ali asareh

This study is focused on the treatment and reuse of agricultural drainage water using permeable reactive barriers (PRBs). To construct the physical model, a cubic iron tank with dimensions of 1×1×1 is used. Drainage pipes with a standard diameter of 16 mm are installed at a depth of 20 cm. To determine the depth of the static level, piezometer tubes are used in the model. After permeability tests and evaluating the obtained results as well as considering the availability of materials, the mixture weight ratios of the materials in PRB are selected as follows: 25% sand, 25% anthracite, 20% zeolite, 20% iron borings, and 10% poplar wood sawdust. The permeability coefficient of the PRB with this mixture after complete saturation over 24 hours is equal to 0.0322 cm/s. An initial nitrate concentration of 100 mg/liter is considered for the column to obtain the break through curve of the synthetic wastewater. It takes 15 minutes to detect the nitrate breakthrough. The breakthrough curve is considered a normal curve, and the only unknown of the problem, i.e., the longitudinal diffusion coefficient (D_L), is obtained by trial and error as 1.5×〖10〗^(-7) m^2⁄s, which is an acceptable value. The Peclet number for the proposed PRB is 14.344, which indicates the identical effects of the dispersion and diffusion processes. In this study, the drainage filter, which includes PRB and sandy loam soil, is able to eliminate nitrate by 99.44% after 24 days.

The limitation of the country's water resources and the aggravation of this limitation, which is caused by the continuous increase in the demand, has caused the maximum use of the available water resources and the increase in productivity and, as a result, the increase in production per unit area. The present research was conducted with the aim of evaluating the water quality of Dez River in terms of efficiency in pressurized irrigation systems.

For quality assessment of Dez River water in terms of efficiency in pressurized irrigation systems, 7 hydrometric stations were selected including Sepid dashte Sezar, Sepid dashte zaz, Tange pange sezar, Tange pange bakhtiari, Dezful, Harmaleh, and Bamdezh. Qualitative data of Dez River water along a decade (2005-2014) were taken from Khuzestan water and power authority.

The Qualitative analysis using piper diagram showed that water quality in Sepid dashte Sezar, Sepid dashte zaz and Tange pange sezar stations was calcium bicarbonate. Although, in Harmaleh and Bamdezh stations the most of samples were neutral. The results showed that salinity amount was increased from the upstream to the downstream of the river. Whereas, Bamdezh station had low to medium limitation at 95 percent of times for drip irrigation usage. Dez River had no limitation for infiltration due to suitable averages of SAR and EC. Besides, cations and anions coefficient of correlation was variable between 0.67 to 0.78 and -0.249 to 0.6 respectively. Chlorine in the river water from Harmaleh station toward the downstream of the river, had low to medium limitation for sprinkler irrigation usage. The most limitation of bicarbonate was observed at 97.5 percent of times in Sepid dashte Sezar station for using sprinkler irrigation. In addition, sodium amount in Harmaleh and Bamdezh stations compared to Dezful station increased 134 and 233 percent respectively. Langelier Saturation Index (LSI) was negative in the entire stations and calcium carbonate sediment won’t be created.

It is necessary to use mathematical models to determine the river's response to pollutants. These models are able to simulate the effect of existing and future pollutants and facilitate related decisions. In this study, the water quality of Dez River and its main feeding drains were extracted and analyzed through sampling and laboratory analysis from Dez diversion dam downstream of Loreh drainage during seven months from March to September 2018. The results of the measured samples were compared with those of the simulated values through the HEC-RAS model. The river path was investigated in the study period and seven sampling stations were determined along the river and six stations at the point of drainage into the river to determine the sampling stations, as well as the sources of pollution of Dez River. The results indicated the lack of self-purification of DO, BOD, NO3, NO2 parameters in Dez River during seven months of 2018 due to the inflow of drains and lower river discharge in this period. Also, the base on NSFWQI index, in drought seasons the first half of the river quality index is less than 68, that indicates average quality, and in the second half of the river, the quality index is less than 50 (poor quality). This decreasing trend of NSFWQI quality index is consistent with the trend of qualitative variables of HEC-RAS simulation and indicates the lack of relative self-purification of the river during the study period.

