Iranian Journal of Health and Environment
Year:2014 | Volume:6 | Issue:4|Papers Count:12

Background and Objectives: Biosorption is a new and inexpensive technique in heavy metals removal and recovery from aqueous solutions. In order to evaluate the potential of this method for the removal of nickel ions, biosorption of nickel ions from aqueous solution was studied using Cystoseira indica biomass in a packed bed column.Materials and Methods: The uptake capacity of nickel ions was investigated using protonated biomass at different influent concentrations and flow rates. In addition, the experimental breakthrough curve obtained under definite experimental conditions was modeled using Thomas, Yoon & Nelson, Dose-Response, and Belter models.Results: It was found that increasing influent concentration from 58 to 100 mg/L led to the increase of driving force for mass transfer and uptake capacity raised from 55.84 to 95.69 mg/g. The investigation of flow rate effect showed when the process is intraparticle mass transfer controlled, a slower flow rate favors the sorption. In the case of external mass transfer control, a higher flow rate decreases the film resistance and leads to an increase in mass transfer. Modeling the experimental data revealed that the abovementioned models were suitable to predict the breakthrough curves, especially Dose-Response. Measurement of pH of the effluent solution indicated that ion exchange is one of the main mechanisms of nickel biosorption using this biosorbent.Conclusion: The results of this study are complementary of the batch equilibrium sorption experiments. Therefore, from process viewpoint, this biomass can be proposed in the sorption columns as a sorbent for nickel ions.

Background & Objectives: Cationic dyes such as basic violet have many applications in different industries. The degradation of basic violet by means of UV, UV/H2O2, US, and US/H2O2 processes was investigated.Materials and Methods: Photolysis process was accomplished in a laboratory-scale batch photoreactor equipped with a 55 W immersed-type low-pressure mercury vapor lamp (UVC) and sonolysis process was investigated in a sonoreactor with high frequency (130 KHZ) Plate Type transducer at 100 W of acoustic power with emphasis on the effect of various parameters and addition of Na2SO4 on discoloration and degradation efficiency.Results: Complete decolonization of cationic BV 16 was achieved in 8 minutes using UV/H2O2 process. In addition, it was found that sonochemical decolorization is a less efficient process, comparing with photochemical process, as the decolorization proceeds to only 65% within 120 min. Low concentration of dye and natural pH resulting from dissolution of salt favors the degradation rate of dye. The results showed that sodium sulfate enhances the rate of sonochemical degradation of dye. In addition, kinetic parameters were obtained by application of first order equations.Conclusion: The results showed that UV/H2O2 and US/H2O2 processes can be effective in the removal of BV16 from aqueous solutions. Considering dye removal efficiency and availability, photochemical process combined with hydrogen peroxide can be recommended as a fast effective method for removal of dyes from aqueous solutions.

Background and Objectives: Optimization of mazut biocracking with different variables is one of the bioengineering applications in petroleum industry. The purpose of this study was to optimize biocracking of mazut by native microorganisms.Materials and Methods: To optimize mazut cracking, using Taguchi method we run 32 experiments using seven factors including amount of microbial inoculation, initial pH, surfactant, glucose, phosphor source, nitrogen source and sea salt; each of them with four levels and factor of microorganism type with two levels for design of experiment using that 32 experiments were designed by them.Results: Results showed that microbial mixture, 0.016 OD600 microbial inoculations, pH 8.3, Tween80 concentration of 2 g/L, glucose concentration of 4 g/L, phosphate concentration of 5 g/L, ammonium concentration of 9 g/L and sea salt concentration of 0.5 g/L were optimized conditions for biocracking of mazut process.Conclusion: Optimized level for each factor was not essentially inevitably the highest or the lowest level. Based on the analysis of variance, phosphor source with 15.8% and pH with 14.8% had the highest effect among other factors; however overally, error factor with 31.6% had the highest influence. Amount of microbial inoculation with 0.63% had the lowest effect on optimizing biocracking of mazut.

