جستجوی مقالات مرتبط با کلیدواژه "غلظت روی" در نشریات گروه "آب و خاک"

The limitations of water resources in Iran have highlighted the need to reuse wastewater and recycle purified water as one of the solutions to obtain new water resources. In order to investigate the effect of wastewater on the quantitative and qualitative characteristics of Banafsheh and Mina plants in the water year of 2022, different percentages of mixing water with urban wastewater (25-50-75 and 100 percent) obtained from Torbat Heydarieh wastewater treatment plant as experimental treatments were compared with city water as the control treatment. It was implemented in the form of a complete randomized block statistical design with five treatments and four replications. During the growing season, the indicators of the number of flower, green area, flower height and dry weight were measured, and at the end of the growing season, the chemical properties of the soil were measured. Data analysis was done using SAS software at a confidence level of 95% and the results were compared using the LSD test. Based on the obtained results, different proportions of water and sewage had a significant effect on the number of flowers and green surface in both Banafsheh and Mina. But the use of these treatments showed a significant effect on the flower height only in the Banafsheh. By replacing 75% of irrigation water with wastewater the green area and the number of flowers increased by 11% and 54% in the Mina and by 22% and 10% in the Banafsheh respectively. Irrigation with wastewater caused an increase in Na, Ca and Mg elements, a decrease in Fe and an increase in soil EC and SAR compared to the control area. It is recommended to investigate the long-term effects of irrigation with wastewater on the concentration of elements, especially heavy metals, in soil and plants in order to achieve more accurate results.

Wheat is considered the most important grain and one of the vital food products in Iran. After nitrogen, phosphorus is the most important nutrient required by plants and holds a high priority for the growth, yield and quality of plants. However, due to the introduction of phosphorus in various reactions in the soil, a small amount of consumed phosphorus fertilizer is removed by the plant and the rest of it is left in a non-absorbable form in the soil. The efficiency of using phosphorus fertilizers and the availability of this nutrient is considered as a limiting factor for the production of agricultural products in calcareous soils with alkaline reaction of Iran. Since graphene and its oxidized form, with large amounts of active oxygen groups and high specific surface area, have been proposed by many studies as non-toxic and biocompatible materials in the production of compounds with improved efficiency of using nutrient, therefore to increase the efficiency of phosphorus consumption in soil, in this study, phosphorus was loaded on graphene oxide (GO-P). The present study aims to assess the influence of this compound as a source of phosphorus and its mixing with triple superphosphate fertilizer (GO-P-TSP) compared to triple superphosphate soluble fertilizer (TSP) on the amount of water retention of fertilizers in soil and phosphorus concentration in aerial parts of wheat plant.

Methods and Materials:

Graphene oxide was prepared based on the modified Hamers method. Then graphene oxide was adjusted to certain pH and iron sulfate as a source of iron ions was added to the graphene oxide suspension with vigorous stirring. The mixture was stirred for one hour and then centrifuged for 30 minutes. Then the supernatant was removed and the residue of the compound was dry frozen. In the next step, pH was adjusted with sodium hydroxide (NaOH) solution. Then a certain weight of potassium dihydrogen phosphate salt (KH2PO4) was added to the above suspension. The mixture was stirred for one hour and centrifuged for 30 minutes. After centrifugation, the supernatant was removed and the remains of the phosphorus composition based on graphene oxide were dry frozen. Loading tests were performed in three replicates. pH, EC, bulk density, total concentration of phosphorus and iron and X-ray diffraction spectroscopy (EDS) analysis were measured in the sample of phosphorus composition based on graphene oxide. Then three fertilizer formulations were selected, which included (1) triple superphosphate fertilizer, (2) synthesized phosphorus fertilizer based on graphene oxide, and (3) mixing graphene oxide-phosphorus compound with triple superphosphate fertilizer in a ratio of 50:50% phosphorus.To investigate the water retention behavior of fertilizers in the soil, dried samples of the three studied fertilizer formulations was added into a sandy soil completely and weighed. At the same time, dried sandy soil without fertilizer was placed in another beaker as a control.Then each beaker was added distilled water and weighed. The beakers were weighed once every three days at room temperature until they reached constant mass. The water-retention behavior of the soil was calculated.In order to investigate the effect of three fertilizer formulations on phosphorus availability, soil with low amount of phosphorus was selected and physical and chemical properties of the soil sample were measured at a depth of 0-30 cm. A greenhouse experiment on wheat planting was conducted using a randomized complete design with 3 replications. The treatments included three fertilizer formulations at three fertilization levels (10, 15, and 20 mg kg-1) with 3 replications. The control treatment was performed without phosphorus fertilizer. Plants were harvested 72 days after planting, washed with distilled water and dry with tissue paper. The samples were air-dried and then oven dried at 70˚C to a constant weight in a forced air-driven oven. After harvesting, the weight of fresh and dry matter and phosphorus concentration in the soil and aerial parts of the plant were measured. Statistical data were analysed using SAS software (9.4) and the mean values were compared using LSD tests (at 1 and 5% level).

