فاضلاب

One of the most important environmental issues in the world, and especially in Iran, is the accumulation of solid waste because its amount in the gross domestic product and national income is worrying. Solid wastes such as citrus wastes have no economic value and are considered useless. Therefore, it is necessary to use these wastes by providing a suitable method to valorize them. On the other hand, the wastewater of many industries contains a wide range of organic and mineral pollutants. Its cost-effective treatment is necessary to solve the water crisis. The adsorption method using cheap and available biosorbents is one of the most efficient methods for removing pollutants from industrial wastewater. Thus, using citrus wastes and improving their adsorption properties with the physical and chemical treatments, carbonization, and a combination of these methods simultaneously solves the problem of citrus wastes and industrial wastewater. In this review study, different adsorbents obtained from citrus wastes along with their production methods are investigated, and their adsorption behavior is expressed based on isotherm, kinetic, and thermodynamic models. Also, adsorbent regeneration, economic evaluation, and suggestions for the development of this approach are provided.

Today, many countries, including Iran, face natural hazards such as ground subsidence, drought, floods, and acute water shortage. Lack of correct management of underground water resources leads to many of these natural hazards. Artificial recharge of aquifers is one of the solutions proposed in the world to deal with these natural hazards, especially ground subsidence. The quantitative and qualitative effects of the effluent treatment plant on the Damaneh Daran Aquifer recharge were investigated in this research. The results showed that aquifer recharge through the distribution of effluents in the Damaneh Daran River has a positive effect on increasing the water level and releasing effluents in the river will enhance the water level in a larger radius regardless of the quality of the effluents. Based on the result of the present study, it is suggested that all the effluent treatment plants be allocated to aquifer balancing in the future. In the part of replacing wastewater with active wells, due to the lack of wells with industrial and green area use in this region, provided advanced wastewater treatment, all wastewater should be replaced with active wells in the agricultural area.

Due to the scarcity of water resources and ever-increasing demand for it, treated wastewater, if meeting agricultural standards, can serve as an alternative or supplementary water source for achieving sustainable agriculture. In this study, considering the water shortage problem and the presence of arable lands in the province of Qazvin, especially in the Buin Zahra region, the potential of using the effluent of Qazvin’s sewage treatment plant in Buin Zahra’s irrigation and drainage network was investigated. In the first phase, the environmental status of the Buin Zahra region was studied, and subsequently, for one year (2019-2020), monthly samples were taken from the raw wastewater inflow and the treated effluent. Physical, chemical, and microbial analyses of these samples were conducted to evaluate the efficiency of the Qazvin sewage treatment plant. Based on the area's cropping pattern and the quality requirements of agricultural products, a plan for the development of the irrigation and drainage network was devised, considering the quantity and quality of the produced effluent. The evaluations included gravitational transfer, significant aquifer depletion, soil characteristics, and the area's cropping pattern. Taking these factors and the social acceptance of the plan into account, the network development was proposed using 20.8 million m3 of effluent annually, covering 2000 ha of Buin Zahra's lands, and the appropriate cropping pattern and irrigation system were determined. Finally, given the importance of health and environmental issues, a comprehensive program for monitoring the quality of various components of the plan, including effluent, soil, agricultural products, and project workers, was prepared and presented to ensure the sustainable and safe use of this resource.

Critical to human survival, water resources, including groundwater and particularly rivers, are under threat from anthropogenic pollution. The major Kashafrud River, located in northeastern Iran, is a seasonal watercourse currently encountering numerous challenges. At present, a stretch of this historic river (Parkandabad to the basin's exit) carries wastewater, comprising industrial, urban, agricultural, and even livestock effluents, transforming it into a conduit for sewage. This study reviews existing research on the challenges faced by the Kashafrud River, including pollution, climate change, and its impacts, as well as reduced runoff and drought. It outlines the crisis afflicting the river and then explores solutions to mitigate the current conditions. This research process involved reviewing previous studies on the challenges of Kashafrud, conducting field visits, engaging in discussions with local residents, and validating these findings through consultation with regional water experts responsible for overseeing this water course. Research indicates that there has been a limited focus on the pollution issue in Kashafrud, underscoring the evident necessity for comprehensive scientific inquiry aimed at presenting suitable solutions to tackle river contamination. In conclusion, through analyzing solutions proposed in previous studies and summarizing their strengths and weaknesses, 13 practical solutions were presented to provide the most effective strategies for addressing the challenges of this significant river.