Background and Objectives: Nemone Tehran Poultry Slaughterhouse having an area of 13000 m2 is located at District 3, Region 5 of Tehran Municipality and in Morad Abad Quarter .This study aimed at analysis the environmental impacts of the abovementioned slaughterhouse. For this purpose, we applied analytical hierarchy process (AHP) as one of the multiple criteria decision making methods (MCDM).Materials and Method: First, we determined the criteria and options required through analyzing the project impacts. Then, for final validity of criteria, we used experts questionnaire. Special vector technique through using the Expert Choice software was used in order to set priorities for criteria and options.Results: Analysis of the slaughterhouse effluent indicated that it can neither be discharged into the surface water and well nor suitable for irrigation and agricultural purposes. Noise evaluation showed that rate of noise measured is beyond the standard limits. The laboratory experiment results on air pollutants was lower than the standard level.Conclusion: The results indicated that from the pollution perspective in the slaughterhouse, wastewater weighted 0.497 is the primary preference and sound, air, and odour weighted 0.229, 0.136 and 0.080 are the subsequent preferences. Cultural and socioeconomical environment ranked hgiher relative to the chemical-physical environment and then biological environment. Finally, regarding to the main significant environmental problem of slaughterhouse (Wastewater), optimization of the slaughterhouse wastewater treatment system and constant monitoring of the external sewage quality is in priority.

Backgrounds and Objectives: Nowadays, global concerns about nitrate in groundwater and its adverse impact on health have increased. This study aims to evaluate the efficiency of nitrate reduction from aqueous solution through modified Fenton process using Nano scale zero-valent iron.Material and Methods: This research was an experimental study and performed at laboratory scale. Nitrate reduction was conducted by advanced oxidation process of Feo/FeІІ/FeШ/H2O2 at pH 2-10, contact time 10-90 min, nitrate concentrations of 50-300 mg/L, and the molar ratio of [H2O2]/[Fe] 0.5-5. The effect of adding H2O2, molar ratio of reagents, contact time, and pH on nitrate removal was examined and optimal conditions for each of these parameters were determined. Spectrophotometer Dr/5000 was used to measure nitrate in the effluent.Results: We found that the optimal parameters in our study were pH 3, the molar ratio [H2O2]/[Feo] of 0.5, and the contact time 15 min. By applying these conditions, nitrate removal efficiency at the retention time 15 min, initial nitrate concentration of 100 mg/L, iron concentration of 10 mg/L, and pH 4 for FeIII FeІІ, Feo, FeІІ/Feo/H2O2 and FeIII/Feo/H2O2 was 10.5, 27.6, 36.5, 62.3, and 74% respectively.Conclusion: According to the experimental results, it was determined that modified Fenton process using zero iron nano-particles can reduce nitrate under optimal conditions and this method can be used for the removal of similar compounds.

Background and Objectives: Development of cosmetics industry has increased the affinity to use these products by people especially women for makeup and toilet. Due to the presence of metals such as lead and cadmium as preservative and colored element in these products, concentrations of these metals in sunscreen cosmetics, lipstick and hair color were determined.Materials and Methods: Different brands of cosmetics were analyzed to determine Cd and Pb concentration (in mg/kg dry weight) using graphite furnace atomic absorption (AA-670).Results: We found that generally mean concentration of Cd was lower than Pb. There was no significant difference of Cd level between different brands of sunscreen and lipstick (p>0.05), whereas, a significant difference of Pb between the brands studied was observed (p<0.05). No significant difference was obtained between concentration of Cd and Pb in various brands of hair color (p>0.05).Conclusion: Though levels of Pb and Cd in selected brands of cosmetics were lower than standard limits, their low concentration in compared with the results of previous research works could induce serious hazards on human health and the possibility of occurrence or exacerbation of disease including allergy, inflammation, skin diseases, cancer and so on. Hence, preparation and use of these products must be done according to current standards.

