Ahmad Khodadadi-Darban

Tarbiat Modares University | TMU · Faculty of Civil and Environmental Engineering

One emerging approach for eliminating organic and inorganic pollutants from wastewater is electrocoagulation, often coupled with traditional methods to enhance efficacy. This study investigates the simultaneous elimination of nickel (Ni), cyanide (CN), zinc (Zn), and copper (Cu) from the natural wastewater of a gold processing plant using the photo...

Cyanide and heavy metals pose significant risks as contaminants in certain industrial effluents. This study aims to concurrently eliminate cyanide and specific heavy metals from synthetic wastewater resembling gold processing effluent, employing an improved electrocoagulation method incorporating ozone and UV-LED. The investigation delves into the...

Sulfidic mine tailings are one of the massive hazardous solid wastes, containing large amounts of toxic heavy metals. Poor management of tailings can lead to the production of acid mine drainage and the heavy metal transfer emissions into the environment. Thus, in this study, mechanical activation was used to reuse a combination of carbonate tailin...

One of the challenges of the twenty-first century is related to the discharge and disposal of mine effluents and wastewater resulting from mine dewatering, precipitation, and surface runoff in mines, especially acidic effluents that contain a variety of toxic and heavy metals and are the main sources of surface and groundwater pollution. Various ph...

Researchers have recently focused their attention on emerging contaminants (ECs) in wastewater because they pose serious health and environmental risks. Because ECs are persistent in the environment and have the ability to disrupt the physiology of target receptors, they have been labeled as contaminants of recent environmental concern. For removin...

Proper management of mine tailings containing high amount of sulfide is a crucial issue in order to reduce their environmental hazards including generation of acid mine drainage and release of heavy metals. This study was conducted targeting to understand the effects of using lead-zinc sulfide tailings (LZSTs) as cement substitution on the hydratio...

One of the new methods used to remove the contaminants from effluent is the electrocoagulation method, which is sometimes combined with other methods to increase the removal efficiency of contaminants. To simultaneously remove nickel, cyanide, zinc, and copper, the combined method of photo-electrocoagulation was used along with an oxidizing agent,...

The twofold extraction behavior of light and heavy rare earth elements transforms into a more selective extraction of heavy rare earth elements when Di-(2-ethylhexyl) phosphoric acid (D2EHPA), one of the commonest cation exchange extractants, is employed. However, why this phenomenon has not been fully investigated from the quantum perspective yet....

Treatment and reuse of water in wetlands are considered as an alternative, cost-effective, economical, and environment-friendly method. In most cases, salinity degree of purified water is increased especially in arid and semiarid regions. Using phytoremediation method can help to solve the said problem to a great extent. In this study, tests with d...

Treatment of organic leachate is one the most controversial topics around the world which led this study to assess the efficiency of the combined oxidation and adsorption treatment (COAT) process in the treatment of forest polluting site (FPS) leachate by considering local experiments. The removal of effluent parameters (TDS, COD, BOD) was enhanced...

This study was aimed to investigate the effectiveness of compounds containing iron and manganese to reduce the mobility of arsenic and its effective adsorption and optimize the arsenic adsorption process by CCD. In this study, MnFe2O4 nanoparticles (MFO-n) were synthesized using the co-precipitation method to remove arsenic and reduce its toxicity...

In recent years, mining pollution has become a serious, worldwide public health concern. One major issue in this field is concerned with arsenic-contaminated sediment. This paper, therefore, intends to determine the extent to which enhanced Electrokinetic (EK) remediation is effective for remedying a case study of arsenic-contaminated sediment. The...

Background Enormous amounts of gold mine tailings (GMT) are produced as a result of mineral activities, but these mine tailings produced from previous ore processing still contain significant amounts of elements (e.g. strontium (Sr)) and rare earth elements (REEs) such as cerium (Ce). In this study, extraction of Ce and Sr from GMT using an adapted...

