Environmental Health Engineering and Management Journal

173-182

Authors: Vahid Gholami, Marhemat Sebghati, Zabihollah Yousefi *

Background: Although experiments on water quality are time consuming and expensive, models are often employed as supplement to simulate water quality. Artificial neural network (ANN) is an efficient tool in hydrologic studies, yet it cannot predetermine its results in the forms of maps and geo-referenced data. Methods: In this study, ANN was applied to simulate groundwater quality and geographic information system (GIS) was used as pre-processing and post-processing tool in simulating water quality in the Mazandaran Plain (Caspian southern coasts, Iran). Groundwater quality was simulated using multi-layer perceptron (MLP) network. The determination of groundwater quality index (GWQI) and the estimation of effective factors in groundwater quality were also undertaken. After modeling in ANN, the model validation was carried out. Also, the study area was divided with the pixels 1×1 km (raster format) in GIS medium. Then, the model input layers were combined and a raster layer which comprised the model inputs values and geographic coordinate was generated. Using geographic coordinate, the values of pixels (model inputs) were inputted into ANN (Neuro Solutions software). Groundwater quality was simulated using the validated optimum network in the sites without water quality experiments. In the next step, the results of ANN simulation were entered into GIS medium and groundwater quality map was generated based on the simulated results of ANN. Results: The results revealed that the integration of capabilities of ANN and GIS have high accuracy and efficiency in the simulation of groundwater quality. Conclusion: This method can be employed in an extensive area to simulate hydrologic parameters.

191-196

Authors: Amirreza Talaiekhozani *, Mohammad Reza Talaei, Mehdi Yazdan, Seyed Masoud Mir

Background: Human hair can be used as an inexpensive and accessible adsorbent to remove a variety of pollutants from air. Although several studies have been done on removal of formaldehyde from wastewater by human hair, to date no study has investigated using hair to remove formaldehyde from air. Therefore, the aim of this study was to remove formaldehyde from synthetic contaminated air by a reactor packed with human hair. Methods: Air contaminated with formaldehyde was introduced into a cylindrical reactor packed with human hair at the initial concentration of 8500 mg/L. Formaldehyde concentration was measured in the influent and effluent of the reactor to indicate formaldehyde removal efficiency. Other measurements of parameters effective on formaldehyde removal were taken including amount of human hair and environmental temperature. Results: Results of this study revealed that each gram of human hair was able to remove 0.13 to 0.49 g of formaldehyde from air. Human hair adsorbed 98% of formaldehyde from synthetic contaminated air under 20˚C. These results demonstrate that increased temperature had a negative effect on formaldehyde removal. Conclusion: Results of this study show that human hair can be applied as a simple and inexpensive adsorbent to remove formaldehyde from industrial air exhaust. In addition, results of these tests can be considered as a small step to promote better air quality.

203-208

Authors: Asadollah Karimi, Esmaeil Fatehifar *, Reza Alizadeh, Iraj Ahadzadeh

Background: Sulfur compounds must be removed from petroleum because they contribute to environmental pollution. A strong alkaline solution such as caustic soda is used to remove these compounds. This spent caustic has high values for chemical oxygen demand (COD) concentration, pH and total sulfur. In this study, the regeneration and treatment methodology of sulfidic spent caustic was investigated by applying the analytic hierarchy process (AHP). Methods: The evaluation index system developed was based on group decision-improved AHP. Expert Choice software was used to simplify decision-making when choosing a practical method and prioritizing treatment of spent caustic. Cost, environmental considerations, availability and scale-up were chosen as criteria and wet air oxidation and biological and catalytic methods were selected as alternative methods. The treatment and regeneration of spent caustic was carried out in a batch bubble column reactor loaded with IVKAZ catalyst and the effluent was treated in a precipitation-stirred tank reactor. Results: Evaluation indicated that cost ranked first among criteria at 40.9%. The results showed that the proposed process produced about 13% (wt) of caustic, 50 g/L of COD and 36 g/L of S2-. Conclusion: The results indicate that the catalytic method was more effective (0.45) than wet air oxidation and the biological method. This process regenerated more than 85% of initial caustic and the economy of the process improved by the recycling of the stream of caustic.

