JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY
Year:2009 | Volume:11 | Issue:2 (41)|Papers Count:13

The emission of the flue gases from industrial units affects the ambient air quality. These pollutants have a strong impact on humans’ health and environment, and therefore should be removed. The Electron-Beam method is an effective and economical way for simultaneous removal of pollutants, and could be an alternative for conventional methods.In this paper, the technical and economic considerations for the removal of SO2 and NOx as well as the application of this technology in related industries are studied. The results show that the EB method presents many economic and technical advantages compared with the conventional methods. This method could be a very effective way for the control of air pollutants in industrial units.Moreover, if the energy costs for EB are reduced, it can be used in less developed countries.

Over the past 6 years, the country’s energy production has increased as much as 8.29% per year on the average. At the present time, power plants play a major role in the production of greenhouse gases and the optimization of the systems of the newly-constructed power plants is one of the country’s main environmental challenges. Therefore, the assessment of the construction of energy recovery systems aiming at increasing the efficiency of gas power plants with little pollution can be a great help to the environment.In this study, a techno-economic evaluation of energy recovery systems has been done in Kerman power plant considering air pollution reduction.Fortunately, the potentials for the construction of combined cycle power plants exist in the country. Since such power plants save the fuel and increase the efficiency, they can reduce contaminating gases. The application of energy recovery systems in gas power plants is quite economical and their pay-back rate is 9-10 years.The results of the present study show that with these plants, 152 million liters of gas-oil and 58.3 billion cubic meters of natural gas will be saved over a period of 30 years. As a result, 1.652 million tons of greenhouse gases will be reduced.

Chromium is one of the major causes of environmental pollution. To remove heavy metal ions from water, microorganisms can be used. In this study, dead fungal biomass of Aspergillus niger is used. The biomass was boiled in 0.5 N NaOH solutions to increase the metal removal capacity of A.niger and was applied when the pH of wash solution was in the normal range. The optimum adsorption pH value observed for chromium (VI) ions was 2. In these experiments, the influence of contact time, pH, Cr (VI) concentration, temperature, stirring speed, and different concentrations of biomass were evaluated.The results show that the experimental points fit both Freundlich and Langmuir models. Meanwhile, the curves of both of them were drawn. In Langmuir model, R2=0.9544 and in Freundlich model, R2=0.992. The Cr (VI) removal rate increases with the increase in temperature; that is, they are positively related. The removal rate of total chromium after 24 hours was %74.6. The results revealed that boiling biomass in NaOH had a better effect on biosorption of chromium so that adsorption would increase by many times. During the study, the amount of toxicity decreased as Cr (VI) was reduced to Cr (III). Part of Cr (VI) was also removed through surface adsorption.

It is now evident that uncontrolled growth and development will have negative consequences. Sustainable development is indeed a solution to this problem. It is a multi-faceted approach, which extensively involves many aspects of human life. Transportation-as a vital part of today's life-that strongly interacts with all other key dimensions of societies appears in many sustainability-related studies. In a viewpoint, sustainable transportation is considered to include three main dimensions, namely economy, environment and social aspects. In this viewpoint, sustainable transportation is achieved by establishing balance and concordance among these dimensions.In this study, the interaction between transportation and the tripartite dimensions is analyzed. Sustainable development is qualitative in nature, and many studies have been conducted to quantify it. However, few studies have been done in this field at a national level.Therefore, this paper attempts to analyze sustainable transportation more quantitatively and at a national level. To this end, relevant indicators for Iran are introduced, and then using a multi-criteria approach-the analytical hierarchy process (AHP)-, sustainable transportation policies are assessed and ranked.