Production of acid mine drainage and emission of heavy metals from tailings, especially sulfide tailings, to the environment is one of the serious challenges in the management of mine tailings. The use of cementation process and replacement of cement with mine tailings in the manufacture of concrete is one of the practical approaches to the managem...

The extraction behavior of two lanthanides (La³⁺ and Y³⁺) in the nitric acid solution was studied using a bifunctional ionic liquid, namely Trihexyl-tetradecyl-phosphonium Decanoate ([P6,6,6,1,4] [Decanoate]). On comparative study on D2EHPA as a molecular extractant, the ionic liquid revealed remarkably higher extraction capacity of the total are e...

Dear researcher We are going to launch Volume 1 Issue 1 of the peer-reviewed online journal entitled “Journal of Advanced Environmental Research and Technology” publishing original research articles. Journal of Advanced Environmental Research and Technology is a peer reviewed, international, open-access and interdisciplinary journal with a focus o...

Hazardous effluents containing heavy metals and toxic compounds such as cyanide are among the contaminants produced annually by mining activities. In this study, the electrocoagulation method was used to simultaneously remove cyanide and lead from the synthetic and natural effluents of a gold mine processing plant. The effect of four parameters inc...

This study probed the selective separation of lanthanum and yttrium in a nitrate medium in the presence of aluminum and calcium impurities using di-(2-ethylhexyl) phosphoric acid (D2EHPA). The factors studied in a central composite design (CCD) included extractant concentration, pH, concentration ratio of total impurities to rare earth elements, an...

A large amount of mine wastes is generated every year through mining and mineral processing operation. The management of mine tailings is an attractive topic for researchers from both environmental and economic aspects. Mine tailings have shown a capacity as a raw material for the construction industry or a substitution for previous materials to pr...

The generation of self-protective mine-wastes through a superficial secondary layer to prohibit the leaching of toxic elements can be a new perspective for future environmental studies. The bioleaching-based treatment can lead to the surface passivation of contaminated minerals, which inhibit trace elements mobility. In this work, the electrochemic...

The large amount of residues and pollutants left over from the drilling industry could cause irreparable damage by entering the human and animal food chain. Therefore, drilling waste management is of particular importance. Electrokinetic (EK) remediation is one of the methods used to remediate all types of soils contaminated with metal and organic...

The aim of this work has been to examine the effect of intensive ball milling of sphalerite in the wet and dry modes on the microstructural changes and the subsequent effect on its dissolution rate. Sample characterization showed that the BET surface area and the amorphization degree were obtained to 18.2 m²/g and 78.92% in the wet mode and 7.72 m²...

The number and positioning manner of the ligands present in the first shell of every cation of rare earth elements are key parameters in determining the stoichiometry of the reactions of solvent extraction from nitrate systems, especially when acidic extractants are used. In addition to determining the hydration and coordination of nitrate ligands...

This study was conducted to investigate the feasibility of Electrokinetic Remediation to remove lead and zinc from real mine tailings, collected from the Lacan’s lead and zinc Mineralized Flotation Processing Plant (Markazi province, Iran). High buffering capacity, high organic matter, and heavy metal contamination were the unique characteristics o...

Electrokinetic (EK) by coupling surfactants is an enhanced promising remediation technology to eliminate hy-drophobic organic contaminants (HOC s) from low-permeable soils. It is also applied to remediate kerosene-contaminated soils using anionic (SDS) and non-ionic (Tween 80) surfactants at different concentrations. There was negligible removal ef...

Indigenous acidophilic bacteria separated from mine-waste can be used in return for the addition of the reagents like sulfuric acid. Among the tailings bacteria, Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans are of the moststudied ones for the bioleaching and bioremediation of elements. In this work, the isolation and characteriz...

Remediation of soils contaminated with hydrocarbon materials is of particular importance due to their association with food chain. One of the remediation methods, which has been taken into account in recent years by researchers, is the electrokinetic technique. In this study, the electrokinetic method was used in combination with the Fenton techniq...

