مجله محیط زیست و مهندسی آب
سال هشتم شماره 1 (بهار 1401)

The advanced oxidation process using zero-valent iron particles and radicals activated by ultraviolet sulfate to remove phenol from synthetic wastewater is known as a highly efficient method. The aim of this study was to investigate the pH and kintic changes in ZVI/PS/UV process for the removal of phenol from wastewater. Each experiment was performed in a Plexiglas reactor equipped with 2 sources of ultraviolet radiation (254 nm). The characterization of zero valent iron was determined by XRD, SEM, EDAS, and BET analyzes. The results showed that the specific surface area of ​​zero valent iron was 4.43 m2/g. The average size of iron nanoparticles was 35.48 nm. SEM analysis showed that the crystals had a suitable crystalline structure. The adsorption results showed that at an initial pH of 6, the highest phenol removal rate of 94.87%±3.85 was obtained. The kinetic study showed that the ZVI/PS/UV process for phenol removal follows  second order and pH is effective in removing phenol from wastewater.

In this study, quantitative changes in groundwater in Bijar-Divandere plain with MODFLOW code in GMS software were investigated. Aquifer simulation was performed for a period of six years and a monthly step from October 2010 to June 2016. The SPI annual drought index was calculated for the statistical period of 1987-2015. The results of groundwater simulation showed that during the annual simulation period, there was a decrease of about 0.5 m water level in the aquifer, the intensity of which varied in different areas. Therefore, due to the decrease and taking into account the area and the average amount of storage capacity of the aquifer, the volume of the aquifer has been reduced by about 1.3 MCM per year. The results showed that if the current management process continues, over the next few years we will see a sharp decline in the aquifer and irreparable damage. The results of SPI index also indicated that the drought situation was close to normal, which means that drought has a much lesser effect on the groundwater level of the aquifer in different years.

In order to study the concentration of heavy metals in important rivers in the southern part of the Caspian Sea, samples were collected in three upstream points, estuary and depth of 1 to 10 m of the sea, a surface sediment sample and a core sample. Granulation analysis, organic matter assay, and determination of heavy metal concentrations were performed on each sample. The highest concentrations of iron (45000 ppm), aluminum (74000 ppm), chromium (142.78 ppm), cobalt (33.67 ppm) and lead (56.70 ppm) in Ramsar, arsenic (18.45 ppm) and Zinc (110.3 ppm) was observed in Gorganrood river, nickel (60 ppm) in Qarahsu river and copper (52.63 ppm) in Sefidrood. Moreover, the lowest concentration of elements in the core of Gorgan Bay (K5) and a depth of 85 cm with an approximate age of 1400 years was obtained, which was used as the baseline reference. Based on the contamination degree (Cd) index, three rivers of Babolrood, Cheshmeh Kileh and Sardabroud were classified in the range of moderate contamination and Gorganrood, Qarahsoo, Tajan, Ramsar and Sefidrood rivers were classified in the area of ​​significant contamination. Based on the modified contamination degree index (mCd), all rivers were in the range of low to medium contamination degree, and pollution load index (PLI) was in the range of more than 1 (slightly polluted to polluted) at most stations. In terms of ecological risk index (RI), rivers were in the low-risk range. Enrichment index (EF) in sediments of estuarine sections showed that the rivers are probably enriched by various factors such as geology, climatic conditions, and human factors having moderate to severe pollution.

The occurrence of oil spills in the seas and oceans causes many short-term and long-term damages to the coasts and marine ecosystems. Therefore, in order to reduce the damage, comprehensive coastal vulnerability maps can be provided to coastal management decision-makers as well as the emergency response team as a powerful tool. In the present study, by combining the mathematical model of oil slick routing and ArcGIS software, the northern coasts of the Persian Gulf were evaluated based on exposure to oil pollution. For this purpose, 20 hypothetical fall scenarios with oil type and time of random occurrence in summer and winter were designed. Then, using GNOME Lagrangian software, the path of the oil slick and its arrival time to the shores were simulated, and based on that, the matrix of exposure of each coastal area to pollution was formed. Finally, the northern shores of the Gulf were classified into five levels of vulnerability. The results showed that in summer Assaluyeh and Bushehr ports with a cumulative probability of 120 and 94%, respectively, and in winter Assaluyeh port with a cumulative probability of 119% in all scenarios were in a very high vulnerability. In addition, the ports of Bushehr and Assaluyeh had the highest potential for damage to the region. According to the results of this study, coastal vulnerability is significantly affected by seasonal changes in climatic conditions and flow conditions.

