فهرست مطالب ehsan derikvand

The over-drilling of deep wells and the excessive exploitation of groundwater sources cause the groundwater level to decrease daily, resulting in more energy to power pumps. Artificial recharging is the injection of water into a permeable formation to recharge the groundwater aquifer and reuse it with a different regime and quality and by creating additional facilities or changes in the region's natural conditions (Fazl Avali, 1998). Placing artificial recharge systems are one of the basic principles of creating these systems. The selection of sites based on scientific and natural points plays a critical role in the success and efficiency of the development of these systems to achieve the relevant goals. This process must be undertaken with considerable care. Identifying artificial recharge areas and substrates can be accomplished using various methods and parameters. No matter the method used, the results from different studies must be analyzed jointly, and then the most appropriate area for the study must be determined. Due to the presence of various characteristics in location, continuous changes of influential factors, and the need to examine the evaluated criteria, the use of GIS due to special features and capabilities, can be beneficial to this endeavor. The multi-criteria analysis method has been mentioned as a valuable model for integrating information layers in artificial recharge. Numerous studies have been conducted to locate recharging sites for artificial recharge.
Ramalingam and Santhakumar (2002), using GIS and remote sensing techniques, investigated suitable artificial feeding areas in a state in India which considered geomorphological, geological, soil, slope, land use, runoff intensity, and groundwater depth. As part of the research conducted by Hekmatpour et al. (2007), areas of the Varamin plain that can be artificial recharge were identified through classification and layer combining in a GIS environment and using a decision support system to make decisions.

Electrocoagulation (EC) is a safe method for removing environmental pollutants without the need for additional chemical materials. This study investigates the performance of EC in removing chemical oxygen demand (COD), total organic carbon (TOC), total suspended solids (TSS), and turbidity from drilling waste generated by oil rigs. An experimental study was performed on a pilot scale in an EC reactor provided from a cylindrical glass cell (height: 30 cm and inner diameter: 5 cm), a pair of aluminum and iron electrodes, a power supply, an aeration system. wastewater Samples were collected from one of the drilling rigs in Khuzestan. The effect of current density, operation time and pH parameters on removal of COD, TOC, TSS and turbidity were determined and the optimal values of the parameters were determined. It was found that system voltage, operation time and pH values on the removal efficiency of pollutants were statistically significant at the 0.01 level. The optimum values of pH, current density and operation time were obtained 7, 20 mA/cm2 and 60 minutes, respectively and the removal efficiencies of COD, TOC, TSS and turbidity under the optimum conditions were 72%, 79%, 67% and 63%, respectively. Also, the consumption of energy was estimated to be 8.4 kWh/m3. The results indicated that the EC process is a cost-effective method in removing pollutants caused by drilling of oil rigs and its efficiency can be improved by applying optimal conditions such as current density and pH.

The present descriptive cross-sectional study was conducted by altering the type of blowers in the wastewater treatment system of Abuzar hospital in Ahvaz during the first and second quarters (6 months). In every month, inlet raw wastewater, aeration tank one, and effluent were sampled in one week (Saturday-Friday), which resulted in harvesting a total of 42 samples. Then, they were assessed based on the techniques provided in the book entitled "standard methods for evaluating water and wastewater", and data were evaluated through employing statistical analyses. The average removal efficiency of total and organic phosphorus, phosphate, and ammonia in the effluent was respectively determined 46.47, 34.45, 18.14, and 68.49 before starting up a new aeration system, which reached 69.36, 76.21, 65.09, and 96.53 during the second period, respectively. In addition, the average concentration of nitrate varied from 21.79 to 44.11 mg/l, while that of nitrite changed from 0.04 to 0.03 mg/l. Further, an increase (39.19 to 67.19%) was observed in the average nitrogen removal efficiency in effluent. Based on the results, EAAS process was efficient in eliminating nitrogen and phosphorus by using the helicoidal pumps of aeration blowers and regulating aeration rate. Thus, aeration plays an effective role in activated sludge systems despite the microorganism diversity in aeration tank sludge. The produced effluent was consistent with Iran national standards in terms of the parameters under study, especially phosphorus and nitrogen, and can be discharged into the environment.