The use of natural processes, including the physiological potential of plants, is a suitable solution. In this study in order to assess the effect of waste leachate and industrial wastewater on the absorption of heavy metals by the Vetiver plant, two separate factorial experiments were performed in the crop year 2020-2021 as a completely randomized design. Experiment treatments factors included waste leachate and industrial wastewater use separately on 5 levels (0, 25, 50, 75, and 100%) in three replications (B1, B2, B3) and two irrigation periods of 5 and 10 days (A5, A10). The amount of iron, zinc, copper, manganese, potassium, and sodium measured in vetiver showed waste leachate had a significant effect at the level of 5% (P <0.05). Meanwhile, the use of industrial wastewater had a significant effect on the amount of iron, zinc, copper, manganese, and sodium absorbed by the vetiver at the level of 5% (P <0.05) but it had no significant effect on the potassium amount (P> 0.05). R4A1 and W5A1 treatments showed a relatively good response with a decrease in biomass production below 10% compared to the control treatment. According to the results, the Vetiver species has relatively high compatibility in the absorption of heavy metals with unconventional waters and can have a special application for soil and water protection.

Due to the simplicity of operation, Stepped Chutes are among the most common water buildings to reduce water flow energy in irrigation systems. So this research has studied the impact of structure slope, the number of stairs and structure height on energy dissipation rate in stepped chutes. Experimental models used in 2, 20 and 30 cm height, 26.5-degree slope channels (1: 2) and 33.3 degrees (1: 1.5) and in 3, 5, and 7 stairs were built. All tests were done in 4 different rate discharges 10, 13, 15 and 20 liters per second in the laboratory flume, Islamic Azad University of Ahvaz. The results showed that by increasing the amount of  the energy dissipation rate will be reduced. It can be also seen that for a certain value of  Yc/Δz, the increase in the number of stairs reduces the amount of relative energy dissipation. Also Results showed that increasing the slope, the relative energy dissipation rate increases. In this study, the maximum amount of relative energy dissipation for a model with a slope of z = 2 and a height of 30 cm obtained and the minimum amount of energy dissipation for a model with a slope of z = 1.5 and a height of 20 cm obtained. Results showed that increasing the Froude number, the energy dissipation rate will be reduced.

Water resources limitation and plant stress due to water shortage is one of the important and common environmental stresses in agricultural production, including forage production in hot and dry areas. Therefore, the selection and development of drought-tolerant cultivars are very important. In irrigated lands of Iran, the average of irrigation efficiency is 37% and water productivity is 0.8 kg per cubic meters, which is lower than the world average. For increasing water efficiency, maintaining the production capacity and creating sustainable agriculture, it is necessary to identify the effective factors on the reduction of irrigation water productivity and provide an appropriate solution. In arid regions such as Khuzestan province, by using both a proper irrigation program and irrigation levels below the water requirement, obtaining the acceptable yield of alfalfa could be expected. In order to achieve these objectives, determination of the irrigation water productivity of tropical alfalfa cultivars and their drought tolerance under different irrigation regimes were the main aims of this study.

For evaluating tropical alfalfa genotypes under different drought stresses, an experiment was carried out based on split plots design with three replications in Safiabad Agricultural Research Center, Dezful, Iran, in 2019-2020. The main factor was four levels of irrigation (25, 50, 75 and 100% of water requirement) and the second factor was five alfalfa cultivars (Baghdadi, Nikshahri, Yazdi, Mesasirsa, and Omid). In this experiments, plant characteristics including dry and wet forage yield, percentage of dry forage, leaf to stem weight ratio, chlorophyll index (SPAD), electrolyte leakage from the leaf cell membrane (EL), relative leaf water content (RWC), and Maximum quantum yield in the dark-adapted conditions (ΦPSɪɪ) were determined.

The results showed that by applying drought stress, wet and dry forage yields, RWC, and ΦPSɪɪ were decreased but the percentage of dry forage, leaf to stem weight ratio, EL, and SPAD were increased. Among the studied genotypes, the Baghdadi genotype had the highest dry forage yield in all situations; non-stress conditions (16.9 t/ha), mild drought stress (15.094 t/ha), moderate drought stress (9.58 t/ha) and severe drought stress (4.664 t/ha). The Yazdi genotype had the lowest dry forage yield; 9.9, 9.7, 5.7 and 3.6 t/ha for non-stress, mild, moderate, and severe drought stresses conditions, respectively.

