JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
Year:2019 | Volume:21 | Issue:8 (87)|Papers Count:27

Background and Objective: Considering the importance of environmental protection and necessity of using new energy sources and innovative fuels, using of renewable energies have been a great concern. Due to this necessity, in this study, mathematical modeling and simulation of a batch bioreactor to produce methane from livestock waste was investigated numerically. Method: The relationship between microorganism’ s growth rate and substrate concentration were established by Monod model. The equations of mathematical model were solved with fourth order Rung Kutta. The effect of initial microorganisms’ concentration on methane production was also investigated. Initial concentration of substrate and microorganisms are 51. 74 g/L and 1. 61 g/L, respectively. Findings: The results revealed that the mathematical model average deviation from experimental data is 8. 53%. The amount of methane produced after 70 days is equal to 10. 29 g/L. The substrate disintegration and methane production are a function of substrate retention time. Enhancement in the initial concentration of microorganisms causes methane gas production in less time. The amount of methane gas produced is independent of initial microorganisms’ concentration. Discussion and Conclusion: The model which presented in this study could be used to predict the time required to carry out the reaction, ooptimum performance of bioreactor, the relevant process equipment design, scale up of equipment such as digestive and appropriate control of operation to produce high-purity methane and higher volume of biogas in the bioreactor.

Background and purpose: Nowadays environmental strategic assessment as a tool for incorporating environmental considerations into the early stages of decision making has attracted the attention of planners. Scholars have attributed characteristics such as attention to the relationship between different layers of decision-making from policy making to implementation, consideration of cultural-political context and organizational structure of development as well as reflection of socio-economic considerations to environmental strategic assessment. Method: Despite these characteristics, the usual process of strategic environmental assessment does not have the ability to comprehensively assess the effects of cultural, social and ecological contexts. Criteria that do not provide clear results to decision makers are also used to measure the sustainability of development types. For this reason, in this study, the process and structure of the strategic environmental assessment based on the theoretical foundations of the resilience approach has been improved. Based on the resiliency approach, uncertainties and disturbances in socio-ecological systems can be analyzed. It is also incorporated into the evaluation process by reference to the multi-scale concept resiliency approach. Findings: In this study a three-step process for strategic environmental assessment is proposed. Each step is based on the basic concepts of the resiliency approach. Discussion and Conclusions: The sum of these characteristics makes environmental assessments possible on the basis of the unpredictable future, the inevitability of change, and the vulnerability of ecological systems.

Background and Objective: Treating wastewaters containing nitrogenous compounds is an essential issue due to environmental hazards. New biological technologies such as simultaneous nitrification-denitrification (SND), ANAMMOX and SHARON were developed in the last decades. Such techniques are economical and more effective compared to conventional methods. The aim of this work was to investigate physico-chemical properties of SND process. Method: In this study, subsequent to constructing a comprehensive survey on papers published in the last two decades, the impacts of effective parameters such as temperature, pH, dissolved oxygen, organic carbon, floc size and sludge retention time (SRT) on SND process were investigated. Findings: SND process reduces carbon source demand. Dissolved oxygen should be adjusted in a particular range to maintain an equilibrium between the nitrification and denitrification. The process efficiency was higher in the basic pH. The optimum temperature for the growth of SND bacteria were 20-30 ℃ . There was no linear correlation between efficiency of process and SRT. Discussion and Conclusion: The results of this research approved that new biological processes for nitrogen removal such as SND were promising owing to reducing the need for aeration and carbon source. By controlling the Physico-chemical conditions in process, good efficiencies can be achieved.

Background and Objective: Dead trees are an important factor for structure and activity controlling in forest temperature. For the sake of survey role of dead trees in the regeneration of trees species, regeneration density of environs dead trees in Lalis forests, Nowshahr was studied. Method: For a sampling of snags by circle plots (500 m2 area) and snag in the center, and also in the logs used of along plots into width four-meter and dead trees length. Decay classes of dead trees, topographic position and canopy gap area due to dead tree inscribed according to average diameter of canopy opening. In this study gaps were divided into five groups, including close canopy, very small (<50 m2), small (50-150 m2), medium-size gap (150-250 m2) and large size (250-480 m2). Findings: Results of regeneration show that beech species had the most regeneration density. According to the results of density in decay classes, the fourth class had the most regeneration density for total species. Also with the increase in the size of gaps area, accrue in regeneration density and fifth class includes most regeneration. Differences mean values of density between slope and altitude classes weren't significant, but the density of Beech, Persian Maple, Cappadocian Maple, and Alder species were significant in different aspects. Discussion and Conclusion: The findings of the present study show that recognizing natural processes in virgin stands of forest ecosystems provides useful information for managers to make the right decisions.