In this work, the manganese ferrite was synthesized, and its effect on arsenite immobilization in soil was studied. The results of characterization using various experiments, including field emission scanning electron microscopy (FE-SEM) coupled with an energy-dispersive X-ray spectrometer, X-ray fluorescence (XRF), X-ray diffraction (XRD), Brunaue...

The geopolymerization of solid substances rich in calcium and aluminum including mine tailings by sodium silicate is mainly believed to be under the influence of alkali activation. However, mine tailings' relative neutral condition can decrease sodium silicate's overall alkalinity to an unfavorable condition for alkaline reactivity. The decreased s...

Transportation of fugitive dust over long distances because of wind erosion is a severe environmental threat. Different approaches are experienced to control wind erosion, but durability and costs are the main drawbacks of existing techniques. This study hereby investigates sodium silicate usage as an alkaline additive to bind soil particles and co...

Over the past few decades, as demand for minerals and metals has increased, the amount and volume of wastes and tailings has also increased dramatically. The management and reuse of mineral wastes and tailings not only help protect the environment but also are properly associated with economic benefits. As a result, mineral processing wastes dispos...

The contaminated soil by mining activities could be transported through the erosive effect of wind. In this study, human health risk was assessed for exposure to heavy metals (Cu, Zn, Cd, Pb) present in surface soil of Irankouh zinc–lead mine, (the nearest mine to Isfahan, Iran) as one of the main dust storm sources. The effect of improper mining w...

Enhanced electrokinetic (EK) technique was employed to remediate Cr-contaminated soil using a permeable reactive barrier (PRB) and chelating agents. Synthesized nanomagnetic Fe3O4 was used as a reactive material in PRB. Moreover, EDTA and citric acid (CA) were used as chelating agents. Sequential extraction method (SEM) was employed to determine Cr...

Under the oxidative roasting process, pyrite, as a major mineral in sulfidic mine tailings, can transform to iron oxides. Generated iron oxides, if exhibiting enough magnetic properties, can be recovered via magnetic separation resulting in partial mine tailings valorization. However, due to the presence of various minerals and sintering possibilit...

Every year, a large amount of wastewater is discharged from various industries into the environment, and various methods are used to treat wastewater in order to reduce the amount of pollutants. Electrocoagulation (EC) is an electrochemically-based technique that generates coagulant species in situ from the electro dissolution of sacrificial anodes...

The discharge of toxic elements from tailings soils in the aquatic environments occurs chiefly in the presence of indigenous bacteria. The biotic components may interact in the opposite direction, leading to the formation of a passivation layer, which can inhibit the solubility of the elements. In this work, the influence of jarosite on the bio-imm...

The co-precipitation method was used to synthesize nano-magnetic adsorbent MnFe2O4 (nMFO), characterized through XRD, SEM, EDS, and BET techniques. The synthesized nMFO was used for hexavalent and trivalent chromium ions elimination from the aqueous phase. The optimum pH for the adsorption of Cr (VI) and Cr (III) was determined as 2 and 5, respecti...

The continuous presence of toxic elements in the aquatic environments around mine tailings occurs due to bioleaching or chemical extraction promoted by the mining operations. Biogenic passivation treatment of tailings dams can be a new environment-friendly technique to inhibit the solubility of heavy metals. In spite of current bioleaching research...

Cyanide, as one of the most toxic pollutants existing in the gold mine tailing dams, threatens human health and other species life. The main objective of this study was to simulate the oxidation of cyanide from mineral effluent of the Moteh Tailing Dam (Iran), as a method for removing cyanide.We employed PHREEQC software to model the oxidation of c...

p>Gold mine tailings dams are a high risk part of mining as they contain hazardous materials such as cyanide, mercury and arsenic from processing operations which present a risk to the public and to the environment. When tailing dams fail, the impact is disastrous for humans and the natural environment. The International Commission on Large Dams (I...

Background: Biochars are the new generation of sustainable soil amendments which may be applied both to fertilize and remediate the impacted soils. The aim of current research has been synthesis and characterization of pulp and paper-derived biochars and determination of their mechanisms in simultaneous immobilization of heavy metals (Cu2+, Pb2+,...

