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581.
Study on the kinetics of cerium(III) adsorption-desorption on different soils of China 总被引:1,自引:0,他引:1
The kinetics of Ce(III) adsorption-desorption on four typical soils in China has been studied by using the batch method with the radioactive nuclide 141Ce. Results indicated that Ce(III) adsorption was rapid and nearly finished in less than 0.5 min. Desorption procedure was about completed in 1-30 min in the tested soils. Ce(III) desorption equilibrium times vary with different soils. The amounts of Ce(III) desorption on different soils in the same time were different. The Elovich equation proved to be the best models for fitting the data of Ce(III) desorption reactions in fluvo-aquic soil and black soil; and the parabolic-diffusion equation was the best model in red earth and loess soil. 相似文献
582.
Tsai CH Huang YJ Chen JC Liao WT Fang GC 《Journal of the Air & Waste Management Association (1995)》2003,53(10):1225-1232
The traditional technologies for odor removal of thiol usually create either secondary pollution for scrubbing, adsorption, and absorption processes, or sulfur (S) poisoning for catalytic incineration. This study applied a laboratory-scale radio-frequency plasma reactor to destructive percentage-grade concentrations of odorous dimethyl sulfide (CH3SCH3, or DMS). Odor was diminished effectively via reforming DMS into mainly carbon disulfide (CS2) or sulfur dioxide (SO2). The removal efficiencies of DMS elevated significantly with a lower feeding concentration of DMS or a higher applied rf power. A greater inlet oxygen (O2)/DMS molar ratio slightly improved the removal efficiency. In an O2-free environment, DMS was converted primarily to CS2, methane (CH4), acetylene (C2H2), ethylene (C2H4), and hydrogen (H2), with traces of hydrogen sulfide (H2S), methyl mercaptan (CH3SH), and dimethyl disulfide. In an O2-containing environment, the species detected were SO2, CS2, carbonyl sulfide, carbon dioxide (CO2), CH4, C2H4, C2H2, H2, formaldehyde, and methanol. Differences in yield of products were functions of the amounts of added O2 and the applied power. This study provided useful information for gaining insight into the reaction pathways for the DMS dissociation and the formation of products in the plasmolysis and conversion processes. 相似文献
583.
The toxic effect of a combined sewer overflow (CSO) on the phytoplankton community of the river Seine has been studied by means of short-term primary production measurements. As the discharged solids usually do not remain in the water column, only filtered or centrifugated fractions were tested. The collected phytoplankton were grown in the laboratory for 2 days, after addition of N, P and EDTA. Stock cultures in exponential growth were directly tested with heavy metals, but resuspended algal cells were used for effluent testing. The results show an increase of EC50 value for the single metal species in the order Cu相似文献
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586.
Kinetics of quinoline degradation by O3/UV in aqueous phase 总被引:1,自引:0,他引:1
The kinetics of quinoline degradation by O3/UV in aqueous phase was studied in this paper. It was found that the stoichiometric factor for the number of ozone molecule consumed by per quinoline molecule was 1. The second-order rate constants at 15 degrees C for the direct reaction of quinoline with ozone and that for the reaction of quinoline with *OH were determined to be 51.0 and 7.24 x 10(9) M(-1)s(-1), respectively. In O3/UV reaction system, *OH was the more important oxidant to degrade quinoline than ozone. For a comparison, in O3 reaction system, the relative importance of the two oxidants depended on the pH value greatly. To make the degradation of quinoline more practical, improvement of the concentration of *OH is more feasible. 相似文献
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588.
氨氮废水处理技术研究进展 总被引:4,自引:0,他引:4
氨氮废水是造成水体富营养化的主要因素之一 ,本文综述了氨氮废水的几种主要处理技术 ,介绍了它们的处理原理以及适用条件 ,指出了今后研究工作中需要解决的问题和氨氮废水处理技术今后的发展方向 相似文献
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改进的硫酸盐-聚乙烯醇法包埋藻菌脱氮除磷研究 总被引:1,自引:0,他引:1
采用改进的硫酸盐-PVA固定化法将藻与菌混合固定。在三种不同藻菌比的情况下,固定化系统对氮去除均可达100%,但是去除速度与固定的细菌量有关,细菌量越大,对氮的去除速度越快;对磷的去除随实验进行,最大去除率逐步下降,其下降速度与固定藻的量有关,藻量越大,下降速度越慢。由此说明脱氮的主要贡献者是细菌,而藻对除磷起了主要作用。为达到有效的脱氮除磷,应适当提高固定化藻的浓度,藻菌比应大于2:1。透射电镜照片显示,在聚乙烯醇载体上,藻类的生长没有受到限制。 相似文献