Dam's weir is one of the most important dam structures that play a significant role in flood routing in the dam reservoir. Since the dam's level significantly affects the storage, changing the level and increasing its height can increase storage volume and flood control in some situations. Shahid Abbaspour Dam (Karoon 1), due to the reduction of the dam volume, affected by the accumulation of sediments and the construction of upstream reservoir dams, it is necessary to increase the dam's weir height. This research used a numerical simulation of the weir with Flow3D software. Moreover finally, after the model verification, its height was increased. All model outputs were compared with the physical model results and the dam's data, and the simulation fit well with both systems. According to the model results, in exchange for changing the level of the dam from 510 to 513.5 and the fully opening of the Gates, no negative pressure is created on the weir surface, and the cavitation index is within the allowable range.

Introduction Due to the increase in population and the inappropriate temporal and spatial distribution of precipitation, the implementation of dam construction projects is essential. This, along with the increasing abstraction of water and discharge of wastewater and sewage, has caused the river ecosystems to be negative affected by dam construction projects. In dam construction, more attention is paid to the needs of drinking, agriculture, and industry, and less to the environmental flow of rivers. In order to maintain the ecosystem, however, it is necessary to determine the environmental requirements of the dams downstream.   Methodology There are various methods for determining the environmental flow of the river, including hydraulic, hydrological, comprehensive, etc. The use of a combination of modern sciences and other conventional methods in this field has been widely used. In this study, taking into account the environmental needs of downstream and using the new integrated hydrological method of Tennant and simulating the river BOD parameter using Qual-2k model and solving game theory (calculating the Nash function), the optimal amount of environmental flow of the Karun river was estimated under three different quantitative and qualitative scenarios.

 Chloroform, as a hazardous chemical, can contaminate water resources via the reaction of chlorine as an antiseptic chemical with humic acids resulted from agricultural activities. In humans, chloroform may cause dizziness, heart disorders, and disorders of the nervous system. Hence, its removal is of crucial importance.

 The current study aimed to propose cheap and efficient adsorbents to remove chloroform from water.

 Four different nanomaterials (ZnO, ZnO/graphene oxide (ZnO/GO), ZnO/GO/Zeolite, and GO/Zeolite nanocomposites) were prepared and characterized with X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) images. Textural properties of the nano- adsorbents were evaluated using Brunauer Emmet Teller (BET) and Barrett-Joyner-Halenda (BJH) techniques. Different isotherms and kinetic models were studied. The effect of pH on the removal efficiency of the nano-adsorbents was tested. Regenerability of the nano-adsorbents towards the removal of the chloroform was also evaluated.

 XRD patterns and FESEM images of the nanocomposites confirmed lattice structures and nanoscale particle size of the prepared nanocomposites. According to the BET and BJH models, all samples had mesoporous structures. The BJH cumulative surface area of pores of ZnO, ZnO/GO, ZnO/GO/Zeolite, and GO/Zeolite nanocomposites were 8.5, 26.4, 17.2, and 20.8 m2/g, respectively. The best removal speed and efficiency were obtained according to the different isotherm and kinetic models for the removal of chloroform ZnO/GO nanocomposites. All adsorbents revealed characteristic adsorption in the pH range of 7 to 8.

 The ZnO/GO, a cheap and efficient nanocomposite, showed the best performance to remove chloroform from water samples due to its superior textural property. Hence, it can be used to remove chloroform from water for up to 5 cycles.

Restrictions of surface water resources in arid and semiarid regions, along with increasing population and agricultural development, have led humans to exploit groundwater reserves as an important water resource. It is in arid and semi-arid regions that the change in groundwater quality caused by mismanagement of groundwater is an introduction to the degradation of water resources and other resources, both directly and indirectly. Recently, numerous studies have been conducted on water quality with different models (Farajzadeh and Mohammadi, 2010; Kholghi and Hosseini, 2009; Mokarram et al., 2019; Taghizadeh Mehrjerdi et al., 2008). Mehrjerdi et al. (2008) explored the application of chemical parameters such as EC, TDS, and CI in groundwater quality zoning of Ardakan-Yazd plain. Sanches (2001) and Thoradeniya et al. (2019) have also investigated water quality assessment and zoning. Therefore, studying and evaluating the quality of groundwater and identifying suitable sites for groundwater recharge in these areas can help with proper management of water resources. The purpose of this study was to evaluate groundwater quality using fuzzy method in Kohgiluyeh and Boyer Ahmad, Iran, in different geomorphological units. In order to determine groundwater quality in the study area, parameters such as Na, electrical conductivity (EC), Ca, Mg were measured in 30 sample points.

Antibiotics are considered important and integral parts of modern life, and are widely used for treating human and animal illnesses, in medicine and veterinary medicine. However, they can cause environmental pollution and may lead to increased bacterial resistance even at low concentrations.

