Feasibility Study for Reuse of Zarand Thermal Power Plant Wastewater Passed through Reverse Osmosis Process

Increased urbanization and industrialization have disturbed the balance between water demand and water supply. Thermal power plants are among the largest water consumers and wastewater producers, while wastewater reuse can deal with the both concerns. Effluents of thermal power plants contain various pollutants, so remediation is needed before any other usage. Assessment the efficacy of Reverse Osmosis (RO) system in treatment of Zarand power plant wastewater for reuse was the aim of present work. Physical and chemical parameters including pH, temperature, turbidity, BOD, COD, chromium, sulphate, chloride, nitrate, and phosphate ions were determined in samples collected from three locations of power station: feed water, influent to RO, and effluent. Sampling was done in the first six months of 2012. Data was characterized using descriptive statistics and Excel software. The average performance of RO in the removal percent of turbidity, BOD, COD, chromium, sulphate, chloride, nitrate, and phosphate was 57.5, 14.5, 27.4, 28, 46, 26, 73, and 99% respectively. In spite of less satisfying values of efficiency, mean values of pH, turbidity, BOD, COD, chromium, chloride, nitrate, and phosphate measured in effluent passing through RO were 7.5, 0.14 NTU, 1.8, 2.83, 0.018, 320, 1.6, and 0.001 mg/l respectively, all in compliance with discharging or irrigation standards, while 704 mg/l of sulphate ions detected in effluent, were much higher than acceptable limits

Effect of Magnetic Field on the Type and Amount of Monomers in Polyhydroxyalkanoate Copolymer

Many studies have been conducted on production of biodegradable polymers such as polyhydroxyalkanoates (PHAs) in overcoming the environmental problems due to the accumulation of synthetic plastics as waste materials and excessive activated sludge produced in municipal waste water treatment plants. In this study; the effect of magnetic field intensity of 5, 10, 15, 20, 25 and 50 milliTesla (mT) was investigated on the type and amount of monomers produced in the copolymer and PHA production in activated sludge and the results were compared simultaneously with the results of PHA production without the magnetic field (0 mT). The experimental procedure included the transfer of the activated sludge into the batch reactor, addition of sodium acetate, magnetic field generation by magnets, aeration for 30 h, sampling at definite timing, measurement of PHA by gas chromatography. In summary, this research indicated that, the maximum PHA content was produced at 20 mT which was equal to 0.75 g/L, whereas the lowest PHA content was observed at 50 mT (0.55 g/L). In addition, the magnetic field was influenced by the type and amount of monomer produced in PHA. The highest amount of valerate was observed at 50 mT, while this magnetic field decreased the amount of PHA (8.33%) compared to the control sample. Also, the maximum amount of butyrate monomer in the copolymer was observed at 5 and 20 mT, which were equal to 81% and 74 %. According to the results obtained, the mass percentage of valerate in the control sample and those exposed to magnetic field with negative effects was more than the mass percentage of butyrate; an indication of better copolymers on the basis of their mechanical properties

Evaluation of sequencing batch reactor performance for petrochemical wastewater treatment

Sequencing batch reactor (SBR) technology has found many applications in industrial wastewater treatment in recent years. The aim of this study was to determine the optimal time for a cycle of the sequencing batch reactor (SBR) and evaluate the performance of a SBR for petrochemical wastewater treatment in that cycle time. The reactor was operated with a suspended biomass configuration under aerobic conditions. Carbon removal and operating parameters such as pH, temperature and dissolved oxygen (DO) were monitored during the wastewater treatment. The SBR was run at different cycle times and amongst the cycle times tested, the best performance was obtained with a 7 h cycle time composed of a fill time of 15min, reaction of 6 h, settling of 30 min, and withdrawal of 15 min. The SBR with the determined cycle time was used to study the treatment of wastewater with various organic loading rates (12.88 gr COD/L.d, 18.02 gr COD/L.d and 31.39 gr COD/L.d). The SBR performance was evaluated by chemical oxygen demand (COD), total solids (TS) total suspended solids (TSS) removal efficiencies. During the shock loading tests, the maximum COD, TS and TSS removal efficiencies were 84%, 67% and 92%, respectively