The aim of this study was to investigate the effect of different levels of drip irrigation treatment on yield, yield components and quality of green tea leaves during drought. This research was conducted for the first time during 2017 and 2018 in the tea garden in Bazkiagorab area of ​​Lahijan in Gilan province. The experiment was performed as split plots in a randomized complete block design with three replications. Irrigation treatment considered was consisted of five levels of 0, 25, 50, 75 and 100% of irrigation needs. Drip irrigation program in the period of water stress was carried out twice a week based on monitoring soil moisture at the depth of root development. Full irrigation of 2225 and 1610 m3/ha in two successive years of experiment caused the production of harvestable shoots in summer to increase by 162 and 153%, respectively, compared with the area without irrigation. Increased water stress at incomplete irrigation levels led to an increase in solids (woodiness) of tea shoots. Conversely, as the amount of irrigation water in the drip irrigation system increased, the weight of the shoots increased. The biennial average of the highest yield of green tea leaves was equal to 9125 kg/ha with 100% irrigation requirement and the lowest yield of 3468 kg/ha was obtained from the area without irrigation. Improvement of tea quality characteristics such as total polyphenols, caffeine, total ash and nitrogen percentage of shoots was also observed by complete irrigation in the drip system.

Phytoremediation is one of the most important sustainable biological methods to deal with the increasing effects of pollutants. In this study, the efficiency of Avicennia marina for refining heavy metals such as lead, cadmium and nickel from aqueous media was investigated. For sampling of mangroves and sediments in 2019, 20 stations throughout Khorkhoran wetland located in the west of Bandar Abbas were identified and samples were collected from water, sediments and different parts of the plant. According to the results, the highest accumulation of metals with a value of 4.38 mg/kg in the root of mangrove was related to lead and the lowest accumulation of metals with a value of 0.261 mg/kg in the root of the mangrove was related to cadmium. The results of transfer coefficient for lead and cadmium in mangrove roots was greater than 1 and for nickel less than 1. Moreover, there was a statistically significant correlation between pH and temperature parameters with the mean concentration of all heavy metals in sediment and between EC and the mean concentration of all heavy metals except nickel in water (P> 0.05). According to the results, the difference in the concentration of metals in the leaf and root tissue of mangroves may be due to differences in the physiological structure of the tissues; Therefore, mangrove roots seem to be more suitable than heavy leaves for refining heavy metals.

Sulfur is one of the elements in fossil fuels that is converted to sulfur dioxide, which is one of the most important air pollutants, when burned in a car engine. In the present study, the adsorption capacity of an organic sulfurized compound from a diesel fuel model containing 300 ppm thiophene was evaluated using x13 zeolite modified with 3% by weight of copper metal. Moreover, the effect of three parameters of contact time (15, 30, 60, and 120 min), adsorbent value (0.5, 1, 2.5 and 3.5 g) and temperature (25, 40, 50 and 60 °C) was assessed in a discontinuous system. In order to activate the adsorbent surface cations, x13 zeolite was washed with deionized water and 0.1 M copper nitrate salt and then copper nanoparticles were loaded on it. The maximum adsorption capacity was 2.5 g of adsorbent at 60 min at room temperature, and the amount of thiophene for adsorption modified with copper nanoparticles increased from 300 to 138 ppm. The adsorption results showed that an increase of more than 2.5 g of adsorbent would not cause a significant change in the adsorption efficiency. In addition, FT-IR, SEM and N2 physisorption studies showed that the adsorbent would maintain its regular structure after nanoparticle loading. Finally, the modified zeolite showed better performance for desulfurization of the diesel fuel model.

