Evaluation of Carbon Nanotubes Efficiency for Removal of Janus Green Dye from Ganjnameh River Water Sample

Background: Dyes are widely applied in the textile, paper, plastic, leather, food and cosmetic industry and color manufacture. Many of these dyes are toxic and carcinogenic. Therefore, removal of dyes from the effluents is essential for environmental protection. The aim of this research is evaluation of the removal efficacy of Janus Green dye from real samples of Ganjnameh River water using multi-walled carbon nanotube. Methods: This study was performed at field-lab scale in the spring of 2012 on a sample from the Ganjnameh River. All of the experiments were done under optimum conditions and multi-wall carbon nanotubes were used in batch. The effect of variables such as pH, amount of adsorbent initial dye concentration and contact time on the efficacy of dye removal was studied. Finally, the adsorption isotherm of Janus Green dye onto the multiwalled carbon nanotubes were investigated based on Langmuir, Freundlich and Temkin models. The diagrams were created by Sigma Plot 10 and descriptive statistics was performed by SPSS 18. Results: The results showed that removal efficiency increased until 0.02 gr adsorbent and 75 min contact time. The optimum pH for Janus Green removal was 7. Also the isotherm equations revealed that Janus Green dye adsorption onto multiwalled carbon nanotubes best fitted the Langmiur adsorption isotherm. Conclusions: The MWCNTs are effective and available adsorbents for removal of Janus Green from industrial wastewater. Key­words: Multi walled carbon nanotubes, Janus Green dye, Adsorption isotherm, Ganjnameh River, Hamada

Evaluation of the Water Quality Pollution Indices for Groundwater Resources of Ghahavand Plain, Hamadan Province, Western Iran

Background: Due to the increasing pollution of water resources, this study was carried out for evaluation of water quality pollution indices for monitoring of heavy metals (As, Zn, Pb and Cu) contamination in Ghahavand Plain, Hamadan Province, Western Iran during spring and summer 2012. Methods: Totally, 20 ground water wells were chosen randomly. The samples were filtered (0.45 μm) and maintained cool in polyethylene bottles. Samples were taken for the analysis of metals, the former was acidified with HNO3 to pH lower than 2. Metal concentrations were determined using ICP-OES. Results: The mean values of Contamination index (Cd), Heavy metal pollution index (HPI) and Heavy metal evaluation index (HEI) in samples for spring season were -2.27, 9.01 and 1.73 respectively and in samples for summer season were -1.95, 8.69 and 2.04 respectively. It indicates low contamination levels. Comparing the mean concentrations of the evaluated metals with WHO permissible limits showed a significant difference (P<0.05). Conclusion: The mean concentrations of the metals were significantly lower than the permissible limits. Although the heavy metal pollution of the ground water in Ghahavand Plain is lower than WHO permissible limits, but severe precautions consideration such as manage the use of agricultural inputs, prevention of use of wastewater and sewage sludge in agriculture, control of overuse of organic fertilizers and establishment of pollutant industries are recommended in this area

Residual Levels of Diazinon and Benomyl on Greenhouse Mushrooms

Background: Pesticides are one of the important sources of environmental pollution that influence human health. The aim of current study was to determine diazinon and benomyl residues levels in mushrooms grown in greenhouses. Methods: Mushroom samples were obtained from 10 active greenhouses of Hamadan Province, Iran, every 14 days from May 2014. The absorbance of diazinon and benomyl were measured at 435nm in a Chemistry laboratory in Hamadan Branch, Islamic Azad University by spectrophotometer. Data were analyzed by one-way ANOVA and one-sample test in SPSS 20 statistical package. Results: Diazinon residue levels in mushroom ranged from 0.026 to 0.185mg/kg. Approximately 90.0% of mushrooms were contaminated with diazinon, which was significantly more than MRL for human consumption provided by European Union (0.05mg/kg). Benomyl residue levels ranged from 0.00025 to 0.097mg/kg. Approximately 50.0% of mushrooms were contaminated with benomyl, which was significantly higher than the MRL for human consumption provided by WHO (0.01mg/kg). Conclusion: Mushrooms of Hamedan Province, Iran, Greenhouses contamination with diazinon and benomyl is higher than international standards