Background and Objective: Destruction of land due to land use change in arid and semi-arid areas has endangered sustainable land use. This research was carried out to investigate the effect of rangeland use change to agriculture and study the physical-chemical properties of soil in Gonbad area of Hamedan province. Method: In this study, 6 soil samples were prepared from soil surface according to the type of land use change. After removing soil samples and preparing samples, some physicochemical properties of soil including Acidity, Electrical Conductivity, Silt, Clay, Gravel, Nitrogen, Potassium, Sodium, Organic Matter, Calcium and Magnesium were measured. In this research, Soil Texture was determined by hydrometric boiling, Acidity and Electrical Conductivity, using pH meter and EC meter, Organic Oatter using Walkley-Black, Calcium and Magnesium by titration, Sodium and Potassium using flame photometer and Nitrogen were measured by Kjeldahl method. Findings: After analyzing, it was determined that the change in the use of rangeland to agriculture caused a significant decrease in Acidity and Potassium at 5% and Organic Matter at 1% level. Average Nitrogen content in agricultural was 0. 18% and in rangeland was 0. 9% (p<0. 01). There was no significant difference in Soil Texture components, Electrical Conductivity, Sodium, Calcium and Magnesium with land use change. The amounts of Silt, Sodium, Calcium and Magnesium in rangelands were more than agriculture area. Discussion and Conclusion: The results of this study showed that the land use change causes changes in the chemical and physical properties of the soil. One of the most important changes was soil texture alteration caused by selective soil erosion. The results of this research showed the necessity of paying more attention to the development of land management and land use planning programs according to the capabilities of the studied area.

Background and Objective: Today, desertification is considered as a severe problem in most countries of the world, including the developing ones. Despite the serious environmental, social and economical impact of desertification phenomenon, few studies have been done to provide optimal alternatives. The aim of this study was to evaluate the alternatives for combating desertification in order to achieve optimal alternatives in the context of the sustainable management of deserts. Method: To achieve this goal, the Multi-Attribute Utility Theory (MAUT) has been applied in the context of Multi-Attribute Decision-making (MADM) models. In order to determine the weights of criteria and alternatives, it was used the modified Delphi and Shannon entropy techniques, while the final rating of alternatives was performed using the Multi-Attribute Utility Theory (MAUT) function. The model was applied to evaluate the efficiency in providing the optimal alternatives in Khezerabad Region of Yazd Province. Findings: The results showed that, the alternatives of prevention of unsuitable land use changes (A18) by a utility factor of 0. 7429, vegetation cover development and reclamation (A23) by a utility factor of 0. 6573 and modification of ground water harvesting (A31) by a utility factor of 0. 3184 respectively were identified as the most important alternatives for combating desertification in the region. Discussion and Conclusion: These results might able the managers to properly and efficiently use the limited available facilities and funds in order to control the desertification. In addition, achieveing better results, this might prevent the waste of national resources.

Background and purpose: If sustainable urban development is considered as economic efficiency, social equality and environment protection, one major perquisite for its realization is optimization of urban land uses; otherwise the cities would suffer from sprawl or uncontrolled expansion. Various models have been proposed for understanding the city shape and its scattering measurement. Material and Methods: This work aims at calculating Tehran urban sprawl in various decades using different models including temporal analysis of urban density, quartile distribution, degree-balanced distribution, degree of aggregation and Holdern model, and its impact examines on nearby farms. Results: Findings of this work show that Tehran is shifting from concentration and gradual growth to excessive urban sprawl and rapid and uncontrolled growth. In The following, using satellite images of the years 1357 and 1385 we examines the rate of change of land use especially the quality and quantity of changes of farmland to urban uses with using ArcGIS software. The image has converted to maps through visual processing or visual interpretation. At the end with map have obtained with using compilation and synthesis method that can show to how land use changes during the period (28 years). Discussion and Conclusions: The results of research in this section indicate that the total agricultural land in study area in 1979 was about 38952 hectares that Half of which have been eliminated in the course of 28 years 1996-2006 and have decreased directly or indirectly through urban development and reached 19. 4 thousand hectares in 2006. If the growth and development of the city continues as sprawl distribution. The same amount of land will be destroyed in the future development.