217-224

Authors: Ali Akbar Mohammadi, Mansour Ghaderpoori, Mahmood Yousefi, Malihe Rahmatipoor, Safoora Javan *

Background: One issue of concern in water supply is the quality of water. Measuring the qualitative parameters of water is time-consuming and costly. Predicting these parameters using various models leads to a reduction in related expenses and the presentation of overall and comprehensive statistics for water resource management. Methods: The present study used an artificial neural network (ANN) to simulate fluoride concentrations in groundwater resources in Khaf and surrounding villages based on the physical and chemical properties of the water. ANN modeling was applied with regard to diverse inputs. Results: The MLP1 model with eight inputs of parameters such as root mean square error (RMSE) and correlation coefficient of actual and predicted outputs exhibited the best results. The lowest fluoride concentration (0.15 mg L-1) was found in Sad village, and the highest concentration (3.59 mg L-1) was found in Mahabad village. Based on World Health Organization (WHO) standards, 56.6% of the villages are in the desirable range, 33.3% of them had fluoride concentrations below standard levels, and 10% had higher than standard concentrations of fluoride. Conclusion: The simulation results from the testing stage for MLP1 as well as the high conformity between experimental and predicted data indicated that this model with its high confidence coefficient can be used to predict fluoride concentrations in groundwater resources.

115-121

Authors: Farzad Kazemi, Zabihollah Yousefi , Reza Ali Mohammadpour

Background: Dental wastes are one of the environmental issues due to toxic and pathogenic agents such as pathological wastes, pharmaceutical and chemical etc have particular sensitivity. The aim of this study was to determine the dental waste management and related factors in the city of Ilam. Methods: In this cross-sectional study, the studied community was all the sixteen dental clinics in Ilam. Five samples of each clinic per week (Saturday, Sunday and Wednesday) were selected. Thereafter waste sample was manually separated into 36 components and were weighed using a laboratory scale with an accuracy of 0.01 g. Each component was weighed five times and the mean value obtained for each component was considered. Production per capita was calculated for each person. Data were analyzed using descriptive statistics, SPSS and Excel software. Results: The per capita percent for infectious waste section was 51%. The average of infectious waste is 201.13 g. The per capita percent for chemical, pharmaceutical waste section was 36% with an average of 142.48 g. The per capita percent for toxicity section was 13% in the dental clinics with the weighted average of 48.78 g. According to the results of the checklist, further dental clinics have been poorly managed. Conclusion: According to the presence of various materials and different components with different characteristics in the dental wastes, the optimal management of this type of wastes should be carried out based on the specific characteristics, which include programs to reduce waste production, segregation, recycle and reuse.

131-135

Authors: Oshin Rezaei Raja, Soheil Sobhanardakani , Mehrdad Cheraghi

Background: Fruits especially citrus species are an integral part of human diet. Contamination of foodstuffs by heavy and toxic metals via environmental pollution has become an inevitable challenge these days. Therefore, the effect of pollutants on food safety for human consumption is a global public concern. In this regards, this study was conducted for Al and Cu health risk assessment through the consumption of citrus species (orange, grapefruit, sweet lime and tangerine) in Hamedan city in 2015. Methods: After collecting and preparing 4 samples from each citrus species with acid digestion method, the concentrations of Al and Cu were determined using inductively coupled plasma optical emission spectrometry (ICP–OES) with three replications. In addition, SPSS was employed to compare the mean concentrations of metals with maximum permissible limits (MPL) of the World Health Organization (WHO). Results: The results showed that the mean concentrations of Al in citrus samples were 3.25±0.35 mg/kg and higher than WHO maximum permissible limits. The mean concentrations of Cu in citrus samples with 0.16±0.05 mg/kg are lower than WHO maximum permissible limits. Also, the computed health risk assessment revealed that there was no potential risk for children and adult by consuming the studied citrus. Conclusion: Based on the results, consumption of citrus species has no adverse effect on the consumers’ health, but as a result of the increased utilization of agricultural inputs (metal based fertilizers and pesticides, sewage sludge and wastewater) by farmers and orchardists, regular periodic monitoring of chemical pollutants content in foodstuffs are recommended for food safety.

