Iranian Journal of

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Background and Objectives : Propylene glycol is the main compound of anti-freezing chemicals. A significant amount of propylene glycol is released to the environment after application and contaminates the soil. The main objective of this study was to determine the biological removal of propylene glycol from wastewater and its degradation in soil by the isolated bacteria from activated sludge process.
Materials and Methods: In the present study, the sludge taken from the return flow in a local activated sludge treatment system was used as the initial seed. The performance of the bioreactor in treating the wastewater was evaluated at four different retention times of 18, 12, 6 and 4 h all with the inlet COD concentration of 1000 mg/L. This phase lasted around 4 months. Then, a part of the adapted microorganisms were transported from the bioreactor to the soil which was synthetically contaminated to the propylene glycol.
Results: The average of propylene glycol removal efficiency from the wastewater in detention times of 18, 12, 8 and 4 h in steady state conditions was 98.6%, 97.1%, 86.4% and 62.2% respectively. Also, the maximum degradation in soil was found to be 97.8%.
Conclusion: According to the results obtained from this study, it appears that propylene glycol is inherently well biodegradable and can be biodegraded in liquid phase and soil after a short period of adaptation.

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Background and Objectives: Due to population intensity and industrial activities, quality of groundwater is important in Bushehr province and in particularly in coastal areas. The salinity of groundwater in Asaluyeh plain is increasing from the heights towards the Persian gulf and in some places are not even applicable for irrigation.
Materials and Methods: In order to explore the source of the chloride anomaly, groundwater samples were analyzed and compared with the Persian Gulf samples. Also Water Samples Different diagrams were determined and the reasons of water salinity of Asaluyeh Plain were investigated.
Results: The results of chemical analyses showed the groundwater excessive salinity, especially near the sea. Based on correlation matrix, the highest correlation between the sodium and chlorine ions was observed.
Conclusion: The factors influencing on groundwater salinity in the plain varies and arising from solution of halite and gypsum from surrounding formations, suddenly increas sodium chloride in some parts of plain and forming Cl-Na water type. The results indicated that the Groundwater Type of Asaluyeh is Cl-Na and therefore it is classified as non-potable water.

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Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background and Objectives:Benzene, toluene and Xylenes (BTX) are organic pollutants, which are mainly associated with oil and its derivatives. BTX is environmental contaminants and considered harmful to human health. Application of surface absorbents such as zeolite is one of several methods for the removal of these compounds. In this study, BTX compounds' removal efficiencies were investigated and compared by using clinoptilolite type zeolite and zeolite with copper oxide nanoparticles.
Materials and Methods: In this study, the modified zeolite by hydrochloric acid in the grain size 1-2 mm and modified zeolite with nano particle of copper oxide were used.  Artificially- Contaminated Air flow was used continuously .To determine BTX concentrations, samplings were done by charcoal tube in current input and output. The concentrations of contaminants were determined by gas chromatography with FID detector.
Results: Removal efficiency of benzene, toluene, p-xylene, m-xylene and o-xylene by clinoptilolite were 78.3%, 62.1%, 32.2% 32.15% and 18.8%, respectively. For the clinoptilolite containing copper oxide nano particles efficiency were 25.42%, 35.65%, 36.33%, 33.24% and 29.39%, respectively. Average removal efficiency of BTX compounds observed when the zeolite without nanoparticles used (43.31%) was more than zeolite with nanoparticles (32%). The results showed that the concentration of CO₂ in the outlet air of the zeolite-containing nanoparticle (550 ppm) was more than the zeolite without nanoparticle (525 ppm).
Conclusion: Results showed that adding nanoparticles to the zeolite, although the removal efficiency of benzene and toluene can be reduced. The results showed that adding nanoparticles to the zeolite, although can be reduced removal efficiency of benzene and toluene, which may be due to occupying or blocking of the pollution absorption sites by the nanoparticles on the zeolite, but It cause promote more catalytic effect of zeolite in the decomposition process of contaminants by breaking the molecules of pollutants and their further degradation progress is done for conversion to carbon dioxide