The composition of phosphorus based on graphene oxide (GO-P) in powder form had 35.5% of total P2O5, 31.1% of soluble in water P2O5, 19.6 of total iron and 15.28% of total potassium. The result of EDS analysis confirmed the loading of phosphorus on graphene oxide. The pH of the phosphorus composition based on graphene oxide was 5.8, approximately 2.5 units higher than triple superphosphate fertilizer. The bulk density of the compound (GO-P) was significantly lower than triple superphosphate fertilizer. The EC of the compound (GO-P) was similar to the EC of the triple superphosphate fertilizer. Soil water retention with synthesized phosphorus fertilizer based on graphene oxide (GO-P) was higher than soil (control) and other compounds added to soil. Experimental results showed that the addition of prepared fertilizer formulas (GO-P and GO-P-TSP) increased water retention in the soil for a longer period of time, while in the soil without adding fertilizer and triple superphosphate treatment, respectively, from 10 and 11 days, the absorbed water completely evaporated. Therefore, the combination of soil with GO-P and GO-P-TSP compared to the soil without fertilizer and the combination of soil with triple super phosphate (TSP) fertilizer had better water retention behavior. The greenhouse experiment results of wheat planting showed that all treatments were significant (P<0.01). Among all the treatments and measured levels, the control treatment showed the lowest value. The highest concentration of phosphorus in aerial parts of wheat (0.31%) and in soil after harvesting (9.5 mg kg-1), fresh (10.6 g per pot) and dry weight (2.03 g per pot) of aerial wheat plants were related to the treatment of phosphorus compounds based on graphene oxide at the level of 20 mg kg-1.

The highest concentration of phosphorus in aerial parts of wheat was related to the treatment of phosphorus compound based on graphene oxide at the level of 20 mg kg-1. Therefore, with more research in the future to produce "nutritious plants" in sustainable, efficient and flexible agricultural systems, we can benefit from technologies based on carbon materials.

Dust emission is considered as one of the environmental hazards in arid and semi-arid regions. Understanding the effective variables in increasing dust mass density is very important for early warning and reducing its imposing damages. One of the main and effective variables in the occurrence of dust is the geographical and climate characteristics of the origin areas and areas affected by this phenomenon. Feeding the great rivers of Mesopotamia, it has reduced soil moisture. Also, the wind component is one of the reasons for the increase in dust in these areas. This study examines the relative importance of climatic variables to investigate seasonal and monthly changes in dust emission in West Asia and parts of South and Central Asia.

This study has examined West Asian dust from three perspectives spatial distribution, trends, and their relationship with climate variables. For this purpose, the Dust Column Mass Density (DUCMASS) variable output of the MERRA-2 dataset was used to investigate the spatial distribution of the dust mass density trend, and the AgERA5 dataset was used to investigate the seasonal and monthly changes of precipitation, wind speed, and temperature variables from 1981 to 2020. In this study, the modified Mann-Kendall (MMK) trend test method was used to investigate the trend of dust occurrence in the study area, and the Sen's slope estimator (SSE) test was used to investigate the slope of the trend and to better display the changes in dust mass density in the western region. the results of the SSE test have been examined on a decade scale.

Investigating the possible climate drivers in the changes of dust mass density for different regions by calculating the correlation between the time series of dust mass density and the variables of temperature, precipitation, and wind speed has been investigated. The results showed that there is an inverse correlation between dust mass density and precipitation and a direct relationship between dust mass density and temperature and wind speed. The highest correlations between dust mass density and temperature have been calculated, and this value has reached 0.9 in the warm months of the year. On the other hand, the highest negative correlations have been calculated in the cold period of the year (winter and autumn seasons) between dust concentration and precipitation with a value of -0.7. Thecorrelation coefficient between dust mass density and wind speed in the months of January to May and November to December was mostly above 0.6. This value shows a lower correlation in the summer season.In most months of the year, dust mass density shows an increasing trend in most regions, from March to July, an increasing trend in active dust springs in Mesopotamia, the deserts of Iraq and Syria, the desert of Rub' Al Khali, Ad-Dahna and Al Nufud Al Kabir were observed in Arabia and Thar desert in Pakistan. This increasing trend started cyclically from the beginning of spring and reaches its peak in June and July, and the intensity of the trend decreases from September and reaches its minimum value in December. The important point is that the cycle of changes in the monthly trend of dust mass density coincides with the cycle of changes in dust mass density. The northern parts of Iran and Turkey have the highest frequency among different months of the year with a decreasing trend of dust mass density. The increasing trend of dust mass density in the spring and summer seasons in Mesopotamia, the deserts of Iraq, Syria, and Yemen, the Sistan Plain, and the Thar desert in Pakistan and the southeast of Iran was significant at the level of 0.05.

The results revealed that the seasonal changes in dust mass density show well the active sources of dust in the studied area. In the spring and summer seasons, the activity of the dust centers located in the west of the study area, including the Rub' al Khali, Ad-Dahna and Al Nufud Al Kabir deserts, Mesopotamia, the deserts of Iraq and Syria, increases and on the arrival of dust to the west and southwest Iran affects. The investigation showed that climate variables play a key role in the variability of dust mass density in the study area so the areas corresponding to the summer north wind and the 120-day wind of Sistan have shown the highest dust mass density in annual variability. The correlation coefficient between dust mass density with temperature and direct wind speed and its correlation with negative precipitation have been obtained. The results showed that dust mass density has an increasing trend in most of the regions, so from March to August (spring and summer), the increasing trend of dust mass density is significant at the level of 0.05. The highest intensity of the increasing trend was observed in the spring and summer seasons in Mesopotamia, the deserts of Iraq, Syria, and Yemen, the Sistan Plain, and the Thar desert in Pakistan and southeast Iran.

Zinc, copper and nickel are classified as micronutrients in plant nutrition and as trace elements in environmental chemistry. These elements are essential for plants and organisms, but they cause toxicity in high concentrations. The main mechanisms of entering these elements into the food chain is the soil-plant pathway. Trace elements are present in soil in different forms with different solubility. Determining the fractions of these elements reveals more precise information about their status, and the probability of their deficiency or toxicity in long period, and in the case of changing environmental conditions. Fractionation sequence is a procedure for determining different forms of elements.