In our experiment, the Baghdadi genotype showed a high-stress tolerance index (STI) and we highly recommend planting it in the north of Khuzestan province, but the Yazdi alfalfa genotype despite low dry forage yield under both non-stress and drought stress conditions is not recommended due to low production. We suggest using Yazdi genotype in eugenic plans due to high yield stability index (YSI) under drought stress conditions and having some favorable physiological and photosynthetic parameters associated with drought stress tolerance.

Due to the fact that many variables are effective in the amount of sediment trapping and the amount of water loss in the eddy tube, this study was conducted to investigate the performance of the eddy tube in laboratory conditions. 4 ratio of pipe gap width to pipe diameter (t / d), 0.15, 0.20, 0.25 and 0.3, 3 granulation D1 (particles passing through sieve 8 and remaining on sieve 10), D2 (particles passing through sieve 16 and remaining on sieve 20) and D3 (particles passing through sieve 20 and remaining on sieve 30) were selected at a 45 degree angle with different flow rates. The results showed that if the area is not facing water shortage and water supply problems and preventing sediment from entering the system is preferable to water supply, t / d = 0.3 is a more desirable option; But if it is very important in water supply areas and there is basically water shortage; The better option is t / d = 0.25.

In this research, the simulation and optimization models are integrated to apply the reservoir hedging policy. The simulation of the studied basin is executed using the WEAP model to conduct the system optimization and the multi-objective MOPSO model is utilized so that the first purpose is to maximize the percentage of supplying demands, while the second one is to minimize the violation of allowable capacities of the reservoir during the operation period. In this regard, the operation modeling from the reservoir was carried out based on the current condition for a 360-month period. Finally, by defining the optimized scenario and applying the reservoir hedging policy, the optimization of the operation from the reservoir is conducted and the results were compared with the outcomes of the reference scenario. In this study, by considering 24 decision variables including 12 hedging level variables and 12 hedging coefficient variables, the optimal answers were achieved after 1000 iterations. The results showed that the violation of the allowable capacities has not occurred in any periods, while in the reference scenario the reservoir level has reached the dead level in sequent months with more water shortage which might lead to the lack of water supply in such months and serious damages to the system. Due to the application of hedging policy in the optimized scenario, the percentage of supply in the critical months has increased between 20-35% compared to the reference scenario, which indicates a significant reduction in the failure rate in such months compared to the reference scenario.

Rivers and water resources polloution caused by uncontrolled industrial wastewater discharge. Precence of high concentration of phosphate ' sulfate and nitrate anions in sugarcane indusrial wastewater ' required treatment of the waste water for nutrients and corrosive substances deletion. This study is an attempt to investigate the effect of electrical current' initial wastewater PH and retention time on phosphate ' sulfate and nitrate pollutants removal of sugarcane industrial wastewater. In this study ' the electro coagulation method with aluminum electodes were applied for wastewater treatment in sugar cane of Hakim Farabi. 6 electrodes – aluminium in vertical position were connected to power supply by monopolar method. Septic tank was selected for sampling. Initial wastewater concentration and PH were measured for phosphate' sulfate and nitrate. Then the effect of three operation parameters: PH(5' 7' 9' 11) electrical potential (10 and 30 volts) and retention time (15' 30' 45' 60 minutes) for phosphate ' sulfate and nitrate removal efficiency have been investigated. The results showed that in equal retention time and different initial PH the removal of phosphate' sulfate and nitrate could be promoted by increasing the electrical potential from 10 volt to 30 volt.. The results indicated that the highest removal efficiency of phosphate was observed in neutral condition and increasing PH decreases phosphate removal. whereas the highest removal efficiency for sulfate and nitrate was observed in alkaline PH .also the results proved that in all condition of PH and voltage' increasing retention time cause increasing in removal percent for phosphate' sulfate and nitrate.

Highly-concentrated phosphate and nitrate anions from sugarcane wastewater are often discharged into public waters without standardized treatments. This study assessed the effects of electrical coagulation, initial pH and reaction time in the removal of phosphate and nitrate pollutants.

We used aluminum electrodes to remove the pollutants at Hakhim Farabi Agricultural and Industrial complex, Khuzestan Province, Iran. A septic tank was used for collecting water samples followed by measuring the pH, and the concentrations of phosphate and nitrate in the samples. The pH was set at 5, 7, 9 or 11. Six aluminum electrodes were placed perpendicular to the water flow and were connected to power in a single-polar method. They were used to assess the effects of pH changes, electrical power at 10 and 30 volts and the water retention time at 15, 30, 45 or 60 min. on the efficiency of the pollutants’ removal. 

