Fariba Oulad; Sirus Zinadini; Ali Akbar Zinatizadeh; Ali Ashraf Derakhshan
Abstract
The filtration performance of coupling modified polyethersulfone (PES) membrane by coupling diazonium reaction and 25 wt.% aniline modified polyethersulfone (APES /PES) blended membrane by radically diazonium reaction for treating of licorice aqueous solution was verified systematically and compared ...
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The filtration performance of coupling modified polyethersulfone (PES) membrane by coupling diazonium reaction and 25 wt.% aniline modified polyethersulfone (APES /PES) blended membrane by radically diazonium reaction for treating of licorice aqueous solution was verified systematically and compared to bare NF PES membrane. The effect of operational pressure and cross-flow velocity on permeation flux and rejection were evaluated. All experiments were employed in a lab scale cross-flow filtration equipment with effective area of 40 cm2. The applied operational pressure and cross-flow velocity were diverse from 6 to 12 bar and 0.5 to 2.5 cm/s respectively. The obtained results of rejection for licorice aqueous solution were between 84.4% to 99.2%. The durability and antifouling performance of membranes were assessed through long-term filtration of licorice aqueous solution.
Zahra Rahimi; Ali Akbar Zinatizadeh; Sirus Zinadini
Volume 1, Issue 1 , March 2014, , Pages 13-17
Abstract
An innovative method based on the membrane bioreactor (MBR) technology was developed as a potential remedy for the water shortage. MBRs attracted much attention in the field of wastewater treatment and reuse. It is reported from many researchers that membrane bioreactor technology is feasible and an ...
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An innovative method based on the membrane bioreactor (MBR) technology was developed as a potential remedy for the water shortage. MBRs attracted much attention in the field of wastewater treatment and reuse. It is reported from many researchers that membrane bioreactor technology is feasible and an efficient method for the treatment of wastewater. However, MBRs are faced to membrane fouling which lead to short membrane lifetime and increase operating costs. Here we modified polyethersulfone (PES) ultrafiltration membrane by blending of O-carboxymethyl chitosan/ Fe3O4 nanoparticles in a PES solution (14% polymer weight) and casted by a phase inversion process. Membranes with four different weight percentages of O-Carboxymethyl chitosan bound Fe3O4 magnetic nanoparticles (OCMCs-Fe3O4) to PES of 0.05, 0.10, and 1 wt. % were tested. The OCMCS-Fe3O4 nanoparticles were prepared by the binding of carboxymethyl chitosan (CC) onto the surface of Fe3O4 magnetic nanoparticles, which were prepared by co-precipitating method. The synthesized nanoparticles were characterized by the Fourier transform infrared (FTIR) technique. Moreover, OCMCS-Fe3O4 nanoparticales blend membranes were also characterized using scanning electron microscopy (SEM), and permeation tests. Antifouling performance was studied using activated sludge as a biological suspension and measuring the pure water flux recovery ratio (FRR). The 0.1 wt. % OCMCS-Fe3O4-PES membrane revealed the highest FRR value (89%). The results exhibited that addition of OCMCS-Fe3O4 nanoparticales lead to membranes with high pure water flux compared to the unmodified PES membrane.
Mohammad Yousefi; Ehsan Jabbari; Mehdi Sedighi
Abstract
Water shortages and pollution are so severe that the last decade has been called the international decade for water. In water treatment plants, coagulation and flocculation are used to remove turbidity. This study examined the use of naturalcoagulants and its efficiency compared with existing coagulants. ...
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Water shortages and pollution are so severe that the last decade has been called the international decade for water. In water treatment plants, coagulation and flocculation are used to remove turbidity. This study examined the use of naturalcoagulants and its efficiency compared with existing coagulants. Response surface methodology was used to design the experiments. Type of coagulant and coagulant aid, as well as pH, were considered important factors during experiments. Results of the tests indicate that pH has a significant impact on turbidity removal. The combination of chitosan and polyaluminum chlirode reduces water turbidity effectively. A combination of polyaluminum chlirode (7.6 mg/L) and chitosan (9.28 mg/L) at pH= 8.52 removed 99.85 % of the turbidity. Accordingly, the combined use of polyaluminum chlirode and chitosan reduced the amount of material and enhanced turbidity removal.