In this study, Ampicillin degradation from β-lactam antibiotic family was studied, using a surface methodology consisting of ultraviolet radiation (254 nm) and H2O2 oxidation process in an 8-watt Pyrex reactor. The variables used included the reaction time (30-60 min), Ampicillin concentration (5-25 mg/l), H2O2 concentration (5-25 mg/l), and pH range of 3-9 at three alpha levels of -1, 0 and +1.

The data were analyzed by the analysis of variance test (ANOVA), while the validity was evaluated using regression coefficients. The optimum condition for Ampicillin degradation followed a linear model, at a 60-min. reaction time and pH 3, the Ampicillin (5mg/l) and hydrogen peroxide (25mg/l) provided the maximum antibiotic removal efficiency (82%).

The results suggest a positive and significant effect for the antibiotic concentration and a negative effect for the pH. The Ampicillin concentration with a coefficient of 8.91 had the highest impact on the efficiency of the removal process. Therefore, antibiotic pollution in the environment can be reduced through the UV-H2O2 process, so as to protect human health from the associated hazards.

Since long ago, the flood control and artificial feeding of the groundwater aquifers have been amongst the most important goals in the implementation of the flood distribution systems in arid and semiarid regions. On the other hand, determining proper places for running flood distribution systems based on the various scales and indices is of great importance.

In the present study, quaternary units, slope percentage, alluvia thickness, lands’ competence, and lands’ use cases have been calculated as the influential factors and primary scales in locating the regions suitable for flood distribution and artificial feeding on southern plains of Ilam Province and the weight of each of them has been computed using Multiclass Map Model. Then, these layers were categorized in the GIS environment and their priorities were determined in terms of the effect of each factor on the specification of the regions suitable for flood distribution.

The results obtained from the prioritization indicated that the slope percentage, with a weight equal to 52.5, is the most important scale in locating the regions suitable for flood distribution in the study area. Moreover, the results obtained from the combining and weight assignment of the maps showed that 4.5% of the study area is in the very appropriate class, 10.3% is in the appropriate class, 19.3% is in the somewhat appropriate class and 65.9% is in the inappropriate class in terms of flood distribution.

Due to the scarcity of water in Iran and the growth of population and urbanization, planning for optimal use of water resources and recycling of water from unconventional sources has become more necessary. This study aimed to reuse refined sanitary sewage and agricultural water drainage as alternative sources of irrigation for vegetables. For this purpose, 6 species of seed; red radish, sugarcane, coriander, savory, dill and leek were sown and studied in three replications: 1-irrigation with well water, 2-irrigation with agricultural drainage, and 3-irrigation with treated wastewater. Each seed was seeded at 100 g in 3 replications. Soil quality, heavy metals in soil, water pollution and parasitic tests and water hygiene were measured at different stages. Vegetable weight and height were also measured at harvest time to compare three replications. The results showed that the weight and height of the vegetables in the three replications were not significantly different, but the growth size of the vegetable was higher than the other two replications. Environmental standards for agricultural irrigation were achieved after wastewater treatment, but the amount of heavy metals in soil after irrigation was slightly increased and soil salinity decreased. Finally, it is recommended to conduct continuous health and quality control tests to avoid wasting water from agricultural water drainage for irrigation of vegetables and the use of purified sanitation in special cases.

Antibiotics are among the major concerns in terms of environmental control due to their cumulative properties, adverse health effects on humans, and development of drug resistance. The present study aimed to investigate the efficiency of the combination of UV/H2O2 and moving-bed biofilm reactor (MBBR) systems in the removal of azithromycin from aqueous solutions using the response surface methodology (RSM). In the UV/H2O2 process, a low-pressure mercury vapor lamp with the power of eight Watts, wavelength of 254 nanometers, and intensity of 1.02 mw/cm2 was used to determine the effects of pH, azithromycin concentration, hydrogen peroxide concentration, and contact time on the removal efficiency of azithromycin. According to the obtained results, the highest removal efficiency in the UV/H2O2 process was obtained with the azithromycin concentration of 2 mg/l. Therefore, 2 mg/l of azithromycin was selected as the optimal concentration with the highest removal efficiency. Following that, the optimal concentration of azithromycin was injected into the MBBR reactor. In the combined process of UV/H2O2 and MBBR, the highest removal efficiency of azithromycin was 91.2%. Therefore, it could be concluded that the combined system of UV/H2O2 and MBBR had the highest efficiency in the removal of azithromycin from aqueous solutions.