143-150

Authors: Amirreza Talaiekhozani , Somaye Bahrami, Seyed Mohammad Javad Hashemi , Sahand Jorfi

Background: The biogases are the mixture of gases produced through the microbial decomposition of organic waste which are amply observed in the landfills. The main purpose of this study was to estimate the emission rates of landfill gases such as carbon dioxide, methane and non-methane organic compounds (NMOCs) in the solid waste landfill of Rodan city in Hormozgan province. Methods: All the necessary information such as population, geographic and climate of Rodan city were collected. Solid waste analysis was then conducted. Afterward, the LandGEM software is used in this study for the purpose of estimation of total biogas, methane, carbon dioxide and NMOCs emission from Rodan’s landfill. Results: The analysis of results showed that only 24.18% of the produced waste in this city is perishable. The calculations indicate that the peak of biogas production which is equal to 420 tons per year would be achieved in the year 2019. The production rates of carbon dioxide and methane in the same year would be equal to 308 and 112 tons per year respectively. The pollutants transmittance calculations in the vicinity of the landfill revealed that the maximum pollutant concentration is within the maximum distance of 200 m. Conclusion: The results obtained in this study could be used for the purpose of design and installation of extraction or incineration equipment in the landfill of Rodan.

159-163

Authors: Farokh Legha Servat, Tahereh Soltani, Zahra Derakhshan , Najmeh Khanjani, Akram Sadat Hosseini , Zynab Anbari Nogyni

Background: Leishmaniasis is a parasitic disease, that due to the incidence, dissemination and scattering throughout different parts of Iran is of paramount importance. This study was carried out with the aim of determining the epidemiology of leishmaniasis cutaneous in Khatam during 2008-2012. Methods: This is a cross-sectional and retrospective study of collected demographic and epidemiological information, related to 760 patients with the disease who underwent treatment in health centers in Khatam during 2008-2012. This information was analyzed using SPSS version 16 software and includes the history of disease outbreak, age, sex, place of residence, number of wounds, wound placement and a history of travel to endemic areas in the past year. Results: The results showed that out of a total number of patients with cutaneous leishmaniasis 460 persons were male (60.5%) and 300 persons were female (39.5%); age mean of patients was 22 ± 1.68. The 0-9 years age group was more susceptible to the disease. The lodging for 525 subjects (69.1%) was listed as village, 224 (29.7%) of them lived in the city and 11 people (1.4%) lived on the fringes of the city. 98.8% of these patients were infected with rural cutaneous leishmaniasis. There were 428 cases of wounds on the hands (56.3%) making it the most common type. Conclusion: The rural leishmaniasis is one of the major health problems of Khatam, and given the high disease incidence in children and farmers, continuing education on the care and control of the disease in the region is of very high importance.

