Sajad Shahabi; Masoud Reza Hessami Kermani
Volume 2, Issue 1 , March 2015, , Pages 122-130
Abstract
In this paper we present a method to perform flood frequency analysis (FFA) when the assumption of stationary is not important (or not valid). A wavelet transform model is developed to FFA. A full series is applied to FFA using two different wavelet functions, and then a combined method is investigated. ...
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In this paper we present a method to perform flood frequency analysis (FFA) when the assumption of stationary is not important (or not valid). A wavelet transform model is developed to FFA. A full series is applied to FFA using two different wavelet functions, and then a combined method is investigated. In the combined method, all discharge data which were less than the lowest value of annual maximum (AM) discharge were removed. Furthermore, energy function of wavelet was used for FFA. The data was decomposed into some details and an approximation through different wavelet functions and decomposition levels. The approximation series was employed to FFA. This was performed using discharge data from of the Polroud River in Iran. This paper analysis was performed on the daily maximum discharge data from the Tollat station in the north of Iran. Data from 1975 to 2007 was evaluated by wavelet analysis. The study shows that wavelet full series model results (density function) are too small in compared with the results of combined method and they are both lesser than traditional methods (AM and PD). In other hand the results of energy function method is closed to the combined method when they are compared with the full series data results. These wavelet models were assessed with the AM and PD methods. The concrete result of this paper is that, the basin hydrologic conditions and data's nature are very important parameters to improve FFA and to select the best method of analysis.
Mahdi Majedi-Asl; Rasoul Daneshfaraz; Mehdi Fuladipanah; John Abraham; Mohammad Bagherzadeh
Abstract
In this paper, two groups of datasets including Froehlich (1988) and USGS were implemented to simulate scour depth for bridge piers of three shapes (circular, sharp-nose and rectangular) using support vector machine (SVM) algorithm. The results of the SVM were compared with gene expression programming ...
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In this paper, two groups of datasets including Froehlich (1988) and USGS were implemented to simulate scour depth for bridge piers of three shapes (circular, sharp-nose and rectangular) using support vector machine (SVM) algorithm. The results of the SVM were compared with gene expression programming (GEP) and the non-linear regression model. Independent parameters extracted using dimensional analysis were Froud number (Fr), the ratio of pier length to pier width (L/b), the ratio of sediment particle diameters (d50/d84), the ratio of sediment mean size to pier width (d50/b) and attack angle of water flow (α). Different combinations of independent variables were used to achieve optimum performance of the simulator. The results showed that among three simulators, the SVM algorithm had the best performance to predict local scour depth. The sensitivity analysis revealed that among independent parameters, the descending order of effectivity was Fr, sediment size, L/b, and α.
Nima Asadi; Hamid Soleimanimehr; Aida Mohammad Sadegh
Abstract
Due to the quality of the water entering the water purifiers, sometimes the amount of solutes and hardness in the water is so high that after a short time, these systems become clogged or full. To solve this problem. Several methods have been proposed in this study, acid injection and its effect on reverse ...
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Due to the quality of the water entering the water purifiers, sometimes the amount of solutes and hardness in the water is so high that after a short time, these systems become clogged or full. To solve this problem. Several methods have been proposed in this study, acid injection and its effect on reverse osmosis system by wave software have been investigated. To ensure the condition and accuracy of the incoming water, the necessary tests were performed through the laboratory and the condition of the water and the number of ions and its salts were reported. By injecting acid into the inlet water, the pH value was reduced from 7.58, which is the normal pH of the water, to 5 by micrograph in 0.2 intervals, and after examination, the following results were obtained: With decreasing pH, the LSI number has a suitable decrease, so that at pH 6.1 and lower, the LSI number is negative and this indicates the lack of premature fouling. However, with this reduction, the acidic property of the treated water increases and the possibility of chemical corrosion of the industrial equipment used increases, on the other hand, by injecting acid and lowering the pH, the amount of TDS increased, which should be tried in different ways to minimize this amount. In comparison between injections of two acids performed under the same conditions, the amount of TDS at the time of H2SO4 injection at the pH limit was 10% less than the time of HCl injection.
