Department of Environmental Engineering (2008 - Present)
Environmental Engineering
Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran
Civil Engineering, Environmental Engineering
Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran
Dr. Mokhtarani obtained his Ph.D. in Environmental Engineering from Tarbiat Modares University (TMU), Iran in 2005. Since September 2008, he has been with the Environmental Engineering Department of TMU, where he is an associate professor now. Dr. Mokhtarani has published numerous journal papers, book chapters and a book titled Hazardous Waste Management. His research interests include Solid Waste Management, Waste Minimization, Resources Recovery from Waste, Hazardous Waste Management, Composting Process, Leachate Treatment, Sustainable Development, Biodegradable Polymers and Environmental Engineering Education.
In this study, electro-coagulation-flotation process was investigated in the new baffled reactor to use the advantage of simultaneous flotation in an individual compartment to eliminate the need of separate chamber for flotation. The middle baffle led to the production of larger and denser flocs and consequently, settling velocity, sludge volume index, and floc density increased by 63%, 13%, and 14%, respectively. Effective parameters of electro-coagulation-flotation process in the proposed reactor were optimized due to treatment of Direct Blue 71. In the optimal condition ([dye]=200 mg/L, electrical conductivity=6.7 mS/cm, current density=3.54 mA/cm 2, and pH=8 in 60 min), the removal efficiency of dye, naphthalene ring, COD, and TOC, aver
The present study aimed to compare aerobic biodegradation of MTBE and its intermediate products through a microbial consortium obtained from sludge of municipal wastewater treatment by co-metabolism and direct metabolism via Sequencing Batch Reactor (SBR) method in laboratory scale. For this purpose, the maximum MTBE concentrations, acclimatization speed and duration, shock loading resistance, degradation of intermediate products, bacterial growth, and sludge quality were compared for both metabolisms. MTBE and COD removal efficiencies were 98% and 81%, respectively for co-metabolism and 84% and 93%, respectively for direct metabolism at the highest acceptable MTBE concentration equal to 180 mg/L. This indicates acceptable performance of bo
Municipal solid waste contains mainly organic wastes that can be a good source for anaerobic digestion. Solid-state anaerobic digestion is an affordable and suitable technique to mitigate the organic fraction of municipal solid waste (OFMSW). However, as the organic loading of OFMSW is high, co-digestion with other materials can improve the system's performance. This study aimed to investigate the performance of the co-digestion of OFMSW and sawdust and study the parameters affecting its performance. Based on the experiments, the optimum sawdust/OFMSW ratio was achieved 1:2 with the methane production of 0.3?L/g VS. In addition, the inoculum-to-substrate ration (I/S) was investigated at 1:4, 1:2, 1:1, 2:1 ratios. The best resul
There are several techniques for removing contaminants from water and wastewater. Meanwhile, surface adsorption is one of the simplest, most effective and most economical methods for water and wastewater treatment. This article reviews recent research on the removal of various contaminants with a variety of adsorbents from water and wastewater. In this study, a large number of adsorbents such as natural adsorbents, agricultural waste, industrial by-products, biomass, various types of nanosorbents including carbon-based nanomaterials, new metal-based nanomaterials, metal oxide-based nanosorbents, nanomaterials With spinel ferrite base, nanocomposites, geopolymer cement and dendritic polymers to remove various contaminants from water and wast
Bentonite was modified by intercalation of amino acids into its interlayer space. Different amounts of L-glutamic acid were added to bentonite and its effect was investigated on the reduction of landfill leachate contamination. In the best result, the effect of pH adjustment on the structure and performance of the modified clay was studied. The composite was characterized by various techniques such as FTIR,
Nowadays, Producing and using chemical compounds in different industrials has caused environmental pollution. One of these compounds that can bring a widespread pollution in natural resources is Methyl Tert-Butyl Ether (MTBE). This organic compound that is produced in petrochemical industries is used as a substitute to produce lead free gasoline in all over the world. Human exposure to MTBE may cause dizziness, coughing, fever, headaches, vomiting, muscular aches, sleepiness and skin and eye irritation. Concerning the destructive consequences of MTBE on the environment, and human health, clearing polluted resources are vital. The main objective of this study is dedicated to treat MTBE-contaminated waters through adsorption process in the pr