The use of treated wastewater is considered as a solution for supplying water to green spaces. The reuse of purified urban wastewater in the irrigation of fields and green space can reduce the need to extract water from natural sources and also reduce the discharge of wastewater into the environment. In using treated wastewater instead of water, its quality and reaction with soil is important, and its long-term effects on the irrigation system, soil salinity, product yield and its quality, water-soil characteristics, and environmental effects should be considered. In arid and semi-arid regions, due to less use of water, higher evaporation and lower purification, the concentration of chemical substances in treated wastewater is higher. In the current research study, while checking the daily quality of the effluent from the Chehelbaze treatment plant in Mashhad in a period of 23 months, the possibility of using urban wastewater for irrigation of green spaces with the activated sludge treatment method was investigated. By determining the average amount of biological oxygen demand BOD 6.08 and chemical oxygen demand COD 13.70 and average TSS 3.05, removal of coliform and parasitic nematodes, the average ratio of COD to BOD purification 2.29, the quality status is within the permissible range of Green space irrigation was standardized. According to the examination of qualitative parameters and chemical compounds in terms of average BOD, COD and TSS and microbial parameters, the effluent of this treatment plant can be used in urban green space irrigation.

In recent decades, the management and treatment of sewage and sludge dewatering process have become crucial due to their high nutrient content. However, choosing the right technology in this area is a big challenge due to the complexities and the existence of many uncertainties. In this article, an analytical hierarchy process is used as a decision-making tool to choose the appropriate dewatering method in the southern Tehran treatment plant, in which the criteria structure and the evaluation process are defined by describing several possible options for sludge dewatering to be compared and weighted. The results were analyzed and evaluated using Expert choice software. According to the results, the belt filter press is the best and most appropriate technology for sewage sludge dewatering among pressure and belt filter press, lagoon, centrifuge, and sludge drying beds. Finally, validation had been done based on the sensitivity analysis method, which shows the effect of changes in input parameters on the results and was carried out for technical, economic, environmental, and management criteria, and the sensitivity of the options to the change in the weight of the main criteria was determined and the results showed that the most sensitivity in the economic criteria refers to the lagoon process, in the technical criteria refers to the centrifuge process, in the environmental criteria refer to the centrifuge process, and in the management criteria refers to the belt filter press process. The results show that this method, due to its simplicity and adaptability to different situations and regions, can be considered at the national level for different decision-makers in the field of selecting processes in water and wastewater treatment.

Nowadays ionizing beams such as gamma rays are used to remove organic and inorganic contaminants from wastewater and sewage sludge. The objective of this study was to investigate the effects of gamma rays and titanium dioxide nanoparticles on the concentration of lead and zinc in aqueous solution at different pH. For this purpose, the effect of gamma rays at 4 levels (0, 4, 8 and 16 kGy) and chemical modifier of titanium dioxide at three levels (0, 2 and 4 g.l-1) with 0 and 10% methanol in water solutions with different pH (2, 4 and 6) on the removal of Pb and Cu were investigated. The experiment was performed as a factorial in a completely randomized design. The results showed that the lead and copper concentrations decreased with increasing pH. The concentrations of copper at pH level of six, 16 kGy of gamma radiation and the level of 4 g.l-1 of titanium dioxide (without methanol) decreased more. The concentration of lead at the level of pH six and 16 kGy of gamma radiation and levels of 2 and 4 g.l-1 of titanium dioxide (without methanol and with methanol) had a further decrease. Titanium dioxide showed the highest effect and gamma ray had the lowest effect on the removal of copper and lead from aqueous solution.