Golshan Moradi; Farzad Dabirian; Laleh Rajabi; Ali Ashraf Derakhshan
Volume 2, Issue 2 , December 2015, , Pages 170-175
Abstract
Novel electrospun polyacrylonitrile (PAN) nanofiber mats and PAN fabric were chemically modified by dissolved anhydrous stannous chloride diethyl ether saturated with hydrogen chloride to contain aldehyde groups on their surfaces, which are suitable for ammonium adsorption due to their high adsorption ...
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Novel electrospun polyacrylonitrile (PAN) nanofiber mats and PAN fabric were chemically modified by dissolved anhydrous stannous chloride diethyl ether saturated with hydrogen chloride to contain aldehyde groups on their surfaces, which are suitable for ammonium adsorption due to their high adsorption affinity for NH4+ ion. Scanning electron microscopy (SEM), and Fourier-transform infrared spectra (FT-IR) were employed to characterize the prepared adsorbents. FT-IR spectra of these adsorbents confirmed that aldehyde groups are successfully formed on the surface of these chemically modified adsorbents. The aldehydic electrospun PAN nanofiber mats and aldehydic PAN fabric were assessed for their chelating property with NH4+ ion from aqueous solution. The effects of contact time on the amounts of ammonium adsorbed into the prepared adsorbents were also studied. Results revealed that ammonium removal increased by increasing contact time which finally reached equilibrium at about 3.5 h and 4 h for aldehydic electrospun PAN nanofiber mats and aldehydic PAN fabric, respectively. The adsorption performance of these prepared adsorbents for ammonium adsorption with initial ammonium concentration of 300 ppm via isotherm studies was investigated. The maximum ammonium removal efficiency (% R) was 48.33 and 70 for aldehydic electrospun PAN nanofiber mats and PAN fabric, respectively. Results indicated that the adsorption of ammonium by both prepared adsorbents followed Langmuir isotherm.
Kuljit Kaur; Vipan Kumar Sohpal
Volume 3, Issue 1 , June 2016, , Pages 217-221
Bahram Rezaei; Alireza Safarzade
Volume 3, Issue 2 , December 2016, , Pages 260-270
Nafiseh Aghababaei
Abstract
Reverse osmosis (RO) has proven to be an efficient technique for desalination of seawater, brackish water, and reclaimed wastewater. However, the performance of RO desalination is sensitive to its design parameters and operating conditions. The purpose of this study was to modeling the removal of total ...
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Reverse osmosis (RO) has proven to be an efficient technique for desalination of seawater, brackish water, and reclaimed wastewater. However, the performance of RO desalination is sensitive to its design parameters and operating conditions. The purpose of this study was to modeling the removal of total dissolved solids (TDS) and Rejection of different ions are reported from water of city of Bandar Abbas. The main purpose of this work was the prepared drinking water intrusion model. In this study, a design method based on a simulation technique has been developed for optimizing RO desalination systems. The design is made with the use of Hydranautics design software version 2011. In this paper main focus is on the design part with software. The desalinated water obtained from reverse osmosis at a pressure of 1.2 MPa showed rejections of approximately 88.49 % for SO4 2 −, 61.42 % for TDS, 70.34 for Cl- and 50.85 for Na+. It shows that software gives accurate design with least possible error and user friendly so world while accepted. Blended water, produced by mixing groundwater and surface, was proposed to optimize the produce drinking water with a recovery rate of 95 %. Reverse osmosis is an excellent alternative for the supply of water in Bandar Abbas.
Bahram Bakhtiari; Mohamad Javad Khanjani; Ehsan Fadaei-Kermani
Abstract
Electronic weather stations have increased the availability of weather data for computing hourly and daily reference evapotranspiration (ETo). There is a rational question applied for different climate conditions whether the sum of hourly ETo computation may differ from direct computed daily ETo. In ...
