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Advances in Environmental Health Research - Volume:5 Issue: 3, Summer 2017

Journal of Advances in Environmental Health Research
Volume:5 Issue: 3, Summer 2017

  • تاریخ انتشار: 1396/11/10
  • تعداد عناوین: 7
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  • Zohreh Didar * Pages 123-130
    Waste oil is an inexpensive source for biodiesel production, but the high amount of impurities present (free fatty acids, oxidation products) impedes its practical application. The aim of this work is to assess the purification efficiency of the adsorption process with eggshell and its active carbon. Carbonization of eggshell was done at 200 ºC for 4 hours. For activation of the resultant carbon, sulfuric acid was used, and finally, thermal activation (600 ºC, 1 hour) was performed. The quality parameters of waste oil (free fatty acid, peroxide value, color indices, viscosity, and density) were determined before and after the adsorption process. The results showed an improvement pattern in the measured parameters after the adsorption. Reduction in peroxide and acid value were 71.7% and 51.72%, respectively. Also, produced biodiesel from treated waste oil has better quality indices including acidity, viscosity and specific gravity. Biodiesel yield also increased up to 40 percent.
    Keywords: Waste oil, Eggshell, Active carbon, Biodiesel
  • Mohammad Soleimani, Keivan Khalili *, Javad Behmanesh Pages 131-138
    Considering the complexity of hydrological processes, it seems that multivariate methods may enhance the accuracy of time series models and the results obtained from them by taking more influential factors into account. Indeed, the results of multivariate models can improve the results of description, modeling, and prediction of different parameters by involving other influential factors. In this study, univariate models (ARMA) and auto-correlated multivariate models with the simultaneous autoregressive moving average model (CARMA) were evaluated for modeling Electrical Conductivity and Total Dissolved Solid parameters of the western stations of Urmia Lake Basin. To use the CARMA models, annual flow rate time series, EC, TDS, SAR, and pH values measured across seventeen hydrometric stations between 1992 and 2013 were used. In the studied statistical period, the river flow in the west of Urmia Lake Basin decreased and experienced an incremental increase compared to the EC and TDS values in river flow. By applying influential parameters in CARMA models, the mean error value of the model in training and experimental stages reduces by 32% and 44% for EC values and 34% and 36% for TDS values, respectively.
    Keywords: Time series model, ARMA, CARMA, Water Quality, Urmia Lake
  • Mohammad Amin Karami, Bahram Kamarehie, Mansour Ghaderpoori, Ali Jafari, Ahmad Akrami *, Fateme Baghban Shahri Pages 139-145
    This study describes the biological degradation of TNT by using induced aeration. Three plastic reactors were used. In each reactor 3 kg of soil were used. In order to increase the porosity of the soil, sawdust was added to soil. Textile wastewater treatment plant sludge was also added to soil. TNT at the concentrations of 1000 mg/kg of soil was added thereafter. Rhamnolipid biosurfactant at the concentration of 60 mg/L was added to related reactors. Aeration interval was at every 3 to 5 days. Every two weeks, sampling of soil were done to analyze the explosives. Samples were analyzed by HPLC. The results showed that at the end of 120 days, TNT removal efficiency in induced aeration in reactors containing sludge and biosurfactant was 98 percent. COD removal efficiency in induced aeration in reactors amended by rhamnolipid was 58 percent and in reactors to which rhamnolipid was not added was 41 percent. Follow-up kinetic studies revealed that explosives removal follow the pseudo first order reaction. The pseudo first-order rate constants of rhamnolipid amended experiments were at least 3.89 orders of magnitude higher for TNT than those found for experiments without rhamnolipid. Application of Rhamnolipid biosurfactant could have a protective effect against the toxicity of explosives for bacteria. Textile sludge from wastewater treatment plant can decrease the time needed for explosive removal. Growth of bacteria and degradation of explosives showed that explosives have been used as a nitrogen source.
    Keywords: TNT, sludge, rhamnolipid, induced aeration
  • Mohammad Amin Pordel, Afshin Maleki *, Mehrdad Khamforosh, Hiua Daraei, Reza Rezaee, Saeed Dehestani Pages 146-153
    This study explored the fabrication, characterization, and microscopic imaging of highly porous electrospun nanofibers based on pure and Fe2O3 nanoparticle modified polyacrylonitrile (PAN) fibers. The desired electrospinning mixture comprising polymer and nanoparticles in dimethyleformamide, was prepared. During electrospinning, the precursor solution was injected using a syringe pump. The empirical parameter influences, including nanoparticles dose, polymer weight percentage, and thickness as applied polymer syringe, were studied on the product morphology and uniformity. The products were analyzed by Fourier transform infrared (FT-IR) spectrophotometer, scanning electron microscopy (SEM), and X-ray diffraction (XRD). The results demonstrate that changes in the investigated empirical parameters cause fiber morphology variations and uniformity. Therefore, a strong interaction exists between Fe2O3 and PAN. In general, addition of nanoparticles to PAN solution resulted in a decrease in the average fiber diameter compared to pure PAN.
