Akbar Eslami, Hamzehali Jamali, Shirin Naderi,
Volume 6, Issue 2 (9-2013)
Abstract
Background and Objectives: Water is essential for sustaining life & adequate safe supplies must be accessible to the public. Nowadays, people prefer to purchase bottled water for reasons including taste, convenience, following fashion, and its safety and sanitary conditions. According to the WHO guideline, it is of great importance to control the bottled water because of keeping it for longer period of time and at higher temperature in comparison with the water of distribution networks, reusing containers and bottles without adequate washing and disinfecting, and more growth of microorganisms having less important in the terms of health. The aim of this study was to investigate the microbial and physicochemical quality of bottled water in the stores of Qazvin City and to compare the aforesaid features with national standards and to check the quality with the bottles label.
Materials and Methods: In this cross-sectional study, 51 samples of 11 bottled water brands with different production date were obtained. The features were studied in accordance with Standard Methods. Then, the data were analyzed by T-Test and one way ANOVA analysis using SPSS software. Eventually, the results were compared with the national standards, the WHO guidelines, and the product labels.
Results: Results showed lack of microbial contamination of the samples. Physically and chemically, all the parameters measured were below the national standards level. Study of conformity of the variables to the label indicated that mostly there was a significant difference between the values measured and the values listed on the product labels.
Conclusion: Although the concentration of microbial, physical and chemical features of samples were in the extent of national standards, there was a meaningful difference between labels and measured values so that the average concentration of TDS, TH, SO4-2, Ca2+, Mg2+ and Na+ would be more than the label values and the average of the other parameters was lower than the label values.
Fatemeh Hashemi, Hatam Godini, Ghodratolah Shams Khorramabadi, Loqman Mansouri,
Volume 7, Issue 2 (10-2014)
Abstract
Background and Objective: Phenol presence in water and wastewater is interesting because of its stability in environment and health problems. Therefore, it must be removed for water pollution prevention. The aim of this study was to evaluate phenol adsorption from aqueous solutions using walnut green hull. Materials and Methods: This was an experimental study in which walnut green hull was used as biosorbent with a range of mesh 40. In this study, stock solution of phenol was prepared and effects of effective parameters such as pH (4,6,8, and10), contact time (3-60 min), adsorbent dosage (0.25-5 g/L), and initial phenol concentration (10,20,40, and 50 mg/L) on adsorption process were evaluated. Moreover results were evaluated using Langmuir and Freundlich isotherms and first order and pseudo-second order kinetics. All experiments were conducted in double and the mean adsorption rate was reported. Results: The maximum adsorption capacity of 30.30 mg/g corresponded with Langmuir model. Kinetic evaluation indicated that the adsorption of phenol by the walnut green hull clearly followed the pseudo-second order reaction. It was found that increasing contact time and adsorbent dosage would lead to increasing of adsorption of phenol and increasing pH and initial phenol concentration lead to decreasing of phenol adsorption. Maximum phenol removal was achieved at pH 4, with more than 99.9 % efficiency. Conclusion: The results of this study show that the walnut green hull can be used effectively in phenol removal, because walnut green hull is agriculture waste and is produced annual in high volume hence, it can be used as adsorbent in phenol removal from wastewater.
B. Kakavandi, M. Mokhtari, R. Rezaee Kalantari, E. Ahmadi, N. Rastkari, M. Fatehi, A. Azari,
Volume 7, Issue 3 (5-2014)
Abstract
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-Feo/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-Feo/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-Feo/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-Feo/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.
A. Azimi, A. Safahieh, A. Dadollahi Sohrab, H. Zolgharnein, A. Savari, B. Saffar,
Volume 7, Issue 3 (5-2014)
Abstract
Background and Objective: Present study aimed to investigate response of metallothionein (MT) in oyster Crassostrea sp. to the experimental concentrations of Hg and Cd in order to assess the possibility of MT usage as a biomarker of Hg and Cd contamination in this mollusk. Materials and Methods: Oysters were collected from docks of Imam Khomeini Port. After seven days acclimation period in laboratory, they were exposed with Hg at concentrations of 15 and 75 µg.L-1 and Cd at concentrations of 15 and 150 µg.L-1 for 14 days. MT levels were measured through spectrophotometric method after extraction and precipitation. After preparation and acid digestion, the concentration of heavy metals was quantified by atomic absorption. Results: The amounts of MT in oysters exposed with Hg and Cd were significantly increased compared with control samples (P<0.05). The highest value of MT biosynthesis in oysters exposed with concentrations of Hg and Cd were 137.2±7.6 and 312.4±17.9 µg.g-1 w.w respectively. Exposing the oysters with Cd induced biosynthesis of MT more than three times compared with control samples. Among Hg and Cd, there was only significant correlation between biosynthesis of MT and Cd bioaccumulation in oysters (P<0.01). Conclusion: MT protein in oyster Crassostrea sp. can be considered as a suitable biomarker of Cd contamination in body and environment. Hence, it could be used for assessing and monitoring ecosystems.