Dams are structures that, despite environmental impacts, are built primarily to provide water and energy. The failure of the dam creates a huge current that follows the flood in the downstream areas. For this reason, determining the characteristics of the dam failure current, including the depth of flow and the speed of wave propagation, is of great importance. In this study, the simultaneous effect of the geometric shape of the reservoir on the plan and slope of the sidewall of the reservoir on the pattern and how the flood wave caused by the failure of the dam was performed in a three-dimensional numerical modeling using Flow3D software. For this purpose, four different reservoir shapes were used in the plan, including a wide, trapezoidal, L-shaped and long reservoir with sidewall slopes of 30, 45, 60 and 90 °, taking into account the downstream dry bed. The results of three-dimensional numerical modeling showed that in all studied reservoirs, by decreasing the lateral slope of the reservoir wall, water level fluctuations increased due to the formation of two negative waves that spread on the slope of the reservoir wall and reached the central line of the reservoirs. Moreover, the effect of the geometric shape of wide and trapezoidal reservoirs on the flow characteristics due to dam failure was greater than the effect of reducing the slope of the sidewall of these reservoirs. While in long and L-shaped reservoirs, reducing the slope of the sidewall of these tanks has a great effect on the flow characteristics due to dam failure.

Wick irrigation is a combination of subsurface and pot irrigation methods that provides water to the plant roots through the wick by means of capillary ascent. The salient features of this method are the elimination of evaporation losses and deep penetration, and thus increase plant yield and water use efficiency. The purpose of this study was to investigate the performance and water use efficiency of a wick system designed for corn cultivation in comparison with surface-furrow irrigation method. In this study, after reviewing and selecting the most suitable wick, field studies with two treatments of wick irrigation and furrow irrigation were performed in the summer of 2017 in one crop season and the wick system was prepared and implemented. Based on the results obtained, the total volume of water consumed in the wick system has decreased by about 30% on average compared with the surface system and its wet and dry performance has increased by about 1.4 and 1.7 times, respectively. Therefore, water use efficiency for maize plant in wick irrigation method increased by 2.5 times compared with surface method. The results show the effectiveness of wick irrigation method on yield and water use efficiency for corn cultivation in semi-arid areas compared with surface-furrow irrigation method.

The effect of fluctuating pressures due to turbulence on the hydraulic jump causes significant damage to the relaxation pool. Moreover, the presence of roughness in the bed changes the behavior of flow lines and the formation of vortices during the jump. Therefore, the aim of this study was to determine the effect of the presence of roughness on hydrodynamic pressures in type S hydraulic jump in sudden divergence sections. For this purpose, experiments were performed in a relatively large channel with a width of 0.8 and a length of 12 m in the calm pool with divergence ratios of 0.33, 0.5, 0.67 and 1 in the range of Frued numbers between 2 to 9.5. Roughness elements with a height of 3 cm and specified distances were placed in the channel bed and downstream of the divergence section. In order to determine the effects of roughness on the level of hydrodynamic pressures, the experiments were performed in two separate stages, including a completely flat pool bed without the presence of roughness in the first stage (77 experiments) and with the presence of roughness in the pool floor in the second stage (81 experiments). The results showed that the presence of roughness in the bed reduces the intensity of pressure fluctuations in the relaxation pool. In addition, in sudden divergent sections, due to the formation of lateral vortices, the energy drop increases and the intensity of pressure fluctuations decreases. The maximum reduction rates of pressure fluctuations were estimated to be 27, 46 and 58% for the divergence ratios of 0.67, 0.5 and 0.33 in the rough bed, respectively.

So far, several researchers have conducted many studies on the effective parameters in the design of river breakwaters, which are mostly laboratory-based and are used for limited conditions. Therefore, the aim of the present studywas to optimal design of structure and to present analytical results of Zanjanrood river breakwaters (in terms of length and distance between two consecutive breakwaters) using two optimization meta-heuristic algorithms including the Gray Wolf Algorithm (GWO) and the Election Algorithm (EA). The results were compared with artificial neural network (ANN) method. The data used were randomly divided into two parts: 75% for calibration and 25% for test. The performance of the proposed methods was evaluated using the statistical indicators of coefficient of determination (R2), root mean square error (RMSE) and mean absolute error (MAE). The optimal length of the breakwaters according to the results of GWO and EA algorithms was 19.26 and 18.12 m, respectively. Moreover, the optimal distance between two consecutive breakwaters in the optimal state was calculated to be 52.56 m. On average, according to the results of the optimization, an increase of 28.4 and 35% in length and distance between two consecutive watersheds in Zanjanrood River should be done to be within the recommended design criteria.  In comparison with two methods of EA algorithm and artificial neural network (ANN), based on statistical indicators, the results of GWO algorithm with values ​​of R2 = 0.96, RMSE 0.022 and MAE = 0.016 has a higher efficiency.