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Electronic weather stations have increased the availability of weather data for computing hourly and daily reference evapotranspiration (ETo). There is a rational question applied for different climate conditions whether the sum of hourly ETo computation may differ from direct computed daily ETo. In this study for the Kerman area, daily and hourly reference crop water consumption were estimated by the Penman-Monteith equation, using meteorological data collected in one hour intervals by an automatic weather station at Iranian Academic Center for Education, Culture and Research (ACECR), Kerman city, Iran. The direct computed daily evapotranspiration values were compared with the sum of hourly computed evapotranspiration values. Results indicated that there is a distinctive difference between the values as calculated for this experimental station. Based on two tail 95% level t-test, the direct computed daily ETo was greater than the sum of hourly computed ETo. Finally, the relationship of daily and sum of hourly ETo for the study area were presented which can be utilized to compare and convert the computed values.
Mazen Hamada; Hossam Adel Zaqoot; Ahmed Abu Jreiban
Abstract
This paper is concerned with the use of artificial neural network and multiple linear regression (MLR) models for the prediction of three major water quality parameters in the Gaza wastewater treatment plant. The data sets used in this study consist of nine years and collected from Gaza wastewater treatment ...
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This paper is concerned with the use of artificial neural network and multiple linear regression (MLR) models for the prediction of three major water quality parameters in the Gaza wastewater treatment plant. The data sets used in this study consist of nine years and collected from Gaza wastewater treatment plant during monthly records. Treatment efficiency of the plant was determined by taking into account of influent input values of pH, temperature (T), biological oxygen demand (BOD), chemical oxygen demand (COD) and total dissolved solids (TSS) with effluent output values of BOD, COD and TSS. Performance of the model was compared via the parameters of root mean squared error (RMSE), mean absolute percentage error (MAPE) and correlation coefficient (r). The suitable architecture of the neural network model is determined after several trial and error steps. Results showed that the artificial neural network (ANN) performance model was better than the MLR model. It was found that the ANN model could be employed successfully in estimating the BOD, COD and TSS in the outlet of Gaza wastewater treatment plant. Moreover, sensitive examination results showed that influent TSS and T parameters have more effect on BOD, COD and TSS predicting to other parameters.
Hamed Azimi; Majeid Heydari; Saeid Shabanlou
Abstract
Dam break is an important phenomenon which significantly affects the environment as well as the inhabitants of the downstream areas of the dam. In the present study, the hydraulic break of Malpasset dam as a result of sudden flooding was simulated numerically using the FLOW-3D software. The two-equation ...
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Dam break is an important phenomenon which significantly affects the environment as well as the inhabitants of the downstream areas of the dam. In the present study, the hydraulic break of Malpasset dam as a result of sudden flooding was simulated numerically using the FLOW-3D software. The two-equation k-ε turbulence models and RNG k-ε turbulence model were used to simulate the flow field turbulence. Also, the free-surface variations of the flow were simulated using the VOF (Volume of Fluid) scheme. The results obtained from the numerical model were in good agreement with those predicted by the EDF model. Based on the simulation results, the maximum pressure occurred at the lower layers of the flow and reduced as the free surface of the flow was approached. The maximum pressure increased at each point in time. The maximum longitudinal velocity occurred at the front of the advancing wave resulting from break of the dam, and subsequently decreased due to the increasing depth at the downstream of the dam. Additionally, the effects of obstacles with different shapes on the flow pattern arising from dam break (due to sudden flooding) were also investigated. Examination of these effects revealed that the cubic obstacle placed obliquely in the flow direction produced the maximum separation region at its downstream. Conversely, this separation region was eliminated completely when a cylindrical obstacle was used. The maximum and minimum Froude numbers were obtained for the flow encountering the perpendicular cubic obstacle and the flow impacting the cylindrical obstacle, respectively.
Reza Jalilzadeh Yengejeh; Jafar Morshedi; Razieh Yazdizadeh
Volume 1, Issue 1 , March 2014, , Pages 23-27
Abstract
Pollution sources into the water, the necessity of qualitative studies of water resources is one of the most important new challenges for mankind in almost every parts of the world. Dissolved oxygen (DO) and Biochemical Oxygen Demand (BOD) are among parameters of water quality indexes which are considered ...