Majid Rahimpour; Mohamad Reza Madadi
Abstract
Friction factor is an important hydraulic parameter for design of pipeline systems. There are several formulations for calculating the friction factor, among which Colebrook–White equation is the most accurate and repute formula. Owing to the implicit nature of friction factor in Colebrook–White ...
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Friction factor is an important hydraulic parameter for design of pipeline systems. There are several formulations for calculating the friction factor, among which Colebrook–White equation is the most accurate and repute formula. Owing to the implicit nature of friction factor in Colebrook–White equation, iterative methods are required to calculate this factor. In this study, Regula Falsi iterative numerical scheme was used to solve the implicit nonlinear equation of friction factor in the Mathematica programming tool. Case examples including different series and parallel pipeline systems were presented and solved. The results indicated high capability of Regula Falsi method in solving both the parallel and series systems. It was found that the solution by Mathematica differ significantly from conventional methods and can be desirably used for solving different hydraulic problems. The use of Mathematica with its huge features permits the researchers to be more professional in formulations of engineering problems and interpretations of results.
Setareh Heydari; Jafar Mamizadeh; Javad Sarvarian; Goodarz Ahmadi
Abstract
The optimal design of urban water distribution networks is a significant issue that has been of critical interest in the water industry for many years. The optimal design of the distribution network aims to find the best solution for transferring water from the reservoir to consumers at the lowest cost. ...
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The optimal design of urban water distribution networks is a significant issue that has been of critical interest in the water industry for many years. The optimal design of the distribution network aims to find the best solution for transferring water from the reservoir to consumers at the lowest cost. In this study, optimization of the water distribution network (ZONE 1 of Ilam city, Iran) was performed using the fast messy genetic algorithms (FMGA) tool in the hydraulic model for three different pipe networks. Also, these networks were optimized by using a combination of EPANET and an in-house developed binary genetic algorithm in MATLAB. The costs of the optimized hydraulic networks of polyethylene and polypropylene pipes were lower, respectively, by 20.56 % and 52.94 % compared to the consulting company's original designs, while for the glass fiber reinforced plastic pipe (GRP) pipe network the cost increased by 12.61 %. Also, the results of a developed algorithm for polyethylene pipe decreased by 22.13 %.
Ehsan Fadaei Kermani; Gholam Abbas Barani; Mohamad Javad Khanjani
Volume 1, Issue 2 , June 2014, , Pages 66-73
Abstract
In this paper, a new framework has been developed for compatibility analysis of predictive climatic variables distribution with reference evapotranspiration (ETo) in probabilistic analysis of water requirement. Initially, measured monthly meteorological data of four cities of Iran including Kerman, Shiraz, ...
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In this paper, a new framework has been developed for compatibility analysis of predictive climatic variables distribution with reference evapotranspiration (ETo) in probabilistic analysis of water requirement. Initially, measured monthly meteorological data of four cities of Iran including Kerman, Shiraz, Ramsar and Babolsar synoptic weather station recorded from 1961 to 2003 were considered based on De Martonne climate classification. Then monthly ETo was calculated using FAO-Penman-Moentith (FAO-PM), and optimum Probability distribution function (PDF) was determined. The Chow method has been used for frequency analysis, and compatibility analysis was implemented on results. Based on the results, the Generalized Pareto (GP) was selected as optimum PDF for ETo. Results showed that the optimum PDF for minimum and maximum temperature, solar radiation and relative humidity is GP which had compatibility with EToPDF. Eventually, obtained results in compatibility analysis framework were confirmed using Correlation analysis. The proposed methodology developed in this research has application capability in probability scheduling of design water requirement, and can be utilized to optimize probability estimate of water requirement.
Mohammadali Izadbakhsh; Reza Hajiabadi
Abstract
In this paper, the discharge coefficient of weirs is simulated by the extreme learning machine (ELM). To this end, seven different ELM models are introduced by the input parameters. Also, the most optimal number of the neurons in the hidden layer is computed 7. Furthermore, different activation functions ...
