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421.
This work reports the semiconductor-assisted photochemical degradation of reactive dyes. In an oxygenated-UV-ZnO system almost total decolorization of Remazol Brilliant Blue R, Remazol Black B, Reactive Blue 221 and Reactive Blue 222 was observed in reaction times of about 60 min. Extending the photochemical treatment up to 120 min, mineralization higher than 80% for all the dyes was observed. During the same period, the residual acute toxicity was significantly reduced only for Remazol Black B. A systematic optimization study carried out by factorial design showed that for the reactive dyes tested, the ZnO semiconductor exhibits a better efficiency than that observed with anatase TiO2. A synergistic effect in the coupled TiO2-ZnO system was not observed.  相似文献   
422.
Accumulation pattern of 3,3',4,4'-tetrachlorobiphenyl (PCB 77) and the exposure time needed to activate the monooxygenase (EROD) and conjugation (GST) enzyme systems of fish at the advanced embryonic stage were studied. Eyed stage embryos of rainbow trout (Oncorhynchus mykiss) were exposed to sublethal doses (0, 1, 10, and 100 micrograms/l) of PCB 77. Results indicated direct accumulation of the chemical into the eggs, but the exposure time was not long enough for PCB 77 to reach constant steady state. However, at the two lowest test concentrations (1 microgram/l and 10 micrograms/l) a temporary plateau at chemical accumulation was reached at the third exposure day (185 and 1221 ng PCB/g egg w.w). At the highest concentration (100 micrograms/l) the decrease in the accumulation rate was already evident after the first day (2182 ng PCB/g egg w.w). The chemical uptake increased again at day 7 in all the exposure groups. That event could have been caused by the increased metabolic rate of the embryos in preparation for the upcoming hatching event. The microsomal CYP1A monooxygenase system (EROD) was shown to be a sensitive indicator of embryonic exposure, being induced at the low (1 microgram/l, 182 ng/g egg) PCB concentration and after a short (3 day) exposure time. The conjugation enzyme system (GST) was shown to be functioning already at the advanced embryonic stage, although no response to the studied chemical stress was detected.  相似文献   
423.
Environmental Science and Pollution Research - Persistent organic pollutants (POPs) are still globally distributed and can exert different effects on ecosystems. Little is known about the...  相似文献   
424.
Environmental Science and Pollution Research - Environmental arsenic exposure in adults and children has been associated with a reduction in the expression of club cell secretory protein (CC16) and...  相似文献   
425.
Environmental Science and Pollution Research - Nowadays, the use of different nanoscale structures has been introduced to a large number of research areas. One of these is the treatment and...  相似文献   
426.
Environmental Science and Pollution Research - Potentially toxic elements (PTEs) are of great concern in steel mill wastes. Therefore, in order to use them as potential fertilizers in soil, risk...  相似文献   
427.
Environmental Science and Pollution Research - Nutrient source and transport study in tropical creeks adjacent to megacities are sparse on a regional and global scale. High-frequency chemical data...  相似文献   
428.
Environmental Science and Pollution Research - It is well known that road transport emits various trace elements into the environment, which are deposited in soils in the vicinity of roads,...  相似文献   
429.
Environmental Science and Pollution Research - A linear algebra theorem like Cramer’s rule was used for the analysis of a system of equations obtained from UV spectroscopy, and results were...  相似文献   
430.
Environmental Science and Pollution Research - The utilisation of waste wood from furniture production brings new problems connected with an incomplete thermochemical decomposition of additives...  相似文献   
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