    Keywords: Electrospun, Nanofibrous, PAN, Fe2O3
  • Saeb Ahmadi, Mohsen Vafaie Sefti *, Mohammad Mahdi Shadman, Zahra Azimi Dijvejin, Hooshyar Hosseini Pages 155-163
    The main objective of this work was to assess the optimization of Fe and Cu bioleaching from converter slag using Acidithiobacillus ferrooxidans. Important parameters that contribute to the bioleaching process include initial pH, initial Fe2 concentration and pulp density. In order to optimize these parameters, the response surface methodology (RSM) was applied. The maximum simultaneous Fe and Cu recovery yields were 95% and 100%, respectively. The optimum conditions were initial pH 1.8, initial density 1.4 g/100 mL and initial Fe2 7.3 g/L. The comparison between chemical leaching and bioleaching results showed that bioleaching improved the recovery yields of Fe and Cu by 26% and 33%, respectively. The modified shrinking core model was used to determine the rate-limiting step of the process. It was found that diffusion through the product layer and chemical reaction are the rate controlling steps.
    Keywords: Bioleaching, Converter slag, Acidithiobacillus ferrooxidans, Optimization, Kinetic
  • Ali Azough, Seyed Keyvan Marashi *, Teimour Babaeinejad Pages 163-171
    The presence of large heavy metal concentrations in soil polluted with chemical weapons causes serious operational restrictions against cultivation of agricultural crops like wheat. To solve this problem, the usage of zeolite has been proposed as one of the most efficient practical approaches. The main objective of this research is the investigation of the influence of natural Iranian zeolite on sorption of cadmium (Cd2) and nickel (Ni2) and the investigation of growth characteristics of wheat in soil polluted with chemical weapons. The experiments were carried out in factorial arrangement in a randomized complete design with three replications during 2015-2016 crop season. Treatments with four levels of zeolite included: a1) 0%; a2) 0.5%; a3) 1.5%; and a4) 2.5% of soil weight and two soil samples, one obtained from out of the war zone (without contamination) (b1) and other was from contaminated soil to weapons (b2). Results showed that the polluted soil led to a significant enhancement in amount of Cd2 and Ni2 in shoots and roots of wheat. In addition, the findings revealed that the application of zeolite caused a significant reduction in Cd2 and Ni2 concentrations in shoots and roots and significantly increased dry matter, chlorophyll index and magnesium (Mg2) concentration in wheat. In general, results showed that zeolite released nutrients and stabilized heavy metals in polluted soil and the negative effect of soil polluted by toxic heavy metals was reduced in the plant, which lead to decontamination of soil and increase in safety of environment.
    Keywords: chlorophyll, nickel, root, wheat, zeolite
  • Hatam Godini, Abdollah Dargahi, Leila Tabandeh, Mitra Mohammadi, Yaser Vaziri, Mir Mohammad Hoseini Ahagh, Kiomars Sharafi, Zahra Jalilian * Pages 171-181
    The objective of this study was to determine the performance of modified commercial powdered activated carbon (MCPAC) in removal of ammonia from aqueous solution. The effects of adsorbent dosage (0.5–1.5 g/L), ammonia concentration (100–200 mg/L), pH (3 to 9) and contact time (2 to 120 min) were examined. In this study, experiments were performed based on Response Surface Methodology (RSM). The adsorption isotherm was evaluated using Freundlich and Langmuir models. Kinetics study was analyzed using pseudo first order, pseudo second order and particle penetration kinetic models. By increasing adsorbent dosage, pH and contact time, the removal efficiency increased. According to CCD results, the MCPAC was fitted to a quadratic equation. Also, ammonia adsorption for MCPAC followed the Langmuir (R2 = 0.9831) isotherm model. The maximum adsorption capacity for MCPAC was 40.323 mg/g. The analysis of adsorption kinetic for MCPAC indicated that ammonia adsorption was well fitted by the pseudo second order kinetic model. As thus, we concluded that MCPAC could be considered as an appropriate and economical alternative adsorbent for water and wastewater treatment due to its high ammonia adsorption capacity.
    Keywords: Modified Activated Carbon, Ammonia, RSM, Aqueous Solution, Adsorption Isotherm