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In this paper, the discharge coefficient of weirs is simulated by the extreme learning machine (ELM). To this end, seven different ELM models are introduced by the input parameters. Also, the most optimal number of the neurons in the hidden layer is computed 7. Furthermore, different activation functions of the ELM model are assessed and the sigmoid activation function is taken into account as the most optimal one. Besides, the seven defined ELM models are analyzed and the superior model is introduced. This model approximates the discharge capacity with better performance in comparison with the other ELM models. It should also be noted that the superior ELM model is in terms of the dimensionless factors including Fr, HT/P, Lc/W, A/w, w/P. For the superior ELM model, the R2, VAF and NSC are respectively estimated 0.897, 89.626 and 0.892. Furthermore, the MAE and RMSE statistical indices for the ELM model are respectively estimated 0.024 and 0.031. Also, the most effective input parameters for modeling the discharge capacity of labyrinth weirs using the ELM are detected through the conduction of a sensitivity analysis, meaning that the HT/P is identified as the most influenced input parameter. Lastly, an applicable equation for computing the discharge capacity of labyrinth weirs is suggested which can be used by hydraulic and environmental engineers.
Fateme Dehghan; Jahanger Karami; Kamran Yazdanbakhsh
Abstract
Water is one of the most important resources on earth. However, due to the drought crisis in Iran and the need to save water and study the determinants, this study was conducted to predict environmental behavior by relying on water consumption behavior based on environmental awareness, attitude, and ...
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Water is one of the most important resources on earth. However, due to the drought crisis in Iran and the need to save water and study the determinants, this study was conducted to predict environmental behavior by relying on water consumption behavior based on environmental awareness, attitude, and concern. The research is a survey in which 865 citizens of Kermanshah City answered the research questionnaires by cluster sampling. The data was analyzed by statistical methods using SPSS software. The results showed that the variables of environmental knowledge (31 %), environmental concern (34 %), and environmental attitude (54 %) have the ability to predict the environmental behavior of water consumption. Therefore, people with higher knowledge, concerns and environmental attitudes are more diligent in saving water. According to the results of this study, explaining environmental behavior using three variables of environmental knowledge, environmental attitude, and environmental concern can be suggested to implementers and policymakers for use in developing interventions and educational campaigns and raising people's environmental awareness and knowledge. Also, these results can increase the paying attention to their environmental attitudes toward water consumption, can demonstrate that water conservation is realistic and practicable for people, and can convince them that they can engage in conservation-related behaviors. These results have the potential to raise people's awareness of their environmental attitudes about water consumption, illustrate that water conservation is feasible and achievable for them, and persuade them that they can engage in conservation-related actions.
Lee Fergusson
Volume 2, Issue 1 , March 2015, , Pages 115-121
Abstract
Stormwater represents one of the least researched forms of wastewater in environmental science. Contaminated industrial stormwater, that is stormwater generated by runoff from industrial sites such as refineries, smelters and mine sites, is even less well understood. However, contaminated industrial ...
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Stormwater represents one of the least researched forms of wastewater in environmental science. Contaminated industrial stormwater, that is stormwater generated by runoff from industrial sites such as refineries, smelters and mine sites, is even less well understood. However, contaminated industrial stormwater can have damaging environmental impacts because it generally occurs in sudden bursts of high velocity and can result in significant downstream contamination. Flows of hundreds of thousands of litres of industrial stormwater are not uncommon in heavy rain events, and even when reduced through dilution, infiltration, co-mingling and by subsequent rain events, contaminants in stormwater can pose a risk to healthy urban and industrial environments. For these reasons, more research on contaminated industrial stormwater is desirable. This study considered two laboratory-scale experiments and an on-site field trial to assess three novel approaches to the treatment of heavy-metal contaminated stormwater at a smelter site in London. The approaches included the direct addition of a reagent derived from alumina refinery residue (ARR) and two filtration applications through laboratory and on-site reactive systems, both of which contained a form of pelletised media manufactured from alumina refinery residue. These three approaches resulted in the removal of inorganic contaminants from industrial stormwater, including cadmium from 0.08 mg/L to 0.0008 mg/L and copper from 0.7 mg/L to 0.0 mg/L by direct addition and arsenic from 0.34 mg/L to below the detection limit and antimony from 9.3 mg/L to 0.3 mg/L by filtration, with all post-treatment concentrations below the allowable limits for discharge. Although preliminary in nature, this study confirms other findings associated with the reuse of modified alumina refinery residue as a viable chemical raw material in industrial wastewater and solids treatment applications throughout the world, and the use of filtration of stormwater rather than the more common direct addition approach deserves further consideration.