Z Akbari Jonoush, M Farzadkia, S Naseri, H.r Mohajerani, A Esrafili Dizaji, Y Dadban Shahamat,
Volume 7, Issue 4 (1-2015)
Abstract
Background and Objectives: Increased growing nuclear industry has increased the researchers concerns on uranium presence in the environment and its effects on human health. Uranium is a dangerous radioactive heavy metal with high half-life and chemical toxicity. Therefore, the main objective of this study was to removal uranium (VI) from aqueous solution by uranium benzamide complex using AC_Fe3O4 nanocomposite. Materials and Methods: AC_Fe3O4 nanocomposite was synthesized using co-precipitation method. The experiments were designed as one factor at the time method. The optimum range of pH, contact time, amounts of adsorbent, and concentration of benzamide were determined. Then, kinetic and isotherm of uranium adsorption were studied. In addition, the properties of this adsorbent were characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). Results: The SEM and FTIR analysis confirmed that activated carbon is coated with Fe3O4 nanoparticles and the magnetic property of AC-Fe2O3 was approved. According to the results, the optimum conditions were pH =6, contact time =30 min, and 0.06 g of adsorbent dose. The adsorption of uranium on the AC_Fe3O4 nanocomposite fitted to Langmuir isotherm and pseudo-second order kinetic model. The removal of U(VI) was increased about 6% with increasing in benzamide concentration to 50 mg/L. The best percentage removal of uranium in aqueous solution was 95%. Conclusion: The removal of U(VI) on AC_Fe3O4 nanocomposite with the aid of benzamide is a rapid and highly pH depended process. The maximum sorption capacity (15/87 mg/g) of AC_Fe3O4 nanocomposite shows that this method is a suitable method for Uranium removal.
T Rajaee, R Rahimi Benmaran, H Jafari,
Volume 7, Issue 4 (1-2015)
Abstract
Background & Objectives: The prediction and quality control of the Karaj River water, as one of the important needed water supply sources of Tehran, possesses great importance. In this study, performance of artificial neural network (ANN), combined wavelet-neural network (WANN), and multi linear regression (MLR) models were evaluated to predict next month nitrate and dissolved oxygen of “Pole Khab” station located in Karaj River. Materials and Methods: A statistical period of 11 years was used for the input of the models. In combined WANN model, the real monthly-observed time series of river discharge (Q) and the quality parameters (nitrate and dissolved oxygen) were analyzed using wavelet analyzer. Then, their completely effective time series were used as ANN input. In addition, the ability of all three models were investigated in order to predict the peak points of time-series that have great importance. The capability of the models was evaluated by coefficient of efficiency (E) and the root mean square error (RMSE). Results: The research findings indicated that the accuracy and the ability of hybrid model of wavelet neural network with the attitude of elimniations of time series noise had beeb better than the other two modes so that hybrid model of Wavelet artificial neural network wase able the improve the rate of RMSE for Nitrate ions in comparison with neural network and multiple linear regression models respectively, amounting to 35.6% and 75.92%, for Dissolved Oxygen ion as much as 40.57% and 60.13%. Conclusion: owing of the high capability wavelet neural network and the elimination of the time series noises in the prediction of quality parameters of river’s water, this model can be convenient and fast way to be proposed for management of water quality resources and assursnce from water quality monitoring results and reduction its costs.