Analysis of Heavy Metals in Surface Sediments from Agh Gel Wetland, Iran

Background: Soil and sediment serve as major reservoir for contaminants as they possess ability to bind various chemicals together. In this study the concentrations of heavy metals Cd, Cr and Cu were analyzed in surface sediments of Agh Gel Wetland in west of Iran. Methods: The sediment samples were taken from 10 stations. The samples were subjected to bulk digestion and chemical partitioning and Cd, Cr and Cu concentrations of the sediments were determined by ICP-OES. Geo-accumulation index (I-geo), Contamination factor (CF) and Pollution load index (PLI) were used to evaluate the magnitude of contaminants in the sediment profile. Results: The mean sediment concentrations (mg kg-1 dry weight) ranged within 0.20-0.29 (Cd), 58-71 (Cr) and 23-36 (Cu). According to the I-geo values, the sediments' qualities are classified as unpolluted to moderately polluted category. According to the CF values, the sediments' qualities are classified as low to moderate contamination. Furthermore, the PLI values indicated that there were no metal pollution exists for all sampling stations. Conclusion: The Agh Gel Wetland is potential to be threatened by chemical pollutants such as agricultural effluent. So to preserve the environment of the Agh Gel Wetland from deterioration, periodically monitoring of the water and sediment qualities is recommended

Adsorption of Ni(II) and Cd(II) from Aqueous Solutions Using Modified Rice Husk

Background and purpose: Recently, release of pollutants such as heavy metal ions to the environment becomes one of the most important problems for soil and water. The present study was conducted to introduce modified rice husk (RH) as a new low-cost adsorbent. Materials and Methods: In this study, tartaric acid modified RH (TARH), was used as an adsorbent for removal of Ni(II) and Cd(II) from water samples. This study was conducted in laboratory scale. Employing batch method, solution pH, adsorbent dose, contact time, and initial metals concentration were optimized. Results: The optimum pH for removing of both the investigated metal ions from water solutions was found to be 4.0. The process of Ni(II) and Cd(II) adsorption on TARH reached equilibrium within 45 min. The isotherm evaluations revealed that the Langmuir model attained better fits of the experimental equilibrium data than the Freundlich model. In addition, adsorption kinetics data were well-fitted by the pseudo-second-order rate model with high regression coefficients. Conclusion: It was found that TARH is a highly efficient adsorbent for Ni and Cd from aqueous solution, and the maximum predicted adsorption capacities for Ni(II) and Cd(II) were obtained as 55.5 and 45.5 mg/g, respectively

Predicting arsenic and heavy metals contamination in groundwater resources of Ghahavand plain based on an artificial neural network optimized by imperialist competitive algorithm

Background: The effects of trace elements on human health and the environment gives importance to the analysis of heavy metals contamination in environmental samples and, more particularly, human food sources. Therefore, the current study aimed to predict arsenic and heavy metals (Cu, Pb, and Zn) contamination in the groundwater resources of Ghahavand Plain based on an artificial neural network (ANN) optimized by imperialist competitive algorithm (ICA). Methods: This study presents a new method for predicting heavy metal concentrations in the groundwater resources of Ghahavand plain based on ANN and ICA. The developed approaches were trained using 75% of the data to obtain the optimum coefficients and then tested using 25% of the data. Two statistical indicators, the coefficient of determination (R2) and the root-mean-square error (RMSE), were employed to evaluate model performance. A comparison of the performances of the ICA-ANN and ANN models revealed the superiority of the new model. Results of this study demonstrate that heavy metal concentrations can be reliably predicted by applying the new approach. Results: Results from different statistical indicators during the training and validation periods indicate that the best performance can be obtained with the ANN-ICA model. Conclusion: This method can be employed effectively to predict heavy metal concentrations in the groundwater resources of Ghahavand plain