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Pollution sources into the water, the necessity of qualitative studies of water resources is one of the most important new challenges for mankind in almost every parts of the world. Dissolved oxygen (DO) and Biochemical Oxygen Demand (BOD) are among parameters of water quality indexes which are considered as water pollution indexes. In the present research, DO and BOD of Dez River basin water (in Dezful City) were studied and zoned by applying the Geographic Information System (GIS). Nine stations were considered for sampling during six months in 2013. The results indicate that the average maximum amount of DO at an average of six months is 8.47 mg/l in S1 station and the minimum amount is 1.71 mg/l in S8 station. The average maximum and minimum amounts for BOD during an average of six months are orderly 150.83 mg/l in S8 and 3.16 mg/l in S1. By a qualitative zoning, places that are prone to pollution can be recognized and measures can be taken for monitoring and preserving such areas. Decreasing the amount of water pollution and controlling the pollution sources are possible by adoption appropriate measures.
Amir Hossein Salimi; Sayed Farhad Mousavi; Saeed Farzin
Abstract
Rivers serve as one of the main sources of water supply. Human activities, salts in the soil and rocks and urban runoffs, as well as air contaminants, lead to contamination of river water. In this research, Gamasiab river, which is the upstream of Karkheh river, was selected as a case study. Sixteen ...
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Rivers serve as one of the main sources of water supply. Human activities, salts in the soil and rocks and urban runoffs, as well as air contaminants, lead to contamination of river water. In this research, Gamasiab river, which is the upstream of Karkheh river, was selected as a case study. Sixteen stations were selected along this river to determine the sulfate content of water samples. Samples were taken from these stations according to the guidelines (ISO 5667-5, 1991). The samples were then transferred to laboratory and were filtered using nanoparticles of natural clinoptilolite. The X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) andFourier-Transform Infrared Spectroscopy (FTIR) images were taken to determine the properties of the adsorbents. The images indicated that the selected methods for preparation of the nanoparticles were correctly implemented. After examining the filtered samples, the adsorption efficiency was 95% for clinoptilolite. Whatman filter paper 42 was used for desorption of the natural nano-clinoptilolite. Adsorption isotherm of the natural clinoptilolite was Freundlich with a determination coefficient of R2=0.918. By using Design Expert software and assumption of two pH factors and adsorbent to contaminant ratios (D/C), optimum adsorption points were found and theoretical adsorption values were calculated as well. Results showed that the optimum adsorption points for clinoptilolite were pH = 9.51 (mg)adsorbent/(mg/l)initial and D/C=18.91(mg)adsorbent/(mg/l) initial. Comparison of the adsorbent function indicated that clinoptilolite had good performance in removal of sulfate ion from river water samples.
Mohammad Beidaghdar; Ebrahim Fataei; Behnam Khanizadeh; Ali Akbar Imani
Abstract
Pollution from industrial effluents is more diverse and complex than municipal wastewater due to the use of thousands of new chemical compounds in industry every year. Subsequent introduction of small quantities of these compounds into water streams through industrial effluents has complicated water ...