Background and Objective: Various industries such as petrochemical, oil refinery, pharmaceutical, plastics, paper, steel and, resin produce a substantial of phenol and its derivatives. Wastewaters containing phenol need careful treatment before discharging into the environment due to their poor biodegradability and high toxicity. The objective of this study was to remove phenol by multiwall carbon nanotubes from aqueous solution.Materials and Methods: Adsorption process was implemented in a laboratory-scale batch with emphasis on the effect of various parameters such as contact time (5 to 120 minutes), pH (3, 5, 7, 9, 11), initial concentration of phenol (5, 10, 25, 50 mg/l) and the sulfate and chloride ions (20-200 mg/l) on adsorption process. To achieve a better realization of adsorption process, sorption kinetics and equilibrium isotherms were also determined.Results: The results indicated that maximum adsorption capacity occurred at concentration 50 mg/L and t=30 minutes. The uptake fluctuated very little in the pH range of 3-9, and at greater than 9 the absorption decreased suddenly. Moreover, the presence of sulfate and chloride ions had no effect on the process. It was found that adsorption kinetics and equilibrium data follow a pseudo-second-order kinetics model and a Freundlich isotherm model respectively.Conclusion: It is concluded that carbon nanotubes being effective in a wide range of pH, short time to reach equilibrium and the absence of competing ions on the absorption process can be used effectively in removing phenol from aqueous solution.

Background and Objective: Rice is one of the most consumed food items that is exposed to mycotoxins and heavy metals contamination. Due to the accumulation of heavy metals in the tissues of human body and its side effects on the body and being carcinogenic and mutagenic mycotoxin, the present study was conducted to determine contamination of rice imported in Golestan Province.Materials and Methods: We collected 80 samples of imported rice from India and Pakistan on the Inche boron border in Golestan province between January 2011 and August 2012. We analyzed each sample for the amount of mycotoxins (aflatoxins B1, B2, G1, G2 and total aflatoxins, ochratoxin A, zearalenone and dexynivalenol) and heavy metals (lead, arsenic, and cadmium). We used HPLC to measure mycotoxins and immunoaffinity column (Dexynivalenol purification was conducted using DONSPE column) for purifying. Hydride generation atomic absorption based optical spectroscopy technique was used for determining arsenic. Graphite furnace atomic absorption according AOAC.986.15 was used to determine lead and cadmium.Results: We found that the average level of aflatoxin B1, B2, ochratoxin A, and total aflatoxin were 0.93, 0.036, 0.033 and 0.96 ng/g respectively. Aflatoxin G1, G2 and dexynivalenol was not observed in any of the samples. Average concentrations of lead, arsenic, and cadmium in the samples were 0.067, 0.007, 0.024 mg/kg respectively.Conclusions: All samples were within the accepted maximum limits of Iran National Standards for heavy metals and mycotoxins in rice.

Background and Objectives: bisphenol A and nonylphenol are xenoestrogen materials used as a monomer of plastics in widely volume in the production of plastic materials especially mineral water bottles and disposable plastic containers. In this study, we investigated the potential of migration of bisphenol A and nonylphenol from disposable plastic containers into water at different temperatures and also from mineral water into water at different temperatures.Materials and Methods: We conducted bisphenol A and nonylphenol extraction from each sample through liquid-liquid extraction. For identification and quantitative determination of bisphnol A and nonylphenol, we used gas chromatography equipped with mass detector, and for quantitative determination of these two compounds, we used high-performance liquid chromatography equipped with fluorescence detector.Results: We found that increasing temperature increased significantly the rate of migration of these two compounds in the water. Moreover, it was revealed that only the presence of bisphenol A in water of mineral water bottles was detected and the increase in temperature also increases the rate of migration bisphenol A into water.Conclusion: In general, results of this study showed that improper storage of mineral water bottles and also use of disposable plastic containers for hot drinks would result in increasing consumer exposure to these compounds.

