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801.
MSW(城市固体废物)生物反应器型填埋是一种较新颖的方法.在系统分析现有填埋方法优缺点的基础上,对其加以改进,将强制通风好氧和渗滤液循环2种方式有机地结合在一起,构建了MSW好氧生物反应器.考察了NH3、CH4、CO2、pH和温度等因素,并监测分析了渗滤液中的COD、BOD5、Zn^2+、NH4^+和NO3^-等指标,旨在研究其中垃圾的降解及渗滤液中COD、BOD5、Zn^2+、NH4^+和NO3^-的去除情况,探讨该生物反应器对垃圾和渗滤液相关参数的作用机理.结果表明,该反应器对渗滤液中COD、BOD5、NO3^-的去除率分别达到96.34%、94.58%和99.9%,对其中的Zn^2+也有较好的脱除效果. 相似文献
802.
Ozonation of the azo dye Cationic Red X-GRL was investigated in a bubble column reactor at varying operating parameters such as oxygen flow rate, temperature, initial Cationic Red X-GRL concentration, and pH. The conversion of dye increased with the increasing of pH and oxygen flow rate. As the reaction rate constant and the volumetric mass transfer coefficient increase while the ozone equilibrium concentration decreases with the temperature, there is a minimum conversion of dye at 25 degrees C. The increasing of initial dye concentration leads to a decreasing conversion of dye while the ozonation rate increases. The formation of intermediates and the variation of pH, TOC, and nitrate ion during ozonation were investigated by the use of some analytical instruments such as GC/MS, GC, and IC. The intermediates of weak organic acids lower the pH value of the solution. The probable degradation mechanism of the Cationic Red X-GRL in aqueous solution was deliberated with the aid of Molecular Orbital calculations. The N(12)-C(13) site in Cationic Red X-GRL, instead of the N(6)-N(7) site, is found to be the principal site for ozone cycloaddition in the degradation processes. During the degradation process, among the six nitrogen atoms of Cationic Red X-GRL, one is transferred into a nitrate ion, one is converted into an amine compound, and the remaining four are transformed into two molecules of nitrogen. 相似文献
803.
In this paper, a new alternative method, i.e., selective extraction by weakly basic anion exchange resin, has been developed for the removal of trace cadmium and mercury ions from drinking water sources. The mechanism of heavy metal removal is based on selective extraction as the results of LEWIS-base-acid interactions. Transfer of trace mercury species from liquid to resin phase coincides well with the performance of film diffusion. The results demonstrated that the presence of chlorine has a negligible influence on the removal of mercury. However, humic acids can strongly bind mercury by the formation of complex compounds and therefore become the obstacle in the diffusion progress. At neutral or base pH, the resin material exhibits the favorable uptake of heavy metals. In filter experiments, the studied resin material offers favorable properties in the selective extraction of trace mercury and cadmium. 相似文献
804.
Chenghang Zheng Zhongyang Zhao Yishan Guo Haitao Zhao Weiguo Weng Weihang Zhu 《Journal of the Air & Waste Management Association (1995)》2020,70(7):708-720
ABSTRACT
Electrostatic precipitators (ESP) have been considered as the main particulate matter (PM) removal facility in the energy industry. This paper presents a real-time optimization method for a one-chamber industrial ESP in an ultra-low emission power plant with an intelligent optimization system (IOS). The IOS seeks to optimize the energy consumption of ESP subject to the outlet concentration requirement in real-time. A coordination control logic is designed to regulate the optimized operation set points with varying operation conditions. The operation optimized by the IOS is compared with the operations under PID (proportion-integral-derivative) and manual control. The results show that the IOS improves the emission compliance rate from 95% of manual control to 100% and the medium concentration is tuned to be 46.6% closer to the emission target. Furthermore, a good balance between emission and energy consumption is achieved, with 35.50% energy conservation for the same emission upper limit of 30 mg/m3. These results prove that the IOS significantly contributes to the efficient operation and economic PM removal by ESP for the energy industry. 相似文献
805.
806.
The photocatalytic oxidation of pyrene preadsorbed on TiO2 is examined in aqueous suspension under UV irradiation. Chemical oxygen demand measurements, UV-VIS spectrophotometer, infrared spectrometer and GC-MS analytical techniques were used to monitor the formed intermediates. During the oxidation processes, the ring-open reaction, hydroxylation and ketolysis occurred to produce some intermediate products (4-oxapyrene-5-one, 1,6- or 1,8-pyrenediones, 4,5-phenanthrenedialdehyde, cyclopenta[def]phenanthrene). Some factors affecting the photodegradation rate were also studied. The results were different from other studies: The pH of the dispersion, ratio of Py/TiO2:water had little effect on the photooxidation rate of pyrene catalyzed by TiO2, while the surface coverage, addition of Fe3+ affected it greatly. 相似文献
807.
Li HY Qu JH Zhao X Liu HJ 《Journal of environmental science and health. Part. B》2004,39(5-6):791-803
The effects of Fe(II), Mn(III) and humic substances on the catalyzed ozonation of alachlor, an endocrine disruptor were investigated. Results revealed that small amounts of Fe(II), Mn(II), and humic substances could enhance the ozonation of alachlor, but larger amounts of them would retard the oxidation. These results were successfully identified by an electron paramagnetic resonance (EPR) spectroscopy spin-trapping method that could quantify hydroxyl radicals. The production of hydroxyl radicals was obviously increased with the increasing of Fe(II) concentration, which contributed to enhance ozonation at low concentrations. But the excess Fe(II) consumed some of the radicals when it was added at a higher concentration (1.5 mg/L). However, no obvious radicals were observed when a different amount of Mn(II) was used, and the catalytic ozonation of alachlor by Mn(II) mainly followed the mechanism of "active sites created on the surface of MnO2." The radical pathway was followed when alachlor was ozonated with different concentrations of humic substances because of its radical initiating, promoting, and inhibiting effects. 相似文献
808.
809.
810.
矿化垃圾生物反应床处理NOX废气的研究 总被引:2,自引:0,他引:2
矿化垃圾(稳定化垃圾)是一种良好的生物介质,可作为生物反应床的填料处理NOX废气.实验室研究表明,稳定化垃圾反应床可有效地处理NOX气体,其硝化能力(以N计)可达0.83
g/(kg·d)(干重).NOX去除率受停留时间的影响显著,NOX去除率随着停留时间的缩短而降低.当空床停留时间为1.5
min时,NOX气体的平均去除率为76.7%;空床停留时间为15 min时,NOX气体的平均去除率为91.0%.在NOX进气负荷低于110
mmol/(m3·h)时,NOX消除能力随进气负荷的增加而线性增加.当进气流量一定时,NOX去除能力随着进气NOX浓度的增加而线性增加. 相似文献