Due to the complexity of hydraulic and sedimentary problems in rivers, it is not possible to solve the equations analytically, so numerical methods are used. In the present study, the HEC-RAS 5.0.3 model was used to simulate the sediment flow of the Khondab River. For this purpose, using the topographic map of the route, DEM and TIN of the River route with a scale of 1: 2000, in the HEC-GeoRAS extension package in ArcMap software, 200 sections along 5 km of the river were prepared. Relevant information was inserted to introduce the river geometry to the model. The flow rate was calculated with 25-, 50- and 100-year return periods and was used for river hydraulic simulation. Quasi-volatile flow conditions, boundary conditions and granulation of riverbed materials were introduced to the model. Using sediment transport estimation relationships, river sediment transport capacity was calculated. The results showed that the Mir-Peter and Müller relationship with 26% error is closer to the observed sediment values ​​than the other relationships. Moreover, the study of erosion and sedimentation status of the river using Hjulstrom and Shields criteria showed that a part of the sections of this river is in erosion status and another part is being sedimenting.

In this study, by conducting experiments in the alluvium adjacent to the river, the effect of various biodegradable and non-biodegradable pollutants was investigated on soil pollution around the river and also river water pollution under its influence. A part of Jajroud River, between Latian and Mamlu Dam reservoirs, was selected as the research site and the wells were drilled at distances of 200, 100, and 50 m and adjacent to the river. Rhodanine tracer was used as a non-degradable pollutant and powdered milk was used as a degradable pollutant to increase the organic charge parameter (COD parameter). Uranine test was performed by measuring curve using spectrofluorescence device and COD was measured by DR6000 device according to ISO 15705 standard. The CTRAN module was also compared to evaluate the accuracy of the results from the numerical model based on the finite difference method and the commercial software GeoStudio 2007. The results showed that the travel time from the first well to the fourth well was about 14 days for both types of pollutants and the ratio of pollution concentrations in the first moment to the last moment was about 0.4 for non-degradable pollutants and about 0.55 for degradable pollutants.

Today, the use of subsurface drip irrigation systems for row crops such as wheat is increasing due to its higher productivity than other irrigation methods. The purpose of this study was to investigate the effect of irrigation water depth and displacement depths of subsurface drip irrigation lateral on winter wheat yield and water use efficiency in Sanandaj city. For this purpose, wheat crop (Pishgam cultivar) was cultivated in the fall of 2017 and an experiment was implemented in the form of split plot design based on a completely randomized block design in Sanandaj County. The main and sub plots of the present study included four levels of irrigation water (60, 80, 100, 120% of water requirement) and four lateral irrigation displacement depths (30, 40, and 50 cm) in three replications, respectively. The results showed that, the subsurface drip irrigation system had higher water productivity compared to the surface drip irrigation system. The results also showed that highest irrigation water use efficiency in treatment with lateral displacement depth of 40 cm and irrigation water depth equal 80% water requirement obtained.

In this study, fuzzy linear and fuzzy least-squres regression approach was employed to estimate the monthly reference evapotranspiration of Neyshabour plain. The data used, including maximum temperature (Tmax), minimum temperature (Tmin), mean temperature (Tmean), relative humidity (RH), solar radiation (Rs) and wind speed (U2), were obtained from synaptic meteorological station of Neyshabour. Three different scenarios were designed to estimate the evapotranspiration for either fuzzy linear or fuzzy least-squres regression models. Mean absolute error (MAE), root mean square error (RMSE), and the coefficient of determination (R2) were used to evaluate the performance fuzzy regression models and its comparison with FAO-56 Penman-Monteith. Results indicated that the fuzzy linear regression model in January and the fuzzy least squares regression model in October had the highest and lowest accuracy with R2 of 0.903 and 0.502, respectively. Among the new proposed models, the fuzzy linear regression under scenario FLR1 (Inputs included Tmax, Tmin, RH and U2) had the highest accuracy, however, in both regression models, despite having lower input parameters (Tmean, RH and Rs), the second scenario, was comparable with other and therefore it can be used in data deficit conditions as an optimal approach in determining ETo for irrigation planning and water resource management.