Determining the best extractant and extraction conditions for fulvic acid through qualitative and quantitative analysis of vermicompost

Fulvic acid is a natural tampon and an appropriate chelating agent that has high ion-exchange ability and increasing absorption of minerals in plants. This paper examined the effects of extractants (sodium hydroxide, sodium polyphosphate, urea and EDTA) and the extraction time (1, 7 and 9 days) on the physicochemical properties of vermicompost-produced fulvic acid. Finally, various methods were compared to the universal method of humic substances. Different qualitative and quantitative analysis such as detecting the functional groups (FTIR), measurement of functional groups, spectrophotometric ratios and humification indices were carried out on fulvic acid. Results showed that the highest and lowest amounts of fulvic acid were extracted by the sodium hydroxide and urea, respectively. Various extractants made negligible changes in the type and quality of the Fulvic acid functional groups. Results indicated that sodium hydroxide was the best extractant and the minimum amounts of fulvic acid were extracted by the urea. Urea-extracted fulvic acid had the most functional groups of total acidity and phenolic OH. The most carboxyl functional groups and spectrophotometric ratios were detected in EDTA solution. At the end, by the comparison of various methods, universal method despite the low extraction amount had more functional groups and higher efficiencies compare to others

Prolonged urinary catheterization, a factor associated with intensive care infections and deaths

Background and aim: Health Care Associated Infection (HCAI), especially nosocomial infection (NCI) in intensive care units (ICUs), has remained a major cause of mortality and morbidity. In this study, the rate of HCAI and the factors associated with both NCIs and deaths in ICUs were assessed in a large teaching hospital complex in Tehran, IR Iran. Materials and methods: In this cross sectional study, 300 patients hospitalized in six different ICUs of a large teaching hospital located in Tehran were assessed from January to March 2013. Nosocomial infection was defined as the presence of clinical signs and symptoms of infection in patients at least 48 h after their hospitalization, confirmed by positive cultures of specimens taken from the patients’ blood, urine, wounds, respiratory secretions and other body fluids. The risk factors of NCIs were assessed by a researcher – produced checklist consisting of 109 questions. Results: According to the findings, NCIs were observed in 59 (19.7%) (CI 95% = 15.2–24.2%) patients and the overall mortality rate was 23 (7.7%) (CI 95% = 4.7–10.7%), and the highest infection rate belonged to general ICU-1. The factors associated with the higher rate of NCI and/or mortality were as follows: lower education levels, increased length of stay in ICU, increased duration of antibiotic use, combined antibiotic therapy, long time inserted catheters, anemia, and immunosuppression or chronic diseases. Multivariate analysis showed an independent statistically significant association between prolonged urinary catheterization and both NCIs and deaths. Conclusion: It seems that patients with prolonged catheterization are prone to NCIs and deaths, so they should be treated intensively

Epidemiological Study of Adult Patients with Acute Abdomen Referred to Fatemi Ardabil Hospital from 2020 to 2021

Introduction: The prevalence and causes of acute abdomen can be different in various regions and races. Knowing the epidemiology of the disease can prevent unnecessary surgeries and unwanted complications caused by surgery. The present study was conducted with the aim of epidemiological investigation of adult patients with acute abdomen referred to Fatemi Ardabil Hospital from 2020 to 2021. Methods: A cross-sectional descriptive study was conducted during a year with a statistical population of 1031 patients referred to the Emergency Department of Fatemi Ardabil Hospital with abdominal pain. The sampling method was easy non-probability sampling. The information of these patients was collected through a preliminary questionnaire and analyzed using SPSS 16 software. Results: In this study, the number of 535 participants were male and 496 were female. 53.5% of patients had non-bilious vomiting، 67.6% had normal abdominal function، 53% had anorexia، 16.2% had abdominal distension and 14.3% had fever. 20.1% had pain in the right lower quadrant، 16.1% no tenderness، 15.6% rebound tenderness، 5.4% guarding، 5.8% psoas sign and 16.3% Murphy sign. 27% of abdominal pain was related to appendicitis، 20% to cholecystitis، 15.3% to intestinal obstruction and the lowest number of cases were related to metastasis and ectopic pregnancy with 0.3%. Conclusion: The best tools available for examining and managing abdominal pain are clinical examination and a comprehensive history