Determination of propineb residue in consumed tea

Background: The use of pesticides is essential to pests control in horticultural crops for the production of an adequate food supply for an increasing world population and for the control of insect-borne diseases. Therefore, pesticide residues in environment and food have a negative impact on the health of living organisms especially human. In this regard, the present study was carried out for assessment and comparing of propineb residues in Iranian tea and imported consumed tea. Methods: In this experimental study, according to the Cochran's sample size formula, 12 samples from 4 brand of imported tea and 6 samples from 2 brand of Iranian tea were collected from market basket of Hamadan City in 2015. After preparation and processing the samples in the laboratory, propineb residues in samples determined using a spectrophotometric method to a wavelength range of 400 nm in 5 replications. Recovery tests were carried out using pesticide-free samples. Also, all statistical analyses were performed using the SPSS statistical package version 19 (Chicago, IL, USA). Results: The mean concentration of propineb residues in Iranian tea samples were 1.60&plusmn;0.27 &micro;g/kg and in imported tea samples were 0.78&plusmn;0.63 &micro;g/kg, respectively and lower than the maximum residue limit (MRL) provided by the European Commission (100 ppb). The results of the comparison of the mean concentration of pesticide residues between Iranian and imported tea samples revealed no statistically significant differences between all the samples together (P=0.17). Conclusion: The results showed that the residues of propineb were found in all analyzed tea specimens. But according to the mean concentrations of propineb residues in tea samples marketed in Hamedan City were lower than MRL, therefore, no adverse health effects have been established from controlled consuming of tea. Also, concerning increased use of agricultural inputs especially kind of pesticides for pest management by farmers, regular periodic monitoring of chemical pollutants content in Iranian and imported tea are recommended for food safety

Analysis and Health Risk Assessment of Arsenic and Zinc in Ghee Consumed in Kermanshah City, Western Iran using Atomic Absorption Spectrometry

This study was carried out for analysis and non-carcinogenic risk assessment of arsenic (As) and zinc (Zn) in some of consumed brands of ghee marketed in Kermanshah City, western Iran in 2015. For this purpose, 12 samples of four popular brands of ghee were analyzed for levels of As and Zn after digestion with acids using atomic absorption spectrometry in 3 replications and health index was obtained. The results showed that the mean concentrations of As and Zn in ghee samples were 0.37±0.12 and 272.83±81.55 µg/kg, respectively. The mean concentration of As and Zn in ghee samples were lower than WHO maximum permissible limits (100 µg/kg for As and 10000 µg/kg for Zn). In addition, health risk assessment showed that no potential risk for children and adult by consume of the ghee samples. According to the results, although consumption of studied ghee has not adverse effect on the consumers’ health, but concerning to the grazing the livestock on soils polluted by heavy metals due to the increased use of agricultural inputs by farmers, industrial development and establishment of pastures near the roads, it is very important to take the appropriate measures during the production process and the treat products before selling them to markets by companies

Heavy Metal Levels and Potential Health Risk Assessment in Honey Consumed in the West of Iran

Since the worldwide research on content of heavy metals in honey is narrow, this study was carried out to analyze heavy metals (Cd, Cr, Ni, and Zn) in honey and assess its associated health risk in Hamadan City, Iran, in 2015. Totally, 15 freshly ripened samples of honey were analyzed for heavy metals using ICP-OES with three replications after burning to ash and digesting with dilute nitric acid. The potential health index was then calculated. The results showed that the mean levels of Cd, Cr, Ni, and Zn in the honey samples were 63.18 ± 43.39, 58.05 ± 30.32, 56.15 ± 54.32, and 684.43 ± 190.43 µg kg-1, respectively. Also, the health risk assessment showed no potential risk for children and adults in relation to the consumption of honey in the studied region. According to the results of the current study, although there is no adverse effect for the local population through the consumption of honey, due to the increased discharge of pollutants especially heavy metals into the natural environment, it is very important to assess foodstuff before release to the consumer market