A. R. Karbassi | University of Tehran (original) (raw)

Papers by A. R. Karbassi

Global Journal of Environmental Science and Management, 2017

The ﬂocculation of dissolved heavy metals is a process which has an important effect on decreasin... more The ﬂocculation of dissolved heavy metals is a process which has an important effect on decreasing the concentration of the colloidal elements during estuarine mixing of river water and sea or ocean water. During this important process, a large amount of colloidal elements change into particles in the form of flock and the dissolved loads decline. This study is performed to evaluate the mechanism of self-purification of heavy metals in Sardabroud's estuary. For this purpose, the effect of salinity (varying from 1 to 8.5‰) on the removal efficiency of colloidal metals (copper, zinc, lead, nickel and magnesium) by flocculation process during mixing of Sardabroud River water and the Caspian Sea water was explored. The flocculation rate of Ni (25%) > Zn (18.59%) > Cu (16.67%) > Mn(5.83%) > Pb(4.86%) indicates that lead and manganese have relatively conservative behavior but nickel, zinc and copper have non-conservative behavior during Sardabroud River’s estuarine mixing...

International Journal of Environmental Research, 2008

ABSTRACT: The inter-tidal mangrove environment of Mengkabong lagoon is important as it supports t... more ABSTRACT: The inter-tidal mangrove environment of Mengkabong lagoon is important as it supports the local fishing activities, nursery grounds for many fish and shellfish species, and as well as being central for ecotourism activities. The study showed that in general, the physicochemical parameters (pH, salinity and electrical conductivity), granulometric fractions, organic matter, base cations (Na, K, Ca and Mg) and heavy metals (Fe, Cu, Pb, Zn and Al) showed increasing loadings at high tide compared to low tide. ...

Bus rapid transit is an innovative, high capacity, lower cost public transit solution in metropol... more Bus rapid transit is an innovative, high capacity, lower cost public transit solution in metropolitan cities. Idea is to dedicate lanes for quick and efficient transport of passengers to their destinations. In the present investigation the environmental impact assessment of bus rapid transit in Tehran metropolitan city is brought out. For this purpose bus rapid transit Lane No. 10 is investigated. The bus rapid transit Lane No.10 is about 10 km in distance that moves up and down between Azadi and Simon Bolivar Squares. About 77500 passengers using 50 buses are transited per day in lane No. 10. These 50 buses cover a distance of 9600 km/day. The results of present study showed that about 6.5 million liters of fuel is saved annually. It should be pointed out that environmental costs are also reduced for about US$ 1.7 million/yr. The overall score of environmental impact assessment stands at +10 that is indicative of Lane No. 10 compatibility with the environmental considerations. Lang...

Journal of Water Chemistry and Technology

The Hara Protected Area, one of the coastal marine ecosystems, has so much importance by having b... more The Hara Protected Area, one of the coastal marine ecosystems, has so much importance by having biological diversity covered by mangrove forests. The unique features of this area have led to rapid urban, rural, industrial and tourism expansion and possess economic and social importance. This study has been carried out in order to analyze the quality of physicochemical parameters of surface waters and heavy metals in sediment by selecting 27 sampling stations in the year of 2011. The results of the study proved that the difference between measuring the measuring parameters in 4 months (February, May, August, and November) is mostly considerable. Besides, the measuring parameters in the northern stations of the Hara Protected Area was mostly more than central southern regions which would be due to population density and industrial activities in this area.

International Journal of Environmental Research, 2011

Nowadays, transportation sector consumes about 27 percent of the whole energy in Iran. Therefore,... more Nowadays, transportation sector consumes about 27 percent of the whole energy in Iran. Therefore, after domestic and business sectors which consume about 40 percent of the whole energy, transportation is placed in the second rank. However, the financial value of transportation is of the highest importance. Moreover, having 55percent of gasoline product consumption transportation has been also ranked as the largest consumer of gasoline products. Gasoline consumption in transport showed an increase until 1979. During 1980-1981, it decreased slightly and from 1982 have had a permanent upward trend. Oil products consumption in transport sector in 1950 has been less than average 15 million barrels (equivalent to crude oil) per year. In 1990, the above amount was approximately 140 million barrels per year, while in 2000; this amount was 20.7 times more than 1960s. Gasoline consumption in transport sector is about 98percent of the whole gasoline consumption in Iran. Since gasoline burning ...