The use of sewage sludge with high concentrations of heavy metals increases concentrations of these elements in soil, groundwater and food chain. This study investigated the effects of sewage sludge and CdCl2 application on Cd transport in soil and plant uptake. A filed experiment was carried out in a random block design with five treatments and three replicates (two levels of sewage sludge: 0, 50 ton ha-1 and three levels of Cd: 0, 42.5 and 85 mg Cd kg-1). Air-dried sewage sludge and CdCl2 were applied to soil and were mixed uniformly.In the first stage, cress was planted. Thirty days later, soil samples were collected from a 20-cm depth. Also, plant samples were provided from shoots and roots of cress. In the second stage, lettuce and spinach were planted. One hundred and eighty-four days later, soil samples were collected from 20, 40, 60, 80,100 and 120 cm depths. Plant samples were provided from shoots and roots of lettuce and spinach. The DTPA-Cd and total Cd concentrations were determined in soil samples. Also, Cd concentrations were determined in shoots and roots of plants. The results show that there existed a significant relationship between total Cd and DTPA-Cd in 20 cm depth after 30 and 184 days (R2=0.98 and R2=0.86, respectively ). CdCl2 application significantly increased the concentration of DTPA-Cd in the 20-cm depth. Sewage sludge and CdCl2 application had no significant effect on Cd transport in soil. CdCl2 application increased Cd concentrations in shoots and roots of plants significantly. Also, there were significant relationships between DTPA-Cd concentration and Cd concentration in roots of cress, lettuce and spinach (R2= 0.98, R2= 0.89, and R2=0.76, respectively).

Elaboration and implementation of Green Productivity management in each governmental and nongovernmental organization have certain environmental, social and economic consequences. Therefore, to enhance productivity in the Fourth Development Plan, the input and expenses should be decreased and the output and products should be increased.In this paper, the current situation of Iran Aseman Airline Company is analyzed in terms of energy and water consumption, airplanes’ fuel, and environmental pollutants. At the end of the study, some applicable approaches are suggested for increasing the company’s productivity with the consideration of environmental issues.

Among the main factors affecting the development of different modes of transportation are the direct and indirect costs which should be taken into account in short-, medium-, and long-term plans. The fuel consumed in transportation sector is a significant factor in producing such costs. The main goal of the present study is to estimate and foresee the social costs of fuel consumption in railroad sector using ANFIS, time-series, and structural models.In this research study, such social costs are taken into account and anticipated till the year 2011. The results show that ANFIS model provides us with the best anticipation.

In this project, the prototype production of catalyst converter for dual-fuel automobiles was studied. La (Pd, Co, Ce) O3 Perovskite catalyst was prepared by the citrate route without the use of Pt and Rh. The present researchers just used Pd (1.2 g) and deposited on ceramic monoliths according to a dipcoating procedure, used the catalyst on Rd car with XU7 engines, measured the amount of emission with (AVL) test at SAPCO Company, and compared the catalyst with imported catalysts of Iran Khodro Company. In the end, it was found out that Perovskite catalysts reduced emission better than the imported catalysts, and they do so at a lower price.Monoliths of catalysts were characterized by specific surface area measurements (BET), X-ray diffraction (XRD), X-ray fluorescence (XRF), and coat characterized by scanning electron microscopy (SEM), LINE SCAN and MAP.

Propylene glycol is an organic chemical compound which has wide applications in different industries and its release in the environment poses adverse health and environmental effects. Fixed bed activated sludge process is one of the biological treatment processes that has advantages such as higher biomass concentrations, possibility for a higher rate of treatment, or more efficiency in the same flow rate compared with the conventional activated sludge processes.The main objective of this study was to compare the effects of organic loading variations on the biological removal efficiency of propylene glycol in fixed bed and conventional activated sludge processes. In the first stage, bench scale bioreactors were operated in four HRT of 8, 6, 4 and 2 hrs and constant propylene glycol concentration of 500 mg/l. In the second stage, constant HRT of 6 hr and propylene glycol concentrations of 1000, 1500, 2000 and 2500 mg/l were applied to bioreactors. Propylene glycol removal efficiency of fixed bed activated sludge bioreactor in HRT of 8, 6, 4 and 2 hr was 14.6, 24.5, 41.16 and 57.6 % more than that of conventional activated sludge bioreactor, respectively. Besides, propylene glycol removal efficiency of fixed bed activated sludge bioreactor for propylene glycol feed concentrations of 1000, 1500, 2000 and 2500 mg/l was 19.8, 33.8, 39.45 and 25.96 % more compared to that of the conventional activated sludge.