M Jahangiri-Rad, R Nabizadeh, J Nouri, M Yunesian, F Moattar,
Volume 8, Issue 1 (8-2015)
Abstract
Background and Objective: Nitrate is one of the dissolved anions having great health importance in water. Human activities and natural sources are considered as the main roots of nitrate intrusion in to water bodies. The main objective of this paper was to study nitrate removal by packed bed column filled with (PAN)-oxime-nano Fe2O3. Materials and Methods: PAN-oxime-nano Fe2O3 were synthesized and used as an adsorbent in glass column for the removal of nitrate from aqueous solution. Nitrate solution tank was set above the prepared column. The effect of factors, such as flow rate (2, 5, and 7 mL/min) and bed depth (5, 10, and 15 cm) were studied. Results: It was found that the data fit well with Thomas model and breakthrough curve was designed accordingly. The column performed well at lowest flow rate. As the flow rates and time increased, earlier breakthrough was observed. The column breakthrough time (Ce/C0 = 0.05) was reduced from 9 to 4 h, as the flow rates increased from2 to 7 mL/min. Conclusion: fixed-bed using PAN-oxime-nano Fe2O3 exhibited good removal of nitrate. The adsorption studies showed that at longer bed depth, better removal of nitrate would be achieved. Thomas model was suitable for the normal description of breakthrough curve at the experimental condition. The data also were in good agreement with logistic regression.
M Hatami Manesh, M Mirzaei, M Gholamali Fard, A.r Riyahi Bakhtiyari, M Sadeghi,
Volume 8, Issue 1 (8-2015)
Abstract
Background and Objectives: one of the most important environmental concerns is heavy metals emissions from human activities to natural ecosystems, particularly transfer to soil. The aims of this study were measured the concentrations of Cu, Zn and Cr in landfill soil and hospital waste ash of Shahrekord municipal solid waste landfill. Materials and Methods: Soil samples were collected from three sites: out of the landfill, municipal landfill and hospital landfill. In each site 2, 1, and 1 stations ware selected respectively and each sample was replicated in three times. Results: We found that there was a significant difference between concentrations of Cu, Zn and Cr in the landfills soil (95% confidence, P <0.05). Furthermore, the highest levels of Zn and Cu were detected in the hospital landfill and also for Cr in the municipal landfills. However, the concentration levels of heavy metals in all of the sites were in order as follows: Zn>Cu>Cr. Conclusion: High concentrations of metals determined in the present study represents the high application of these metals in the structure of municipal and hospital solid wastes and also their inaccurate separation. Thus, awareness about physical and chemical characteristics of municipal and hospital wastes and also the landfill soil is necessary for evaluating their effects on the soil quality and surrounding environments.
R Manaffar, B Sehatnia, R Sabzi, A Ehsani,
Volume 8, Issue 2 (8-2015)
Abstract
Background and Objectives: Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental contaminants in aquatic environments. These contaminants are generated through oil spills, manufactory processes, and industrial wastes or naturally through the incomplete combustion of coal, oil, gas, and wood waste. Most of these compounds are noted as carcinogenic and mutagenic. Therefore, detection of these pollutants by a sensitive and inexpensive method is very important. Materials and Methods: In this study, an electrochemical DNA biosensor was used to detect PAHs due to its sensitivity, ability, and high response rate. For this purpose, the bovine thymus double-stranded DNA was fixed on a screen-printed electrode. Then, the electrodes electrochemical behavior was investigated. This electrochemical DNA biosensor works upon the difference between the electrochemical response of guanine bases in DNA structure in the presence and absence of PAH compounds. To evaluate the biosensors performance, the response of biosensor to real samples was compared with conventional pollutant determination methods like liquid-liquid chromatography. Results: Optimum conditions were examined for biosensor response including effect of activation potential and time on electrode pretreatment, applied potential for DNA immobilization, and detection potential. Under optimal conditions, the pretreatment of the electrode obtained in 1.6 V for 350s, then the DNA was immobilized on the electrode surface by applying a potential of -0.5 V to detect different PAHs in real samples in the range of micro molar. Conclusion: Electrochemical DNA biosensors are capable of detecting the sum of PAHs in water samples with high accuracy, sensitivity, and low cost compared with chromatographic methods.
H Zarei, A.h Mahvi, S Nasseri, R Nabizadeh Noudehi, F Shemirani,
Volume 8, Issue 3 (12-2015)
Abstract
Objective and Background: Fluoride is an element widely found in the earth crust. Advantages and disadvantages of fluoride in the human body are depended on its concentration. Long-term consumption of drinking water contaminated with arsenic can cause adverse health effects such as skin lesions and cancer in humans. The aim of this study was to study efficiency of nano alumina on multi walled carbon nano tube for removal As(V) and fluoride from aqueous solution.
