The denitrification for the coking wastewater was conducted by means of original battery principle with Fe-C micro-electrolysis. Fe-C serves as positive and negative electrodes, by which N02?-N and TN were reduced to nitrogen, and then the purpose of denitrifieation for coking wastewater was realized. The influences of pH value, carbon particle size, Fe/C ratio (mass ratio), reaction time and coagulation pH value on removal rate of N02?-N and TN were investigated. Coking wastewater originated from Jiamusi Coal Chemistry Engineering Company. The optimum conditions of treatment were as follows: the initial pH was 3.0, the dosage of Fe 73.5 g/L, reaction time 70 min, mass ratio of Fe/C ratio 1.0:1.3, coagulation pH 9.0 and sedimentation time 40 min. Under those conditions, nitrogen removal efficiencies of N02?-N and TN were beyond 50% and 45%, respectively. 相似文献
Arsenic is an environmental contaminant, its multiple effects on human tend to increase the rate of disease, cancer and other health problems. Some of long non-coding RNAs (lncRNAs) can be induced in major cellular processes such as necrosis, proliferation, and mutation. While the toxicity of arsenic is well established, the association between arsenic exposure and long non-coding RNAs has not been studied enough. This study investigated the association between arsenic and the expression of HOTAIR and LincRNA-p21 in vivo and vitro. In epidemiological studies, the expression of HOTAIR and LincRNA-p21 was increased after long-term arsenic exposure. HOTAIR and LincRNA-p21 expression were positively linked to monomethylarsenic acid (MMA), dimethylarsenic acid (DMA), inorganic arsenic (iAs), total arsenic (tAs), and MMA% and negatively linked to secondary methylation index (SMI). In A549 cells, arsenic exposure resulted in enhanced HOTAIR and LincRNA-p21 expression dose-dependently. The expression of HOTAIR was considerably high in the presence of NaAsO2 and MMA but showed no difference in DMA compared with control group. And LincRNA-p21 expression was increased in the presence of NaAsO2, MMA, and DMA. The expression of HOTAIR and LincRNA-p21 induced by iAs was much higher than that induced by MMA and DMA. Compared with the control group, treatment of A549 cells with NaAsO2/S-adenosylmethionine (SAM) and NaAsO2/glutathione (GSH) combination increased HOTAIR and LincRNA-p21 expression. The expression of LincRNA-p21 in combination of NaAsO2/GSH was significantly decreased compared with NaAsO2 alone. Besides, in the presence of arsenic, both of HOTAIR and LincRNA-p21 were upregulated significantly when P53 was knocked down. We revealed that inorganic arsenic, its methylated metabolites, and arsenic metabolism efficiency affect the expression of HOTAIR and LincRNA-p21.
Environmental Science and Pollution Research - Meteorological factors, which are periodic and regular in a long run, have an unignorable impact on human health. Accurate health risk prediction... 相似文献