可有效阻隔空气,起到阻燃作用;将粉煤灰掺人到一般黄土材料中,可减缓混合土样击实曲线的陡峭性,从而降低材料在碾压中对含水率的敏感度。实验旨在为进行煤矸石山覆盖层碾压提供科学的实验数据及设计参数。 相似文献
848.
Anja Wolf Axel Bergmann Rolf-Dieter Wilken Xu Gao Yonghong Bi Hao Chen Christoph Schüth 《Environmental science and pollution research international》2013,20(10):7124-7139
This study deals with the evaluation of water quality of the Three Gorges Reservoir (TGR) in order to assess its suitability as a raw water source for drinking water production. Therefore, water samples from (1) surface water, (2) tap water, and (3) wastewater treatment plant effluents were taken randomly by 2011–2012 in the area of the TGR and were analyzed for seven different organic contaminant groups (207 substances in total), applying nine different analytical methods. In the three sampled water sources, typical contaminant patterns were found, i.e., pesticides and polycyclic aromatic hydrocarbons (PAH) in surface water with concentrations of 0.020–3.5 μg/L and 0.004–0.12 μg/L, disinfection by-products in tap water with concentrations of 0.050–79 μg/L, and pharmaceuticals in wastewater treatment plant effluents with concentrations of 0.020–0.76 μg/L, respectively. The most frequently detected organic compounds in surface water (45 positives out of 57 samples) were the pyridine pesticides clopyralid and picloram. The concentrations might indicate that they are used on a regular basis and in conjunction in the area of the TGR. Three- and four-ring PAH were ubiquitously distributed, while the poorly soluble five- and six-ring members, perfluorinated compounds, polychlorinated biphenyls, and polybrominated diphenyl ethers, were below the detection limit. In general, the detected concentrations in TGR are in the same range or even lower compared to surface waters in western industrialized countries, although contaminant loads can still be high due to a high discharge. With the exception of the two pesticides, clopyralid and picloram, concentrations of the investigated organic pollutants in TGR meet the limits of the Chinese Standards for Drinking Water Quality GB 5749 (Ministry of Health of China and Standardization Administration of China 2006) and the European Union (EU) Council Directive 98/83/EC on the quality of water intended for human consumption (The Council of the European Union 1998), or rather, the EU Directive on environmental quality standards in the field of water policy (The European Parliament and The Council of the European Union 2008). Therefore, the suggested use of surface water from TGR for drinking water purposes is a valid option. Current treatment methods, however, do not seem to be efficient since organic pollutants were detected in significant concentrations in purified tap water. 相似文献
849.
Tao Huang Xiangyang Li Chongguo Tian Xianming Yang Li Wang Yuan Zhao Jianmin Ma Hong Gao 《Environmental science and pollution research international》2013,20(10):7167-7174
HCHs and DDTs were banned in 1983 in China; however, they are still remaining in various environmental media. Since endosulfan was introduced in China in 1994, it is widely used in agriculture. In this study, temporal and spatial uses of endosulfan, HCHs, and DDTs in Gansu province of China have been presented. It is estimated that the total usage is 701 tons for endosulfan between 1994 and 2007, 1,712 tons for HCHs between 1952 and 1983, and 462 tons for DDTs between 1951 and 1983, respectively. Endosulfan usage increased dramatically in 1998 due to its application on other crops except on cotton. The HCH and DDT usage displayed a rapid increase after 1972, reaching the peak in 1976 and in 1975, respectively; since then, they declined until being banned in 1983. The gridded usage inventories of these three kinds of organochlorine pesticides in Gansu province, with a 1/4° longitude by 1/6° latitude resolution, have been created by using different crops for endosulfan and the area of dry farmland for HCHs and DDTs as surrogate data. The most intensive use was in northwestern regions for endosulfan and southeastern regions for HCHs and DDTs in Gansu province. 相似文献
850.
以炼焦煤原煤、尾煤为研究对象,采用微量热重、常量固定床实验装置对其在热解过程中的质量变化和气相产物进行了对比分析。考察了温度、6种催化剂(CaO、MgO、Fe、Ni、NaOH、A1)及其添加比例对炼焦煤尾煤热解制取富氢燃料气的影响。结果表明,尾煤中富集的无机矿物质对热解制取富氢燃料气有促进作用,单位尾煤热解H2产率要比原煤高出1.93%。温度是影响尾煤热解产气的重要参数,热解终温的上升有利于H2产量的提高,随终温800℃升高到950℃H,产量增长了32.59mL/g。在催化热解实验中,除Al和MgO对尾煤热解有抑制作用外,CaO、Fe、Ni及NaOH均对尾煤热解产H2有促进作用,以CaO和Fe效果最为明显。并且不同添加比例的CaO和Fe对热解制取富氢燃料有一定的影响。 相似文献