Environmental Sciences
Year:2016 | Volume:13 | Issue:4 |Papers Count:18

Tehran suffers from high levels of air pollution which is negative point for human health. Volatile organic compounds, especially BTEX, are the main air pollutants that play a critical role in atmospheric chemistry of Tehran. Benzene is one of these and causes blood cancer and related diseases. In order to control volatile organic compounds, they should be monitored. To measure the amount of pollutants of VOC in the air of Tehran using mobile instruments, 32 stations were selected, including residential areas, areas of heavy traffic, industrial and controlled areas. The measurements were made over two stages (June and September 2010 and March 2011) and the VOC average concentrations at the first and second stages were 3.14 ppb and 3.67 ppb in the urban area, respectively. The results showed that pollutant emissions in high volume are emitted from refineries and oil storage, as demonstrated by location analysis of volatile organic compounds performed with Arcview software in the stations. According to such location analysis of VOCs, emission of VOCs occurred from refineries in huge quantities and some hotspots with high concentration of VOCs were seen.

Dust storms often occur in arid and semiarid regions of the world and carry a huge quantity of materials; hence, they are recognized as one of the most important environmental issues on regional and international scales. This study aimed to evaluate the heavy metal content of dust-fall particles in the cities of Sanandaj, Khorramabad and Andimeshk in western Iran. Sampling the dust-fall particles was conducted every 10 days from 20 June 2012 over one year simultaneously in these three stations using the Deposit Gauge Method and the concentration of metals was measured using Flame Atomic Absorption Spectroscopy for Fe and Mn and Furnace Atomic Absorption Spectroscopy for Zn, Cu, As, Ag, Pb, Cd, Cr, Ni. Pollution levels for the heavy metals were then evaluated using the Geo-Accumulation Index (Igeo) and Index Enrichment Factor (EF). The results obtained for the Igeo index and EF index demonstrated that levels of Ag and Cu pollution among the dust-fall particles from the three stations were higher than for other heavy metals, while concentrations of other heavy metals were not evaluated as contaminant. Although the mean of dust-fall particles on area unit in Sanandaj station was less than Khorramabad and Andimeshk, heavy metal concentrations among the sampled dust-fall particles was relatively higher. The highest amount of dust falling on a unit area was obtained from Andimesh station, more than at the Khorramabad station and, lastly, the Sanandaj station. Moreover, the maximum and minimum levels of dust-fall descending on the three stations were obtained in May and January respectively.

A fundamental problem in cities and urban areas is the declining quality of their efficiency. Before industrialization and urban growth, urban planning principles were based on traditional values, and the identity of the residential texture of the city. As with the lack of balance between the economic, social and environmental variables, cultural and socio-structural breaks in typical urban neighborhoods were created, which has led to inefficiency and a reduction in satisfaction in utilities for residents. This article aims to compare the factors affecting the residential desirability of a spontaneously growing town or new town and a comparative analysis on the residential desirability of these towns. The methodology is based on a structural equation modeling and combination of the two approaches, namely factor analysis and path analysis. The results of the T-test show a significant difference in the two cities' residential desirability and the superiority of Hashtgerd in this case. A standardized coefficients analytical model shows the most desirable residential influence of social factors in comparison with the physical components of these towns. With the importance of the physical components in a new town at 60%, the relation is more than in the old town at 50%. The history of settlement in the city had a direct correlation to the level of residential satisfaction.

The objectives of this research were to synthesize manganese dioxide nanoparticles and determine their efficiency in the removal of lead from aqueous solutions. Consequently, manganese dioxide nanoparticles were synthesized by the cathode electrochemical deposition method and the effect of pH, contact time, lead concentration and quantity of nanoparticles on lead removal efficiency were investigated through the batch system. A scanning Electron Microscope (SEM), XRD and FTIR were used to characterize the synthesized manganese dioxide nanoparticles. SEM results showed that the diameter of the particles is 30-50 nm and the results also showed that the optimum pH value for adsorption was 6. The adsorption capacity increased and the adsorption efficiency decreased with increasing concentration of lead ions and by reducing the amount of adsorbent. In a study of the adsorption isotherm, experimental data from the Langmuir model to follow. The data obtained in this study showed that the absorption of lead absorption kinetics model obeys the model of Hu and colleagues. The overall results of this study showed that the use of manganese dioxide nanoparticles was a suitable method with high potential for the removal of lead from aqueous solutions.