Background and Objective: The object of this study is to investigate the effect of surface modification of Polyvinylidene fluoride (PVDF) membrane on filtration performance and reduction of fouling in membrane bioreactors (MBRs). This study was done based on the photocatalytic properties of TiO2 nanoparticles under ultraviolet light irradiation and to assess the effect of reducing membrane fouling in real EPS extraction of submerged membrane bioreactor as the main foulant. Method: Considering photocatalytic properties of TiO2 nanoparticles under ultraviolet light irradiation, PVDF/TiO2 performance in filtration of extracellular polymeric substances extracted (EPS) from membrane bioreactor which was used for oil refinery wastewater treatment and has been evaluated and compared with PVDF membrane without TiO2 nanoparticles. Findings: The results showed improvement of permeation flux and flux recovery ratio of nano-composite PVDF/TiO2 under UV radiation due to membrane super hydrophilicity which results in irreversible membrane resistance of EPS UV irradiated to 0. 36×1012 m-1 and PVDF/TiO2 membrane total resistance reduction to about 44% comparing to pure PVDF membrane. According to the results by ultrafiltration combined with UV, the flux recovery of about 90% for PVDF/TiO2 membrane can be achieved. Discussion and Conclusions: Considering EPS as the main foulant of refinery MBRs, simultaneous UV irradiation ultrafiltration of EPS extracted from membrane bioreactor by PVDF/TiO2 membranes can be considered as an effective approached in fouling reduction research in future.

Background and Objective: Considering the significance of the issue, this research was performed to study the elements of Zn, Pb and Cd in the rice products available in the markets of Hamedan in 1394. Method: Accordingly, ten types of that rice were sampled through a standard method. After passing the preparation stages of the samples by acidic digestion method, the concentration of elements was read in Atomic Emission Device. Spss was applied to process the statistical data. Findings: The results indicated that the minimum and maximum average of element concentration in rice samples (according to mlg/kg) were as the following: for Zink with 0. 0862± 0. 0002 and 1. 02± 0. 00781 in B rice and C respectively, for Lead with 0. 226± 0. 00529 and 4. 894± 0. 00529 in A and H rice, and for Cadmium with 0. 006± 0. 001 and 0. 043± 0. 00436 in H and A. The results also showed meaningful, statistical deviation of accumulated concentration average of heavy metals in rice samples available in the markets of Hamedan through WHO. Concentration averages of Zinc and Cadmium are less while concentration average of Lead is more than permissible level. Discussion and Conclusion: Finally, it can be stated that the rice product which is being consumed in Hamedan is exposed to Lead pollution which is more than permissible level and it can cause psychological and behavioral problems and health consequences which cannot be compensated.

Background and Objective: Due to its low cost, simplicity and speed of separation and high efficiency, the magnetic separation method widely used to remove contaminants and to solve the problems of the environment. The aim of this study was synthesis of magnetic activated carbon by Fe3O4 and investigating its efficiency in adsorption of Cadmium from aqueous solutions. Method: Magnetic adsorbent prepared by the method of sequestration and physical characteristics and structure of synthesized absorbent were determined by XRD, SEM and TEM. To remove the Cadmium from aqueous solutions, the Box-behnken design (BBD) of response surface methodology (RSM) was employed for optimizing all parameters affecting the adsorption process. The studied parameters were pH (5-9), temperature (25-45 0C) and the amount of adsorbent (0. 5-2 g). 15 experimental runs were calculated by using BBD. Findings: The optimal condition for removal Cadmium by synthesis of magnetic activated carbon by Fe3O4 nanoparticles were pH=7, 450C temperature and the 2 g of adsorbent. Discussion and conclusion: The study showed that magnetic activated carbon has a high potential for removing cadmium. Therefore, it is believed that magnetized active carbon by keeping its physical and surface properties could be a suitable method to solve some related problems including separation and filtration.