The present study was conducted on 13 calcareous soil samples around Yasuj. The samples were selected from virgin and agricultural fields without pervious application of trace elements fertilizers, and were not contaminated trace elements. Different forms of zinc (Zn), copper (Cu) and nickel (Ni) were successively extracted with F1) distilled water (soluble), F2) neutral one molar ammonium acetate (Exchangeable|), F3) one molar ammonium acetate with pH 5 (Carbonatic); F4) 0.04 molar hydroxylamine hydrochloride (NH2OH.HCl) in 25% v/v of acetic acid with a pH of 3 (FeMn-oxid associated); F5) 30% hydrogen peroxide (pH 2) with 5 ml of 0.3 M NH4OAc ammonium acetate in 20% by volume of nitric acid (OM associated); and F6) 7 M nitric acid (Residual) in duplicate and were measured with atomic absorption spectroscopy.

Water extractable zinc, copper and nickel; and neutral NH4OAc extractable copper and nickel were not detectable in the studied soil samples. Neutral NH4OAc extractable zinc was detected in 5 soil samples. The abundance of zinc, copper and nickel chemical forms were as follows: Zn- NH4OAc pH 7< NH4OAc pH 5 Zn< H2O2 Zn< NH2OH.HCl- Zn< HNO3- Zn; H2O2 Cu

The present study showed that the amount of trace elements is generally less than 100 mg/kg and most of these elements exist in residual or stable form. An increase of calcium carbonate can be associated with a decrease in the total amount of these elements and cause their deficiency.

This experiment was carried out in a field near the village of Takhshi Mahalle, located 5 km northwest of Gorgan city with geographical coordinates (54° 17´ 56 ʺ N) (52° 51´ 36 ʺ E) in 2022. The physical and chemical properties of the soil were measured at a depth of 0-30 cm in different parts of the farm and the final composite soil was analyzed in the laboratory. Water was measured using conventional methods of sampling and testing water and wastewater. The experiment was conducted as a randomized complete block design with 3 replications. The treatments included control (with distilled water), foliar spraying of iron sulfate micronutrient elements [FeSO4.7H2O (20%Fe)], zinc sulfate [ZnSO4.7H2O (22% Zn)], and iron sulfate + zinc sulfate at a concentration of 5 per thousand at the 4-leaf stage, the 8-leaf stage and both stages (4-leaf and 8-leaf). Foliar spraying was done in the early morning and drip irrigation was used. Plants were harvested 120 days after planting, washed with distilled water and dried with tissue paper. The samples were air-dried and then oven dried at 70˚C to a constant weight in a forced air-driven oven. Iron and zinc concentrations were determined by an atomic absorption device. In order to determine the protein percentage and yield in different treatments, total nitrogen was measured by the Kjeldahl method. The protein percentage and yield were calculated using the following formula:  
Statistical data were analysed using SAS software (9.4) and the mean values were compared using LSD tests (at 5% level).

The obtained results showed that all treatments effects were significant (P<0.01) (fresh forage P<0.05). Among all the treatments and measured traits, the control treatment showed the lowest value. The highest iron concentration with an average of 175.14 mg kg-1 was obtained using iron foliar spraying in both 8 and 4 leaf stages, which increased 22.73 and 34.39% in comparison with only using iron foliar application in 4 and 8 leaf stages, respectively. Zinc foliar spraying at both the 4 and 8 leaf stages resulted in the highest zinc concentration of 71.02 mg kg-1 in forage corn, increasing zinc concentration by 89.86% over the control. In both 4 and 8 leaf stages, an iron and zinc foliar application had the highest chlorophyll index with an average of 57.63. The highest nitrogen content, averaging 2.80%, was observed following foliar spraying of iron and zinc during both the 4 and 8 leaf stages. This represents an increase of 5% and 23.92% compared to iron and zinc foliar application treatments during the respective stages. Consequently, the highest yield and protein percentage were also attained, averaging 310.75 grams per square meter and 17.50%, respectively, with simultaneous foliar application of iron and zinc during both the 4 and 8 leaf stages. 

The optimal outcomes for measured traits were observed when iron and zinc were concurrently applied at both the 4 and 8 leaf stages. Therefore, it is advisable to administer iron and zinc simultaneously during these growth stages to ensure the attainment of forage with desirable quantitative and qualitative characteristics.

Corn is one of the most widely consumed cereals in the world, which is highly compatible with many climates. For this reason, corn has been cultivated in most regions of the world since ancient times. Therefore, it is also considered a part of people's food all over the world. The effect of nitrogen fertilizer, as an agricultural solution, on the growth and yield of corn has caused it to be split to increase the plant's access time to this nitrogen source. In fact, due to the leaching of nitrogen fertilizer, it is usually not applied in one step. For this reason, based on the prevailing conditions of the field, the operators divide it into two or more divisions and perform nitrogen fertilization during the growth period. In each division, it is necessary to determine and apply the optimal amount of nitrogen fertilizer in order to minimize environmental pollution in addition to being economical. It requires many field experiments, which require a lot of time and money. To solve this problem, the use of simulation and optimization models, such as response-surface modeling, is suggested. The response-surface method is one of the suitable optimization tools that has been considered in various sciences for many years. The statistical basis of this method is very complex and uses a multi-objective nonlinear model for optimization and modeling. The response-surface method first provides a suitable combination of treatments, and by considering them, a statistical model is created that has the best fit compared to other models. Next, the most optimal value is determined for the independent variables so that the value of the dependent variables reached their maximum or minimum.