The water is the major key in sustainable development, so it is necessary to be managed and conserved. The quality of surface water resources is mainly controlled by natural or geogenic factors including chemistry of recharge water, soil and geology processes, as well as the man-made contaminant. Qualitative indicators are used as effective managing tools in decision making programs. Water quality indices (WQI) are the simple and suitable tools to determine the quality statue of the water. In order to calculate the water quality index, many parameters are integrated in mathematical formula to represent the quality condition of the water with a number which classifies the quality in the scales of the weak to excellent. Many water quality indices were introduced by researchers and organizations around the world. Aji-Chay, one of the most important flowing rivers in East-Azerbaijan province, northwest of Iran, is passing through Tabriz plain in its way and finally ends to the Uremia lake. Regarding the focused industrial zones, agricultural field and urban areas in this plain, the river is highly vulnerable to pollution and quality degradation. So, this study was aimed to assess the Aji-chay River based on quality indicators, in order to helps its better management. In this research for assessing pollution of the Aji-Chay river using water quality indices, 16 sampling stations were located along the river and water samples were collected during wet (May 2016) and dry (September 2016) seasons. Electrical conductivity (EC), temperature, dissolved oxygen (DO) and pH were measured in the field and total dissolved solids (TDS), turbidity, major ions (Ca, Mg, Na, K, HCO3, Cl, SO4), nitrate (NO3), phosphate (PO4), biological oxygen demand (BOD), chemical oxygen demand (COD) and biological contaminants (fecal coliform) were determined in the laboratory. Quality indicators including the US national sanitary foundation water quality indices in the two forms of multiplicative (NSFWQIm) and additive (NSFWQIa) and Iranian surface water quality index (IRWQIsc) were used to assess the quality of the Aji-Chay river. Turbidity and Electrical conductivity (EC) is high at the upstream which is related to movement of the River in upper red formation (Miocene series) which enhances the chloride, sodium, calcium and sulfate. Arsenic concentrations are exceeding the drinking standards (0.01 ppm) across all samples mainly from a geogenic sources as well as discharge of wastewater in some areas. The elements Cd, Mn, Ni, Pb, Mo, Co, Zn, Fe and Al are mainly geogenic, whereas Cu, Ba and Cr are mostly originated from anthropogenic activities. Based on the results, river quality at the wet season is highly controlled by the main branch and Gomnab-Chay, but Mehran-rood plays the major role in downstream water quality at the dry season due to its higher discharge rate. The process was confirmed by Piper and Schoeller diagrams. Most of the parameters are increased in middle parts at the river where the concentrated sources of contaminates and discharge of wastewater increased the organic and biological constituents and nutrients especially in dry season. Assessing the river quality for agricultural uses based on modified Wilcox diagram shows except for Mehran-rood, the other samples are unsuitable for agriculture and the dry season quality is better than the wet season. Based on the results, increase in most parameters and so, pollution and quality degradation of the river are observed to the downstream. Assessing quality of the Aji-Chay river using US national sanitary foundation water quality indices in the two forms of multiplicative (NSFWQIm) and additive (NSFWQIa) and Iranian surface water quality index (IRWQIsc) confirmed the bad to very bad qualitative statue of the river in most stations especially in the middle parts of the Tabriz plain. The results revealed that quality degradation of Aji-Chay river is probably due to discharge of contaminants from municipal and industrial wastewaters (effluents), highlighting the need for managing actions to improve quality of this important river. Comparing the quality indices showed the priority of NSFWQIm (multiplicative form of US national sanitary foundation water quality indices) in quality classification and pollution assessment of the Aji-Chay river. Quality degradation of Aji-Chay river is probably due to discharge of contaminants from municipal and industrial wastewater effluents, indicating the need for managing actions to improve quality of this river. In this study priority of NSFWQIm (multiplicative form of US national sanitary foundation water quality indices) in quality classification and pollution assessment of the Aji-Chay river was confirmed.