55-59

Authors: Dariush Naghipour, Zeinab Shaabaninezhad , Abdoliman Amouei

Background: Marine products, especially fish, play an increasingly significant role in human diets and health. This research evaluated the concentrations of cadmium, lead, chromium, and nickel in liver and muscle tissues of Rutilus frisii kutum along the Caspian Sea coasts of northern Iran. Methods: Thirty samples of fishes were taken from five stations (Astara, Rezvanshahr, Anazali, Ramsar, and Tonekabon) during fishing season. An ICP-OES spectrophotometer was used to determine concentrations of the studied metals. Data was analyzed by SPSS 19 using descriptive statistical index, t test, and analysis of variance (ANOVA) test; P < 0.05 was considered significant. Results: Mean concentrations of cadmium, lead, chromium and nickel in the livers were 0.06, 1.1, 2.1 and 1.5 μg/g respectively and in the muscles were 0.05, 0.8, 1.7 and 1.1 μg/g, respectively. In liver: cadmium= 0.01-0.13; lead= 0.3-2.7; chromium = 0.9-4.5; nickel = 0.1-2.8. In muscle: cadmium = 0.01-0.08; lead = 0.2-1.5; chromium = 0.7-2.7; nickel = 0.5-1.5. Mean contents of these heavy metals were higher in the liver than in muscle. The order of heavy metal concentrations in the liver and muscle tissues were: Cr>Ni>Pb>Cd. The results showed statistically significant differences in the concentrations of these metals in liver and muscle tissues (P < 0.05), but no significant difference was observed between males and females. Conclusion: Based on calculations, the estimated permissible tolerable weekly intakes (PTWIs) of cadmium (0.042 and 0.567 mg) and lead (0.0021 and 0.027 mg) in this study are lower than the levels established by the World Health Organization (WHO) (0.455 mg for cadmium and 1.625 mg for lead).

69-73

Authors: Ali Ahmad Aghapour, Sepideh Nemati, Amir Mohammadi , Heshmatollah Nourmoradi , Sima Karimzadeh

Background: Nitrate is an acute and well-known hazardous contaminant, and its contamination of water sources has been a growing concern worldwide in recent years. This study evaluated the feasibility of nitrate removal from water using the traditional coagulants alum and ferric chloride with lower concentrations than those used in the conventional coagulation process. Methods: In this research, two coagulants, alum and ferric chloride, were compared for their efficiency in removing nitrate in a conventional water treatment system. The removal process was done in a batch system (jar test) to examine the effects of coagulant dosages and determine the conditions required to achieve optimum results. Results: The results revealed that ferric chloride at an initial dose rate of 4 mg/L reduced nitrate concentration from 70 mg/L to less than the World Health Organization (WHO) guideline value (50 mg/L N-NO3). However, the removal efficiency of alum was not salient to significant nitrate reduction. Conclusion: In conclusion, ferric chloride was more effective than alumin removing NO-3, even in common dosage range, and can be considered a cost-effective and worthy treatment option to remediate nitrate-polluted water. Furthermore, the removal of nitrate by coagulation can be simple and more economical than other treatment alternatives.

81-89

Authors: Maryam Khodadadi, Alireza Mesdaghinia, Simin Nasseri, Mohammad Taghi Ghaneian, Mohammad Hassan Ehrampoush , Mahdi Hadi

Background: Data mining (DM) is an approach used in extracting valuable information from environmental processes. This research depicts a DM approach used in extracting some information from influent and effluent wastewater characteristic data of a waste stabilization pond (WSP) in Birjand, a city in Eastern Iran. Methods: Multiple regression (MR) and neural network (NN) models were examined using influent characteristics (pH, Biochemical oxygen demand [BOD5], temperature, chemical oxygen demand [COD], total suspended solids [TSS], total dissolved solid [TDS], electrical conductivity [EC] and turbidity) as the regression input vectors. Models were adjusted to input attributes, effluent BOD5 (BODout) and COD (CODout). The models performances were estimated by 10-fold external cross-validation. An internal 5-fold cross-validation was also used for the training data set in NN model. The models were compared using regression error characteristic (REC) plot and other statistical measures such as relative absolute error (RAE). Sensitivity analysis was also applied to extract useful knowledge from NN model. Results: NN models (with RAE = 78.71 ± 1.16 for BODout and 83.67 ± 1.35 for CODout) and MR models (with RAE = 84.40% ± 1.07 for BODout and 88.07 ± 0.80 for CODout) indicate different performances and the former was better (P < 0.05) for the prediction of both effluent BOD5 and COD parameters. For the prediction of CODout the NN model with hidden layer size (H) = 4 and decay factor = 0.75 ± 0.03 presented the best predictive results. For BODout the H and decay factor were found to be 4 and 0.73 ± 0.03, respectively. TDS was found as the most descriptive influent wastewater characteristics for the prediction of the WSP performance. The REC plots confirmed the NN model performance superiority for both BOD and COD effluent prediction. Conclusion: Modeling the performance of WSP systems using NN models along with sensitivity analysis can offer better understanding on exploring the most significant parameters for the prediction of system performance. The findings of this study could build the foundation for prospective work on the characterization of WSP operations and optimization of their performances with a view to conducting statistical approaches.