For this purpose, the data collected from a research project, which was carried out in the 500-hectare farm of the Seedling and Seed Research Institute in two years (2011-2012), were used. Two factors consisted of fertilizer in three levels (N1: 100 and N2: 60% and N3: 50% of fertilizer requirement) and the time of splitting into three methods (T1: the farmer's application with two splittings; T2: three equal divisions and T3: four equal divisions) was considered. The response surface method was used to optimize yield and yield components. In the response-surface method, the code of -1, 0, and +1 for nitrogen indicates 50, 60, and 100 kg/ha of nitrogen fertilizer, respectively. The code of -1, 0, and +1 for fertilizer splitting indicates the number of 2, 3, and 4 nitrogen fertilizer splitting during the growing season, respectively. In this method, to fit the data, multivariate regression was used by adding linear terms, quadratic, and interaction between factors. Then, regression was evaluated based on the analysis of variance. The statistical criteria used included root mean square error (RMSE), normalized root mean square error (NRMSE), mean bias error (MBE), model efficiency (EF), index of agreement (d), and coefficient of explanation (R2).

The results of ANOVA showed that the linear and quadratic regression model for seed yield and the linear regression model for fertilizer efficiency was significant at the 5 % probability level (P-value ≤ 0.05). For water productivity, the splitting factor had a greater effect on the regression than the amount of fertilizer, although both factors did not show a significant effect. The regression model had a significant effect on the 1000 seed weight, number of seeds in a row, number of rows in a cob, cob length, and seed size. The regression of other variables was not statistically significant. Therefore, the response-surface method can be used to predict and optimize variables with significant regression. The results showed that the regression model was capable of predicting variables including 1000 seed weight, number of seeds in a row, number of rows in a cob, corn length, and seed zinc content. But this model had an underestimation error (MBE ≤ 0.0) for all variables. The accuracy of the regression model for grain zinc content was in a good category (0.1 < NRMSE < 0.2) and for other variables in the excellent category (0.0 <NRMSE< 0.1). By increasing the amount of fertilizer (changing from code -1 to + 1), the yield initially decreased and then increased. With the increase of fertilizer splitting, corn yield decreased first and then increased. The effect of the amount and splitting of fertilizer on changes in the 1000 seed weight was linear and with the increase of these two factors, the 1000 seed weight also increased. This result was also observed for the number of seeds in the cob. In terms of cob length and grain zinc percentage, the two factors of fertilizer amount and splitting had similar effects on the increase of these two variables, but at low values of both factors, the mentioned variables decreased slightly. Increasing the amount and distribution of fertilizer caused an increase in the number of rows in the cob, but high amounts of these two factors had no effect on the increase in the number of rows in the cob. Except for the number of rows, other variables increased along with increasing the amount of fertilizer and its splitting. Providing 100% fertilizer requirement and increasing the number of divisions to 5 times, can increase maize yield by up to 1.5 tons per hectare. This was about 28% of the average yield and 6 % of the maximum corn yield in this study. The weight of the thousand seeds increased to 3.5 grams under optimal conditions, which increased by 32 and 9 % compared to the average and maximum values in this study, respectively. The variable of the row was not much of a change in the average variable (1.5 cm) and increased by only 1 %. The optimal length increased to 3.5 cm and the optimal rate increased to 62%.

In general, the optimization results of all variables showed that if the fertilizer requirement is applied as N1 and in five splittings; the amount of yield, 1000 seed weight, the number of seeds in a row, the length of the cob and the amount of seed will increase by 6, 9, 12, 18.5, and 19.6% respectively compared to the maximum values of these variables. Therefore, it is suggested to apply this scenario in the field to improve yield and yield criteria such as zinc concentration in corn seeds.

Tea is a permanent and evergreen plant that grows adeptly in acidic soils. The tea plant naturally absorbs aluminum and accumulates it in various shoot parts. Although aluminum is essential for tea growth, it is harmful to human health. Evaluating aluminum status in both soils and tea green leaves is necessary to better understand their relationships in order to improve the quality as well as quantity of tea yields. For this purpose, 38 samples of the soils and the third green leaves of tea (as an index leaf) were collected randomly from tea plantations of Guilan Province. In soil samples, besides the general properties, the values of pHw, pHCaCl2, exchangeable aluminum, calcium and magnesium, total nitrogen and available concentrations of phosphorus and potassium were determined. Concentrations of the aforementioned nutrients along with iron and zinc were also evaluated in the tea leaves. Based on the results, the mean values of pHw and pHCaCl2, and the mean concentrations of soil exchangeable aluminum and leaf aluminum were 4.51, 4.04, 256 mg/kg, and 1362 mg/kg, respectively. The soil exchangeable aluminum had inverse power relationships with pHw and pHCaCl2 with the coefficients of determination of 66% and 84%, respectively. This indicated that the pHCaCl2 was more valid than pHw. Leaf Al concentration showed no significant correlation with soil pH, but had significant relationship with soil exchangeable aluminum (r=0.69**). Furthermore, the total polyphenol content of the green tea leaves had no significant correlation with leaf Al concentration, but had significant relationship with (Al/(Fe+Zn)) ratio in tea leaves (r=0.64***). According to the lower limit of optimum pH for tea plantations (pH=4.5), the maximum permissible concentration of soil exchangeable aluminum was estimated to be 153 mg/kg. In order to control soil exchangeable aluminum and adjusting soil pH, it is recommended to use lime or dolomite, based on the soil buffering capacity.