One of the general principles of sustainable landscape management strategies that urban planners have outlined for the success and expansion of green space in arid and semi-arid areas is the use of lower quality water resources. Among the different sources of wastewater and recyclable sources, domestic wastewater is a top priority due to its high volume and better quality after the treatment processes. Therefore, it is believed that urban wastewater effluent can be used as water needed for urban and forest parks, on the outskirts of cities and industrial complexes to develop green space and reduce air pollution. For this purpose, we investigated the effect of water, effluent and wastewater on the germination characteristics of the Fraxinus excelsior. This design is a completely randomized design with three replications in the treatment plant of Parkandabad 1 in 1395-1396. Experimental treatments consisted of irrigation with ordinary water, wastewater and wastewater. Each experimental treatment was performed at 4 levels of irrigation (50, 80, 100 and 120 plants water requirement) and applied to the seeds by weight method. The results showed that the mentioned treatments resulted in a significant difference in germination percentage, sperm germination rate at 1% and significant difference at 5% level in sparrow seed vigor index between treatments. The effect of treatments on chlorophyll a, b and t had significant effect at 5% level between treatments. The effect of irrigation treatments with ordinary water, wastewater and wastewater on the amount of zinc, copper and lead leaf of ash leaf had a significant effect at 5% level between treatments.

Due to its especial geographic condition, Iran, as a semi-arid country, suffers from water shortage for domestic, industrial and agricultural usages. As limited water supplies, the use of non-conventional water resources, such as industrial or municipal wastewater, is a common practice in many parts of the world including Iran. It is estimated that at least 20 million hectares in 50 countries are irrigated with raw or partially treated wastewater. Also, it is estimated that the potential volume of wastewater in urban and rural areas of Iran will be 4369 and 823 million m3, respectively. On the other hand, the use of sewage sludge in agricultural soils has been widespread in many countries around the world, also in Iran. The use of sewage sludge in agricultural has been shown to improve the soil’s characteristics such as organic matter, nutrients, porosity, aggregate stability, bulk density and plant productivity. Despite the growing interest in wastewater and sewage sludge usage, excessive use of them may have some harmful effects such as human health problems, runoff and leaching of nutrients to surface and groundwater, undesirable chemical constituents, pathogenesis, accumulations of heavy metals in plants and soils, negative environmental and health impacts. So, wastewater and sewage sludge use should be under controlled conditions to minimize the health risks of pollution to agricultural products, soil. Heavy metals are extremely persistent in the environment; as they are non-degradable and thus, readily accumulated at toxic levels. Metals can also accumulate in the soil at toxic levels due to long term use of wastewater. There is potential for inorganic nutrients and heavy metals present in wastewater and sewage sludge that transfer in the soil column and pollutant surface and groundwater. Today, medicinal plants are cultivated commercially in the polluted environments where soil, water and air contain rather high levels of pollutants. These plants appear to be a good choice for phytoremediation since these species are mainly grown for secondary products (essential oil) thus, the contamination of the food chain with heavy metals is eliminated. Aromatic and medicinal plants also have a demonstrated ability to accumulate heavy metals. The Mint (Mentha spicata) is a medicinal plant which has received considerable economic importance due to the large demand for its essential oil in food, pharmaceutical, cosmetic and hygiene industries. The purpose of this study was to determine the leach of heavy metals (Zn, Pb, Niand Cd) from the wastewater and sewage sludge to the soil column under Mint cultivation. This study was conducted at the Bu-Ali Sina University greenhouse located in Hamedan, western Iran. The experiment was run in May 2015- February 2016), including 5 months for soil preparation (in lysimeters) and 5 months for crop cultivation and harvesting. To evaluate the use of wastewater and its sewage sludge on on transferring heavy metals in soil column under Mint cultivation, a factorial experiment based on completely randomized was designed with three replications in 27 lysimeters. The factors included three types of watering: tap water (W1), raw wastewater (W2) and treated wastewater (W3), and three sewage sludge levels: 0 (S1), 50 (S2) and 100 tha-1 (S3). Therefore, 9 treatments (W1S1 to W3S3) were considered for investigation. 27 volumetric lysimeters were applied as cultivation beds (26 × 30 × 30 cm). The soil had two layers: the upper layer (0 to 50 cm) with sandy loam texture, and the bottom layer (50 to 110 cm) with sandy clay loam texture. After beds preparation, Mint (Mentha spicata) was planted in them. The raw and treated wastewaters as well as sewage sludge were prepared from wastewater treatment plant of Hamedan. Overall, 13 irrigation programs with 10-day intervals were applied. Zn, Pb, Ni and Cd concentrations in leachate were measured after each watering. The results showed the effect of watering and sewage sludge on heavy metals concentration of drainage water was statistically significant. Also, the result showed that wastewater and sewage sludge increase all (except Cd) leached heavy metals comparing to the control. In all treatments, concentrated Zn, Pb, Ni and Cd in the soil profile ranged from 0 to 1.66, 0 to 0.05, 0 to 0.05 and 0.0 to 0.0 mg/l, respectively. The concentrations of all heavy metals in drained water, was very lower than the FAO standard. By performing continuous irrigations, the trends of heavy metals (zinc, lead and nickel) were irregular schema (especially the use of wastewater and sewage) at different times. The first five irrigations showed an upward and the others showed a downward path.