Background and Objective: Application of compost containing heavy metals can increase the concentration of metals in soil and groundwater. Therefore, the aim of this study was to investigate leaching lead, chromium, and cadmium from three soils (a sandy loam, a sandy clay loam and silt clay loam) amended with compost from the municipal solid waste.Material and Method: First, the selected soils were repacked into columns (with an inner diameter of 100mm and a height of 600mm). Treatments included (a) low metal content compost (LMCC), (b) enriched metal content compost (EMCC) and (c) control. Then soil columns were incubated at room temperature for 9 days and were irrigated daily with deionized water to make a total of a 250 mm. Leachates were collected and analyzed for pH, EC, Pb, Cr, and Cd concentration.Results: It was found that the application of EMCC was significant (p≤0.05) on reducing pH, increasing electrical conductivity and leakage of metals compared with control in all three soils. But application of LMCC was not significant (p≥0.05) on the metals leaching compared with control in all three soils. The overall quantities of metals leached followed the sandy loam> sandy clay loam> silt clay loam.Conclusion: The concentration of metals in the leachates depended on the soil characteristics and on the type of compost added to the soil. Therefore, application of enriched metal content compost on the soils containing a high percentage of sand may pose a risk in terms of groundwater contamination with heavy metals.

Background and Objective: Humic substances in drinking water react with chlorine and form carcinogenic compounds. Humic acid is a principal component of humic substances and its separation from surface waters is crucial. Adsorption process is among different methods for separation of humic acid from surface waters and because of its simple and economical nature it has attracted considerable attention. The aim of this research was to examine performance of silicon nanoparticles in adsorption of humic acid in water.Materials and Methods: Experimental study was conducted on both synthetic and real water samples collected from Zarrineh Rood River, Tabriz before its entrance to water treatment process. We used instantaneous sampling method. The chemical quality of crude sample and its humic acid was determined and then the influence of pH, absorbent amount, and time on the removal of humic acid was evaluated. Therefore, the optimal conditions for each of these parameters were determined. In order to get better insight into the process of adsorption, the adsorption kinetic and equilibrium isotherm were studied. We measured humic acid concentration and TOC using spectrophotometer (Shimadzu /UV-1800, Japan) at a wavelength of 254 nm and TOC analyzer (Shimadzu model TOC-VCSH) measured. SPSS software and regression were used for data analysis.Results: At pH=4, retention time of 10 minutes, adsorbent amount of 0.25 g/L, we found that the highest percentage of humic acid adsorption was 88.4 and 81.8 for synthetic and real solutions respectively. The finding revealed that the removal of humic acid follows Freundlich isotherm (R2=0.8172) and the second order kinetic model (R2=0.9936).Conclusion: Removal in both real and synthetic solutions was less due to the reaction of influencing factors. However, considering the high percentage of humic acid removal under optimal conditions and its comparison with other methods, the removal of humic acid using SiO2 can be considered as an efficient method.

Background and Objective: Milk and milk products are very suitable medium for growing microorganisms (e.g. Bacillus cereus). B. cereus is spore former bacilli, which easily survives during pasteurization and makes several problems in dairy industries. The aim of this study was to investigate aerobic spore and B. cereus of receiving raw milk from three UF plants.Materials and Methods: Samples were gathered from raw milk transport tankers arrived to plants during 30 days in winter. Also, the swab test was used for detection of B. cereus residual on milk contact surfaces.Results: High contamination level of aerobic spores (AeSC) and especially B. cereus were found in most samples compared with the criteria established by national and international standards. Although total viable count (TVC) in samples from industrial farms (IF) was lower than those from traditional farms (TFs) and milk collection centers (MCCs), considerable AeSC and B. cereus were transmitted to the UF plants from IFs. The highest and lowest TVC and B. cereus were found in samples from IFs and MCCs, respectively. In addition, our investigation in IFs revealed that teats contamination to soil and feces, as well as contaminated bedding might were the most important sources of B. cereus and AeSC of raw milk. Moreover, the results of swab tests confirmed that the “cleaning in place” system may not remove B. cereus effectively.Conclusion: It seems that for classifying raw milk quality, AeSC might be used as a more effective quality factor than TVC. Management commitment is effective to improve quality by balance between the amount and quality of receiving raw milk. This leads to the lower contamination in dairy plants and final products.