In the world, attention to the content of heavy metals in the soil has increased due to their potential risks to the environment and human health. In recent decades, many studies have been reported on soil contamination by heavy metals in Iran, but most studies do not show heavy metal status in soils on a national scale. On the other hand, despite the importance of background concentration of heavy metals for the assessment of pollution and environmental risks of these metals, no study has yet been published for soils of Iran at the national scale. In this study, an attempt was made to provide a comprehensive understanding of the status of heavy metals in soils of Iran on a national scale based on quantitative and qualitative analysis of the results of studies reported. To conduct this research, a total of 247 studies (both articles and final reports of research projects on field monitoring of heavy metals in soils of Iran that were published until November 2021 were collected. The required information (analysis results of about 21,400 soil samples) were extracted from the studies and first evaluated in terms of quality assurance and quality control criteria. Then, studies were classified into agricultural, urban and industrial based on the type of land use, and after screening and selecting studies that had the minimums required in terms of quality control, various statistics such as weighted average, median, background concentration and pollution index for heavy metals As, Pb, Cd, Cr, Co, Ni, Cu and Zn were calculated and analyzed....

The process of soil particles splash by raindrops and their transport by splash or surface shallow flow is considered as interrill erosion, which can reduce soil fertility and cause surface water pollution. Slope gradient and soil type can be the main factors affecting interrill erosion processes in semi-arid regions; therefore, it is important to determine which soil textures in such slopes are more sensitive to interrill erosion processes. This research was conducted to investigate the effect of surface slope on interrill erosion in different soils. For this purpose, laboratory experiments were carried out on eight soils with different texture (silty clay, clay, sandy loam, sand, loam, sandy clay loam, clay loam, sandy loam) on tree slopes (10, 20 and 30%) under simulated rainfall (a constant intensity of 30 mm.h-1) with three replications (72 test units). The interrill erosion was measured at intervals of one minute from beginning of runoff in each experimental unit. The results showed that interrill erosion in all soils is affected by soil texture (P<0.0001), surface slope (P<0.0001) and their interaction (P<0.0001). Loam soil was the most susceptible to interrill erosion (10.76 g.m-2.s-1) and sandy soil was the most resistant soil (0.75 g.m-2.s-1). Surface slope had a significant effect on the amount of interrill erosion in all soils (P <0.000). Also, with increasing the slope percentage, the amount of interrill erosion in all textures increased significantly. This shows that it is necessary to prevent surface erosion in fine textured soils, especially on slopes in Zanjan region.

Wastewater treatment of steel industries as one of the most important and water-consuming industries is of high important, especially in terms of wastewater reuse. One of the most important and newest methods for industrial wastewater treatment is the coagulation and flocculation method, in which the efficiency of the process can be greatly improved by controlling various factors such as temperature, pH, retention time and coagulation concentration. In this study, the efficiency of polyaluminum chloride in removing the turbidity of simulated hot-rolled effluent of a steel plant was evaluated in the presence of independent variables of pH, stirring time, temperature, oil concentration and suspended solids. The experiments were performed by Design expert 8 software. To do so, the central composite design method was applied as the most common type of design in the response procedure method. The results showed that increasing the polyaluminum chloride coagulant to about 5 mg / l increases the turbidity removal efficiency, thus reducing the turbidity to less than NTU 20, which is a standard for water turbidity used in the rolling process. Increasing the temperature from 27 to 55 degrees has slightly enhanced the turbidity removal efficiency. According to the test design results, the best turbidity removal efficiency from the studied effluent (51 to 62%) was achieved at polyaluminum chloride of 1 mg / l, the amount of suspended solids of 1500 mg / l and the stirring time of 30 seconds. In this case, the range of turbidity removal efficiency was. The results showed that pH, temperature and oil content had the lowest effectiveness. Overall, the results of the present study indicate that the optimal addition of polyaluminum chloride to the effluent improves the effluent turbidity removal.

Chromium is one of the heavy and toxic metals for microorganisms, animals, and plants, which the use of the sources that contain them may lead to serious environmental pollutants. High concentrations of chromium are considered a stress factor for plants that can affect plants' physiological and biochemical properties as a growth-limiting factor. Due to an active chromite mine in the Forumad area of ​​Mayamey city, Semnan province, this research is to determine the status of chromium contamination in water resources, the soil of the region, and plant samples. Regarding the mentioned issue and for the identification, simultaneously sampling of all water resources in the region, including wells, springs, and aqueducts, are implemented. Besides the qualitative analysis and determination of ions (anions and cations), the total chromium concentration is investigated in the Soil and Water Research Institute. The results indicate pollution centers in the areas of Forumad, Pole Abrisham, Estarband, Kalateh-ye Sadat. A sampling of crops, horticulture, and medicinal plants in the region showed that the amount of chromium adsorption in pepper as a national index product of the region was less than the allowable limitation (less than 1 mg/kg), and the initial concerns were largely resolved. The absorption of total chromium in pistachio and pear crops is also within the allowable range, considered in the region's cultivation program. Since the absorption of chromium in sesame seeds, wheat, alfalfa, figs, and some crops is higher than the allowable level, incentive policies should be implemented to improve the cultivation pattern and replace it with contaminated crops. Contamination of soil sources in the region with chromium was investigated at 32 points. The results showed that almost all soil samples are more contaminated with chromium (range 386-142 mg/kg). The results showed that the concentration of total chromium in the four samples sent from Forumad and the Pole Abrisham before treatment was 123.5, 107.2, 127, and 110.6 μg / l after treatment of zero, 6.7, zero, and 4.2 μg / l, which indicates the use of reverse osmosis in drinking water.