Mohammadmehdi Razmi; Mojtaba Saneie; Shamsa Basirat
Abstract
In this paper, the ANFIS network was optimized using three algorithms comprising the Particle Swarm Optimization (PSO), Firefly Algorithm (FFA), and Genetic algorithm (GA) for the first time. To ameliorate the ability of the numerical models,the Monte Carlo simulations were utilized. Moreover, in order ...
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In this paper, the ANFIS network was optimized using three algorithms comprising the Particle Swarm Optimization (PSO), Firefly Algorithm (FFA), and Genetic algorithm (GA) for the first time. To ameliorate the ability of the numerical models,the Monte Carlo simulations were utilized. Moreover, in order to assess the simulation outcomes, the k-fold cross validation technique was implemented. Initially, using all inputs, five different parameters were used for producing theANFIS, ANFIS-GA, ANFIS-PSO, and ANFIS-FFA methods. After that, a computational fluid dynamics (CFD) model simulated the discharge coefficient (DC) and the outcome of all simulations were compared. The analysis of the results demonstrated that the ANFIS-FFA model approximates the DC with higher precision. For instance, the amount of the coefficient of determination and the scatter index were surmised as 0.961 and 0.039. Also, the side weir height ratio tothe upstream depth (P/y1) was detected as the most influential parameter. About 85% of the DC simulated by the ANFIS-FFA model had an inaccuracy of less than 5%. The performed uncertainty analysis proved that the best model possesses an underestimated efficiency. For this model, the influence of the inputs were analyzed in a ±10% range. Finally, a computational code was presented for the simulation of DC by hydraulic and environmental engineers.
Farzaneh Shahbakhsh; Mahdi Safdari; Ali Sardar Shahraki
Abstract
Water is the basis of life, the foundation of nature, and the pillar of social, economic, and cultural development of societies. So, the supply of safe and consumable water has always been a concern. On the other hand, a major challenge of modern societies is the lack of precipitation and frequent droughts. ...
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Water is the basis of life, the foundation of nature, and the pillar of social, economic, and cultural development of societies. So, the supply of safe and consumable water has always been a concern. On the other hand, a major challenge of modern societies is the lack of precipitation and frequent droughts. Thus, the present paper assesses the principles of water governance in the Sistan region with respect to the development of water exploitation systems with an environmental approach and presents an integrated multi-attribute decision-making model with a water governance approach in the Sistan region. The simple additive weighting (SAW) method that is used here is one of the multiple attribute decision making (MADM) methods. The indicators of water governance principles were derived from the opinions of 30 water experts, faculty members, and water users in the Sistan region by the SAW method, and weights were assigned to them to form MADM matrices. According to the results, six indicators were derived as the indicators determining the principles of water governance. ‘Traditional users’ was selected as the strongest system and ‘irrigation and drainage networks exploitation companies’ as the weakest system. Also, according to the results of water experts, the first rank was assigned to ‘irrigation and drainage networks exploitation companies’ (A2) with the final crisp score of 6.818 followed by ‘water user cooperatives’ (A4) with the final crisp score of 6.515 in the second rank and ‘private firms’ (A6) with the final crisp score of 6.308 in the third rank.
Mehraban Sadeghi; Akram Najafi Chaleshtori; Neda Masoudipour; Behnam Zamanzad
Volume 2, Issue 2 , December 2015, , Pages 164-169
Abstract
Nitrogen in treatment plants effluent causing problems such as oxygen depletion, toxic impacts on aquatic organisms, eutrophication, and negative impacts on public health. The aim of present study was to determine the performance of integrated system activated sludge/nitrifying trickling filter to improve ...
