ABSTRACT
Nowadays, the increasing concentration of pollutants in water resources, especially ground water, has been a matter of concern. Nitrate has been considered as a chemical indicator of water pollution for a long time. The aim of this study was to determine the chemical characteristics of drinking water and changes of nitrate in drinking water in Diwandareh villages. This was a cross-sectional study to determine the quality of drinking water of 30 villages in Divandareh. A total of 60 samples were obtained in two phases from water supplies and were analyzed according to the standard methods. Descriptive statistics, Piper, Schuler and Wilcox diagrams were used to interpret the results. The results showed that apart from nitrate, the concentrations of the other chemical quality parameters were below the standard limits. The mean and standard deviation of nitrate during the first and second stages of sampling in water sources were 26.13 +/- 25.61 mg L[-1] and 28.47 +/- 29.80 mg L[-1], respectively. According to Schuler diagram, the drinking water quality was moderate to good. Although the mean nitrate concentration in 80% of samples was lower than the latest national standard for nitrate, continuation of the current trend, particularly in the agricultural activities and uncontrolled use of groundwater resources in agriculture will change and lower the quality of water. Therefore, monitoring of agricultural practices and fertilizer use are necessary
ABSTRACT
Millions of liters of color effluents are produced by textile industries and plants. Every liter of effluents may contain more than 20gr of pigments and mediators produced by their degradation which can result in environmental problems. Chemical dyes used in textile industries have some potential risks including carcinogenic and mutagenic effects on human. Further, these dyes can penetrate into surface and ground water. The aim of this study was to investigate the efficiency of combined CAC-SBR system for removal of Reactive yellow 3 dyes. This experimental study was conducted based on a batch scale, and two SBR reactors were used for the experiment. We used synthetic wastewater samples in this study [COD=1800]. After adjusting the reactors, reactive yellow3 dye was injected into the system and its removal efficiency was investigated during different reaction times. Then SBR system efficiency in dye and COD removal was determined. After 24 hours of reaction, the efficiency of SBR system in the removal of reactive yellow3 dye was 58%. But the efficiency of SBR system in COD removal was 98% after 14 hours of reaction. In this study, by increasing the reaction time SBR efficiency increased and stabilized in a distinct time. SBR efficiency in the removal of dye and COD, together with high efficiency of anaerobic system in dye removal reveals that a combination of aerobic and anaerobic systems can be suitable for synchronic dye and COD removal.
Subject(s)
Azo Compounds , Textile Industry , WastewaterABSTRACT
Methyl-tributylether [MTBE] is a volatile organic compound which has detrimental effects on the environment, surface water and groundwater resources and it can change the taste of drinking water. The aim of this research was to determine the efficiency of activated sludge reactor with fixed bed in biological removal of methyl-tri-butyl ether from synthetic wastewater. This was an intervention-applicable study. The applied reactor was made of plexiglas and after transfer of activated sludge to it; the system ran for 4 weeks discontinuously. During a period of one month, concentration of glucose of the solution reduced and that of MTBE increased. 32 days after running the system, the whole COD input was provided through MTBE. COD, TSS, MLSS, SVI, temperature, PH, and dissolved oxygen parameters were analyzed in duplicate forms by excel software. The results of this research indicated that by increasing the organic input load, the efficiency of the reactor decreased to some extent. The mean values of efficiency of COD removal during hydraulic remains of 4, 6, 8 and 10 hours were 82.7, 92.45, 95.97 and 96.1%, respectively. The results of this study showed with organic loadings up to 3 and 4/5 kg COD/m 3.d, the combined activated sludge reactor with fixed bed is capable of meeting the standards of household and industrial wastewater according to the standards of Environmental Protection Organization of Iran as to effluent wastewater COD for discharge in accepting water resources. Therefore we can conclude that the activated sludge reactor with fixed bed is an efficient, reliable and applicable technology for the treatment of strong wastewater
ABSTRACT
Reactive dyestuff has potential of toxicity, carcinogenesis and mutagenesis for mammals and aquatic organisms. The current physical and chemical methods such as adsorption, coagulation, precipitation, filtration and. can been used for removing of dyestuff. Biological treatment which is effective and economic for decontamination of dyestuff wastewaters was preferred because of limitation and difficulty of physicochemical methods. In order to investigate the trend of pollution reduction of color compounds, ability of Remazol Black-B dyestuff removal from aqueous medium by bacterial consortium under anoxic conditions was studied. The mix culture of bacteria from textile industries activated sludge was enriched in luria broth medium containing RB-B dyestuff as a carbon source. Then biodegradation was assessed in 4 batch reactors. Microbial population of bacterial and decolorization quantities of samples were detected by MPN and UV-Vis spectrophotometer. Decolorization efficiency by the bacterial consortium was obtained more than 99% for 50 and 250 mg/L concentrations in 72 and 144 h [3 and 6 days] respectively, while for the initial concentration of 500 mg/L was 98.1in 240 h [10 days] of biodegradation period. Dyestuff reduction rate after completed removal was about 0.69, 1.74,2 mg/L/h for initial concentration of 50, 250, 500 mg/L respectively. Results showed that Alcaligenes denitrificans and Alcaligenes xylosoxidans bacteria which were isolated from activated sludge have good potential of RB-B dyestuff removal and this removal is depending on primary concentration of dye. Removal efficiency increased as primary concentration went up
ABSTRACT
Effect of lipocalin 2 on the expression of heme oxygenase I, II and NF-kB transcription factor was the purpose of this survey. Lcn2 was cloned to pcDNA3.1 plasmid by using genetic engineering method. The recombinant vector was transfected to CHO and HEK293T to establish stable cell expressing lipocalin 2. The presence of lipocalin 2 gene in these cells was confirmed by using through RT-PCR and western blot analysis. Expression of Lcn2 was also down-regulated by siRNA in A549 cell line. Expression of heme oxygenase I, II and NF-kB transcription factor were determined in both ectopic expression Lcn2 cells and Lcn2 down regulated cells by using of RT-PCR and western blot analysis. The results showed that the expression of heme oxygenase I and those of NF-kB were higher in cells expressing recombinant lipocalin2 compared with the control cells. On the other hand, expression of heme oxygenase I and NF-kB in siRNA transfected cells was down-regulated. These findings indicate that lipocalin2 induces the expression of HO-1 and suggest Lcn2 through NF-kB induces HO-1 expression