The phosphorous as one of the agricultural, industrial, and urban pollutants has an important role in the eutrophication phenomenon of the surface waters. In this research, the effect of three species of aquatic plants, including Salicornia (Persica), Typha, and Juncus, were investigated and compared with the potential of phosphate uptake. After preparing the condition and cultivation of plants, they were irrigated by synthetic wastewaters with various phosphate concentrations (7, 18, and 28 mg. L-1) for 28 days. In this test, the adsorbed phosphate was calculated based on mg. g-1 of the plant dry tissues weight using two methods mass balance and wet digestion methods. The results showed that increase in the pollutants concentration and passing time had a significant effect on the accumulative increase in phosphate uptake in all three plants at 5% level. Thus, the maximum adsorption capacity was obtained on the 28th day in high concentration of pollutant which was measured for Salicornia, Juncus, and Typha as 9.68, 6.37, and 7.68 mg. g-1 of plant dry tissues weight, respectively. Also based on the reported regression coefficients values and the obtained equations, it can be concluded that the variable ‘time' was more effective than the ‘concentration' variable in terms of adsorbed phosphate by the studied plants. The results of the measurement of phosphate uptake in the terrestrial and aerial parts showed that the maximum uptake was measured as 6.35 and 10.33 mg. g-1 of terrestrial and aerial parts dry weight in Salicornia plant, respectively. Moreover, the results showed that the translocation factor in Salicornia, Juncus, and Typha plants were 1.54, 1.12, and 1.46, respectively, as Salicoenia was maximum and Juncus was minimum. Finally, according to the obtained results from research, all three plants can be known as the hyper-accumulate plants, and they can be used for phytoremediation of phosphate from the agricultural soils according to the high capacity of these plants and prevent these pollutants from entering to the surface waters.

Nowadays at the same time with population growth in urban areas, healthy potable water supply has become a challenge especially in arid and semi-aris countries who intend to fulfil a sustainable development. Due to the increasing importance of water treatment and its key role throughout the world, improvement of water treatment plants is becoming more visible. In this research, the criteria and effective factors influencing the quantitative performance evaluation of three treatment plants were investigated using AHP approach. The three treatment plants used in this study were selected from three provences in Iran including Hamedan, Ilam and Kermanshah. The model performance were quantitatively evaluated by using the physical, chemical, and biological characteristics of effluent data. Model performance evaluation revealed that E. Coli; turbidity; ammonia, nitrate and nitrite is most important microbilogical, physical, and chemical water quality parameters when assessing the performance of effluent quality of treatment plants. Based on the the evaluated results, the performance of treatment plants in Kermanshah was better than the other two treatment plants. It will also be equaliy important to indicate that if any of the treatment plants met the effluent standards set by the Iranian authorities.

One of the important environmental problems is finding a place suitable for municipal solid waste disposal (Landfill). Choose the wrong place causing damage to the environment, human health and pollution of surface and groundwater. Several factors affect landfill site selection and there are different ways to this issue. In this paper, GIS and analytic hierarchy process (AHP) have been used to identify suitable locations for landfill in the city of Susa. For this purpose, four main factors selected that have a substantial impact on the landfill site selection consisting of technical and operational criteria, ecological and biological, socioeconomic and physical. According to these criteria, 15 information layers prepared. The final score of the parameters were calculated by using the paired comparison. After combining 15 data layer using fuzzy analysis and AHP method and helping ARC GIS software, the final map was prepared for Solid Waste. Based on the results, western parts of the city of Susa were proposed for landfill. Because of the great distance from the city of Susa and lack of proper access road, this section has been ignored as the best place appropriate waste disposal. A closer look at the result, 3 regions, with the suitable level of value, range and access road, were determined.

Analysis of the double curvature concrete dams is accurate when the models are properly prepared and analyzed by three dimensional finite element. In this research, the double curvature concrete Bakhtiari dam is analyzed with the use of three dimensional finite element method. To this end, the ADSHAPE program which can model all kinds of dam body is encoded in the MATLAB program. Then, its output is given to encoded AD ANALYSIS program which can analyze three dimensional finite element dam body. For the accuracy and calibration the program, the model cantilever beam to define its result was employed. This method in all kinds of elements with different elements size and with different Gussian points is analyzed and the results are compared. The effect of charges of elements and Gussian points in the results will be considered. Then Bakhtiari dam is analyzed with regard to proper principle of mesh generation and accurate model and stress and deformations are studied. The results showed the acceptable accuracy of coded programs in modeling and three dimensional finite element analysis of Bakhtiari dam.