Low availability of some nutrients is one of the major factors for the widespread occurrence of plant nutrient deficiency in calcareous soils. Therefore, any strategy for solution of this problem is important. For this purpose, an experiment was carried out in four sites (Chogha Narges, Mahidasht, Najaf Abad and Ghomsheh in Kermanshah Province), with different contents of available sulfate, using complete randomized blocks design with three replications, in 2018-19. The amounts of sulfur paired with Thiobacillius bacterium inoculants included no sulfur (S0), 250 kg sulfur/ha along with 5 kg/ha Thiobacillus bacterium inoculant (S1), 500 kg sulfur/ha with 10 kg Thiobacillus/ha (S2), and 1000 kg sulfur/ha with 20 kg Thiobacillus/ha (S3). The combined analysis results showed that the effect of sulfur, location, and their interaction on grain yield, 1000- grain weight, oil percent, and nutrients concentration in rapeseed grain in Chogha Narges, Mahidasht, Najaf Abad, and Ghomsheh were significant at 1% (p<1%). The highest grain yield, 1000- weight, oil percent and nutrients concentration was obtained in S3 treatment, which increased wheat yield by 647, 756, 474, and 406 kg.ha-1 in Chogha Narges, Mahidasht, Najaf Abad, and Ghomsheh, respectively, compared to the control treatment. Oil percent increment at the mentioned regions were 2.1%, 1.4%, 1.2%, and 0.5%, respectively.

Soil loss can cause many intra-regional and extra-regional problems, on the other hand, the effect of soil moisture on processes of soil loss and sediment yield for the identification and simulation of soil hydrological response is necessary. Therefore, the application of soil conditioners is essential for soil and water conservation. The present study was conducted to investigate the effect of soil conditioners of vermicompost and nano-manure on variables of soil loss and sediment concentration at moistures of air-dried, 15 and 30%, and rainfall intensities of 50 and 90 mm h-1. The obtained results in addition to confirmation of the significant effect of each conservation treatment at the level of 99 percent on the intended components showed that the conservation treatment of vermicompost compared to nano-manure treatment had more effect on measured variables. Also, the conservation treatment of vermicompost could decrease the soil loss at soil moisture air-dried, 15, and 30 percent with rates of 72.15, 66.63, and 78.76 percent (50 mm h-1), respectively, and 45.01, 35.57, and 10.45 percent (of 90 mm h-1), respectively. The effect of conservation treatments, soil moistures, and rainfall intensity and the interaction effects of conservation treatments × rainfall intensity and rainfall intensity × soil moisture on changes of soil loss and sediment concentration were significant at the level of 99 percent. The application of vermicompost and nano-manure had acceptable results on studied parameters but the vermicompost effect was more than nano-manure. Therefore, due to the widespread use of different types of conditioners, nowadays, it is needed to move the application feasibility of conditioners such as vermicompost and nano-manure that these have not the adverse effects of environmental.

Fluorine (F) is a necessary element for human and plant, however, high concentration of this element poses a risk to grazing animals and plants. Soil ingestion has been highlighted as a pathway for causing possible F toxicity in grazing animals. In this paper, total and soluble F concentrations and their relationships with selected soil properties in soils around Ahar City, East Azarbayjan Province, were studied. For this purpose, 21 composite soil samples were taken from around Ahar City and their major characteristics, total F concentration, and soluble F were measured. Results showed that the Ft and FCaCl2 concentrations ranged from 204.7- 574.3 and 0.7- 5.9 mg F kg-1soil with means of 334.8 and 4.1 mg F kg-1soil, respectively. These values were well within the range of non-polluted soils. Total fluorine showed significant correlation with total P concentrations, organic matter, and Al oxides contents of the studied soils; whereas such correlations were observed for total and free soluble fluorine concentrations with organic matter and pH, respectively. Concentration of F species in soil solution was much less than the critical concentrations of F for plants (0.3-0.5 µg/mL for oat and 32 µg/mL for tomato). In general, it seems that at normal soil ingestion rates, the soils are unlikely to cause F toxicity to grazing animals.

Soil erosion is one of the most serious environmental issues in the world, causing soil degradation, reduction of land productivity, increasing flood, water pollution and pollutions transportation; it is also a serious threat to sustainable development in the world. Therefore, the soil conservation and the prevention of soil erosion and use of conditioners as the nanoclay can be considered as a solution to improve   land productivity and protect environment. The present study was, therefore, conducted to address the effect of the application of montmorillonite nanoclay with three rates of 0.03, 0.06 and 0.09 t ha-1 on changing runoff and soil loss variables under laboratory conditions. The results showed that the nanoclay with the rate of 0.03 t ha-1 could decrease the runoff coefficient, soil loss and sediment concentration with the rate of 40.65, 88.38 and 82.19 percent, respectively. The average of soil loss in control treatment and conservation treatments of nanoclay with various rates was measured to be 3.76, 0.44, 1.33 and 3.16 g, respectively. Also, the results showed that the most sediment concentration was the control treatment with the rate of 5.84 g l-1 and the conservation treatments with nanoclay in the applied rates was 1.04, 3.47 and 2.96 g l-1, respectively. Also, the results showed that the nanoclay effect was significant on changing the soil loss and sediment concentration at the level of 99 percent. Finally, due to the effect, the use of this conditioner in natural conditions and investigation of the effects on environment and aggregates stability are recommended.