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Nitrogen in treatment plants effluent causing problems such as oxygen depletion, toxic impacts on aquatic organisms, eutrophication, and negative impacts on public health. The aim of present study was to determine the performance of integrated system activated sludge/nitrifying trickling filter to improve nitrification in the wastewater treatment plant of Isfahan. In this applied experimental study, an integrated activated sludge (AS) process (in full scale) was used with a trickling filter (TF) (in semi-industrial scale). The diameter and height of TF were 1.8 m and 3 m of steel, respectively. The volume of polypropylene media was 8 m3 and surface area of 240 m2/m3. The hydraulic loading rate during the startup period was 2.4 m3/h which was raised to 7.2 m3/h in the operation period. Flow rate, BOD5, COD, pH, TKN, N-NH3, N-NO2-, N-NO3-, alkalinity and temperature were measured weekly according to standard methods during the operation period. The effect of filter depth on nitrification was studied in 3.6, 4.2, 5.4 and 6 m and HRT of 3.6 m/h. The samples were analyzed by SPSS. The results showed that the best hydraulic and ammonia loading rate achieved here were 3.6-4.2 m/h and 2-2.5 g N/m2d, respectively. The AS/TF system efficiency were 86 % COD removal, 94 % BOD5 removal, 70 % turbidity removal, 94.4 % TSS removal, 55.5-75.5 % TKN removal and 85 % nitrification, respectively. The highest efficiency to reduce of wastewater pollution and nitrification was occurred in depth 4.5 m. Integration of the activated sludge and trickling filter processes, especially in old wastewater treatment plants is a good way to reduce the amounts of nitrogen in treatment plants effluent.
R.Kannan Seenivasan; Veerasamy Maheshkumar; Palanikumar Selvapandian
Volume 3, Issue 1 , June 2016, , Pages 209-216
Saeed Aghel; Nader Bahramifar; Habibollah Younesi
Volume 3, Issue 2 , December 2016, , Pages 253-259
Arash Azari; Milad Asadi
Abstract
In the simulation models of water resource systems, calibration processes should be performed to approximate the simulated values to the observed values due to the errors in such models. However, due to being time consuming and the difficulties associated with manual calibration, an automatic calibration ...
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In the simulation models of water resource systems, calibration processes should be performed to approximate the simulated values to the observed values due to the errors in such models. However, due to being time consuming and the difficulties associated with manual calibration, an automatic calibration model can be a resolver. In this research, the simulation of Jareh Dam and network system was conducted using the WEAP model. Then, by linking this model to the NSGA-II algorithm, its automatic calibration was performed by this algorithm. Nach statistical parameter was used to check the calibration accuracy of the model. The whole system was in the form of a multi-objective NSGA-II algorithm, in which the first objective function, which was to minimize the difference between the observed and the calculated reservoir storage volumes, was assessed versus the second objective function, which was to minimize the difference in the calculated and the simulated discharges, at two Mashin and Jokank stations. The results showed the remarkable ability of NSGA-II algorithm for automatic model calibration, so that the operation status of the dam and river was of the greatest consistency with reality.
Ali Roholamin Kasmaei; Mehdi Nezhad Naderi; Zaynab Bahrami
Abstract
Application of N fertilizers in agricultural operations is one of the important sources of nitrate entry into groundwater. In Iran, especially in coastal areas with a high groundwater level, in agricultural areas, there is a risk of pollution of groundwater and surface water to nitrates. This research ...
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Application of N fertilizers in agricultural operations is one of the important sources of nitrate entry into groundwater. In Iran, especially in coastal areas with a high groundwater level, in agricultural areas, there is a risk of pollution of groundwater and surface water to nitrates. This research was conducted with the aim of determining the concentration of chemical parameters of drinking water wells in a Tonekabon village and comparing with acceptable standards. The present study was carried out on groundwater resources of Zawar village of Tonekabon city for six months and then data were analyzed to determine the concentration of chemical parameters and water resources type based on anions and cations in water. The results of this study during the investigation of different wells showed that the total number of samples tested from a drinking water well in Zawar, Tonekabon, the range of nitrate concentration from 8 to 33.7 mg / L, TDS from 233 to 435 mg in liters and the total hardness varied from 211 to 372 mg/L. According to the definition of pollution, the wells were classified in the permitted class in terms of nitrate. However, the approach of nitrate levels in some wells to 20 mg per liter (a sign of the impact of human activities) is also worthy of serious consideration. determining the quality of the area reduces the amount of nitrate in the groundwater and thus increases the quality of groundwater.