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Pollution from industrial effluents is more diverse and complex than municipal wastewater due to the use of thousands of new chemical compounds in industry every year. Subsequent introduction of small quantities of these compounds into water streams through industrial effluents has complicated water pollution problems and posed many challenges in removing contaminants from water. The purpose of the present study was to remove phenol contaminants from the effluent of petrochemical wastewater treatment plants using advanced photochemical oxidation method (ultraviolet/hydrogen peroxide/ozone) in a laboratory scale. The experiments were performed using UVC light, 30 % H2O2 as oxidizer and phenol (100 mg/L). The effective parameters studied in phenol removal included pH, H2O2concentration, solution temperature and UVC irradiation time. The experimental results showed an increase in phenol removal efficiency with increasing H2O2 concentration up to 400 mg/L while decreasing with increasing oxidizerconcentration to 500 mg/L, thus suggesting a concentration of 400 mg/L as the optimal value. Using a flow rate of 200 mg/L of ozone for 80 min, by optimizing other conditions, increased the phenol removal efficiency by 98 %. The phenol removal efficiency was much higher at acidic conditions than at alkaline and neutral ones. The phenol content decreased significantly with increasing contact time. In other words, prolonged contact time increased the phenol removal efficiency in the tested sample. The highest phenol removal efficiency (75.7 %) occurred at the pH value of 4 and the phenol removal efficiency in the sample decreased with increasing pH value. Prolonged contact time caused more phenol concentration to be removed from the test sample, so that 69.8 % of the phenol concentration in the sample was reduced. The results of this study showed that advanced oxidation reduced the phenol content in the analyzed sample. To conclude, the advanced oxidation methods can be useful in the process of treating petrochemical wastewater andeffluent of units containing toxic aromatic compounds such as phenol.
Yahya Choopan; Somayeh Emami
Abstract
Optimizing the crop cultivation pattern, in order to reduce water consumption, in arid and semi-arid regions such as Iran, due to water scarcity and food intake, is an essential solution for food intakes needs. Optimizing the crop cultivation pattern, in order to reduce water consumption, in arid and ...
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Optimizing the crop cultivation pattern, in order to reduce water consumption, in arid and semi-arid regions such as Iran, due to water scarcity and food intake, is an essential solution for food intakes needs. Optimizing the crop cultivation pattern, in order to reduce water consumption, in arid and semi-arid regions such as Iran, due to water scarcity and food intake, is an essential solution for food intakes needs. In this study, new methods based on the election algorithms (EA) and gray wolf optimizer (GWO) algorithms were used to determine the optimal cultivation pattern in Moghan plain during the statistical years of 2007-2016. The objective function in the agricultural sector was based on each product and its yield, net from each product and the cultivar. Then, maximization of the objective function was performed using GWO and EA algorithm. The results of using GWO algorithm in determining the optimal crop pattern in Moghan plain showed that using economic policies such as changing the cultivar pattern, we can obtain a better result compared to EA algorithm in the agricultural sector. In general, the results of GWO algorithm showed that in the Moghan plain with 0.9, 140 billion rials, that is, about 42 % will have economic growth. In sum, the results showed that GWO algorithm with high values of statistical criteria (R2=0.96, RMSE=0.022 and NSE=0.75) has a higher efficiency in optimizing the crop cultivation pattern of Moghan plain, which can be applied to the correct planning for other cultivation areas to be employed.
Amin Hajiahmadi; Mojtaba Saneie; Mehdi Azhdari Moghadam
Volume 1, Issue 2 , June 2014, , Pages 80-85
Abstract
In this century due to population growth, the use of river water has become more complicated. Since most rivers pass across loose and erodible areas, they always act as the most important factor of transferring eroded materials from the solid crust of the earth. Vortex basins are among the solutions ...
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In this century due to population growth, the use of river water has become more complicated. Since most rivers pass across loose and erodible areas, they always act as the most important factor of transferring eroded materials from the solid crust of the earth. Vortex basins are among the solutions known for the high-speed separation of solids from liquids (filtration). One of the problems of such basins is the settling of sediments in their floor which necessitates the performance of required investigations and researches in order to present a method to exclude or reduce such sediments. The present research presents and investigates a plan to resolve this problem. This paper proceeds to perform an experimental study on the effect of a group of curvature submerged vanes in different positions at the floor of a vortex settling basin with a 90ᵒ radial section on the efficiency of the basin. The experiments were performed on a physical model with 96 cm height, 206 cm diameter, 10% floor slope, tow discharges of 45 and 37 L/S, and three orifices with 59, 46 and 36 mm diameters. Uniform aggregate (d50=0.22 mm) was applied in experiments. The efficiency of the basin was determined in six different positions of curvature submerged vanes and the values were investigated compared to each other. The results of experiments showed that the efficiency is higher when the vanes are placed more distant from the orifices while changes in orifice diameter and discharge considerably effect on the efficiency.
