[Modified Fenton oxidation of pyrene in contaminated soils using iron nano oxides]

Problems related to conventional Fenton oxidation, including neccesity of having a low pH and production of considerable amounts of sludge, have prompted researchers to consider chelating agents to improve the pH operating range and iron nano-oxide particles to reduce excess sludge. The main objective of this study was to remove pyrene from contaminated soils by a modified Fenton oxidation method at neutral pH. Experiments were conducted using various concentrations of H2O2 [0-500 mM], iron nano-oxides [0-60 mM], reaction times [0.5-24 hours] and several chelating agents, namely, sodium pyrophosphate, ethylene diamine tetra-acetic acid, sodium citrate, fulvic and humic acids, to eliminate pyrene from soil [concentrations of 100-500 mg/kg]. The efficiency of removal of pyrene at an initial concentration of 100 mg/kg was 99% at the following reaction conditions: H2O2 and iron nano-oxide concentrations of 300 mM and 30 mM, respectively; pH=3; and a reaction time of 6 hours. The initial pyrene concentration of 100 mg/kg decreased to 7 mg/kg at optimum conditions using sodium pyrophosphate as the chelating agent at pH 7. The modified Fenton oxidation method, using iron nano-oxide at optimum conditions as defined in this research, is an efficient alternative for chemical remediation or pre-treatment of soils contaminated with pyrene at neutral pH

[Evaluation of electrochemical treatment in degradation of wastewater contaminated by propylene glycol]

Propylene glycol is applied in many industries as raw material and can be released to the environment through wastewater of such industries. The biological treatment of solutions containing high concentration of propylene glycol is difficult and some problems can be observed during this process. The main objective of this study was the investigation of electrochemical degradation of propylene glycol and the parameters influencing on improving removal efficiency. In this study the degradation of propylene glycol was made by passing an electrical current though the synthetic wastewater containing propylene glycol. In order to investigate this process several types of electrode with applied voltage ranging between 5 to 50 V was used. Due to the effect of NaCl concentration on removal efficiency which was mentioned in the literature, the experiment was performed for different NaCl concentrations. In optimum condition, the maximum removal efficiency of propylene glycol [based on COD] was obtained equal to 90%. The results showed that rising applied voltage, NaCl concentration and retention time increase the removal efficiency. The optimum retention time was obtained equal to 50 min. The maximum removal was obtained when aluminum electrode was used. It can be attributed to the production of coagulant material such as Al[+3] during this process. The results revealed that this process can be useful for treating the industrial wastewater containing propylene glycol

[Determination of near infrared radiation[IR-A] at work unit in one of the Iran steel industries]

As industries are developed, human uses of the energy in the huge scale and release the loss energy in the form of electromagnetic radiation such as infrared into the environment, that it could affect on the man health. According to the available standards, if the IR-A could be controlled and consequently health of workers could be provided, it would reduce the total industrial expenses. To control this radiation, it is necessary to measure it and compare the results with the available standards. Hence, in this study, we try to measure this radiation in a unit of industry. For this porpuse the unit of steel company that settled in southeast of Ahvaz is selected. The determinations were done every month during one year in all selected units. These results are compared with the available standards, and finally the differences are statistically evaluated by some suitable statistical For measuring the dispersal of ray in the different height, bat hard data compared with ACGIH standard and SPSS software is used for changing Radiation. The average amount of IR-A at this industrial unit is 1.18 mW/cm2 which is more than the standard value in such industries, and based on our founding the natural solar source of this radiation increases such effects in out-door work places