Saideh Fatemeh Shafeii Darabi; Nader Bahramifar; Mohamad Ali Khalilzadeh
Abstract
Present study explored the adsorptive characteristics of eosin Y and red X dyes from aqueous solution onto treated rice husk (TRH). Batch experiments were carried out to determine the influence of parameters likes initial pH, adsorbentdose, contact time and initial concentration on the removal of eosinY ...
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Present study explored the adsorptive characteristics of eosin Y and red X dyes from aqueous solution onto treated rice husk (TRH). Batch experiments were carried out to determine the influence of parameters likes initial pH, adsorbentdose, contact time and initial concentration on the removal of eosinY and red X. The adsorption kinetics of the two dyes on to TRH was found to follow pseudo-second-order kinetic model. The equilibrium data is successfullyfitted to the Freundlich and Langmuir adsorption isotherm for eosin Y and red X, respectively. The thermodynamic analysis indicated that the sorption process was endothermic for eosin Y and exothermic for red X and the negative value of change in Gibbs free energy indicated feasible and spontaneous adsorption for both of dyes. The removal percentage of dyeswas about 90% (q e= 31.72 mgg-1) for eosin Y and 93.44 % for red X(qe=32.44mgg-1). Overall, the present findings suggest that this environmentally friendly, efficient and low-cost adsorbent is useful for the removal of eosin Y and red X from aqueous solution.
Soraya Mohajeri; Hamidi Abdul Aziz; Mohamed Hasnain Isa; Mohammad Ali Zahed
Abstract
Electrochemical oxidation process has been shown to be a favourable choice for Chemical oxygen demand (COD) and color removals from various types of wastewaters. The technique was employed for mineralization of semi-aerobic landfill leachate. Leachate sampling were carried out from Pulau Burung Landfill ...
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Electrochemical oxidation process has been shown to be a favourable choice for Chemical oxygen demand (COD) and color removals from various types of wastewaters. The technique was employed for mineralization of semi-aerobic landfill leachate. Leachate sampling were carried out from Pulau Burung Landfill Site (PBLS), Penang, Malaysia. The main objective was to determine the effectiveness of electrochemical oxidation in leachate treatment using aluminum electrodes which are relatively nontoxic and cost-effective. The influence of pH, reaction time, current density, electrolyte concentration, agitation rate and dilution on COD and color removals was investigated. The highest COD and color removal were obtained as 57.1% and 72.0% respectively at pH 8, current density 60 mA/cm2, electrolyte concentration 2000 mg/L, agitation rate 400 rpm, dilution 50% and reaction time 4 h. The energy consumption was determined as 128 kWh/m3 for this type of landfill leachate. The study shows that electrochemical oxidation can be used as a step of shared treatment.
Peyman Mahmoodi; Mehrdad Farhadian; Ali Reza Solaimany Nazar; Amin Noroozi
Volume 1, Issue 1 , March 2014, , Pages 18-22
Abstract
The efficiency of diazinon (as insecticides) and nitrate (related to nitrogen fertilizer) removal from contaminated water is investigated through NF membrane technique. The effects of nitrate concentration (40-160 mg/l), diazinon concentration (10-1000 µg/l) and pH (5-9) on the efficiency of a ...
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The efficiency of diazinon (as insecticides) and nitrate (related to nitrogen fertilizer) removal from contaminated water is investigated through NF membrane technique. The effects of nitrate concentration (40-160 mg/l), diazinon concentration (10-1000 µg/l) and pH (5-9) on the efficiency of a commercial polyamide nanofilter membrane at a constant pressure of (800 KPa) are investigated. The response surface method (Box-Behenken design) is applied in design of experiment. As the diazinon concentration and pH are enhanced, the contaminant removal efficiency increases from 85% to 90%; while nitrate concentration has an opposite effect (removal efficiency reduces about 10%). The regression models obtained for nitrate and diazinon rejection show good fitting to the experimental results (r-squared equal to 94% and 98%, respectively). The models are able to predict the evolution of diazinon and nitrate as a function of concentration and pH at a constant pressure.