Mostafa Bayesteh; Arash Azari
Abstract
One of the most important issues in planning and managing water resources is the accurate estimation of monthly input discharge of the reservoirs in the future years, which is always associated with uncertainty. To cover these uncertainties, synthetic stream flow data generation models have been used ...
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One of the most important issues in planning and managing water resources is the accurate estimation of monthly input discharge of the reservoirs in the future years, which is always associated with uncertainty. To cover these uncertainties, synthetic stream flow data generation models have been used by various researchers to generate stochastic time series. The computational basis of different stochastic models for generating monthly data has been different and this can have a significant effect on their performance. Therefore, selection of the best model of stochastic data generation for accurate planning and management of a water resource system is one of the major concerns of water resources specialists. In this research, the performance of parametric models of synthetic stream flow generation including Thomas-Fiering, Fragment and ARMA (1,1) and ARMA (1,2) combined with Valencia-Schaake and Mejia and Rousselle models were compared and evaluated. For this purpose, 30 years data of monthly discharge of Marun river in Khuzestan province were used and 900 synthetic monthly flow time series were generated using each of the models mentioned above. Based on the obtained results, the ARMA (1,2) model combined with the Valencia-Schaake model was recognized as the best model, considering the very desired performance in preserving the statistical parameters of historical data and generating maximum and minimum discharges related to wet and dry periods in different probabilities. This model can be used with greater confidence to analyze river systems and reservoirs, manage drought and apply water rationing rules in future drought conditions.
Akram Fatemi
Volume 2, Issue 1 , March 2015, , Pages 131-136
Abstract
The suitability of Gharasoo River water for irrigation uses was evaluated in Kermanshah city, Iran. Long-term datasets including major cations, anions and other parameters such as electrical conductivity (EC), total dissolved solids (TDS) were analyzed. Sodium absorption ratio (SAR), magnesium ratio ...
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The suitability of Gharasoo River water for irrigation uses was evaluated in Kermanshah city, Iran. Long-term datasets including major cations, anions and other parameters such as electrical conductivity (EC), total dissolved solids (TDS) were analyzed. Sodium absorption ratio (SAR), magnesium ratio (MR), % sodium (%Na), residual sodium carbonate (RSC), permeability index (PI) and Ca2+/Mg2+ ratio were calculated to evaluate the suitability of Gharasoo River water for irrigation purposes. Piper trilinear diagram reveals that the water is the alkaline earth than alkaline type. Based on the SAR values plotted in the U.S. Salinity Laboratory Staff diagram, Gharasoo River water belongs to class medium-salinity hazard and low-sodium hazard (C2S1) which indicates that there is no limitation to use water for irrigation. According to FAO method, soil degradation risk was low in the study area and potential plant nutritional disorders will not be expected. Different indices showed the regional sodicity problems: the high risks for %Na, PI, Ca2+/Mg2+ and magnesium ratios for soil and clogging of irrigation systems only at one station.
Mohammad Sadegh Talebi; Mehran Fatemi
Abstract
Growing water demand in various sectors including agriculture, industry, drinkingwater and eventually increasing production and risk of pollution have imposedmounting pressure on water resources. The relative stability of renewable waterresources makes it necessary to pay special attention to the conservation ...
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Growing water demand in various sectors including agriculture, industry, drinkingwater and eventually increasing production and risk of pollution have imposedmounting pressure on water resources. The relative stability of renewable waterresources makes it necessary to pay special attention to the conservation andoptimal use of these resources, especially in desert areas such as Iran, and thisrequires careful and principle planning for the optimal use of existing waterresources. In this research, a descriptive-analytical method was adopted. The datawere collected from fifteen wells during an 8-year period (2010-2017). TheKolmogorov-Smirnov method was recruited to assess the normality of datadistribution. Also, since the classical data (water quality data) did not take intoaccount the spatial distribution of groundwater quality parameters, we used thegeostatistics for this purpose. The results suggested that the dominant groundwatertype in the Bahadoran region was sodium chloride (NaCl), which is highly volatile.This volatility can be attributed to cationic and anionic exchanges as well as thedissolution of salt and gypsum in the neogene formation of the region. On the otherhand, overexploitation and increasing drainage of agricultural, residential and evenindustrial wastewaters in the plain water resources have drastically influenced thegroundwater quality. In the second period of the studied period (2012-2013), thelevel of maximum classes of most parameters has increased compared to the firstperiod, and these changes have increased with a greater slope in the third period.According to the studies, the most important formations in terms of reservoir rock,feed source of alluvial plains and groundwater quality are lower cretaceouscalcareous sediments of Bahadoran.