In this study, the adsorption of mercury from aqueous solutions by agricultural waste (wheat Husk) was investigated. The effect of such parameters as solution pH, initial concentration, temperature, particle size, and adsorbent quantity was studied in batch experiments.The results show that the decrease in the initial concentration, increase in adsorbent quantity, decrease in paticle size, and increase in temperature cause an increase in adsorption. The increase in pH up to 4 increases adsorption. However, for pH>4, the adsorption remains constant. Meanwhile, Langmuir and Freundlich models were applied to determine isotherm equilibrium curves. The results show a better conformity with Freundlich model.

The Jajrood River originates from the Alborz Mountains north of Tehran, mounts Shemshak and Johnson, and flows towards southwest. After joining the Garmabdar and the Routeh rivers, it turns towards southeast and when joining the Big and the Small Lavasanat rivers, it pours in Latyan Dam. About 295 mm 3/y of the water of Latyan Dam is sent to Tehran's 4th water treatment plant in Tehranpars. The rest is released as riparian right for agricultural uses in Varamin Plain. The Jajrood River serves many villages on the trans-passing course and receives their entire wastewater because the region’s hills, the lack of facilities for wastewater treatment, and the problem of solid waste disposal on the river banks.The Jajrood River supplies the drinking water of about 2,600,000 people in the east of Tehran through Latyan Dam. That is why the management of its water quality seems to have a very high priority.During a period of 6 months in 2004, samples were taken from 18 villages before the water flowed in and after it flowed out of them. Then, the important factors of water quality of the samples were compared with those of the previous years and the standards. Changes in the amounts of certain parameters such as BOD, COD, and TDS were easily observed after the river passed through every village. Tests proved that the water would get polluted after passing through villages. It became clear that the sources of pollution were domestic sewage and leakages from fruit gardens as well as partially domestic solid wastes dumped into river banks. In the end, offensive and defensive methods of water quality management are recommended.

In this study, the diversity and distribution of economical bony fishes in less-than-ten-meter depths, CPUE and population features such as total length, weight and age were investigated in the southern part of the Caspian Sea in 1385-6.Sampling was done in five regions: Amir Abad, Larim, Izdeh, Kheyroud, and Nashtarood with Gilnet in mesh sizes of 26, 33, 40, 60, 100, and 150 mm. In total, 227 fishes were caught: 110 Rutilus frisi kutun, 32 Ciprinus carpio, 36 Caspiolasa kesslerri, 38 Liza auratus, 8 Stizostidion lucioperca and 3 Vimba vimba.The CPUE was 3.66 for Rutilus krisi kutum, 0.5 for carpio, 0.52 for Caspiolasa, 0.63 for auratus, 0.13 for Stizostidion lucioperca, and 0.05 for Vimba vimba per catch.The average total length of Rutilus, carpio, Caspiolasa kesslerri, Liza auratus, Stizostidion lucioperca, Vimba vimba are 37.9±7.2, 31.6±7, 23.1±4.4, 22.6±2.3, 23.6±3, 20.5±2 cm, respectively.And the averages of the total weight are 683.5±361.2, 379.5±242.6, 112.3±125.9, 104.6±33.4, 225.6±4, 91.6±2 gr., respectively:Regarding their ages, Rutilus frisi kutum was in 2+, 3+, 4+, 5+, Cyprinus carpio was in 2+, 3+, 4+, Caspiolasa kesslerri was in 2+,3+,4+, Liza auratus was in 2+, Stizostidion lucioperca was in 2+, 3+ and Vimba vimba was in 3+.