Wastewater from the textile industry is one of the most polluted industrial effluents. Many different methods have been used for treatment of this type of effluents. Since ozone is a powerful oxidizing agent and attacks the double bonds of the dye molecules, it can be efficiently used for treatment of this type of wastewater. The present study aims to determine the optimum running time and pH for removal of pollutants from the effluent. In the present research, experiments were carried out in a 4.2 l reactor with a 1393.431 mg inlet ozone. Colour and COD removal efficiencies were measured at different time periods and at pH values of 5 and 9. Results show that using the ozonation method under the optimum condition of a pH value of 9 and a running time 90 minutes reduced chemical oxygen demand (COD) by 21.6% and colour by 82.56% (Pt-Co scale), 73.63% (at 400 nm wavelength) and 90.76% (at 575 nm wavelength). Since the use of ozone alone to achieve the desired level of treatment is not cost effective, it is recommended to use this method in combination with other methods.

Today, population growth, modern life and changing patterns of consumption have led to the production of significant quantities of waste daily and lack of land for disposal of waste and the long-term residues of certain types of waste such as glass and plastic, leading to undesirable environmental effects (pollution of soil, water and air). So, waste management is important, especially for household waste and one of the solutions for this is the separation of household waste. Tehran Municipality has attempted to encourage its citizens towards waste separation over recent years. This study was aimed at investigating the role of training and knowledge in the management of residual household waste in District 8 of Tehran Municipality during 2015. Four hundred of residents of this district were selected by employing a quota-random sampling method and the information required was gathered through questionnaires. Analysis was conducted usingSPSS software. The results showed the level of respondents’ knowledge about waste was high, but that citizen participation was at a medium level. The results of tests the hypotheses showed, statistically, there was a positive and direct relationship between training, the amount of training and knowledge about waste with waste separation behavior. No significant relationship was found between the demographic variables of age, sex, education and income on waste separation behavior. In general, the results of this study support empirically the effect of training on waste separation behavior by citizens and also presented the need to pay attention to other social and cultural factors. In other words, factors of training and improving knowledge cannot lead to the separation of waste alone and a comprehensive study should be undertaken alongside other factors influencing the behavior related to waste separation.

Due to recent droughts and global warming, in the modeling and prediction of climatic parameters it seems inevitable that the approach of using data mining algorithms to predict climatic elements has been widely used. Therefore, in this study the use of the CARD and CHAID data mining algorithms to predict the air temperature at Arak synoptic stations was evaluated. The data provided are the average monthly data from the Arak weather station, including: “sunshine hours”, “dew point”, “relative humidity”, “average wind speed” and “saturation vapor pressure deficit” over a forty-six-year period from 1960 to 2005. The output variable used was “average temperature months later” on a monthly basis. After introducing the weather data as a monthly mean to the algorithm as an input variable of air temperature months later. Then to the CART and CHAID algorithms were evaluated using correlation coefficient (R2) and mean absolute error (MAE). According to the two statistical indices, the CHIAD Tree model has a better function by R2=0.915 and MAE=2.77 in forecasting the monthly average temperature for the months later.

Due to extensive threat factors facing the global biosphere as well as a lack of adequate conservation funds, we need to develop more efficient methods of conservation management in accordance with a comprehensive vision of biodiversity and that reinforces ecosystem-based actions. Meyghan Wetland which shows high ecosystem values as well a wide range of threat factors was selected as a case study. As a transitional zone as well being diverse habitats, the wetland has covered a wide range of diverse plants and animals in the aforementioned area. Due to its natural potential for establishing an Important Bird Area (IBA) as well as designation as an international wetland, the importance of this area from the ecological and ecotourism point of view has increased. Moreover, the absence of the permanent streams, drought events, overharvesting of the underground waters, changes in the hydrologic gradient, decline in the water quality, the influence of chemical pollution, erosion as well as the lack of any appropriate program for land use planning has created several environmental challenges in the aforementioned region. Therefore, compilation and assessment of the basic ecological data, accompanied by an appropriate management plan, can be effective for the management of this wetland.

It is a long time that human being have paid attention to the importance of environmental issues, nevertheless, the environmental threats are part of a development process that may not be denied. Inattention to the effective criteria of sustainable development can cause irreversible costs for various societies. Based upon the role of education in the prevention of environmental degradation, the purpose of this research is to study the effect of education in production and emission of greenhouse gas of carbon dioxide during the period of 1992 to 2012. For hypotheses testing of the research, the Dynamic Panel Data (DPD) through the Generalized Moments Method (GMM) has been used for 12 selected countries including Iran in Middle East and North African Countries (MENA region. The findings of this study indicate, the positive and significant impact of the education variable on the improvement of environmental quality and reduction of air pollution. Besides, the results show that there is a direct relation between the political agencies and the lessening of population growth to the decline of air pollution. With the raise of the average schooling in total population, the growth of air pollution is declined. As a consequence, increasing investment in education and the average schooling can lead to lessen CO2 emission in selected MENA countries including Iran.