Mina Doltshah; Ali Akbar Zinatizadeh; Sirus Zinadini; Hadis Zangeneh; Shohreh Azizi; Mohamed Abdulgader; Malik Maaza
Abstract
In this study, the polyethersulfone (PES) membranes were established by surface modification using C, N codoped-TiO2/WO3 (LTW) photocatalytic nanocomposite to amelioration of the membrane performance in terms of antifouling and self-cleaning properties. The nanocomposite membranes were characterized ...
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In this study, the polyethersulfone (PES) membranes were established by surface modification using C, N codoped-TiO2/WO3 (LTW) photocatalytic nanocomposite to amelioration of the membrane performance in terms of antifouling and self-cleaning properties. The nanocomposite membranes were characterized by ATR-FTIR, SEM, AFM, and water contact angle (WCA). The photocatalytic membranes' performance was evaluated using assessment of the pure water flux (PWF), antifouling behavior, photoactivity, and long-term filtration. The membrane modification improved morphology and hydrophilicity of the membranes surface, contributing to the enhanced permeability (PWF of 49.65 kg/m2.h), and substantial antifouling property (FRR of 96.96 %) as well as photoactivity (94.36 % dye removal) of the optimal photocatalytic membrane (M3 membrane). The long-term filtration of the optimal membrane represented its high performance and noteworthy antifouling resistance.
Mohammad Eisapour Chanani; Nader Bahramifar; Habibollah Younesi
Volume 2, Issue 2 , December 2015, , Pages 176-182
Abstract
The main objective of this study was to synthesize an environmentally friendly nano-structural adsorbent. These nano magnetic particles can be applied to remove heavy metal ions from industrial wastewater because the surface of the particles is covered with SiO2, and the SiO2 is inactive and can adsorb ...
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The main objective of this study was to synthesize an environmentally friendly nano-structural adsorbent. These nano magnetic particles can be applied to remove heavy metal ions from industrial wastewater because the surface of the particles is covered with SiO2, and the SiO2 is inactive and can adsorb heavy metal ions. Tests were then conducted to study the adsorption of Cu(II) ions onto Fe3O4@SiO2 from an aqueous solution for the effect of contact time, adsorbent dose, solution pH and concentration of metal ions in batch systems. The equilibrium data were analyzed using the Langmuir and Freundlich isotherm by nonlinear regression analysis and found that the adsorption isotherm data will better fit by Langmuir model. The maximum adsorption capacities of Cu (II) were 47 mg/g. Fe3O4@SiO2 was regenerated and found to be suitable for reuse in successive adsorption-desorption cycles 5 times without significant loss of adsorption capacity.
Zahra Shaykhi Mehrabadi
Volume 3, Issue 1 , June 2016, , Pages 222-231
Mojtaba Ahmadi; Pegah Amiri
Volume 3, Issue 2 , December 2016, , Pages 271-276
Maryam Habibi; Ali Akbar Zinatizadeh; Mandana Akia
Abstract
The degradation of an industrial wastewater (Tire Cord factory) with low BOD5/COD ratio (0.1-0.2) was investigated using advanced oxidation processes (AOPs) (i.e. hydrogen peroxide, UV/H2O2, O3/H2O2 and UV/O3/H2O2 treatments). In order to investigate the effects of influential variables on the process ...