Materials and Method: In this study, nano-scale crystalline alumina was synthesized on single walled carbon nanotube by sol-gel method for using as a sorbent for solid phase extraction of Fluorine ion and arsenic(V). Response surface methodology based on Box-Behnken was used to assess the effect of independent variables on the response function and prediction of the best response value. In this study, effect of different parameters, such as contact time (10 to 120 min), pH (3-9), adsorbent dosage (0.25-1.5 g/L) and initial concentration of fluoride (2-8 mg/L) on efficiency of process was investigated. The structure of nano-scale alumina on multi walled carbon nano tube was determined by XRD and SEM techniques. Moreover, Freundlich and Langmuir isotherm models were used to calculate equilibrium constant.
Results: It was found that by increasing contact time and adsorbent dosage the rate of fluoride removal increased. However, by increasing pH and initial concentration the efficiency of fluoride removal decreased. High value for R2 (0.94) shows that removal of arsenic(V) can be described by this model. The Freundlich isotherm was the best fitted graph for experimental data with R2 more than 0.997.
Conclusion: In this study, it was observed that efficiency of arsenic(V) and fluoride removal was greatly increased by using nano-scale alumina on multi walled carbon nanotubes (MWCNTs).
K Naddafi, A Beiki , R Saeedi, G Ghanbari, A Niati, L Sori,
Volume 8, Issue 3 (12-2015)
Abstract
Background and objectives: In the outbreak of infectious diseases, the on time epidemiological, environmental, and laboratorial investigations result in rapid diagnosis of cause and source of the outbreaks and decrease the diseases spread and public health loss. Following the outbreak of gastroenteritis in Pardis Town in January 2014, this research was conducted to identify the cause, source, and route of transmission of the outbreak.
Materials and methods: First, the descriptive epidemiological study was conducted using checklist and the stool samples were prepared and analyzed. The drinking water quality in Pardis during and before the outbreak was obtained from National Environmental Health Network. The community water supply system consisting of watershed, water resources, pipelines, storage reservoirs, disinfection systems, and distribution network were inspected and sampling and detection of thermotolerant coliforms and norovirus in water samples were performed according to the Standard Methods.
Results: There were 6,027 patients with symptoms of nausea, vomiting, cramps, mild diarrhea, and mild fever. The distribution of the disease in all age groups, gender, ethnicity, and location was uniform. Out of nine stool specimens, molecular testing of norovirus in six samples was positive. Hazards identified in the water supply system consisted of a water pipe fracture occurred two days before the outbreak, illegal connection of landscape irrigation system to the drinking water supply network, the use of unprotected Fellman wells as the resource of water supply, and discharge of domestic wastewater into the water resource upstream of the Fellman wells. The water samples taken from the Fellman wells had fecal contamination (11 out of 12 samples), but because of weakness and limited experience in identifying norovirus in water samples, norovirus was not detected in the raw water samples.
Conclusion: This study showed that the pathogen came from a single source. Clinical symptoms, epidemiological evidence, the results of analysis of human stool samples, fecal contamination of raw water samples and norovirus resistance to the standard amounts of free residual chlorine in water indicated that the outbreak caused by consumption of contaminated drinking water (discharge of domestic wastewater to water supply system). In order to prevent similar outbreak, resolving the observed bugs in the water supply system and implementation of water safety plan is recommended.
M.m Amin, M Giyahi, M Mansourian,
Volume 8, Issue 4 (3-2016)
Abstract
Background and Objectives: Perchlorate, as an emerging contaminant, has attracted notice of the most individuals and organizations. Presence of perchlorate in the human body can lead to inappropriate regulation of metabolism in adults. Moreover, due to inhibition of iodide uptake in the thyroid gland, it causes neurological and behavioral problems in infants and children. United States Environmental Protection Agency (EPA) has enacted 15 µg/L perchlorate in drinking water as a guideline value. Regarding the possible sources and potential presence of perchlorate in the environment of the study area, and the unique characteristics of this pollutant, such as extreme water solubility, high mobility in soils and stability in the environment, the status of its contamination was assessed in soil, surface water and drinking water in the study area (Khorramshahr County).