Detergents are the main organic pollutants in the industrial and domestic wastewater. Electro-chemistry methods are advanced purification methods developed with high efficiency features. The goal of this study was to investigate the possibility of using electrocoagulation and the complementary flocculation process to achieve the highest removal efficiency of the detergent COD. So, with iron electrode, synthetic samples at the concentrations of 500, 750 and 1000 mg/l (with COD of 217, 268 and 370 mg/l, respectively) and with the initial pH levels of 5, 7.3 and 9 were tested. Variable parameters during the electrocoagulation process included the current duration at 3, 5 and 10 minutes, and the current density was at 4, 10, 16 and 22 mA/cm2. The primary results showed that in the optimum conditions, the coagulation process and complementary flocculation could reduce the sample’s COD with an initial concentration of detergent (500 mg/l) from 217 mgO2/l to 81.30 mgO2/l. The electrocoagulation method could reduce the chemical oxygen demand to below the standard limit of environmental discharge (200 mgO2/l) and compensate for the possibility of the irrigation of green spaces due to water shortages.

Contamination of soil and plants with heavy elements including zinc, due to industrial activities, might have significant adverse effects on human health. Industrial factories and mines, fertilizers, pesticides and waste water are the most important sources of water, soil and plants contaminations. In Zanjan province, there is a wide range of zinc processing and production factories and mining activities that can contaminate soil, water and plants. The aim of this study was to investigate the zinc concentration of the soil, shoot and root and zinc translocation factor (TF) in dominant rangeland plants (Hulthemia persica and Chenopodium album) in different distances and directions from factory.
This study was conducted as factorial in a completely randomized design with three replication. The experimental treatments included three directions (northeast, east and west of the factory), six different distances from the factory (0-250, 250-500, 500-7500, 750-1000, 1000-1250, 12500-1500 meters) and two plants (Hulthemia persica and Chenopodium album). The soil and plant samples were collected from the selected sites. Shoot and root samples were digested by concentrated nitric acid and available zinc in soil was extracted by DTPA. The zinc concentrations were measured by atomic absorption spectroscopy.
The results showed that the effect of direction and distance from the factory was significant on zinc concentration of shoot and root and also translocation factor, (P In the northeast direction (dominant wind), plant and soil pollution was mostly influenced by wind. The main contamination factors of the soil and plant at distances close to the factory were waste water and waste in the east and west direct, respectively. Hulthemia persica, with a broad and thick root system, was able to absorb more zinc and transfer it to the shoot part. But in the northeast direction, the atmospheric deposition of the factory played an important role in soil and plant contamination. Chenopodium album with high vegetation biomass absorbed more zinc from the air in its shoot than Hulthemia persica with rough and blubber stems. For this reason, in the dominant wind direction, the TF was also found in the Chenopodium album at as far from distances higher than Hulthemia persica. Therefore, the absorption of atmospheric zinc was higher in Chenopodium album. In waste disposal areas, Hulthemia Persica had a more translocation factor.