The purpose of this study is nutrient resources recovery by achieving the optimal chemical oxygen demand (COD) and carbon to nitrogen ratio (C/N) in co-composting wastewater treatment plant sludge with Municipal Solid Wastes (MSW). In this effort, the co-composting has been conducted in form of a case study in the northern region of Iran. In this research, 192 tests were carried out on four series of samples examined in terms of waste to sludge ratio, different aeration period, the percent of porous materials and the moisture content. This study was carried out at a temperature of 50 C for a 15 day period by application of the in-vessel system and shows that the best ratio for waste to sludge is 2: 1, while the 8 hour period is the best aer
Removal of petroleum hydrocarbons from contaminated soil using electrokinetic method or biological processes has been considered in recent century. The most limiting factors in the electrokinetic process are extreme changes in pH around the electrodes and non-polarity of some pollutants. On the other hand, the key factor of biological treatment is simultaneous presence of microorganisms, pollutants (carbon source of microorganisms), electron acceptors, and essential nutrients for microorganisms’ growth. But in fine-grained soils with low permeability, it is difficult to uniformly distribute bacteria, electron acceptors and nutrients, or making pollutants available for microorganisms. To solve these problems, bioelectrokinetic method is us
By developing of the consumerism and rapidly progress of industrial and commercial lifestyle in most of the countries, the solid waste production has been growth rapidly in the recent years. The leachate production starts shortly after the production of waste and cause the pollution of environment and especially contamination of the soil. Chemical processes are usually considered as the most effective processes for degradation of soil pollutants. In these processes, the chemical reagents are added to make the desired reactions take place. But it is sometimes necessary to increase the amount of reagents so that the reactions take place completely. This may cause chemical reagents to remain in the soil. Ozone, which acts as a powerful oxidize
Removal of petroleum hydrocarbons from contaminated soil using electrokinetic method or biological processes has been considered in recent century. The most limiting factors in the electrokinetic process are extreme changes in pH around the electrodes and non-polarity of some pollutants. On the other hand, the key factor of biological treatment is simultaneous presence of microorganisms, pollutants (carbon source of microorganisms), electron acceptors, and essential nutrients for microorganisms' growth. But in fine-grained soils with low permeability, it is difficult to uniformly distribute bacteria, electron acceptors and nutrients, or making available pollutants for microorganisms. To solve these problems, bioelectrokinetic method is used
AbstractCrude oil and its derivatives are among the most important sources of energy in the world. Petroleum-based pollutants enter the environment through a variety of factors, such as non-standard wastewater disposal and related industry waste, the breakdown of transmission lines, leakage from storage tanks and crash of tankers. The purpose of this study was to investigate the effect of different factors on the ozone treatment of the diesel-contaminated soil. In this laboratory-scale study, the effect of ozone mass flow rate, process time, pH, soil water content, and initial pollution concentration on the removal of Total Petroleum Hydrocarbon (TPH) from soil were evaluated. The results indicate that moisture content and pH are two factor
In this study, a baffled photocatalytic reactor was used for the treatment of colored wastewater containing the azo dye of Acid Orange 52 (AO52). A study on the active species of the photocatalytic process using TiO2 nanoparticles indicated that hydroxyl radical and superoxide have the greatest contribution to the dye degradation process respectively. Given that a level of biological oxygen demand/chemical oxygen demand (BOD5/COD) equal to 0.4 was achieved after about 5 hr from the beginning of the experiment, the reactor seems to be capable of purifying the wastewater containing AO52 dye after this time in order to discharge into a biological treatment system to continue the treatment process. The results of the liquid chromatography-mas