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MicrosoftInternetExplorer4 Background and Objectives: Aniline has been used in different processes of chemical industries, however due to its side effects on the environment, several methods have been considered for its removal. In this study, we evaluated the performance of photocatalytic process using ZnO nanoparticles (nZnO) and ultraviolet (UV) irradiation for removal of Aniline from a synthetic effluent.
Materials and Methods: A 5L photocatalytic reactor made from Plexiglas, which the UV lamp (20w) installed in the center of that (inside a quartz jacket), was designed and nZnO (0.2-0.5 g/l) was being added into synthetic effluent with Aniline concentration of 250 ppm. After retention times of 30, 60, and 90 min, samples were centrifuged and supernatant was filtered using a 0.2 µ PTFE filter. The liquid-liquid method and Gas Chromatography instrument was used for extraction and analysis respectively.
Results: Results showed that the photocatalytic process of nZnO+UV could effectively remove Aniline from effluent. Increasing trend in the removal efficiency of Aniline using nZnO = 0.5 g/l was slower in comparison with other nZnO concentrations and the ANOVA analysis shows no significant difference between removal efficiency of Aniline in different concentrations of nZnO. The most removal efficiency of Aniline (76.3%) was observed in alkaline pH, retention time of 90 min and nZnO of 0.5 g/l.
Conclusion: It could be concluded that the photocatalytic process of nZnO+UV could be suitable technique for Aniline removal from effluents.

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MicrosoftInternetExplorer4 Background and Objectives: Cyanide is a toxic pollutant existing in the various industrial effluents such as iron and steel, coal mining, non-ferrous metals manufacturing and metal plating. Its presence in water resources and wastewater, as serious hazardous substances leads to undesirable effects on both the environment and human. Thus, its concentration control is essential for human health. The main goal of this study was to evaluate Fenton process efficiency in cyanide removal from aqueous solution.
Materials and Methods: This is an experimental study Conducted at Lab scale in a batch system. We investigated effect of different variables including pH, mole ratio of Fe²⁺/ H₂O₂, contact time, and initial concentration of cyanide. Data were analyzed using Excel software.
Results: We found that cyanide with initial concentrations of 0.4 mM/L was reduced by 92 %. This removal result was related to oxidizing agent of hydroxyl radicals under optimum conditions including pH = 4, molar ratio Fe²⁺/ H₂O₂= 0.046 (Fe²⁺=0.27 mM/L) after 6o min reaction time. An increase in reaction time was not improved cyanide removal efficiency. Moreover, the Fenton process efficiency in cyanide removal decreased from 92 to 60 %, by increasing the initial cyanide concentration from 0.4 to 0.6 mM/L.
Conclusion: It can be concluded that Fenton oxidation Process can be considered as a suitable alternative for cyanide removal to achieve environmental standards.

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Background and Objectives: Phenol is one of priority pollutants produced through leather, paint, resin, and pharmaceutical industries and it can contaminate groundwater after entering to the environment. Hence, it is necessary to use a suitable method for its removal. The aim of this study was synthesize and efficiency evaluation of magnetic nanocomposite of activated carbon powder-zero valent iron/silver (PAC-Fe^o/Ag) in the removal of phenol from aqueous solution. Material & Methods: Reduction method was used for converting bivalent iron to zero valent iron and co-precipitation method for depositing of iron on activated carbon. For coating silver on nano zero valent iron, rapid mixing at high temperature was used. The adsorbent was characterized using SEM, TEM, and XRD techniques. Then, the impact of pH, contact time, agitation speed, temperature, adsorbent, and initial phenol concentration were evaluated and optimized by one factor at the time method. Reaction kinetics and isotherms were also determined. Results: It was found that PAC-Fe^o/Ag has cubic and intertwined structure and has a diameter in the range from 40 to 100 nm. The optimum conditions for phenol removal by PAC-Fe^o/Ag were as pH=3, 90 min contact time, 200 rpm agitating speed and adsorbent concentration equal to 1 g/l. Isotherm and kinetic equations showed that the experimental data of phenol adsorption onto PAC-Fe^o/Ag are correlated to the Langmuir (R²>0.969) and pseudo-second order (R²<0.965) models, respectively. Conclusion: Under optimum conditions, modified adsorbent by zero valent iron and silver with maximum efficiency of 97% has quickly and effectively ability in removal of phenol and it can be easily separated from the solution sample by magnet because of its magnetic properties.