masoud ghanbarian

Excess fluoride ions in drinking water cause several diseases so the defluoridation of drinking water with excess fluoride is necessary for human health. Hence this work describes fluoride removal from water using MgFe2O4 – chitosan nanocomposite.

In this work a nitrate salt of Mg and Fe were used to synthesis MgFe2O4 through a combustion route. Then MgFe2O4 - chitosan nanocomposite was synthesized using epichlorohydrin as a linker. Characterization of the sorbent was performed with FESEM, TEM, VSM, EDX and XRD techniques. Effective parameters on the adsorption process such as pH, contact time, adsorbent dosage and fluoride concentration was optimized by response surface methodology (RSM) using Box – Behnken design (BBD). Isotherm study was studied at the fluoride concentration range of 10 – 100 mg/L.

The optimum value of pH, contact time, adsorbent dosage and fluoride concentration were 2.8, 4.5 min, 19.0 mg and 28.87 mg/L, respectively. At the optimum condition maximum removal efficiency was 98.1%. Results showed that adsorption process followed Langmuir model with capacity of 181.1 mg/g.

The result of the present work showed that the nanohybrid has good potential as a cheap magnetic sorbent for environmental remediation purpose as can be used for effective removal of fluoride from water solution.

High levels of nitrate anion are frequently detected in many groundwater resources in Fars province. The present study aimed to determine the removal efficiency of nitrate from aqueous solutions by electrocoagulation process using aluminum and iron electrodes. A laboratory-scale batch reactor was conducted to determine nitrate removal efficiency using the electrocoagulation method. The removal of nitrate was determined at pH levels of 3, 7, and 11, different voltages (15, 20, and 30 V), and operation times of 30, 60, and 75 min, respectively. Data were analyzed using the SPSS software version 16 (Chicago, Illinois, USA) and Pearson’s correlation coefficient was used to analyze the relationship between the parameters. Results of the present study showed that the removal efficiency was increased from 27% to 86% as pH increased from 3 to 11 at the optimal condition of 30 V and 75 min operation time. Moreover, by increasing the reaction time from 30 V to 75 min the removal efficiency was increased from 63% to 86%, respectively (30 V and pH = 11). Pearson’s correlation analysis showed that there was a significant relationship between removal efficiency and voltage and reaction time as well (P < 0.01). In conclusion, the electrocoagulation process can be used for removing nitrate from water resources because of high efficiency, simplicity, and relatively low cost.

Reactive dyes, anionic compounds with high water solubility, are widely used in textile industries.. The present study aimed to assess the feasibility of the photo-Fenton process in removing Reactive Red 198 dye from aqueous solutions and determine the optimal conditions for maximum removal.. This study was performed on a laboratory scale using a 4-liter photochemical reactor. The spectrophotometer DR5000 (wavelength 520 nm) was used to determine the dye concentration. The effect of the influencing parameters, including pH (3–9), Fe (II) concentration (10–200 mg/L), H2O2 concentration (25 - 150 mg/L), initial dye concentration (50–200 mg/L), and reaction time (15 - 120 minutes) were studied.. According to the results, the photo-Fenton (UV/ H2O2/Fe (II)) process significantly removed dye from the aqueous solution. The Reactive Red 198 dye removal efficiency from aqueous solutions was more than 99% at optimal conditions (pH = 3, Fe (II) = 10 mg/L, H2O2 = 75 mg/L, initial dye concentration = 50 mg/L, and reaction time = 120 minutes).. The present study demonstrated that the UV/ H2O2/Fe (II) process could be used as an efficient, reliable method for removing Reactive Red 198 dye from textile wastewater..

Introduction & Indoor air quality, particularly in health care facility, is important. One of the most important factors affect the air quality is aerosols due to carrying microorganisms and deposit in the respiratory tract. Therefore, the purpose of this study was to measure the concentration of suspended particles in outdoor and indoor ‎of Dena hospital and determine the relationship between these parameters.‎ A cross-sectional study was done in Dena hospital in Shiraz in 2012. 315 samples were collected for analysis. Sampling was performed by using a sampler Aerosol Mass Monitor, Model GT-331, made in Japan to ‎measure the particle concentrations of PM10 and PM2.5. To compare the concentration of indoor suspended particles ‎in air in different wards and outdoor particle, t-test was used. Then the data ‎were analyzed using SPSS version 16. Results showed that average PM10 in the air in hospital wards as well as all the outdoor air is significantly less than the standard 24-hour WHO and the standard 24-hour USEPA (p<0.001). The Significant relationships were seen for the average concentrations of PM2.5 in all the sampling sites ‎and the 24-hour standard of WHO and USEPA (p<0.001‎)‎. The concentration of particle matter in indoor air in Dena hospital was less than the outdoor air that indicate the proper functioning of air-conditioning systems inside the different department of the hospital.