International Journal of Environmental Science and Technology, 2019

Heavy metals are one of the main problems in aquatic systems as they affect the ecological balanc... more Heavy metals are one of the main problems in aquatic systems as they affect the ecological balance of the water body. Biological availability of a metal is dependent on its chemical form. Speciation of metals in aquatic systems is of high importance and can provide a proper framework for managers to determine the probable risks resulted from metals. Therefore, this study was performed in Anzali Wetland to investigate the speciation of heavy metals and metalloids, and determine the factors controlling them. For this purpose, six stations were sampled and the relations among water quality parameters were identified by cluster analysis. Water chemistry software (HSC Chemistry) was used to draw Eh/pH diagrams. According to the results, oxidation-reduction potential (Eh) values ranged from − 280 to + 135 mV. The metals including arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), mercury (Hg), cerium (Ce), copper (Cu), aluminum (Al) and iron (Fe) were affected by Eh and pH. Salinity played a significant role in controlling nickel (Ni), magnesium (Mg), calcium (Ca) and strontium (Sr) in the water. The HSC Chemistry diagrams showed that all the studied metals were within the two lines of water stability range. As, Cd, Co, Cr, Ni, lead (Pb), Al, Ca, Ce, Fe, manganese (Mn), Mg, silicon (Si) and Sr were present in a bioavailable species in the wetland water. Some metals such as As, Cd, Cr, and Fe existed in very toxic forms. It was found that changes in the Eh-pH values as a result of anthropogenic and different activities in the wetland can alter the speciation of metals. Eh/pH diagrams also showed that the elements can exceed the water stability range and become unstable in three states (pH < 5, Eh < − 380 mV or Eh > 780 mV).

Journal of Hydrology, 2015

Summary When the number of computational grids increases, water quality simulation complexities a... more Summary When the number of computational grids increases, water quality simulation complexities arise. Therefore, using a reduced order framework to express the variations of the objective parameter may facilitate the simulation task and also the interpretation of computational results. In this regard, a new reduced-order approach was proposed to link a water quality simulator model (CE-QUAL-W2, W2) with a data reduction technique (proper orthogonal decomposition, POD). The W2 model simulated spatio-temporal variations of nitrate in the Karkheh Reservoir, Iran. Thereafter, the POD model reduced the dimensions of simulated nitrate in the computational grids. The performance of the developed reduced-order model (ROM) results was evaluated through the comparison of the regenerated nitrate data by the model, and the simulated ones by W2. Findings indicated that the first four modes among 1825 computed ones by ROM conserved approximately over 91% of the nitrate variations. It means that the ROM was capable of showing the spatio-temporal variations of nitrate in the reservoir using the first few modes. Finally, confirmation of ROM indicated that the error of order of magnitude was less than 0.001, for nitrate ROM to regenerate nitrate data using 100 basis functions.

International Journal of Environmental Science and Technology, 2015

Earthquakes can lead to different levels of damages and subsequently produce significant volume o... more Earthquakes can lead to different levels of damages and subsequently produce significant volume of debris. Management of such huge amount of debris needs special attention. Thus, it is vital to develop a comprehensive and cost-effective management plan. The present study was carried out to estimate post-earthquake debris volume in the 22 districts of Tehran under various earthquake scenarios [magnitudes of 5, 6.5, and 7.5 on the moment magnitude (M W) scale]. Subsequently, required machineries and manpower and equipment for removal of debris were calculated. Finally, best practical methods for reduction and recycling were also examined. The shortest routes for transportation of post-earthquake to disposal sites were also proposed using network analysis. Results showed that about 83, 321 and 4802 million cubic meters of debris will be generated at 5, 6.5 and 7.5 M W , respectively. Disposal site of about 13 km 2 is marked within the area of study for the management of debris. Preparedness, emergency operations, rehabilitation and reconstruction are among the main activities that can reduce the earthquakeinduced damages.