The results indicated that under equal retention time and varying pH values, as voltage increased from 10 to 30, the phosphate and nitrate removal increased progressively. It was further demonstrated that the maximum phosphate removal efficiency was achieved at pH7, while it declined at higher pH levels. The highest possible nitrate removal efficiency was achieved under alkaline pH levels. The overall results showed that at every pH and voltage, the percentage of phosphate and nitrate removal increased over time.

This study demonstrated that electro-coagulation process is an appropriate and efficient method to remove phosphate and nitrate pollutants from sugarcane wastewaters.

Water deficit is known as the most important limiting factor in agricultural products, especially in the arid and semi-arid regions. Agriculture has been negatively influenced by low obtainable water and because of climate change, making water stress conditions for economic crucial plants. As Iran's major region is consisting of the arid and semi-arid areas with limited water resources, in case of the minimum plant water use is not maintained, the plant would experience drought stress and the products would suffer irreparable losses. One way for optimal use of the water resources and their preservation is the use of superabsorbent polymers which not only provide conditions for improved products quality but also results in increased water consumption efficiency in the arid and semi-arid areas. Superabsorbent polymers could absorb and retain water up to several times of their weight. Due to the drying up of the environment, the water retained in the superabsorbent will gradually discharge, and thus the soil would remain moist for a long time, without needing further irrigation. This property is the great importance to confront water shortage and reduce the harmful effects of drought stress in plantations. Superabsorbent polymers cause water retention in the soil and reduce the number of irrigation frequency up to 50%.

In this study, the effect of water stress and different levels of superabsorbent on cucumber crop (variety of super dominus hybrid) in a farm with sandy soil, in Seymareh region, Ilam province, Iran was evaluated. This experimental farm was conducted at 33° 09′ N and 47° 24′ E, and with an elevation of 982 m. Seymareh region has a Mediterranean summer and winter. The average annual precipitation is about 350 mm and the average temperature is about -2° C in the winter and about 45° Celsius degrees in the summer. The hydrophilic polymer: Super-AB-A-300 used in this study. This polymer is a granular type and produced by Rahab Resin Co. with product license holding of Iran Polymer and Petrochemical Institute. This hydrophilic polymer is a terpolymer of acrylamide, acrylic acid, and acrylate potassium. The experimental design was according to a split-plot method in a randomized complete block design that was done with 12 treatments and 3 replications. In this study, 3 different depths of irrigation were considered as the main treatment including I1, I2, I3 as 100, 80 and 60 percent of water requirement of plant respectively and different levels of superabsorbent were used as secondary treatment including S0, S1, S2 and S3, equal to 0 (control), 15, 30 and 45 g m-2 respectively. The size of each plot was 4 * 1.2 m2 including 6 lines. The Superabsorbent for each line in each plot was distributed in a depth of 30 cm from the soil surface. The cucumber variety of this plan was planted manually in April as spring planting and in August as summer planting. The space between planting rows was 20 cm, and between each plant in each line was 40 cm, so a total density of planting was 60 plants per each plot. Three grains were planted at each point which after germination, they were thinned out to one plant. From the 3 to 4 leaf stage (after the complete establishment of the seedling) the deficit irrigation treatment was applied. For planning and determining the irrigation interval, by adopting the no water stress treatment as the criterion, the soil moisture index and the soil matric potential were incorporated. The percentage of soil moisture content was measured through sampling to the depth of plant root in the days before irrigation and when the weighted mean of the volumetric soil moisture reached the allowable depletion for the cucumber plant, the next irrigation was performed; therefore, the irrigation interval was determined; concerning the treatment with no water stress (control) and simultaneously all the treatment plans with equal irrigation intervals and with different water depths were irrigated.