Materials and Methods: Soil and water samples were taken during February to April, 2013. Combined sampling was used for soil sample collection and the random sampling was used for water (surface and drinking water) samples. Each sample was analyzed using ion chromatography. In this study, 15 samples of surface soil and 22 samples of surface and drink water were tested for perchlorate analysis.
Results: It was found that all surface soil and water samples collected from the study area were contaminated with perchlorate and exceed the standard level. Concentration of perchlorate in surface water and drinking water was 1400-5800 and 700-5900 µg/L respectively and in surface soils was 3.3-107.9 mg/kg.
Conclusion: The assessment of perchlorate in soil, surface water, and drinking water in the study area is extremely higher than recommended standards and therefore is a threat to the health of consumers.
R.s Hajimirmohammad Ali, H Karyab,
Volume 8, Issue 4 (3-2016)
Abstract
Background and Objective: The concentration of nitrate, factors affecting the balance sheet, and the changes in an aquifer is of utmost importance. Because modeling is an efficient method to predict the concentration of ions in water resources, in this study using lumped-parameter model and Monte Carlo simulation model, the nitrate concentrations in groundwater resources of Qazvin Plain were estimated and analyzed.
Materials and Methods: A total of 19 wells in different climates of saline watershed in Qazvin Plain were selected and entry and exit routes of nitrate to these sources were analyzed using lumped-parameter model. Finally, Monte Carlo simulation was used to determine the probability of the estimated nitrate concentration in aquifer.
Results: Application of lumped-parameter model for a part of a part of groundwater resources in Qazvin Plain watershed predicted the nitrate concentration in the range of 8.12 to 15.94 mg/l. The maximum concentration was estimated in cold-dry climate with 12.8±0.04 mg/L. Moreover, it was found that the difference between the estimated nitrate concentration and factors affecting its concentration in different climates was significant (p<0.05).
Conclusion: Despite the predicted concentrations of nitrate in the study area were in accordance with the Iran national standard for drinking purposes, the cumulative probability of Monte Carlo simulation showed that the possible violation of nitrate from the safe limit of 10 mg/l in the study area is 90% (p = 0.005).
H Aslani, R Nabizadeh,
Volume 8, Issue 4 (3-2016)
Abstract
Background and Objectives: Considering the complexity, cost, and time-consuming techniques of detecting Cryptosporidium oocysts and Giardia cysts, B. subtilits spores have been introduced as microbial indicators of these pathogens to evaluate the efficacy of disinfection studies. The present study was aimed to investigate the feasibility of B. subtilis spores inactivation using hydrogen peroxide combined with copper and silver ions. A new glutaraldehyde based compound used for surface disinfection was also tested.
Materials and Methods: In order to sporulation, vegetative bacteria were allowed to grow on a medium with insufficient nutrients, and after 5 days incubation at 37˚C, spores were washed and purified. Spore suspension was used to prepare synthetic water. Disinfection efficiency was reported as logarithmic decrease of initial spore count.
Results: This research found that none of the disinfection compounds was able to spore inactivation in low initial concentration. The highest spore reduction efficiency was related to HP/Cu+2 with 1.48 log inactivation, and HP/Ag+ compound placed in the second rank with 1.03 log reduction. Maximum spore reduction of 0.6 log was achieved when glutaraldehyde based disinfectant was used in disinfection process.
Conclusion: According to the results, it can be concluded that spores are very resistant even to combination of disinfectants. Spore reduction potential of the studied compounds was as follows: HP/Cu+2> HP/Ag+> glutaraldehyde based compound.
B Sepehrnia, R Nabizadeh, A.h Mahvi, S Naseri,
Volume 9, Issue 1 (6-2016)
Abstract
Background and Objective: In this study, WQI was estimated using an Iranian software called IWQIS to assess drinking water quality in Ray Township distribution systems.
Materials and Methods: The assessment of 73 samples of drinking water during 2013 and the comparison of 18 physicochemical parameters with the standard Code of 1053 (Iran National Standard) was done.
Results: The results showed that the concentration of 7 parameters is out of normal range in special percentage of the samples. Those parameters are as follow: total hardness (31.5%), Mg (46.6%), nitrate (50.68%), Na (45.2%), F (42.46%), Cl (2.7%), Sulfate (28.76%) of samples. The medium concentration of theses parameters was: total hardness (375 mg/L), Mg (32 mg/L), Nitrate (47.43 mg/L), Na (187 mg/L), F (0.5 mg/L), Cl (169 mg/L), and Sulfate (263 mg/L). It is estimated that 5.6% of the population of this township are highly exposed to nitrate, 79.1% to fluoride and 13.5% are exposed to sodium. The average WQI in Rey Township in a good spectrum is 71.22.