In the present study, simple and ordinary kriging methods, inverse distance and linear regression based on digital elevation model of the earth were evaluated for estimating annual rainfall using twenty-year statistics of precipitation data (1998-2018) in 33 rainfall stations in Chaharmahal and Bakhtiari province. For this purpose, first in ArcMAP, for each model in Kriging method, its variogram was calculated and using two-way evaluation technique, the error of the maps was estimated. The best method among geostatistical methods was conventional kriging method with Gaussian model. MAE, MBE and RMSE statistical indices for this method were 74.44, 0.48 and 93.72, respectively. Then, rainfall and altitude data of the stations were used using a linear regression model in Curve Expert environment. Finally, in order to determine the best model for spatial distribution of precipitation as well as comparing statistical and geostatistical methods, linear regression and ordinary kriging models were compared with each other and the MAE, MBE and RMSE statistical indices for regression method obtained were 115, 3 and 155, respectively. As a result, due to the accuracy, precision and error rate of the prepared maps, the most suitable method for interpolation of annual precipitation is the conventional kriging method with Gaussian model.

The entry of materials extracted from municipal, industrial, and hospital waste into the marine ecosystem is one of the serious environmental problems in coastal cities. The increase in waste due to the upward trend in human population growth has led to a significant accumulation of these pollutants in the sea. One of the most important environmental challenges is the improper and unprincipled disposal of waste on the coasts. The Kharchang Coast is one of these beaches that is subject to improper waste management disorders in Iran. In the present study, the possible environmental hazards of the landfill site on the mentioned coast were investigated.

The study area is located in the coastal strip of Konarak (25 ͦ 24 ̍ 58 ̎ N: 60 ͦ 25 ̍ 57 ̎ E) with a distance of 40 km from Chabahar and 5 km from Konarak. This research was based on field observations and visits during the years 2018 to 2021 from Kharchang Coast, as well as documentary and library studies with the aim of investigating environmental pollution at the location of the landfill on the coast of Konarak in the Oman Sea.

It was noticed that the waste collection and disposal of system on this coast is completely inefficient and lacks a material recovery facility, so the landfill on the coast is full of polymer, plastic, glass, and metals, which are broken down into smaller pieces and enter the water streams due to high temperatures, wind, and weather. Kharchang Coast is a gathering place for many native and migratory birds, the abandoned plastics attract the birds' attention, and swallowing them causes digestive problems and eventually leads to their death. The region also has a variety of coral ecosystems that the accumulation of plastic and its entry into the water will endanger the health of ecosystems. The respiratory roots of mangrove shrubs have become accumulated with waste and macro-plastics, threatening the health of organisms living in mangrove habitats and the mangrove shrubs themselves. Moreover, the entry of organic matter and micronutrients into the seabed through the leachate of municipal waste and its subsequent mixing with seawater can provide the necessary nutrients for the growth and blooming of seaweed and phytoplankton.

The present study showed that the waste disposal system on the Kharchang Coast is non-standard and lacks mechanized systems and does not pay enough attention to the discussion of the principles of waste management and recycling system. This disrupts the health of the coastal region and aquatic ecosystems, pollutes the air, soil, and marine waters of the region, and consequently threatens the health of aquatic organisms and humans. Therefore, it is clear that the collection and disposal of municipal waste and the restoration of the environment and change the approach to municipal waste disposal in this area to reduce the risks is of great importance. Appropriate measures are taken to adopt appropriate scientific and practical management in order to reduce pollution sources and to support and protect the areas exposed to pollution in order to prevent further destruction of ecosystems, health risks, and soil and water pollution crisis in the region.

Improving soil quality and stability leads to continued soil fertility, maintaining environmental quality and increasing plant and human health. Land use change is one of the main drivers of changing soil quality by changing the structure and performance of ecologists. Increased population and double pressure on the ecosystem to provide food resources, has led to widespread changes in the use of natural land in the northern forests of the country to agricultural land. Therefore, this study was conducted to assess the effect of land use change on the health and soil quality of sloping lands south of Gorgan.