Environmental Monitoring and Assessment, 2015

Sediment samples were collected from the Petrochemical Special Economic Zone of Mahshahr Bay, Per... more Sediment samples were collected from the Petrochemical Special Economic Zone of Mahshahr Bay, Persian Gulf, and analyzed for possible trace metal contamination by means of a chemical partitioning method. The heavy metal contents in the sediments follow the order of Al>Sr>Mn>Zn>Ni>Ba>Cr> Cu>As>Co. The degree of sediment contamination was evaluated using pollution load index (PLI), modified degree of contamination (mC d), geo-accumulation index (I geo), and enrichment factor (EF). All these indices compare present concentrations of metals to their background levels in crust and shale. In a specific area with high geological background like Mahshahr Bay, such a comparison may lead to erroneous conclusions. Due to the remarkable contribution of lithogenous fraction, as the natural component, to the bulk concentration of trace metals in the sediments of such an area, assessment of chemical hazard to the surrounding aquatic environment should not be carried out through traditional approaches. In the present study, anthropogenic portion of the metals was determined through one-step chemical sequential extraction and lithogenous portion substituted for the mean crust and shale levels in the new pollution index (RI Aquatic). PLI, mC d , and I geo revealed overall low values, but EF, pollution index (I POLL), and newly developed pollution index were relatively high for all samples.

Caspian Sea, the largest sea in the world, faces serious environmental challenges. Unusual and ra... more Caspian Sea, the largest sea in the world, faces serious environmental challenges. Unusual and rapid growth of oil resources consumption from this sea has caused irreparable environmental damages to its ecosystem. With increase of Caspian`s oil production by Iran`s neighboring countries such as Azerbaijan, the possibility of oil spill to the sea has risen sharply. Azerbaijan owns most of oil wells in the Caspian Sea with the highest level oil production rates is known as the most pollution country in terms of oil spill in that region. Transportation and fate of oil plume depends on many elements including meteorological and hydrodynamic factors. The counterclockwise transportation of the oil plume in the southern part of the Caspian sea was modeled from the beginning until Reaching Iran`s shoreline. Results of this study could be implemented in adopting appropriate strategies for pollution control and remediating oil stains, which are major priorities of the Caspian sea`s environmen...

Environmental Progress & Sustainable Energy

This study aims at providing a reduced-order neural network model (RONNM) based on proper orthogo... more This study aims at providing a reduced-order neural network model (RONNM) based on proper orthogonal decomposition (POD) for online prediction of the 5 days biochemical oxygen demand (BOD5). To achieve this goal, the POD method is used to reduce the input vectors to neural network (NN) model. Evaluation of the selected RONNM and its comparison with the model fed with all input vectors (NN model) shows that it reduces not only the output error but also computational cost. Results depict that Pearson correlation coefficient (R) and root mean square error for the best fitted RONNM are 0.94 and 7.75, respectively. Furthermore, accuracy analysis of the output results of models based on developed discrepancy ratio statistic reveals that RONNM is superior. Thus, developed methodology can be considered as an effective tool to train the water resources managers for online evaluation of water quality related to BOD5. (c) 2011 American Institute of Chemical Engineers Environ Prog, 32: 120127, ...

Journal of Radioanalytical and Nuclear Chemistry, 2015

ABSTRACT Physicochemical factors, major and some minor ions and 222Rn concentration was measured ... more ABSTRACT Physicochemical factors, major and some minor ions and 222Rn concentration was measured in Todruyeh, Fotuyeh and Sanguyeh thermal balneutherapy springs in Bastak, south of Iran. Water type of these springs is Na–Cl and water-mixing phenomena seem possible in them. The average of U concentration in Fatuyeh’s, Sanguyeh’s and Todruyeh’s water are 2.2, 1.1, 0.306 ppb, respectively, and the concentration of heavy metals such as Ag, Cd, Co, Cr, Cu, Hg, Ni, Pb, Se, Zn varies from 1 to 10 ppb. The concentration of 222Rn in the water of Fotuyeh, Sanguyeh and Todruyeh Springs includes 125–253, 53–104, and 7.4–134.7 kBq/m3, respectively. Values of mean annual effective doses for inhalation from these waters are below the reference level recommended by WHO.

Present study consists an Integrated Coastal Tourism Zone Management (ICTZM) plan regarded simult... more Present study consists an Integrated Coastal Tourism Zone Management (ICTZM) plan regarded simultaneously social, cultural and economical criteria along with spatial planning in terms of environmental capabilities to overcome the various problems., Areas with tourism potentiality owing less environmental vulnerability were identified using Fuzzy and Boolean logics in the environment of IDRISI KILIMANJARO Software. Thereafter a strategic planning for tourism management was presented for the selected zones using SWOT Method. Based on the country's macro policies for tourism industry, an Integrated Coastal Tourism Zone Management (ICTZM) framework was provided in the form of a conceptual model. Results revealed that the main strategy to implement the sustainable coastal tourism in the study area should be based on a conservative approach and after the improvement in the conditions; the development and construction strategy can be executed in the coastal zone.