Nano-magnetic MnFe2O4 was prepared and examined to immobilize Cr(VI) in the soil. According to the results of scanning electron microscopy (SEM) and X-ray diffraction (XRD) the formation of nano-magnetic MnFe2O4 with the particle size of less than 200 nm was demonstrated. Compared with the untreated soil, the leachability of Cr(VI) was reduced from...

The influence of methyl-silane as a water reducing agent was examined within cemented paste backfill CPB containing nano-silica. The key goal of using such high-technology admixtures in mine tailings management is to facilitate the filling operation and reduce the binder consumption. The amounts of binder (Portland cement) and nano-silica (tetraeth...

Processing of gold ores with high sulfide minerals is problematic as they consume cyanide and reduce gold leaching. Optimization of gold leaching and cyanide consumption requires a methodology to estimate the amount of exposed cyanicides, their leaching kinetics, and speciation of cyanide complexes that consume the free cyanide and compete with gol...

Interests in the use of natural fibers–fillers in composite materials are growing rapidly due to the low cost and high availability. However, poor surface adhesion and mineralization are the main drawbacks that restrict the use of natural fibers in different applications. Thus, it is essential to perform a treatment that can improve the surface pro...

The aim of this study is to evaluate the effect of Fe3O4 nanoparticle, stabilized with polyacrylic acid on cadmium removal from the contaminated soils. To investigate the effect of important parameters, including nanoparticle concentration, pH, contact time, and the ratio of contaminated soil mass to nanofluid volume, several batch tests were perfo...

One of the main challenges in the copper oxide processing industry is implementation of a flotation method to reduce operating costs. Sulphidising flotation is the most common used technique in which a sulphidisation agent is used to sulphidise the surface of the oxide minerals. In this research, the mentioned technique was used sequentially for th...

An organic–inorganic composite of chitosan, nanoclay, and biochar (named as MTCB) was chosen to develop a bionanocomposite to simultaneously immobilize Cu, Pb, and Zn metal ions within the contaminated soil and water environments. The composite material was structurally and chemically characterized with the XRD, TEM, SEM, BET, and FT-IR techniques....

The influence of amine (polar) and vinyl (nonpolar) functionalized organosilanes were investigated on the total performance of neat high-density polyethylene (HDPE) and wood-HDPE composites. Thus, micro-size silicate-based mineral fillers were treated with 3 mass% amine and vinyl silanes and then 15 and 30 mass% plus 1 and 5 mass% of treated minera...

Upon neutralization by acid mine drainage (AMD) a semi-solid silica gel forms from sodium silicate. During the solidification of silica gel, the surrounding positively charged toxic heavy metals can also be adjoined to the negatively charged silica network in a similar manner by forming a newly metal-silica bond. Simultaneously, sodium silicate add...

Isobaric volumetric heat capacities of aqueous solutions of K4Fe(CN)6, K3Fe(CN)6, K3Co(CN)6, K2Ni(CN)4, and KAg(CN)2 have been measured at 298.15 K over the approximate concentration range 0.02 to 0.4 mol·kg–1 using a Picker flow calorimeter. These data were combined with measured densities to calculate the corresponding apparent molar isobaric hea...

Magnetite nanoparticles were produced from iron ore tailings and used to remove arsenate ions from water. The produced spherical nanoparticles were 25±3 nm in diameter and had ferromagnetic properties as discovered by XRD, FTIR, TEM, and VSM analyses. The kinetic and equilibrium of the arsenate (As5+) adsorption by the magnetite nanoparticles was i...

The consumption of cyanide during processing operations is a major economic cost in the extraction of gold from its ores, while the discharge of cyanide wastes may result in significant environmental pollution. Many factors influence the levels of consumption and discharge of cyanide, including ore mineralogy and lixiviant solution chemistry. This...

In this study, surface soils of the Bama Pb-Zn mine-impacted area were sampled for an area surrounding the mineral processing plant. After collecting 65 samples and analyzing them for initial Cu, Pb, Zn, and Cd metal contents, the area was zonated based on the concentration distribution using ordinary kriging in R. A single homogenous sample was pr...