Shoukat Ali Shah
Abstract
Reference Evapotranspiration (ETo) counted as the main factor for assessing the amount of water, needed for crops as well as for the planning of water resources management. Several techniques, methods, and equations have been used for computing ETo. Thus, required weather data sets are the main challenge ...
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Reference Evapotranspiration (ETo) counted as the main factor for assessing the amount of water, needed for crops as well as for the planning of water resources management. Several techniques, methods, and equations have been used for computing ETo. Thus, required weather data sets are the main challenge for evaluating this factor. FAO Penman-Monteith is the most popular technique to determine the ETo. The FAO 56-PM equation requires accurate weather data like air temperature, humidity, solar radiations, and wind speed. Unfortunately, not all these data are possible to reach easily on the station's side. Therefore, FAO 56 recommended another equation namely Hargreaves-Samani (HS) equation when sufficient weather data may not be available to estimate ETo by FAO56-PM. In the context of this, this study aimed to estimate ETo using the HS equation. For this purpose, historical annual, seasonal, and monthly temperature and wind data were collected from 1981 to 2020 using ‘The Prediction of Worldwide Energy Resources (POWER)’ web portal. It is concluded that the HS method in conjunction with the POWER datasets and spatially mapping with IDW interpolation gave reliable and accurate results of ETo. This technique gives an idea of water losses in a district and demonstrates a trend of historical annual, seasonal, and monthly ETo.
Mohammad Zeynoddin; Hossein Bonakdari
Abstract
Given the climate changes, achieving rainfall forecast is of high importance and facing such challenges affected markedly in vast areas of societies. Accordingly, numerous nonlinear and linear methods have been developed. Most hydrological phenomena like rainfall are consisted of both linear and nonlinear ...
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Given the climate changes, achieving rainfall forecast is of high importance and facing such challenges affected markedly in vast areas of societies. Accordingly, numerous nonlinear and linear methods have been developed. Most hydrological phenomena like rainfall are consisted of both linear and nonlinear parts. Modeling such phenomenon with stochastic methods like seasonal auto regressive moving average model (SARIMA), which are linear, demands data preparation prior to modeling. In this study, by investigating different forms of data preparation methods, variations in stochastic modeling results are scrutinized. The pre-processing methods used are categorized in two parts, normalization and stationarzition of data. The rainfall series is initially normalized by 4 transforms, namely: Manly(Mn), John-Draper (JD), Yeo-Johnson (YJ) and Scaling (Sc). The series, then, are stationarized by differencing, standardization (Std) and spectral analysis (Sf). After achieving preferred results by numerous tests, the preprocessed data are then modeled by stochastic SARIMA model. With regards to error and model sufficiency indices and graphs results, the acceptable results, but not the best, was obtained by the Sc-Diff combination, with SARIMA (0,0,1) (3,0,3)12 model and coefficient of determination, 0.355, variance accounted for, 0.353, root mean square error, 0.313, scatter index, 1.030, mean absolute error, 21.355), corrected Akaike Information Criterion, 1227.03. The results revealed that concerning the severe fluctuations in data, a supplementary method, like hybridization with artificial intelligence (AI) methods, is needed to achieve preferable results.
Jalal Sadeghian; Mohammad Reza Mihani
Abstract
The hydrous bed of the rivers covered with coarse alluvial materials is a goodresource along with other resources to provide the needs of the water. Therefore,studying and investigating the flow behavior around wells excavated in these bedsand determining their discharge capacity is very important. Since ...
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The hydrous bed of the rivers covered with coarse alluvial materials is a goodresource along with other resources to provide the needs of the water. Therefore,studying and investigating the flow behavior around wells excavated in these bedsand determining their discharge capacity is very important. Since the flow to thewells is radial and previous research on coarse, porous media, there has beenmainly for parallel flows, and yet any equation replacing the Laplace relationship incoarse, porous media, is not provided for non-Darcy radial flows with a free surface,Therefore, the extraction of the differential equation ruling on these types of flowsin the cylindrical coordinates and a method for numerical solution of them in thisresearch has been followed. Based on the research carried out in this research, thepower (exponential) equation as the most suitable basic relation for the analysis ofradial flows was determined and used. Also, in order to solve the governingequations a numerical model was developed using finite volume method. Thedeveloped numerical model act well for the analysis of radial flows in the coarsealluvial beds. The results of the implementation of the numerical model indicate thatthe pressure distribution can be considered hydrostatic.