99-106

Authors: Aida Tayebiyan , Thamer Ahmad Mohammad

Background: Several reservoir systems have been constructed for hydropower generation around the world. Hydropower offers an economical source of electricity with reduce carbon emissions. Therefore, it is such a clean and renewable source of energy. Reservoirs that generate hydropower are typically operated with the goal of maximizing energy revenue. Yet, reservoir systems are inefficiently operated and manage according to policies determined at the construction time. It is worth noting that with little enhancement in operation of reservoir system, there could be an increase in efficiency of the scheme for many consumers. Methods: This research develops simulation-optimization models that reflect discrete hedging policy (DHP) to manage and operate hydropower reservoir system and analyse it in both single and multi-reservoir system. Accordingly, three operational models (2 single reservoir systems and 1 multi-reservoir system) were constructed and optimized by genetic algorithm (GA). Maximizing the total power generation in horizontal time is chosen as an objective function in order to improve the functional efficiency in hydropower production with consideration to operational and physical limitations. The constructed models, which is a cascade hydropower reservoirs system have been tested and evaluated in the Cameron Highland and Batang Padang in Malaysia. Results: According to the given results, usage of DHP for hydropower reservoir system operation could increase the power generation output to nearly 13% in the studied reservoir system compared to present operating policy (TNB operation). This substantial increase in power production will enhance economic development. Moreover, the given results of single and multi-reservoir systems affirmed that hedging policy could manage the single system much better than operation of the multi-reservoir system. Conclusion: It can be summarized that DHP is an efficient and feasible policy, which could be used for the operation of existing or new hydropower reservoir system.

1-7

Authors: Sakine Shekoohiyan, Gholamreza Moussavi , Samira Mojab , Ahmad Alahabadi

Background: The efficacy of NH4Cl-induced activated carbon (NAC) was examined in order to adsorb RR198, an azo reactive model dye, from an aqueous solution. Methods: The effects of pH (3 to 10), adsorbent dose (0.1 to 1.2 g/L), dye concentration and contact time on the adsorption efficiency were investigated. Results: The results showed that the removal of dye was highest at a solution pH of 7 and a powder dose of 1.1 g/L. The 85.9%, 72.6% and 65.4% removal of RR198 was obtained for a concentration of 25, 50 and 100 mg/L, respectively, at a relatively short contact time of 30 minutes, and at optimum pH and NAC concentrations of 1 g/L. The experimental data for kinetic analysis illustrated a best fit to the pseudo-second-order model. The study data on equilibrium were modeled using Langmuir, Freundlich and Dubinin–Radushkevich models; the Langmuir equation provided the best fit for the data. Conclusion: Therefore, the NAC appears to be an efficient and appropriate adsorbent for the removal of reactive azo dyes from waste streams.