WaterGEMS software provides a numerical model which simulates different parameters in water supply systems based on the principles of hydraulics. The most remarkable chemical substance used in water refinement procedure is the chlorine. Hence, WaterGEMS software models the chlorine to detect its concentration in each pipes of the water supply system. If the chlorine concentration exceeds 3mg/lit, it would be dangerous for the Man health. In addition, the model may calculate water age in water supply networks. And more, the WaterGEMS can trace the chlorine substance as well. In this research, the chlorine concentration, water age and chlorine trace parameters have been simulated by WaterGEMS for a case study: Vahidieh district (located on the west part of Tehran province). Meanwhile, other quantitative items have also been calculated in Vahidieh water supply network system. For example, flow discharge, flow velocity, water head loss in pipe networks. This is because, there are important relationships between qualitative and quantitative parameters for the optimization design of water supply networks. For more comfortable comparison and interpretation of the above concept, three pipes in different places of Vahidieh water supply network have been chosen (i.e. 18th,168th and 293th pipes put in the left, middle and right side of water supply network, respectively). The innovation of present research work is to provide quantitative and qualitative items for the simulation of Vahidieh region where it has not yet been found out up to now. In addition, modeling of all mentioned items will result in a comprehensive view to the design of water supply networks. A miniature previous research work on the subject is mentioned. Aghasi (2018) who has presented a model by WaterGEMS to determine appropriate points for injecting of chlorine in a part of Mashhad water supply network. He concluded that the appropriate points for chlorine injection dependent upon the network geometry, pipes diameter and the pattern of consumption. Javadinejad et al. (2019) utilized a pump and gravitational statuses in Semirom water supply by using WaterGEMS. They stated that in pumping method, water qualitative management may guarantee a better system. Vidhi and Geeta (2019) simulated a rural region in India by WaterGEMS. They resolved that the remained chlorine concentration in the pipes are in standard status (i.e. less than 3mg/lit).

The WaterGEMS numerical model has been designed by Haestad Methods company. Meanwhile, it is dependent upon the American hydraulics council. In the software, the analysis of water distribution networks is given step by step as: firstly, network drawing based on the nodes coordinates, pipes situation, reservoirs, tanks and other elements. Secondly, defining the network hydraulic traits. Thirdly, defining the distribution network for a hydraulic performance. Fourthly, defining the network analysis method. After that by running the software, the network parameters are obtained. Finally, the network quantitative and qualitative results may be achieved. The Vahidieh town water supply network where used as a case study; its population will be 78600 person at the end of 30 years design period. In so, for the total consumption of water will be 215lit/day per capita. The amount of water consumption in the region has been estimated 195lit/s. There are 2 reservoirs and 2 tanks in the new water supply network system. Volume of each reservoir is 5000m^3 and the volume of each tank is 500m^3. Meanwhile, a chlorination house has been designed to disinfect the region water that the maximum chlorine injection will be 3mg/lit. The pipes material was polyethylene. For modeling Vahidieh town water distribution network by WaterGEMS software, first of all, the nodes and pipes are drawn by AutoCAD software. Secondly, the reformed information imports to the WaterGEMS software. In this step, it is necessary to extract nodes altitude codes from ArcView software. Thirdly, other elements of network, consumption pattern and different scenarios are defined. Finally, the software reports will be analyzed and the results are obtained.

In this paper, a successful simulation has been carried out of a water supply network using WaterGEMS software. The numerical simulation reproduced the complex flow patterns in the pipes network associated with a particular water consumption in the Vahidieh water supply network are presented as a case study. On the basis of the analysis made by applying WaterGEMS, the following results are obtained: The chlorine concentration in 18th, 168th and 293th pipes were selected and have been studied, in more detail. Meanwhile, three defined scenarios are used: (1). Primary concentration in reservoirs, tanks, pumps, valves and nodes are 2, 0.5, 1, 1, 0.1 mg/lit. (2). The chlorine concentration reaches to 10 mg/lit in reservoirs, while its concentration is the 1st scenario in other ingredients. (3). The chlorine concentration reaches to 5 mg/lit in tanks, while its concentration is the 2nd scenario in other ingredients. Based upon the numerical model reports in 18th pipe, water age is higher than that of 168th and 293th pipes. According to the Vahidieh town population distribution, less population surrounded by 18th pipe in comparison to the other two pipes. Plus, in 18th pipe, the maximum water age is 3 times of maximum water age in 168th pipe. According to the WaterGEMS reports, under the different scenarios, chlorine concentration in 168th pipe is equal to injected chlorine concentration to reservoirs (the pipe which is closer to reservoirs). In addition, 168th pipe chlorine concentration is 10% higher than the other two pipes under three scenarios. The chlorine concentration computation in the selected pipes indicates much higher influence on the reservoirs chlorine concentration on chlorine concentration in water supply network pipes. Furthermore, based on the third scenario, when the chlorine concentration increases in the tanks, there is not tangible variation in pipes chlorine concentration. The reason is that much higher volume of reservoirs in comparison with the tanks volume occurs. Based upon the obtained results from WaterGEMS reveals that in 18th pipe the maximum water provision probability from the 1st tank is about 45%. Additionally, 168th pipe water provision probability from two reservoirs is the same. Also, 293th pipe water has surely been supplied from 2nd tank. As well, flow velocity, water head loss and water discharge can be studied in each 24hour period based on hourly consumption pattern. Based on the WaterGEMS outputs, the maximum water flow velocity in 18th pipe is 0.3 m/s. This result is reasonable, because of water age item in the pipe which is higher than that of the other two pipes. As a consequent, it seems that sedimentation probably occurs along pipe 18th. Moreover, 168th pipe reaches a maximum head loss of 0.4 meter, and 293th pipe receives a maximum water discharge of 8lit/s.