Conclusion: 17 samples (23.2%) were assessed in excellent spectrum, 54 samples (74%) in good and 1 sample (1.4%) in very poor spectrum and 1 sample in unsuitable condition were assessed. No sample was assessed in poor situation. The samples of the autumn showed the worst quality.
A Beiki, M Yunesian, R Nabizadeh, R Saeedi, L Sori, M Abtahi,
Volume 9, Issue 1 (6-2016)
Abstract
Background and objectives: Swimming is one of the most popular sport fields and entertainments that has considerable benefits for human health, but on the other hand microbial water contamination in swimming pools through transmission and spread of infectious diseases is a significant threat against public health. In this study, microbial water quality of all public swimming pools in Tehran were assessed and effective factors on microbial water quality were analyzed.
Materials and Methods: This cross-sectional study with the analytical approach was performed in 2013. The whole public swimming pools in Tehran were inspected and water samples were taken for measurement of microbial indicators including thermotolerant coliforms, heterotrophic plate count (HPC), and physicochemical parameters affecting the microbial water quality including turbidity, free residual chlorine and pH and an integrated swimming pool microbial water quality index were used to describe the overall situation. Operational parameters with probable effects on microbial water quality were checked through inspection using a checklist.
Results: The assessment of the swimming pool microbial water quality indicated that the compliance rates of thermotolerant coliforms and HPC were 91.4 and 84.5%, respectively. Compliance rates of free residual chlorine, turbidity, Ph, and temperature were also obtained to be 82.7, 45.5, 85.6, and 65.4% respectively. Based on the integrated swimming pool microbial water quality index, the proportions of swimming pools with excellent and good microbial water quality were 39.6 and 50.4% respectively and the others had not proper microbial water quality. The parameters of water free residual chlorine and turbidity, swimmer density, water recirculation period, dilution amount, cleaning, usage rates of shower and disinfection basin and operation of water treatment systems had significant effects on the microbial indicators (P<0.05).
Conclusion: The study showed that the overall microbial water quality status of public swimming pools in Tehran was acceptable and analysis of the results determined the most efficient interventions for improvement of the microbial water quality of the pools.
S Dehestaniathar, Sh Amini, A Maleki, B Shahmoradi, N Reshadmanesh, P Teymouri,
Volume 9, Issue 2 (9-2016)
Abstract
Background and Objectives: Fluoride has both beneficial and detrimental effects on health. Therefore, it is important to determine its concentration in drinking water. Dental fluorosis and skeletal fluorosis are health effects caused by long term exposure to high levels of fluoride in drinking water. The aim of this research was to investigate fluoride removal using modified diatomite-supported ferric oxide nanoparticles and to determine the adsorption kinetics and isotherm.
Materials and Methods: This fundamental and practical study was performed at laboratory scale. The effects of pH (3.5-9.5), contact time (20-100 min), adsorbent dosage (1-5 g/L), and initial concentrations of fluoride (5-25 mg/L) on the adsorption efficiency were evaluated. The properties of adsorbent were investigated using XRD, XRF, FTIR and FESEM. Finally, the suitability of pseudo first and second order kinetics, and Langmuir and Freundlich isotherms for the data were investigated.
Results: This study showed that the removal efficiency of F- increased with increase in contact time, decrease in pH, increase in adsorbent dose, and increase in initial fluoride concentration. The highest removal efficiency was observed at pH=3.5, 60 minutes contact time, and 3 g/L of adsorbent dose in the initial concentration of 5 mg/L F-. Pseudo first order and Freundlich were the best fitted kinetic and isotherm models, respectively, for describing F- adsorption process.
Conclusion: The present study indicates that the modified diatomite-supported ferric oxide nanoparticles can be used as an effective and environmentally friendly biosorbent for the removal of fluoride ions from aqueous solutions.