Background and Objective: Given the impact of the environment on human life and hence human survival, environmental protection is considered essential. Therefore, in order to achieve this goal, it seems obvious to identify the items that provide environmental sustainability. Therefore, in this study, we will determine the pattern of resource sustainability in environmental protection. Method: The method used in this research is fractional programming. The fractional programming is the most common type of mathematical programming with relative targets. The purpose of fractional programming is to find the optimum value of a function which contains linear restrictions with respect to the variables. Findings: This study evaluates in two scenarios; in the first scenario it is assumed that all land should be used. Result of this section showed cultivation of barely, alfalfa and silage maize are the optimum cropping pattern in the region to sustain environmental resources. In the second scenarios it is assumed that strategic crops such as wheat, barley and sugar beet cultivation in the list of products exist. Result of this section showed cultivation of wheat, barley, sugar beet, cucumber and alfalfa are the optimum cropping pattern in the region to sustain environmental resources. Discussion and Conclusions: The results of this study showed that the pattern presents cultivation of crops in the area of environmental sustainability is not effective and that major changes must be made.

Background and Objective: Most of industries in terms of production rules, environmental concerns and economic interests are under pressure. A supply chain model is a network of facilities and activities which involve processes related to procurement of materials from suppliers, production and product development in production centers and distribution of consumer products in final destination. Long-term strategic decisions such as construction of facilities in the network need financial assets and optimal program. Issue of designing a supply chain network has attracted lots of attention of many researchers during the recent years. The main objective of this paper is to present a mathematical programming model that seeks to minimize the environmental impact in a closed-loop supply chain. Method: Researcher through library research and preparing a questionnaire to estimate parameters and data associated with the uncertainty of parameters and then through interviews, expert opinions about the limits and changes to the decision-making parameters have been collected. Then a fuzzy multi-objective mixed integer programming model is presented that model to minimize costs, minimize environmental impact and minimize the time of delivery of product. Findings: After running the model, increasing objective function is to minimize the total cost, minimize environmental impact and minimizing the time the product reaches the customer contact temperature limits for different values were obtained. These values using Epsilon limitations in the software GAMS obtained. Discussion and Conclusion: In this study, the proposed mathematical programming model is solved with an exact solution. The results showed the location and facility capacity and output in the manufacturing centers are determined.

Background and Objective: The impact of tectonic activities on environmental pollution was investigated by lead and zinc mines at Surmeh. Method: In this study, the 6EPA standard method was used and tested 7 times around the water and soil around the area and was expected to have adverse environmental effects, like other lead and zinc mines in the country such as Angoran and Zahabad. Finding: Studies have shown that the amount of lead in soil and water is standard for agricultural use and has little environmental impact. Discussion and Conclusion: Based on stratigraphic columns prepared in the Surmeh Mountains containing the salt marshes of the Hormoz and calcareous Dalan Formations and the Nare Evaporites, the tectonic effects of alpine activity acting in two tensile-shear and compressional conditions have resulted in the Dalan calcareous formation containing ore deposits. Lead and some clay minerals are marl, located in the core of the Surma anticline which provides salt diapirism conditions in different tectonic phases and eventually due to the calcium carbonate uptake in the Dalan Formation and the high uptake capacity of clay and salt minerals in the lead. Higher levels prevent lead release in groundwater and its derivatives in confined air and soil. Thus it can be said that the regional tectonics has resulted in the creation of a natural filter for active adsorption of lead in the range.

Background and Objective: Agriculture as an important part of the economy has a great role to achieve sustainable development using scientific methods and knowing environmental potentials. In this regard, there is a close relationship between agriculture development and environmental resources. Onarchay is one of the watersheds in the center of Ardabil province that has a critical role in local people’ s livelihood. The purpose of this study was to evaluate ecological land capability and determine the suitability rate for agriculture and range activities in Onarchay watershed in 2016. Method: First, by reviewing of the sources, 13 criteria for agriculture-rangeland capability evaluation were defined. In the next step, all of the criteria were imported to the Geographic Information System (GIS) with the same format and were standardized. Then, Analytical Hierarchy Process (AHP) and binary comparison matrix were used to weight to the criteria and sub-criteria and finally, all of the criteria were combined using Weighted Linear Combination (WLC) method. Findings: Based on the results 11659 hectares (84/19%) for agricultural activity have very good to weak potential and 2189 hectares (15/81%) for rangeland activity have good, moderate and weak potential. Discussion and Conclusion: Results showed that there is no balance between current land use and land potential in Onarchay watershed.