Petroleum hydrocarbons are considered as the most major aquatic and terrestrial ecosystem pollutants in the world. The US Environmental Protection Agency (EPA) has announced that it is harmful to the environment. It is toxic and cause cancer, too. Polycyclic aromatic hydrocarbons enter the soil and the groundwater through oil tanks leak, so cause environmental pollution. Polycyclic aromatic hydrocarbons (PAHs) are organic compounds that are mostly colorless, white, or pale yellow solids. They are a ubiquitous group of several hundred chemically related compounds, environmentally persistent with various structures and varied toxicity. They have toxic effects on organisms through various actions. Generally, PAHs enter the environment through various routes and are usually found as a mixture containing two or more of these compounds, e.g. soot. Some PAHs are manufactured in the industry. The mechanism of toxicity is considered to be interference with the function of cellular membranes, as well as enzyme systems which are associated with the membrane. It has been proved that PAHs can cause carcinogenic and mutagenic effects and they are also potent immune-suppressants. Effects have been documented on immune system development, humoral immunity and host resistance. PAHs can be formed both during biological processes and as products of incomplete combustion from either natural combustion sources (forest and brush fires) or by man-made combustion sources. Thus, PAHs are commonly detected in air, soil, and water. Therefore, PAHs are considered ubiquitous in the environment. The ubiquitous nature of PAHs in the environment has been well recognized in researches. The term “PAH” refers to compounds consisting of only carbon and hydrogen atoms. Chemically the PAHs are comprised of two or more benzene rings which are bonded in linear, cluster, or angular arrangements. Such molecular arrangements are considered toxic. Although there are many types of PAHs, most regulations, analyses, and data reporting focus on only a limited number of PAHs, typically between 14 and 20 individual PAH compounds. Petroleum contaminated is currently treated using three processes: physical, chemical, and biological. A range of cleaning techniques have been successfully developed to limit the environmental impacts caused by oil pollution, but timely and effective remediation is necessary to mitigate the detrimental effect of petroleum hydrocarbons on the environment. The present study aims to evaluate the efficiency of PAHs adsorption prediction of the groundwater contamination. Adsorption of these pollutants using the various natural adsorbents is among the crucial objectives of this study, as well. This investigation has been done in these steps: at first, the ecological characteristics of Tehran Oil Refinery have been identified and the water quality of its wastewater treatment plant was evaluated, briefly. In the second step, to estimate PAHs adsorption in soil and optimize the adsorption process using activated carbon, bentonite, talk powder, rice bran, and saw dust, we prepared a rectangular pilot plant with an interlaced plate as drainage at the end of it, and after packing it with each of the adsorbents in specific weight and height, oily wastewater containing (PAHs) influence on it. The column pressure head and its conditions have been stable during experiments. The adsorption of PAHs on these adsorbents was estimated by measuring the concentration of PAHs in effluents of the drainage, every 30 minute intervals up to 4 hour, and the bed of adsorbents at the end of experiments.
Since water has seriously been polluted by PAHs nowadays, PAHs adsorption by the Bentonite, Talcum powder and Clay is considered in this research. Then, PAHs distribution coefficient and the maximum adsorption have been determined according to the results, by Freundlich adsorption isotherms, and Langmuir isotherm. This study also compares the suitability of two predictive models, Freundlich isotherm and Langmuir isotherm, in analyzing the adsorption of PAHs on soil and the five types of adsorbents which were mentioned above. The results indicated, the adsorption data were well fitted by the Freundlich model. Also, Results show that the Bentonite has a high potential for PAHs adsorption. Distribution coefficient (kd) and the maximum adsorption are 0.008 lit/g and 0.101 mg/g. Since distribution coefficient for the absorbents including clay and Talk powder 0.0028 lit/g and 0.0023 lit/g, respectively. Furthermore, the maximum adsorption coefficient for the absorbents including clay and Talk powder is 0.042 mg/g and 0.003 mg/g in this research.