15-21

Authors: Samira Namavari , Farid Moeinpour

Background: Lead (Pb) is a heavy metal that is widely utilized in industries. It contaminates soil and groundwater. Its non-biodegradability, severe toxicity, carcinogenicity, ability to accumulate in nature and contaminate groundwater and surface water make this toxic heavy metal extremely dangerous to living beings and the environment. Therefore, technical and economic methods of removing Pb are of great importance. This study evaluated the efficiency of Ni0.5Zn0.5Fe2O4 magnetic nanoparticles supported by Aloe vera shell ash in removing Pb from aqueous environments. Methods: The adsorbent was characterized by several methods, including x-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR). Then, the potential of Aloe vera shell ash-supported Ni0.5Zn0.5Fe2O4 magnetic nanoparticles to adsorb Pb (II) was investigated. To determine the amount of lead absorbed by this adsorbent, different pHs (2, 4, 5, and 6), adsorbent doses (0.01-0.40 g), Pb concentrations (5, 10, 20, 30, 40, 50, 60, 80, 100, 200, 300, and 600 mg/L), and exposure times (0, 5, 10, 15, 20, 30, 40, 50, and 60 minutes until reaching equilibrium) were tested using an atomic absorption spectrometer (Varian-AA240FS). Residual concentrations of Pb were read. Results: The results show that a time of 15 minutes, pH value of 9, and adsorbent dose of 0.2 g are the optimum conditions for Pb (II) removal by this adsorption process. Increasing the initial concentration of Pb (II) from 5 to 600 mg/L decreased removal efficiency from 98.8% to 73%. The experimental data fit well into the Freundlich isotherm model (R2 = 0.989). Conclusion: Ni0.5Zn0.5Fe2O4 magnetic nanoparticles supported by Aloe vera shell ash comprise a low-cost, simple, and environmentally benign procedure. The maximum monolayer adsorption capacity based on the Langmuir isotherm (R2 = 0.884) is 47.2 mg g-1. The prepared magnetic adsorbent can be well dispersed in aqueous solutions and easily separated from them with the aid of an external magnet after adsorption. The process for purifying water presented here is clean and safe. Therefore, this adsorbent is applicable to managing water pollution caused by Pb (II) ions.

29-34

Authors: Mohammad Malakootian , Behnam Hatami, Shidwash Dowlatshahi , Ahmad Rajabizadeh

Background: Microalgal lipid is a promising feedstock for biodiesel production. The aim of the present study was to investigate the effects of cultivation temperature on the growth and lipid accumulation properties of Nannochloropsis oculata microalgae. Methods: Nannochloropsis oculatacan grow in a wide range of temperatures (5 ~ 35°C). Late in the stationary growth phase of microalgae, biomass production and lipid accumulation were measured. The methanol-chloroform extraction method was used to extract total lipids from dried cells. The direct esterification method was used to measure fatty acids. Constituents were identified by gas chromatography. Results: The results show that the maximum specific growth rate at 20°C was 0.1569 day-1, and the maximum biomass production of microalgae at 25°C was 2.2667 g/L. The highest percentage of biomass conversion into lipid (35.71%) occurred at 30°C. Maximum lipid productivity was seen at temperatures of 15°C, 20°C, and 25°C, but the analysis of fatty acids in the three temperatures shownare maximum accumulations of triglycerides in the microalgae cells at 20°C and 25°C. Conclusion: In the cultivation of Nannochloropsis oculata, the optimal temperature range for maximum efficiency in biodiesel production from lipids is 20°C to 25°C.

41-46

Authors: Ali Asghar Najafpoor, Sina Dousti , Ahmad Joneidi Jafari , Ahmad Hosseinzadeh

Background: Phenol is an organic pollutant found in industrial effluents that is very toxic to humans and the environment. This study used pomegranate peel ash as a natural absorbent to remove phenol from aqueous solutions. Methods: In this study, pomegranate peel ash in different doses was used as a new adsorbent for the removal of phenol. The effects of contact time, pH, adsorbent dose and initial phenol concentration were recorded. Then, the adsorption data was described with Langmuir and Freundlich adsorption isotherms; Excel software was used for data analysis. Results: The highest percentage of phenol adsorption was observed at pH = 7. The optimum amount of adsorbent was 0.6 g/l, and after 120 minutes, the process reached an equilibrium state. The adsorption of phenol decreased following an increase in the pH of the solution. It was also observed that contact time significantly affected the rate of phenol adsorption. The experimental data fit much better in the Freundlich (R2 = 0.9056) model than in the Langmuir (R2 = 0.8674) model. Conclusion: Pomegranate peel ash has the potential to be utilized for the cost-effective removal of phenol from aqueous solutions.