M Ahmadee, A Shahidi, Z Ghorbani,
Volume 9, Issue 3 (12-2016)
Abstract
Background and Objective: The role of groundwater has always been an important issue in order to provide drinking water especially in desert areas. However, studies and decision-making on water supply from the water source is more costly and difficult rather than surface water. Therefore, it is important to note the newest methods like zoning. Due to the effects of water chemical parameters on the quality, application of AHP, ANP, FAHP, and FANP methods lead to more accurate results. The aim of this research was to zone groundwater quality using ANP and FANP models and comparison of the results obtained by those achieved, by AHP and FAHP models.
Materials and Methods: For this purpose, the study was conducted to zone groundwater quality in Tabas aquifer located at the east of Iran with latitude between 33˚ 19’-33˚ 50’ and longitude between 60˚ 42’-63˚ 12’. In this study, the parameters studied were Mg, Ca, SO4, Cl, total dissolved solids (TDS), electrical conductivity (EC), and total hardness (TH). Raster maps for each parameter were prepared and these maps were converted to fuzzy maps. Then, the maps were integrated together using the weights from AHP and ANP methods.
Results: The research indicated that the most weighted parameters using ANP method were Cl (0.172), Mg (0.161) and EC (0.159). Cl (0.457), TDS (0.163) and EC (0.141) were the most weighted parameters using AHP methods. In addition, the concentration of each parameter was increased from the east and southeast to the northeast.
Conclusion: Based on the results and groundwater flow path, water quality was reduced due to water flow in aquifer (from the east and southeast to northeast). Hence, the east and the southeast were the best location to provide drinking water. The area of these regions were 22.12, 25.08, 57.35 and 58.24% out of total area as determined using AHP, ANP, FAHP, and FANP, respectively.
Ar Mesdaghinia, S Nasseri, M Hadi,
Volume 9, Issue 3 (12-2016)
Abstract
Background and Objective: Exposure to chemicals such as heavy metals can be occurred through the route of drinking water consumption. Chromium is an important pollutant because of its role in the appearance of carcinogenic and non-carcinogenic health effects in humans. In this study, we studied the carcinogenic risk and non-carcinogenic hazard of chromium due to the consumption of bottled drinking water distributed throughout Iran.
Materials and Methods: The Hazard Quotient (HQ) and Excess Lifetime Cancer Risk (ELCR) indices were calculated. Monte-Carlo simulation technique was adopted for simulating uncertainty in the estimation of HQ and ELCR based on the input variables namely the concentration of pollutant, per capita water consumption, body weight, reference dose, biological availability, and source contribution factors.
Results: The average concentration of chromium in bottled waters determined was 4.79 ± 2.32 µg/L. The amounts of HQ and ELCR for the age groups of lower than 2, 2 to 6, 6 to 16 and over 16 years old were 0.000354, 0.00292, 0.00236, 0.00147 and 4.04×10-11, 5.99×10-10, 8.61×10-10 and 2.34×10-9, respectively.
Conclusion: In regard to the concentration of chromium in bottled waters in Iran, the incidence probability and the possibility of carcinogenic and non-carcinogenic effects by this pollutant due to the consumption of bottled water are considerably low and there is no health concern for any age groups.
S Shakur, Aa Nadiri, A Asghari Moghaddam, M Vadiati,
Volume 9, Issue 3 (12-2016)
Abstract
Background and Objective: Human health depends on clean and safe drinking water more than anything. In Bilverdi Plain, the main source of drinking water is groundwater that has got a low quality in some places. Therefore, the drinking water of this area needs detailed evaluation of quality. In this research, the drinking water of Bilverdi Plain was evaluated based on fuzzy and deterministic methods.
Materials and Methods: Totally, 15 samples were collected from different places in September 2013. Major water ions including fluoride and nitrate of the samples taken were measured at hydrological lab of University of Tabriz. To check the quality of water, Schoeller diagram in GWW environment and MATLAB software in fuzzy inference system were used and their results were compared with each other.
Results: Based on the results in deterministic method, the quality of drinking water was classified ranging from good to undesirable. However, in fuzzy method in addition to water quality, the potability confidence of samples was offered in which water in six samples with reliability percent from 13.8 to 14.7; in five samples with 50% confidence level and in four samples with confidence percent from 73 to 85 were desirable, acceptable and unacceptable respectively.
Conclusion: The results show the higher accuracy and capability of fuzzy method rather than deterministic method. Because it is proper to deal with uncertainty in the different parameters and all effective parameters on water quality could be considered together in the evaluation and it offers confidence level for potability of water.