Determination of propitiate pollution indices is important for the design of wastewater refinery systems in small communities and rural area. This study aimed to determine the best indices of pollution for the design of wastewater refinery systems in small communities based on short-term data. For this purpose, wastewater samples were taken from Dehmilan, Hotkan, Sarbagh and Sekukan refineries in 10 replicates, each at one week interval. Different parameters including BOD, COD, TOC, EC, TSS, TDS, DO, TKN, TP, pH, Temp, Turb and Alk and also the concentrations of Cd, Zn, Pb, Ni and Mo were measured using the standard methods. Results showed that the amounts of BOD, COD, TOC, TSS, DO, pH, Temp, Turb, Cd and Pb differed significantly among the refining systems, whereas, significant differences (p

The increase in water demand and its services due to population growth and the raising of the standards of living, health, and hygiene along with the limitation of water resources, droughts, and climate change has attracted water specialists and planners to explore the use of unconventional water resources, such as sewage and saline waters. Moreover, industrial and rural wastewater disposal and the penetration of their pollutants to the surface- and ground-water resources is an important concern in many countries, including Iran. Wastewater treatment and its application for various uses reduces the negative externalities of wastewater release on the environment and human health. Accordingly, in this paper the methodology for economic and environmental evaluation of wastewater collection and treatment, and the necessary holistic view taking into account the issues that must be considered in this regard has been addressed. Furthermore, the steps and framework of a modified cost-benefit analysis of the Tehran wastewater collection and treatment plan have been discussed.

Water quality is one of the most affective factors on soil infiltration. The widespread use of wastewater in recent years caused the accurate estimation of soil infiltration to be essential for achieving proper irrigation management. Therefore, Philip, Kostiakov, Kostiakov-Lewis, Green-Ampt,Horton, SCS and linear regression models for soil infiltration estimation were evaluated. Infiltration experiments were carried out in an area of 190 ha of agricultural lands under wheat cultivation, around the Zabol refinery of municipal waste water for six soil texture classes include silty clay, clay loam, sandy loam, loam, loamy sand, silty clay loam. These lands are irrigated with treated wastewater for over 10 years. The study area was divided into pixels with 150mÍ150m size. The cumulative infiltration was determined using double ring experiment. Some physicochemical soil properties were determined in soil samples taken from the center of each pixel. Despite of significant relation between soil infiltration and EC, sand, clay and silt percentage, exchangeable sodium and bulk density, transfer functions didn’t led to satisfactory results for cumulated infiltration. Kostiakov and Horton models were the best profitable models for silty clay soils. Whereas, the others were the best for cumulative infiltration estimation in silty clay loam soils. Green-Ampt and Kostiakov models were the best fitted on the observed cumulative infiltration data with root mean square, mean bias error and efficient coefficient of 0.16 and 0.15 cm, -0.03 and 0.04 cm, and 0.74 and 0.78 cm, respectively. The considerable reduction in soil infiltration due to over accumulation of salt and sodium in the surface soil layers through long term application of waste water in the study area.

In this study, raw and treated wastewater of Serkan Wastewater Treatment Plant, located at 70 km east of Hamedan, were reused for potato irrigation under lysimetric conditions. The factorial experiment executed with a statistical completely randomized design in three replicates and two factors. The factor of watering programs which were categorized as follows: Raw wastewater (T1), treated wastewater (T2), a combination of 50% raw wastewater and 50% fresh water (T3), a combination of 50% treated wastewater and 50% fresh water (T4), and fresh water (T5). The factor of soil cores depths which were depths of 0-10 cm and 10-20 cm. The effects of watering treatments were significant on accumulation of Mn, Fe, Cu and Zn in the soil layers. Also the interaction effects were non-significant on accumulation of Mn, Cu and Zn. The interaction effect was significant on the Fe concentration. The maximum and minimum Mn, Fe, Cu and Zn concentration in the soil was obtained in T1 and T5, respectively. Also, the Mn, Fe and Zn concentration decrease with soil depth but concentration of Cu increase. Overall, based on the accumulation of heavy metal in the soil, the watering treatments were ranked as follows: T1> T3> T2> T4> T5. Based on the accumulation of heavy metal in the soil, heavy metals were ranked as follows: Fe> Mn> Zn> Cu.