In this study, two hills, one with forest use and the other with marginal agricultural land, which has more than 50 yr of cultivation history, were selected. Sampling was performed in July 2020 due to severe land degradation from only two positions of shoulder and back slope and completely randomly from a depth of 0-20 cm of forest soil and adjacent cultivated land and then samples were analyzed. Properties evaluated include soil organic carbon content (OC), percentage of soil texture components and bulk density of soil, percentage of lime equivalent soil, EC, pH, the amounts of high consumption elements (NPK) and CEC were as indicators of soil quality.

The research showed the highest coefficient of variation as a result of land use change was related to the two parameters of OC. Based on the correlation matrix, the physical parameters of saturated mud percentage, total porosity percentage with the percentage of organic carbon and soil clay at the level of one percent (P <0.001) show a positive and significant relationship. Among the chemical variables, as expected, there was a significant positive correlation between cation exchange capacity, percentage of total nitrogen and potassium levels available with organic matter and percentage of clay at the level of 1%. Analysis of variance and mean comparison showed land use change from virgin forest to agriculture has significantly reduced soil quality in all parameters evaluated except absorbable phosphorus. The reason for this can be considered improper cultivation operations in arable lands, which causes the breakdown of aggregates and exposes the organic matter trapped in the aggregates to microbial decomposition. As a result, the surface horizon of the soil loses its original structure and is easily affected by erosion and physiographic processes of the hill.

the study of OC as the most important indicator of soil quality showed that this parameter with an average of 6.07% in forest use and an average of 0.59% in agricultural use with a 90% decrease as a result of land use change. High reduction of organic carbon and soil clay as the most important indicators for assessing soil quality in arable lands, indicates unstable use and highly unstable ecologists in the sloping lands of south of Gorgan. It is suggested that in future studies, the effect of land use change on erodibility and land production should be studied and evaluated, considering that the continuation of cultivation in this area causes an increasing decrease in soil quality.

Our farmers are a vital part of the national economy, providing jobs for people in rural communities and food for our tables. Farmers can play an essential role in sustainable development by protecting agricultural water resources. To achieve this, they need training to be able to conserve water optimally. In this regard, this study was conducted with the aim of the effect of communication and information channels in adopt agricultural water protection behavior.

The statistical population of the study was all households of wheat farmers in Khorramabad County (N = 12500). The sample size was determined using Cochran's sampling formula of 240 heads of farmers' households. The data collection tool was a questionnaire, which its validity was determined by a panel of experts including faculty members of the Department of Agricultural Extension and Education, Agricultural Sciences and Natural Resources University of Khuzestan and its reliability for communication channels and water protection behavior were confirmed using Cronbach's alpha coefficient and Split Half method, respectively. Data analysis was performed in two sections of descriptive and inferential statistics by SPSS software.

The results showed that most of the water conservation behaviors used by farmers included "irrigation of the land to the extent that the land is able to absorb it" and "irrigation of the land is uniform" and minimum operations include "storing excess water at each irrigation for subsequent irrigation" and "storing water in the pool". The results also showed that the most used channels in the field of water conservation included participation in promotional rounds and television programs. The results of discriminate analysis showed that the dimensions of communication and information channels (face to face, electronic, audio and text) can be about 87% of farmers who carry out water conservation operations than other farmers in Properly separate these fields of activity.

The agricultural sector as the most important sector of water consumption needs special attention to be used optimally for water. The media can help farmers in this important matter.

Knowledge and awareness of temporal and spatial changes of quality parameters, especially salinity in groundwater and surface water resources and the preparation of zoning maps can be an important step in proper management and planning in the use of water resources. In this research, the trend of spatial and temporal changes of some groundwater quality parameters in Guilan province has been evaluated. Measurement data of some cations and anions sampled from 150 wells in September and March of 2011-2018 and water level data of 282 piezometric wells were collected. The zoning maps obtained by ordinary kriging method were examined. These maps show that in terms of quality parameters, groundwater resources in the central part of Gilan province have higher values ​​and in the growing season due to agricultural activities and fertilization, groundwater quality decreases. Effect of groundwater depth on the concentration of the parameters was assessed. According to the map of groundwater depth changes, the largest area of ​​Gilan province has a water level of 0.23 to 5.5 m. The results of classification of qualitative parameters show that in shallow groundwater depths the concentration of qualitative parameters increases.