Drought monitoring in Urmia Lake by fuzzy index

Drought is a climate phenomenon with a lack of moisture and rainfall compared to normal conditions.  This phenomenon strongly affects all aspects of human activity. In this Article, were discussed the drought situation in Urmia Lake using MATLAB software and system capabilities combined indicators SEPI on two-time scales 6 and 12 months. Therefore was used climate data of temperature and precipitation for 5 synoptic stations basin of Lake Urmia (Tabriz, Maragheh, Urmia, Saghez, and Mahabad). Results indicated that SEPI index show features of SPI and SEPI index. As well as it enters temperatures as a powerful factor in the drought severity in order to the investigation of the drought conditions; So SEPI drought index is better than the SPI for the study of drought. Drought studies on SEPI index indicated that drought trend in Urmia Lake Basin is increasing. The temperature has an increasing trend with more intensity. The longest duration of drought in the basin of Lake Urmia is in Urmia station on a scale of 6 months from May 2005 to November 2006 for 19 months. The highest percentage of drought observed in Urmia and the lowest percentage in Mahabad stations

Performance Evaluation of Moving-bed Sequencing Batch Reactor for Livestock Wastewater Treatment by SND Process

In this study, the performance of moving-bed sequencing batch reactor with intermittent aeration strategy (IA-MBSBR) was evaluated for treatment of livestock wastewater in simultaneous nitrification-denitrification process. The statistical design and analysis were employed to optimize independent variables such as sludge retention time (SRT), temperature, and aeration rate using response surface methodology (RSM) through Box-Behnken design (BBD). The effect of variables was investigated on chemical oxygen demand (COD) removal and SND efficiency . The analysis of variance (ANOVA) was conducted to confirm the suitability and significance of the quadratic models. Based on the results, a very high regression coefficient was achieved between the variables and the responses: COD removal and SND efficiency were R2 = 0.9788 and R2 = 0.9600, respectively indicating an excellent evaluation of experimental data by polynomial regression model. Long SRT reduced the negative effect of low temperature, but lowered COD removal and ESNDin high temperature. Further, appropriate aeration rate was vital for the SND to reach equilibrium between the nitrification and denitrification processes. The optimal conditions obtained from the models were SRT= 20 d, temperature = 19.16 °C and aeration rate= 0.1 , which results in COD removal and ESND of 92.9 and 91.3%, respectively. It was found that an alternating anaerobic/aerobic conditions with step-filling mode is an effective, economic, and environmentally-friendly strategy for the biological treatment of livestock wastewater in the moving-bed sequencing batch reactor

Spectroscopic analysis of bosentan in biological samples after a liquid-liquid microextraction

Introduction: Microextraction processes with UV-Vis measurement have been developed and validated for analysis of bosentan in biological samples. Methods: In this work, liquid–liquid microextraction procedures (DLLME & USAEME) were employed for cleanup, pre-concentration, and determination of bosentan in biological samples by UV-Vis spectroscopy at 270 nm. The method was validated and applied to the determination of bosentan in spiked serum, exhaled breath condensate and urine samples. Results: Various experimental factors including type of extraction and dispersive solvents and their volumes, pH, sonication time and centrifuging time were investigated. Under the optimum conditions, the method was linear in the range of 1.0–5.0 μg.mL−1, with coefficient of determination (R2) of > 0.998. The limit of detection (LOD) was 0.07 mg.L−1. Recovery of the target analyte in biological samples was 106.2%. The method could be easily applied for higher concentration of bosentan and needs more improvement for application in the pharmacokinetic investigations where more sensitive methods are required. Conclusion: A simple, low cost, precise and accurate spectrophotometric analysis of bosentan in biological samples after liquid-liquid microextraction were developed and validated for routine analyses