Abbas Parsaie; Amir Hamzeh Haghiabi
Volume 1, Issue 2 , June 2014, , Pages 74-79
Abstract
Allocation and removing of excess water from the irrigation and drainage network is one of the most important activities in the management of these networks. Side weir is one of the most common structures for this purpose. Study on the flow Hydraulic characteristics of this structure included two parts, ...
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Allocation and removing of excess water from the irrigation and drainage network is one of the most important activities in the management of these networks. Side weir is one of the most common structures for this purpose. Study on the flow Hydraulic characteristics of this structure included two parts, defining the water surface profiles and estimating the discharge coefficient. To estimate the discharge coefficient, many ways as experimental formulas and artificial intelligent models are propose. The empirical formula for simplifying in developing process that assume by the authors, contained significant error so using the AI models are inevitable. In this paper, some of the famous empirical formula and AI models such as Multilayer neural network (MLP) and Adaptive Neuro fuzzy inference system (ANFIS) are assessing with a laboratory experiment. Among the experimental formula, Borghei formula is most accurate (R2=0.83) and the performance of the AI model in Training and testing stage is more suitable (R2=0.96).
Ahmadreza Mazaheri; Mehdi Komasi; Ali Mohammadzadeh; Behrang Beiranvand
Abstract
It is important to design and optimize the dimensions of the dam drainage system to keep the dam's downstream shell dry and to prevent the increase of pore water pressure in the earth dam body. It will also be possible to find the minimum factor of safety (FOS) to reduce construction costs by optimizing ...
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It is important to design and optimize the dimensions of the dam drainage system to keep the dam's downstream shell dry and to prevent the increase of pore water pressure in the earth dam body. It will also be possible to find the minimum factor of safety (FOS) to reduce construction costs by optimizing the drainage dimensions. In this study, Marvak earth dam was modeled by GeoStudio software with real material parameters, and by changing the dimensions of drainage, the material of the material, and slope of the dam, the minimum factor of safety of the dam was obtained. To predict the minimum factor of safety, the software results were used in different cases in the two-layer neural network. By training the neural network from the data obtained from the modeling of the Marvak dam, the minimum factor of safety for horizontal drainage was obtained. To optimize, a command appropriate to the neural network function is taught, by which the optimal values of the dam parameters are calculated. The results of the study show that the two factors of the internal friction angle of the drainage material and the slope of the dam have the greatest impact on determining the minimum factor of safety of the dam.
Abdolhossain Mohammadi; Reza Ghazavi; Rohallah Mirzaie
Abstract
The present study investigates the effect of treated wastewater and sludge on some vegetative characteristics of the Nitraria schoberi plant. This study was conducted in a randomized block template using several treatments include five levels of irrigation with wastewater (0, 25, 50, 75, and 100 %), ...
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The present study investigates the effect of treated wastewater and sludge on some vegetative characteristics of the Nitraria schoberi plant. This study was conducted in a randomized block template using several treatments include five levels of irrigation with wastewater (0, 25, 50, 75, and 100 %), two types of soil (arable land and desert soil of Meighan desert area), and two levels of sludge (presence and absence of sludge) with 6 repetitions for each treatment. SPSS software was used to perform the statistical analysis of plant morphological characteristics. The results showed that the highest increase in height, collar diameter, and the crown cover was observed when a wastewater level of 100 % was applied in the catchment basin soil of the Meighan desert at both presence and absence treatment of sludge. However, the same characteristics of Nitraria schoberi plant for cropland soils in the present treatment of sludge were at wastewater level of 100 % and in the absence treatment of sludge for plant height, collar diameter and crown cover diameter were at wastewater level of 50 %, 100 %, and 75 %, respectively. According to the results, different levels of wastewater have a significant impact on Nitraria schoberi plant height and crown cover diameter (P<0.01(. But different treatments did not show a significant difference in the collar diameter of the Nitraria schoberi plant. We can conclude that the use of wastewater should have a favorable effect on plants and soils of the desert area and should protect soil and water resources, but the environmental impact of treatments should be examined.
