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采用海藻酸钠对光合细菌进行包埋,并在固定化过程中加入壳聚糖,研究添加了壳聚糖的固定化细胞在不同条件下对活性艳红X-3B的脱色效果及其降解动力学.实验结果表明,在厌氧条件下,X-3B的脱色效果较好;染料浓度在30~300 mg/L之间变化时,厌氧降解动力学方程均符合一级动力学方程;降解速率与染料初始浓度之间关系符合Michaelis-Menten方程,反应动力学参数Km=374.96 mg/L,Vmax=7.53 mg/L·h.振荡有利于脱色并使半衰期缩短;固定化小球可重复使用. 相似文献
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Comparative studies of the Fe3+/2+-UV, H2O2-UV, TiO2-UV/vis systems for the decolorization of a textile dye X-3B in water 总被引:4,自引:0,他引:4
Xu Y 《Chemosphere》2001,43(8):1103-1107
The degradation of a common textile dye, Reactive-brilliant red X-3B, by several advanced oxidation technologies was studied in an air-saturated aqueous solution. The dye was resistant to the UV illumination (wavelength λ 320 nm), but was decolorized when one of Fe3+, H2O2 and TiO2 components was present. The decolorization rate was observed to be quite different for each system, and the relative order evaluated under comparable conditions followed the order of Fe2+–H2O2–UV Fe2+–H2O2 > Fe3+–H2O2–UV > Fe3+–H2O2 > Fe3+–TiO2–UV > TiO2–UV > Fe3+–UV > TiO2–visible light (λ 450 nm) > H2O2–UV > Fe2+–UV. The mechanism for each process is discussed, and linked together for understanding the observed differences in reactivity. 相似文献
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National Threatened Species Listing Based on IUCN Criteria and Regional Guidelines: Current Status and Future Perspectives 总被引:3,自引:0,他引:3
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Assessment of Contamination By Percolation Of Septic Tank Effluent Through Natural and Amended Soils
Fly ash has been found to be a potential material for the treatment of municipal and industrial wastewater, and may be useful in the treatment of septic tank effluent. Laboratory columns (30 cm) were used to determine the sorption capacity and hydraulic properties of lagoon fly ash, loamy sand, sand, and sand amended by lagoon fly ash (30 and 60%) and red mud gypsum (20%). The removal of chemical oxygen demand (COD) was high in all column effluents (71–93%). Extent of nitrification was high in Spearwood sand, Merribrook loamy sand and 20% red mud gypsum amended Spearwood sand. However, actual removal of nitrogen (N) was high in columns containing lagoon fly ash. Unamended Spearwood sand possessed only minimal capacity for P sorption. Merribrook loamy sand and red mud gypsum amended sand affected complete P removal throughout the study period of 12 weeks. Significant P leakage occurred from lagoon fly ash amended sand columns following 6–10 weeks of operation. Neither lagoon fly ash nor red mud gypsum caused any studied heavy metal contamination including manganese (Mn), lead (Pb), zinc (Zn), cadmium (Cd) and chromium (Cr) of effluent. It can be concluded that Merribrook loamy sand is better natural soil than Spearwood sand as a filter medium. The addition of lagoon fly ash enhanced the removal of P in Spearwood sand but the efficiency was lower than with red mud gypsum amendment. 相似文献
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Summary. Infochemicals are known to play a key role in mediating predator-prey interactions, both in aquatic and terrestrial communities. However, state-dependent variation may exist in how effectively individuals can use this information, depending on genotype, life stage and experience. For our study, we used the predator-prey model system fish-waterflea Daphnia magna Straus (Cladocera, Daphniidae). Adult Daphnia use fish-derived infochemicals, so-called kairomones, as indicators of predation risk, and exhibit a spectrum of morphological, behavioural and life-history responses to the presence of fish kairomones. Here, we investigate whether diapausing eggs, an embryonic resting stage in the life cycle of D. magna, also use fish kairomones and tune their hatching to the risk of fish predation, as reported for diapausing stages of dinoflagellates. In two laboratory experiments, we studied hatching proportion and time until hatching of D. magna diapausing eggs in the absence and presence of fish kairomones. D. magna families differed significantly in their response to the presence of fish kairomones; some families reduced hatching proportion, whereas others increased it. Our results imply genotype-dependent differences in the hatching reactions to fish kairomones as observed for other traits in adult Daphnia. 相似文献
207.
磁性肥料能明显促进水稻的生长和提高生物产量,在以广州发电厂的粉煤灰为主要磁性物质时,对赤红壤和水稻来说,其磁性肥料磁处理的最佳磁感应强度是0.22T. 相似文献
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