In the new drainage conditions in the center and southwest of Khuzestan Province, by reducing the depth of drainage installation and controlled drainage, studying the dynamics of the mixing zone, understanding the specifications of this region, and its effect on the flow rate of drainage water and salinity is important. In this study, seven groups of piezometers, each consisting of 8 piezometers placed at different soil depths (0.8 to 5m) and at different distances from the drainage water collector were studied in two research farms, namely, field R9-11 Dabal Khazaei agro-industry (with an average drainage depth of 2 m and distances of 65 m) and field R8-7 in Salman Farsi agro-industry (with an average depth of 1.4 meters and 42 meters distances).Water level in piezometers, water salinity in different soil layers, and drainage water flow rate and salinity were monitored daily in three periods of heavy irrigation of sugarcane (March to October of 2013, 2014 and 2017). Results indicated that by starting a heavy irrigation, hydraulic head increased and hydraulic head variance between bottom layer (4 and 5 m) relative to the surface layers, established vertical flow and saline inflow upwards. Reducing the installation depth of drains up to 60 cm from in R9-11 compared to farm R8-7 and moving away from the collector up to 400 m in each farm, reduced the installation depth of drains up to 40 cm, and increased the hydraulic load by an average of 8-12 cm. The thickness of the mixing area was up to one meter and the reduction of the average salinity line in the mixing area was 8%. It was found that in addition to irrigation water salinity, drainage water salinity was affected by groundwater salinity and the difference in drainage depth, position of the impermeable layer, and the presence of sand lenses. By decreasing drainage depth, the drainage water discharge decreased sharply, such that the averag drainage water from each lateral in farm R9-11 was 10 mm/day, and in farm R8-7 it was 3.3 mm/day. The results showed that with increasing the thickness of the salt and fresh water mixing zone due to the optimal reduction of drainage depth, the volume of water consumed in each irrigation cycle decreased due to plant use of this zone, which can be an effective factor in conserving soil and water resources.

The erosion of the deposited cohesive sediments by flow is a complex phenomenon. In general, hydraulic transmission of fine-grained sediments include depositional processes, consolidation and erosion. Cohesive sediments caused by physical-chemical effects on particle surfaces due to their strong ionic surfaces tend to form masses of low density or flocs. Depending on the conditions of the flow and resistance of the sedimentary masses, the erosion of sediments can occur in three different forms of floc, superficial and massive states (Mehta, 1991; Winterwerp and van Kestern, 2004). This study focuses on the effect of consolidation time on erosion rate of the deposited cohesive sediment in an annular experiment flume.

Considering the high cultivation area of pomegranate in Iran, it is necessary to pay attention to this plant nutrition in order to increase quantitative and qualitative of pomegranate fruit. Nutrition management is one of the most important factors for determining the yield and quality of fruit that there are a few studies to reach the optimal management of nutrition in pomegranate. Therefore, the present study was conducted to investigate the effect of different levels of organic component and chemical fertilizers on quantity and quality characteristics of Punica granatum fruit cv. KhazarBardaskanas a factorial design based on randomized complete blocks design with three replications. Treatments include vermicompost in three levels of 0, 12.5 and 18.75 (V1, V2, V3) kg tree-1 and humic acid in two levels of 0 and 5 g tree-1 (H1, H2) as the soil application and zinc chelate in the two levels of 0 and 0.005 (Zn1, Zn2) as foliar spray. The measured factors were yield, length and diameter of fruit and some qualitative characteristics of fruit juice such as total phenol, antioxidant activity, titratable acidity (TA), total soluble solids (TSS). Also, the concentration of nitrogen, phosphorus, potassium and zinc were determined in leaves. The results of present study showed that the effects of treatments were significant for more measured parameters. The maximum amount of yield 29.09 kg tree-1, antioxidant activity (39.79 %) and total phenol (863.12 mg GAE 100g-1) were observed in V2H2Zn2 treatment of 12.5 kg tree-1 vermicompost, 5 g tree-1 humic acid and 0.005 foliar sprayof zinc. Also, the level of nitrogen, potassium and zinc in the leaves were obtained from the above mentioned treatment (V2H2Zn2), which compared with the control treatment can be recommended as the superior treatment.

Groundwater resources,as one of the most important resources of water supply, have been faced with the qualitative decline and increasing the concentration of pollutants in addition to a quantitive problems in recent years. According to the importance of the role of water supply quality in exploitation, recognizing the aquifer and factors affecting it is very important. This study was conducted to investigate the movement of pollutants with the view of assessing aquifer vulnerability in one of the branches of Zanjan River. Accordingly, two types of intrinsic and special vulnerability in the region were investigated by two methods of drastic and HPI. The results of vulnerability index show that the soil of region is effective in decreasing the concentration of heavy metals under study (lead, chromium, nickel, cobalt, zinc) and the concentration reduces in the direction of groundwater flow. The results of vulnerability index showed that the Drastic index is more than 80% in the medium to low and low ranking and the HPI index of the basin with an average of 30.3 is in the low risk, however, this basin has the potential to develop pollution. In order to determine the direction of pollution and the role of alluvial in the area MODPATH numerical model was used to simulate under the influence of the advection process in order to determine the direction of pollutants movement and the role of alluvium of the region. The numerical simulation of the region was carried out for three years after modeling and calibrating the MODFLOW model. Based on the results, the wells located along the groundwater and surface water flow path in the center of the basin have longer length compared to the wells that are around and far from the center of the basin. Based on the results, different patterns can be used such as creating barriers to modify and reduce the amount of pollutants transfer in this basin and other basins leading to Zanjan River.