Wastewater from the textile industry, especially that containing azo compounds, often contains toxic materials that persist in the environment. Therefore, it is necessary to evaluate the performance of various methods for their removal. Acid red 37 combinations represent a single structure in the azo dyes which have already been widely used in the textile industry. The purpose this study is the optimization of effective factors and investigation performance of the electrofenton and electrocoagulation methods in synthetic wastewater for Acid Red 37 dye removal from aqueous solutions. In this study, synthetic wastewater was formed from Acid Red 37 dye and pilot Scale and the concentration, pH, electrical density and temperature parameters were investigated. Ultimately the optimum conditions were determined as well as the amount of energy consumption at 90 percent efficiency. To investigate the pollutant degradation GC-Mass was used and the results show that both methods had the ability to remove Acid Red 37. Electrocoagulation was found to be more efficient than the electrofenton method; respectively, the optimum conditions for removal by the electrofenton and electrocoagulation methods were pH=3, time=120 min, density- 30 mA.cm2, concentration=50 mg/L, consumption energy 142.8 KWh/Kg Dye and pH=7 time=120 min, density- 30 mA.cm2, concentration=150 mg/L, consumption energy 130.2 KWh/Kg Dye. These results show that the electrocoagulation method was better than electrofenton with its high ability for removal Acid Red 37.

Quantifying and anticipation of the impacts of changes in water-related services caused by human activities is a complicated aspect of environmental assessment which can be facilitated by the application of dynamic and spatial models of ecosystem services. This paper aims to examine the application of the WW PSS model in the Sarvelat and Javaherdasht forested landscape in order to calculate the water balance and water- related services of the ecosystem in a baseline condition and, then, to measure the impacts of changes in natural forest cover on the services' quantity and quality based on a scenario developed. The result of running the model indicates that the surfaces covered with dense forest have decreased by 29% in recent 13 years, but the semi-dense and poor forest covers have increased by 14% and 15%, respectively. Then, the impacts of such structural changes on water services were measured and this showed an overall decrease in water balance of 1.5 mm/yr and an increase in runoff of 12, 197, 528 m3/yr which is caused by a reduction in evapotranspiration due to cutting forest trees. In the final stage, the environmental consequences of changes in ecosystem services were quantified by the model which depicts an increase in soil erosion of 0.57 mm/yr on average and exacerbation of the potential of water contaminate distribution across the study landscape.

This study was conducted in order to analyze the impacts of IPM/ FFS programs on various outcomes by a broad range of stakeholders - including farming communities, local and national governments, and researchers - who are supporting such programs in Iran. This study is unique in that it uses an impact evaluation with a sociological perspective to explore the trigger and accumulation function of the effects of IPM/FFS programs in conformity with the community capital and adaptive management approaches. A total of 86 IPM/FFS stockholders were sampled. The principal component analysis was used to identify the impact factors of IPM/FFS programs and explore several factors, including the enhancement of social welfare, the improvement of farm health and safety, technical and social (leadership) skills development, risk management and marketing, improvement ofproduction quality as well as expansion of farmers’ experiential abilities, and the establishment of adaptive ecological management. According to the trigger and accumulation function of the effects of IPM/FFS programs, it was concluded that the IPM/FFS stimulated social learning and that it strengthened human and political capital by developing technical, social and leadership skills, which apparently prompted social and financial capital through expanding the range of local activities, relationships and policies related to improved agro-ecosystem management (natural capital). Finally, based on the trigger and accumulation function of the effects of IPM/FFS programs, in particular for providing long-term effects, an adaptive management approach was recommended to emphasis on developmental impacts through a participatory approach.

In many work environments, human errors are of great importance, since they result in adverse events. Therefore, in order to prevent or reduce the consequences of human errors, it is necessary to identify the cause interpolation. The aim of this study is to identify, assess and manage the risks of human errors in the desalting unit and compression station at Maroon. After assessing different parts of the control room in the desalting unit in terms of health and safety, in order to identify risks and potential damage to human factors (critical tasks), the method of Walking & Talking Through was used. To analyze the critical tasks in the desalting unit and compression station, Hierarchical Task Analysis (HTA) was applied and, then, the risks and potential human damage were evaluated and classified in view of the probability of occurrence and intensity of effects. The Human Hazop method was used in the process of risk assessment and the results of the risk calculation work sheet for the Maroon units indicate that the most important reasons behind errors in this company are as follows: (a) not performing job tasks (88.33%) as the most important job tasks, and (b) human errors with the highest percentage of 41.66%. The consequences of human errors can be classified into three categories: (1) economic consequences (44.96%), (2) management consequences (32.55%) and (3) environmental consequences (22.48%). The Human Hazop method can be used for eliminating human errors and also for reducing the intensity of their consequences, by altering education, design and safety systems and instructions which, in turn, increases the tolerance of errors in designs or operations.