Background and Objective: The countryside is among the settlements that are the scene of the formation, growth and adaptation of opportunities and threats that affect the quality of life and the way the needs of the inhabitants are met. On the one hand, access to services in cities and, on the other hand, urban ecological threats and the attraction of immigrant populations and their associated complications have created complex conditions in these villages that are of great importance to the biodiversity of these villages. The purpose of this study was to identify the biodiversity differences in the surrounding villages of Izeh. Method: The focus of the current study was the rural area located in 3 to 12 km of Izeh. The livability of these villages was investigated using 3 indices and 64 subindices. In this study which used a descriptive-analytic methodology to analyze data, t-test and Pearson correlation test in SPSS and Fuzzy TOPSIS technique was used. Findings: According to the results of the fuzzy TOPSIS decision making model, the villages around Izeh city are biodegradable in three categories: moderate, undesirable and unacceptable. Also, the results of T-test indicate that the western suburbs have better viability than the two eastern suburbs and the Netherlands. Finally, the results of Pearson correlation test show that there is a direct and significant relationship between the status of livelihoods and the population of the villages. Among the twelve components, pollution, housing, facilities and services, outlook and participation had the strongest relationship with the distribution of population in the villages around the city, respectively. Discussion and Conclusions: According to the findings, it has been shown that there is no improvement in the habitability score among the villages. Because none of the villages are acceptable and tolerable at the level of viability, and all of them are at moderate to unacceptable levels.

Background and Objective: Calculating the environmental impact assessment during a product's life cycle is very important. Therefore, the purpose of this study was to evaluate the environmental effects of soybean oil production (Glycine max) in Ardabil province. Method: Lifecycle assessment was conducted to compare environmental burdens of this crop. Four categories (eutrophication, acidification, global warming potential and photochemical oxidation) of environmental impacts were used to define in this method. Inventory phase was conducted in 1393. Findings: The production of one-ton soybean in Ardabil in eutrophication potential, acidification potential, photochemical oxidation and global warming are 13. 671 kg PO4eq, 13. 680 kg SO2eq, 0. 093 kg C2H4 eq and 857. 128 kg CO2eq respectively. Discussion and Conclusion: It was found that the effects from the three crops comes generally from manufactured fertilizer, manure, diesel combustion, agricultural practices, and electricity for irrigation. It can be said that the indirect effects associated with these inputs are related to producing and processing, which had negative impacts. Result indicated that input performance of production of one-ton soybean is low. With increasing crop yield per input can decrease environmental burdens.

Background and Objective: Arsenic concentrations in soil and water can be increased by natural processes such as sedimentation of volcanic ash, mining, geothermal debris, oxidation and dissolution of minerals. Also, application of herbicides and animal fertilizers in agriculture can increase the concentration of arsenic in the environment. In the Hashtrood area of East Azarbaijan province, evidence of arsenic contamination has been reported, possibly due to arsenic contaminated water, soil and crops. The purpose of this study was to identify the amount of pollution of water resources, soil and crops in the region to arsenic Method: Sampling of surface water resources, soil, and plants cultivated in the area in four seasons and the concentration of arsenic was determined in samples. Findings: Analysis of water samples showed the average concentration of arsenic 0. 341 mg/lit. The mean concentration of arsenic in the soil in the area is 127. 95 mg/kg. The concentration of arsenic is less than permissible 1mg/kg in agricultural products in both regions. Discussion and Conclusions: The results of the comparison samples with standard values represent water and soil arsenic contamination in this area which in the most samples is higher than the standard. The low concentration of arsenic in the plants in the area can be due to the alkalinity of the soil and high clay content. Arsenic has a low solubility in this type of soil and is absorbed on soil clay particles and plants grown on these soils cannot easy to absorb arsenic from the soil.