Environmental pollution with heavy metals and their transfer to plants is an increasing universal problem. In this study، raw and treated wastewaters were reused for potato cultivation under lysimetric condition. Consequently، a completely randomized test was designed، with four irrigation treatments and three replications. The irrigation treatments were categorized as follows: irrigation with raw wastewater (T1)، treated wastewater (T2)، a combination of 50% raw wastewater and 50% fresh water (T3)، and a combination of 50% treated wastewater and 50% fresh water (T4). The soil of each treatment was sampled in order to assess the Cd، Zn، Cu and Pb pollutions on the basis of the Pollution Index (PI) and to analyze the correlation between the mentioned metals in two soil depths. The results showed that the effects of irrigation treatments on PI of Cd، Pb (p ≤0. 05)، Zn and Cu (p ≤0. 01) amounts were significant. The maximum and minimum values of this index were observed in the T1 and T4 treatments، respectively. The ranking of PI magnitude in all treatments was T1> T3> T2> T4. Also، the results showed that the PI values of the mentioned metals except Cu in the soil depth of 0-10 cm was lower than those in the soil depth of 10-20 cm. The maximum Pearson’s correlation coefficient value was observed between Pb and Cu. Also، the values of this coefficient in soil depth of 0-10 cm were more than those in the depth of 10-20 cm (except the values between Pb and Zn and between Cu and Cd). In this study، the PI values of Pb، Zn and Cu، were lower than 1 and the PI values of Cd were between 2 and 3.

The quality of water is as important as its quantity in irrigation. Lack of wastewater purification plant in Rasht, Zarjoub River receives all municipal, industrial and agricultural wastewaters. In this study the effects of irrigation water from five stations along the river and irrigation water from well water on heavy metals accumulation in soil were assessed. A pot experiment was carried out in a completely randomized design with three replications. Irrigation regimes were flooding, saturated condition, field capacity (FC), 0.8FC and 0.6FC. Irrigation was done with water from five stations along the river and water from a well. After physiological maturity, harvest was done and soil heavy metals concentrations were measured with atomic absorption apparatus. Results showed that pot soils in all treatment were polluted with Cd and Cu (being in average higher than 0.3 and 50 mg/kg as maximum allowable concentrations, respectively) however Pb and Zn pollutions were not detected (being in average higher than 250 and 200 mg/kg as maximum allowable concentrations, respectively).

In this study، a completely randomized experiment was designed with five irrigation treatments and three replicates. The irrigation programs were raw wastewater (T1)، treated wastewater (T2)، a combination of 50% raw wastewater and 50% fresh water (T3)، a combination of 50% treated wastewater and 50% fresh water (T4)، and fresh water (T5). The experiments were run within a greenhouse. The lysimeters were built up in September 2009 and they were filled with a two layer soil. The upper (30 cm) and lower (40 cm) layers were sandy loam and sandy clay loam، respectively. The results showed that the effects of watering treatments on transfer coefficients of heavy metals from soil to shoots (except Cd) and tubers of potato (except Zn and Cu) were significant (p <0. 01). Maximum and minimum transfer coefficients of heavy metals were observed in the (T1) and (T5) treatments، respectively. Also، the transfer coefficients of Cd from soil to shoots were lower than tubers. In the case of Zn، Cu and Pb، transfer coefficients from soil to tubers were lower than shoots. In this study، the maximum transfer coefficients to shoots were Cd (0. 331-0. 463)، Zn (0. 383-0. 230)، Cu (0. 173-0. 386) and Pb (0. 003-0. 057)، respectively. Maximum transfer coefficients toward tubers (except T5) were Cd (0. 439-0. 572)، Cu (0. 081-0. 138)، Zn (0. 170-0. 217) and Pb (0-0. 017)، respectively. The combination of wastewater and fresh water use in short-term irrigation might be feasible، but a heavy metal monitoring program is necessary.