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The degradation of an industrial wastewater (Tire Cord factory) with low BOD5/COD ratio (0.1-0.2) was investigated using advanced oxidation processes (AOPs) (i.e. hydrogen peroxide, UV/H2O2, O3/H2O2 and UV/O3/H2O2 treatments). In order to investigate the effects of influential variables on the process performance, four independent factors involving two numerical factors (initial H2O2 concentration and initial pH) and two categorical factors (ozonation and UV irradiation) were selected. The process was modeled and analyzed using response surface methodology (RSM). The region of exploration for the process was taken as the area enclosed by initial H2O2 concentration (0-20 mM) and initial pH (3-11) boundaries at three levels. For two categorical factors (ozonation and UV irradiation), the experiments were performed at two levels (with and without application of each factor). Two dependent parameters (TCOD removal and BOD5/COD ratio) were studied as the process responses. As a result, initial H2O2 concentration showed a reverse impact on the responses; an increasing effect at low concentrations (0-10 m mol/l) and a decreeing effect at higher concentrations (10-20 m mol/l). The maximum and minimum the responses were obtained at H2O2 concentration of 10 and 20 mmol/l and initial pH 3 and 11, respectively. O3/UV/H2O2 system showed better performance with 32 % for TCOD removal efficiency and 0.41 for BOD5/COD ratio.
Mehdi Nezhad Naderi; Omid Zolfaghari
Abstract
A bubble curtain is a system that produces bubbles in a deliberate arrangement inwater. The technique is based on bubbles of air (gas) being let out under thewater surface, commonly on the bottom. When the bubbles rise they act as abarrier, a curtain for prevention of the spreading of particles and othercontaminants. ...
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A bubble curtain is a system that produces bubbles in a deliberate arrangement inwater. The technique is based on bubbles of air (gas) being let out under thewater surface, commonly on the bottom. When the bubbles rise they act as abarrier, a curtain for prevention of the spreading of particles and othercontaminants. In this paper is paid to applications of bubble curtain in protectionof environment of offshore. Due to the salt water intrusion in Panama navigablechannel is causing environmental damage. Construction of bubble curtains alongthe channel can be studied as a playbook. In this study, two-phase flow issimulated with simulation software Fluent6.3 for freshwater input from the left,saltwater input from the right, air from several vertical bubbles and water injection.The model is solved by using of two-phase Mixture pattern. For problem solving isused the k-𝜺 turbulence model. The air inlet velocity is considered 0.6 meters persecond and again 0.2 meters per second. By using air curtains (bubbles) can beprevented salt water intrusion and the density also be reduced. In this paper themultiphase flow is simulated by computational fluid dynamics method in Panamachannel.
Negin Shaabani; Sirus Zinadini; Ali Akbar Zinatizadeh
Abstract
The present work was concentrated to study the ability of nanofiltration membrane as a treatment method of algal colored wastewater discharge from Islamabad refinery, Kermanshah, Iran. The polyether sulfone nanofiltration membrane was modified with sodium dodecyl sulfate (SDS) as an anionic surfactant ...
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The present work was concentrated to study the ability of nanofiltration membrane as a treatment method of algal colored wastewater discharge from Islamabad refinery, Kermanshah, Iran. The polyether sulfone nanofiltration membrane was modified with sodium dodecyl sulfate (SDS) as an anionic surfactant and applied for treatment of colored wastewater. Water contact angle Scanning electron microscopy (SEM) and were applied to characterization of prepared membranes. The pure water flux, relative flux reduction as a parameter that represents antifouling property of membrane and also dye rejection were studied by dead-end and cross-flow filtration system in the present research. The period of the filtration time was extended about 6 hours to evaluate the stability and flux reduction of membrane. The results indicated 23.26% flux reduction was observed for modified membrane that confirms the antifouling property of prepared membrane. The results demonstrated that the permeate was completely transparent (100% dye removal, 98.2% turbidity removal), and the pure water flux was enhanced for modified membrane to 27.21 (Kg/m².h). In the present research nanocomposite polymeric membrane are introduced as an appropriate option for the treatment of natural colored wastewater.