There are different methods for soil stabilization, such as using windbreak, planting and use of mulch. The use of new soil stabilization methods, due to reduced environmental impacts, is a suitable alternative for oil mulch. Soil stabilization by using Nano polymer Polylatice creates a uniformly coherent cortex that is resistant to high wind speed and has less environmental degradation effects. In this research, the soil of the Hossein Abad area, near the salt lake of Qom, has been used for wind erosion test to verify the stabilization with the use of nano polymer Polylatice. After passing through a 2 mm sieve, the soils were stabilized with concentrations of 1, 1.5 and 2 L/m2 of Polylatice in trays with dimensions of 80*80*3 cm. These spe
By developing of the consumerism and rapidly progress of industrial and commercial lifestyle in most of the countries, the solid waste production has been growth rapidly in the recent years. The leachate production starts shortly after the production of waste and cause the pollution of environment and especially contamination of the soil. Chemical processes are usually considered as the most effective processes for degradation of soil pollutants. In these processes, the chemical reagents are added to make the desired reactions take place. But it is sometimes necessary to increase the amount of reagents so that the reactions take place completely. This may cause chemical reagents to remain in the soil. Ozone, which acts as a powerful oxidize
In this study, TiO2/Fe3O4 and TiO2/Fe3O4/MWCNT as a new magnetic nanophotocatalytic materials were synthesized. For this, TiO2 nanoparticle were fixed on an inert surface by sonochemical method. X-ray Diffraction (XRD), scanning electron microscopy (SEM), UV-Vis diffuse reflectance spectroscopy (DRS), vibration sample magnetometry (VSM) were used to characterize the magnetic nanocomposites. SEM analysis indicated that TiO2 and Fe3O4 nanoparticles were adhered to MWCNT. Ability of the nanocomposites to remove organic pollutants were investigated by photodegradation of Acid Red 14, Acid Blue 19, Reactive Red 77, and Methyl Orange dyes simulated conditions similar to sunlight. Furthermore, the removal efficiency of AR14 were investigated under
Acid red 14 is an azo dye which is used widely in textile industry and due to its high consumption, is a serious environmental hazard so that in recent years, a lot of research has been done on the photocatalytic removal of azo dyes from water with nanocomposites. In this research, TiO2/Fe3O4/CNT nanocomposite was synthesized with the sonochemical method and the photocatalytic removal of acid red 14 dye was investigated in a batch reactor by OFAT method. The morphology and structure of the nanocomposite were characterized by FESEM and EDS analysis. The optimum efficiency of 96.53 for AR14 was achieved under following conditions: dye concentration of 50 mg/L, nanocomposite concentration of 0.5 gr/L, Dissolved oxygen concentration of 7.4 mg/L
Removal of petroleum hydrocarbons from contaminated soil using electrokinetic method or biological processes has been considered in recent century. The most limiting factors in the electrokinetic process are extreme changes in pH around the electrodes and non-polarity of some pollutants. On the other hand, the key factor of biological treatment is simultaneous presence of microorganisms, pollutants (carbon source of microorganisms), electron acceptors, and essential nutrients for microorganisms’ growth. But in fine-grained soils with low permeability, it is difficult to uniformly distribute bacteria, electron acceptors and nutrients, or making pollutants available for microorganisms. To solve these problems, bioelectrokinetic method is us
Removal of petroleum hydrocarbons from contaminated soil using electrokinetic method or biological processes has been considered in recent century. The most limiting factors in the electrokinetic process are extreme changes in pH around the electrodes and non-polarity of some pollutants. On the other hand, the key factor of biological treatment is simultaneous presence of microorganisms, pollutants (carbon source of microorganisms), electron acceptors, and essential nutrients for microorganisms' growth. But in fine-grained soils with low permeability, it is difficult to uniformly distribute bacteria, electron acceptors and nutrients, or making available pollutants for microorganisms. To solve these problems, bioelectrokinetic method is used
Activated sludge process is commonly utilized for the treatment of wastewater with the benefits of high efficiency and easy operation. However, during the biological treatment of wastewater, huge amounts of waste biomass (called as “waste activated sludge (WAS)”) are inevitably generated in the process. The WAS should be treated in order to reduce the water content of raw WAS, transform the highly putrescible organic matter into stable or inert organic and inorganic residue, and finally condition the residue to meet disposal acceptance regulations. But, WAS treatment and disposal, representing 50–60% of the total operating costs of the wastewater treatment. WAS is produced in massive volumes; specifically, more than 25, 000 tons of WA
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