[Efficacy of photocatalytic removal of Chromium in the presence of organic matter from aqueous medium by useing TiO2 nanoparticles synthesized by sol gel]

Background and Aim: Widespread use of Chromium and their compounds in many industries, including plating, steel production, and wood protection and tanning leather, can result in the discharge of large amounts of pollutants to receiving waters, leading to toxic effects on human health and the environment. The aim of this study was to determine the efficiency of the photocatalytic process to remove Chromium in the presence of organic matter from the aqueous medium by using nanoparticles of TiO2 synthesized by sol gel

Materials and Methods: This was an experimental study. After nanoparticle synthesis, we used FTIR, SEM, XRD for analysis of nanoparticles. The photocatalytic process for Chromium removal was performed using a discrete stream reactor and Uv light bulb with 30 watts intensity. Then, the effects of independent variables, including pH, concentration of nanoparticles, contact time and the presence of interfering organic matters such as phenol, EDTA, CCl4, methanol and humic acid on the efficiency of the removal of Chromium in an aqueous medium were evaluated

Results: The results showed efficiency of Chromium removal increased after decreasing pH. Also, increasing the concentration of nanoparticles and contact time led to increased removal efficiency. We found reduced removal efficiency after increasing concentrations of the pollutants. Removal efficiency of Chromium increased in the presence of EDTA, but methanol, phenol, humic acid, and carbon tetrachloride reduced its removal efficiency

Conclusion: Photocatalytic oxidation with titanium oxide nanoparticles synthesized by sol- gel method can be an effective way for removal of Chromium from aqueous medium

[Efficiency of Pistaciaatlantica seed extract as natural coagulant in the removal of Reactive Red 198 dye from aqueous solution]

Textile dyes and other dyes used in various industries are among the largest organic compounds which can be a major hazard to the health and environment. Therefore treatment of wastewater before discharging it into the environment is necessary. In the present study we investigated the efficiency of Pistacia atlantica seed extract in a batch system for removal of Reactive Red-198 dye from aqueous solutions. This is a basic- applications study conducted in laboratory. The effects of independent variables such as coagulant dose [0.1-1 ml L-1], initial dye concentration [50, 100, 150 and 200 mg/l] and pH [2-12] were investigated. To measure the residual concentration of dye we used a spectrophotometer at the wavelength of 520 nm. Excel software was used for data analysis. The optimum pH for Reactive Red-198 removal by coagulation using Pistacia atlantica seed extract was 12, with a coagulant dose of 0.5 ml/L. The highest removal rates were 83.12, 84.20, 87.36 and 88.49% at initial dye concentrations of 50, 100, 150 and 200 mg/L respectively, which could be result of precipitation, co-precipitation and adsorption mechanisms. According to the results of this study, Pistacia atlantica seed extract was an inexpensive coagulant, and also quite effective in the removal of Reactive Red-198 dye from aqueous environments

[Investigation of mycological flora in Kurdistan university of medical sciences bath hostels in 2011]

Damp environments with suitable temperature such as swimming pools and public baths produce appropriate conditions for growth and spread of fungi. Investigation of opportunistic and pathogenic fungi in these places can be helpful for elimination or reduction of the rate of potential fungal infections. This study was performed to find fungal contamination in the student hostels in Kurdistan University of Medical Sciences. Samples were collected from the walls and floors of the bathrooms and were cultured in Sabouraud dextrose agar medium containing chloramphenicol [SC], and Sabouraud dextrose agar medium containing chloramphenicol and cyclohexamide [SCC]. All cultures were incubated at 28 C, and were observed weekly for fungal growth. All fungal isolates were identified by macroscopic and microscopic examination. A total of 256 samples were collected.196samples [56/76%] were positivefor fungal growth. The most common fungi were: Cladosporium spp. [28.9%], Exophialla spp. [23.3%], and Rodutorella spp. [13.2%]. Also Trichophitonmentagrophytes and Microsporumgypseum were isolated from baths samples. For prevention of mycotic infections, effective preventive measures such as use of private or disposable slippers and adequate cleaning of the bathrooms after taking bath can be beneficial

[Investigation of the efficiency of activated sludge reactor with fixed bed in biological removal of methyl-tributyl ether from synthetic wastewater]

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

[Survey of activated sludge process performance in treatment of agghala industrial town waste water in Golestan Province in 2007]

One of environmental outcomes in industrial towns is developing environmental pollution such as production of industrial wastewaters. These industrial wastewaters should be appropriately treated before entering to receiving waters. However we can't solve environmental anxieties by establishing of wastewater treatment plants alone; but permanent and regular assessment of these treatment plants performance is necessary for achieving environmental standards. Thus, this research has been done in order to investigation of activated sludge performance in wastewater treatment of Agghala industrial town in Golestan province. This cross-sectional study implemented in sewage treatment plant laboratory of Agghala industrial town in Golestan within 12 months at 2007. Chemical Oxygen Demand [COD] parameter determined twice in week, But Biochemical Oxygen Demand [BOD] test accomplished weekly. pH measured by pH meter daily. Experiment of total suspended solids [TSS] and total dissolved solids [TDS] carried out every 10 days. All tests accomplished according to standard method for water and waste water examination [2005]. Then data analyzed using excel 2007. The average of BOD, COD and TSS in influent was 11196.17, 1854.58, 1232.25 mg/L respectively.Maximum influent organic loading rate was related to Shahrivar and Mehr months. The total average of removal efficiency for BOD, COD and TSS was calculated 99.66, 98.2, and 97.6% respectively. Quality of this treatment plant effluent was according to effluent disposal standards all over year. In sum, efficiency of this treatment plant [activated sludge system] was very good in influent pollutant removing. However occasionally effluent was not adapted with environmental standards but these deficiencies is solvable by accurate management and supervision on flow rate and influent organic loading rate easily

[Investigation of environmental indexes of district 1 primary school in Sari, Iran]

The school is the most appropriate place for flourishes children, adolescents and juniors, and prepares safe and vigorous life. Thus, the aim of this research is to study of the hygienic conditions in primary schools in region 1 of Sari city. This article is a descriptive study. In which 45 non-for-profit and governmental schools were sampled using census method. The Fools of sampling was questionnaire filled in during interview with school principals and direct observation. Collected information was analyzed using "Excell" and spss soft wares. The results of this search showed that%93.4 of schools had dimention smaller than minimum standard. Only in%35.6 of schools, lavatory and drinking places were separate and the quality and quantity of lighting in%32 of. schools were classes proper. The most important finding of this search was the ignorant of indicators in environmental health as overlooking of standards, and the schools are merely established on quantity and urgent need despit of their quality