According to the results, the independent effect of irrigation and superabsorbent treatments at 1 percent level on cucumber crop yield was significant. The maximum and the minimum of cucumber fruit weight and crop yields were 72.86 and 56.90 g, and 3.7 and 1.97 kg m-2 related to the complete irrigation (I1) and severe drought stress (I3) respectively. Results showed that in the drought conditions, superabsorbent application increased cucumber fruit weight and crop yield compared to control treatment. Also, the independent effect of irrigation and superabsorbent treatments at 1 percent level on water use efficiency of cucumber crop was significant. The maximum and the minimum of water use efficiency were 8.11 and 6.15 kg m-3 related to the complete irrigation (I1) and severe drought stress (I3) respectively. In addition, a quadratic function was introduced as the optimum water-yield production function of cucumber crop (variety of super dominus hybrid) in the presence of superabsorbent, in sandy soil. Finally, the results showed that superabsorbent could prevent the significant reduction of cucumber crop yield in sandy soil and under drought stress conditions.

In this study, the effect of water stress and different levels of superabsorbent on cucumber yield (variety of super dominus hybrid) in a farm with sandy soil was evaluated in Seimare region, Elam province, Iran. Experimental design was performed according to split plot method in a randomized complete block design. Three different levels of irrigation were considered as the main treatment including 100 (I1), 80 (I2) and 60 (I3) percent of crop water requirement and four levels of superabsorbent were used as secondary treatment including zero (S0), 15 (S1), 30 (S2) and 45 gm-2 (S3). According to the results, the effect of irrigation and superabsorbent treatments was significant on cucumber yield at 1 percent level. The average maximum and minimum crop yield were 3.7 and 1.97 kgm-2 which were corresponded to the full irrigation (I1) and severe drought stress (I3) treatments. In addition, the effect of irrigation and superabsorbent treatments was significant on water productivity of cucumber crop at 1 percent level. The maximum and minimum water productivity were 8.11 and 6.15 kgm-3 which were corresponded to the full irrigation (I1) and severe drought stress (I3) treatments. Also, a quadratic function was introduced as the optimum water-yield production function for cucumber crop (variety of super dominus hybrid) in the sandy soil amended with superabsorbent. Finally, it was concluded that the superabsorbent could prevent from the significant reduction of cucumber yield in sandy soil and under drought stress conditions.

Increasing water productivity in agriculture is one of the effective strategies for sustainability of water resources. In this research, irrigation management and water productivity in North Karkheh irrigation and drainage network were evaluated by examining the cropping pattern and the use of land use productivity indices, CPD, BPD and NBPD. The results of the study showed that the mean wheat cultivation in the 5 years period of study (2009-2013) increased by 132% compared to the designer's proposed cultivar, while the average barley yield decreased by 470% compared to the design pattern of the designer. Also, the cultivation of fodder plants such as alfalfa and clover has not been welcomed by farmers in the region. The average 5 years of cultivation at the network level was 5924 hectares and the average water consumption per year was 55.5 million cubic meters; if the water required for the designer crop pattern was an average of 86 million cubic meters per year For 6500 hectares. The five-year average CPD index for wheat, as the product with the highest cropping area, was 818 gm-cubic meters, and for spring crop watermelon, as the product that had the highest water intake among cropping patterns It was 2301 grams per cubic meter. The five-year average of BPD and NBPD for wheat was 5870 and 3018 Rials per cubic meter.

To achieve the goal of high yield, deep understanding of physiological, agronomic and environmental factors is necessary to improve the performance and sustainability of agricultural systems. This may not be practical unless the plant complex systems and the type of response to inputs and environmental conditions are known as important factors. In modern agricultural methods the uses of different models are important for management, optimize productivity, accurate understanding of the system and obtaining a precise formulation of the standard. In order to simulation of soil moisture under different water conditions on wheat(Chamran cultivar) a field experiment was conducted at the Agricultural Research Center- Ahwaz. In this experiment, three irrigation levels include I1 ( no water stress ), I2 (stop irrigation at the heading stage and I3(stop irrigation at the milky grain stage) and five levels of nitrogen fertilizer namely N1(no nitrogen fertilizer), N2=40, N3=80, N4=120 and N5=160 kg/ha were used as treatments. In this research, HYDRUS-1D was used as simulation model. Analysis of results for sensitivity of model showed that soil moisture coefficient of model under saturation condition θs is more than other coefficients and a slight change in coefficient caused a large change in output variation of model. The minimum effect was observed in α, I and θr coefficients. Meanwhile, results indicated that model was estimated moisture content less than reality condition. Also, the amount of moisture on the basis of simulated model was estimated less than the real moisture. The model efficiency that reflects to quality and observed data was estimated between 0.67 and 0.90. This was due to high efficiency of simulated model for soil moisture.