The extraction of gold involves using cyanide which has the potential to impact the environment. Many studies have been done to reduce the environmental effects of cyanide. In this research, the cyanide adsorption on zeolite from gold processing plant tailing dam wastewater was investigated. Results indicated that the pH of the solution, contact ti...

The influence of methyl-silane as a water reducing agent was examined within cemented paste backfill CPB containing nano-silica. The key goal of using such high-technology admixtures in mine tailings management is to facilitate the filling operation and reduce the binder consumption. The amounts of binder (Portland cement) and nano-silica (tetraeth...

Use of nanotechnology has proven to be a promising approach toward remediation of all phases of environment. The aim of this work is to investigate the effects of different parameters on using iron III oxide nanoparticles in a continuous flow configuration for the removal of Cd2+ ionsfrom contaminated soils. Also selective sequential extraction tes...

This research aimed to enhance the column bioleaching recovery of uranium ore by Acidithiobacillus ferrooxidans. Seven factors were examined for their significance on bioleaching using a Plackett–Burman factorial design. Four significant variables ([Fe²⁺]initial, pH, aeration rate and inoculation percent) were selected for the optimization studies....

Montmorillonite (MMT) clay was modified using the hydrothermal method through the intercalation and adsorption of the trimethylphenylammonium bromide (TMPA) and applied for the removal of U(VI) from the carbonate- and sulfate-containing solutions using batch experiments. The hydrothermal technique provides a simple, fast, and efficient route for th...

A fundamental study on the kinetics of uranium mineral bioleahing using Acidithiobacillus ferrooxidans has been carried out in stirred reactor (SR) and column reactor (CR). The four factors affecting uranium dissolution kinetic including aeration rate, pH, initial Fe²⁺ concentration and temperature were selected to be optimized in SR. The aeration...

This paper represents a set of experimental tests on remediation of nickel-contaminated kaolin by Electrokinetic method. For this purpose, we conducted unenhanced and EDTA-enhanced Electrokinetic tests in one, three, and five days of treatment. In unenhanced tests, we used deionized water as an electrolyte in the anode and the cathode compartments....

A layered double hydroxide@montmorillonite nanocomposite (LDH@MMT) was synthesized by the coating of growing LDH layers onto the MMT surface through hydrothermal method and used to remove uranyl ion from carbonate-containing aqueous solutions. The adsorption kinetics was described using a pseudo-second-order model and the adsorption isotherms data...

The relation of nutrients from agricultural activities in the Zarivar Lake catchment and hypoxia potential was examined using a novel application of a matrix analysis due to summer water column sampling in two routes, 6 stations and 4 various depths. It is surrounded by local agricultural activities and one seasonal river is terminated to it. Due t...

The effect of hydrodynamic factors such as particle size, irrigation rate and aeration rate on the dissolution of uranium by Acidithibacillus ferrooxidans in column reactor was studied. Response surface methodology (RSM) was applied to predict the behavior of effective parameters and their interactions on the bioleaching process. Under the optimum...

In mineral processing industry, the tailings dams constitute the major environmental problems with heavy metals playing a major role in destruction and degradation of natural habitats. In this study, activated carbon and ferric sulfate were applied for the removal of vanadium from effluent of tailing dam in case of Jajarm Bauxite processing plant....

Feasibility of applying intelligent tools in prediction and optimization of photocatalytic degradation of beta-naphthol using the titanium dioxide (TiO2) nanoparticles were conducted in this study. Biphasic TiO2 nanoparticles were synthesized using the controlled hydrolysis of TiCl4, and their properties were studied using the X-ray diffraction and...

One of the methods of removing cyanide from wastewater is surface adsorption. We simulated the removal of cyanide from a synthetic wastewater in the presence of Titanium dioxide nano-particles absorbent uses VISUAL MINTEQ 3.1 software. Our aim was to determine the factors affecting the adsorption of cyanide from synthetic wastewater applying simula...