Background and Objective: Nowadays, water is considered as one of the factors for improvement and economic growth of societies. The hot and cold seasons of the year and its comparison with the non-segregation of the hot and cold seasons are 26 years. Method: In this study, after studying the accuracy of discharge data, electrical conductivity, soluble matter, chlorine, calcium, sodium, magnesium, acidity and sodium uptake ratio of the two stations, it was tried to find appropriate regression relationships between discharge parameter and qualitative parameters. Provide water. Findings: The results showed that the Chehelgazi sub-watershed in cold months, the liner relationship between discharge with electrical conductivity, dissolved solids, chloride and sodium and also the exponential relationship was suitable between discharging with calcium. In warm months for this sub-watershed, the linear relationship presented the suitable relationship between discharge with dissolved solids, electrical conductivity, magnesium, calcium, sodium and the sodium adsorption. Also, the linear relationship was suitable between discharge with dissolved solids, electrical conductivity, chloride and sodium whereas the exponential relationship was better between the discharging with calcium in Khalifehtarkhan sub-watershed. In this sub-watershed, for warm months, the linear relationship was suitable for the relationship between discharge with dissolved solids, electrical conductivity, chloride, sodium and sodium adsorption. The separation comparison of cold and warm months with non-separation showed that non-separation of cold and warm months is not possible the chloride and magnesium estimation (in Chehelgazi sub-watershed) and calcium estimation (in Khalifetarkhan sub-watershed). Discussion and Conclusion: using obtained relationships and seasonal changes of surface waters quality, with discharge rate can create modeling water quality, extraction and recovery of water quality data.

Background and Objective: Due to increasing population and demand for aquatic products and protein, in recent years the construction of fish farms, especially cold-water fish farms along the rivers has increased, and the effluent discharge of these farms without any treatment to the natural habitats of adverse and destructive effects. Eating the natural balance of the water will help the ecosystems. Among the most important communities of rivers and streams are large invertebrates. These organisms are able to represent water quality changes as a biological indicator. The purpose of this study was to investigate the effect of untreated effluent of fish farms on large invertebrates of Zarrin Ghee brook, because the inflow of these effluents into streams and rivers affects the structure and composition of streams, causing disruption of ecological balance. Method: In the present study large biodiversity of aquatic invertebrates as well as water quality using biomarkers in Zarrin River, Golestan province in winter 2015 and spring 1395 m2 at 4 stations and monthly (at entry, exit and 500 and 1000 m downstream farm) Fish breeding) was done by sampling with a Surface bumper level of 0. 09 m 2 in three replications. Samples were fixed with 4% formalin and isolated, counted and counted in the laboratory. Findings: Increased human activities, including the presence of fish farms in the area, can contaminate the surface water of the river. A total of 2179 specimens of large benthic invertebrates were identified, belonging to 35 genera, 28 families and 9 orders. Frequency of these organisms, were respectively Diptera with 46. 9%, Ephemeroptera with 27. 7%, Trichoptera with 16. 9% and Lmbricida with 2. 31% and the rest with 6. 19%. Discussion and Conclusion: The result sowed that Shannon diversity, Evenness, TBI, IBI and IRWQISC were good indicators for water quality assessment in the study stations. In general, water quality in study area except station 2 (after fish farm) was desirable that the necessity of efficient water management to improve water quality in this region.

Background and Objective: Sea turtles are considered of the globally threatened species in the world. Mortality range of sea turtles in utero is very high due to several natural and human threats, affecting survival and regeneration of these reptiles. Method: Therefore, identification and control threats are vital to support habitat and survival rate. Eggs transfer to a safe place immediately after laying is a management tool for increasing the emergence success of these critically endangered species. In this study, emergence success of Eretmochelys imbricata in the coasts of Qeshm Island was studied. Findings: The emergence success rate was 59/92% out of 102 transferred nests (from Shib-deraz and shib-poiee beach). Results showed that no significant differences between Shib-deraz and shib-poiee beach, considering the emergence success of the transferred eggs. Discussionand Conclusion: According to the results, we believe that best way to protect hawks-bill turtles in this area is transferring eggs and protecting nests in a safe place to raise emerging success.