Removal of copper, zinc and nickel present in natural water containing Ca2+ and ions by electrocoagulation

Optimization of the effect of microelectrodes on Ni2+ removal in three-dimensional electrode system

This study investigated Ni⁺² removal performance in 3DER reactors where electrocoagulation mechanisms and microelectrodes are used together. EDTA modification was carried out on the granule-activated carbon surface to increase the efficiency and affinity of microelectrodes against Ni⁺² molecules. The grafting was examined using BET, FT-IR, SEM, EDS, and the elemental mapping methods. With the surface analyses made in this study, it was revealed that EDTA modification on granulated activated carbon was successfully performed. Also, 8.48%wt by mass of EDTA grafting on granular activated carbon was possible. EDTA functionalization did not affect the surface pore structures of CAC much. Under 10 V potential, 97.82% Ni removal efficiency was obtained with 2D in 35 min, while 96.69% removal in 10 min and 100% removal in 15 min were obtained in the 3D reactor. The Ni⁺² removal mechanism in 3DER reactors has been determined to conform to the pseudo-second-order kinetic model. The k₂ value obtained for 10 V (1.36 10^-2) is 27 times the k₂ value obtained for 5 V for 3DER reactors. In addition, using central composite design (CCD), operational parameters such as time, concentration, and potential difference affecting Ni⁺² removal in 3DER reactors have been optimized. The most influential parameter is the applied voltage, followed by time and concentration. It has been determined that 3DER reactors using EDTA-modified microelectrodes are highly efficient and suitable for Ni⁺² removal.

Determination of optimal operating conditions for AC-powered electrocoagulation process coupling green additive Tartaric Acid to remove Ni2+: Pyomo and RSM approach

A novel Python-based open-source optimization framework, namely Pyomo (Python optimization modeling objects), alongside a conventional optimization method, RSM (response surface methodology), was utilized to determine the optimal operating conditions of an alternating current-powered electrocoagulation (ACPE) process for nickel removal. In this regard, four mutable operating factors, current density (5-9 mA/cm²), initial nickel concentration (200-400 mg/L), initial pH of the solution (5-9), and electrolysis time (30-60 min), along with a fixed amount of an additional eco-friendly substance, Tartaric Acid (155 mg/L) were considered. Metal removal efficiency (OF₁) and operating costs (OF₂) were monitored and evaluated as objective functions with the aim of maximization and minimization, respectively. Experiments were conducted according to the central composite design (CCD), and validation outcomes established a reasonable agreement between the predicted models and the experimental data. The multi-objective optimization process yielded two sets of 30-optimal-solution obtained through Pyomo and RSM. Accordingly, the proposed solutions by the Pyomo were found to be more flexible and eclectic, supplying the local decision maker(s) with a diverse spectrum of optimal operating conditions. Adding TA was also effective in reducing electrical energy consumption by up to 46%.

Photocatalytic removal of pharmaceutical water pollutants by TiO2 - Carbon dots nanocomposites: A review

Pharmaceuticals are becoming increasingly more relevant water contaminants, with photocatalysts (such as TiO₂) being a promising approach to remove these compounds from water. However, TiO₂ has poor sunlight-harvesting capacity, low photonic efficiency, and poor adsorption towards organic pollutants. One of the emerging strategies to enhance the photocatalytic performance of TiO₂ is by conjugating it with fluorescent carbon dots. Herein, we performed a critical review of the development of TiO₂ - carbon dots nanocomposites for the photocatalytic removal of pharmaceuticals. We found that carbon dots can improve the photocatalytic efficiency of the resulting nanocomposites, mostly due to increasing the adsorption of organic pollutants and enhancing the absorption in the visible range. However, while this approach shows significant promise, we also identified and discussed several aspects that need to be addressed before this strategy could be more widely used. We hope that this review can guide future studies aiming to the development of enhanced photocatalytic TiO₂ - carbon dots nanocomposites.

Removal of inorganic pollutants using electrocoagulation technology: A review of emerging applications and mechanisms

Electrocoagulation (ECoag) technique has shown considerable potential as an effective method in separating different types of pollutants (including inorganic pollutants) from various sources of water at a lower cost, and that is environmentally friendly. The EC method's performance depends on several significant parameters, including current density, reactor geometry, pH, operation time, the gap between electrodes, and agitation speed. There are some challenges related to the ECoag technique, for example, energy consumption, and electrode passivation as well as its implementation at a larger scale. This review highlights the recent studies published about ECoag capacity to remove inorganic pollutants (including salts), the emerging reactors, and the effect of reactor geometry designs. In addition, this paper highlights the integration of the ECoag technique with other advanced technologies such as microwave and ultrasonic to achieve higher removal efficiencies. This paper also presents a critical discussion of the major and minor reactions of the electrocoagulation technique with several significant operational parameters, emerging designs of the ECoag cell, operating conditions, and techno-economic analysis. Our review concluded that optimizing the operating parameters significantly enhanced the efficiency of the ECoag technique and reduced overall operating costs. Electrodes geometry has been recommended to minimize the passivation phenomenon, promote the conductivity of the cell, and reduce energy consumption. In this review, several challenges and gaps were identified, and insights for future development were discussed. We recommend that future studies investigate the effect of other emerging parameters like perforated and ball electrodes on the ECoag technique.

High-efficiency and energy-saving alternating pulse current electrocoagulation to remove polyvinyl alcohol in wastewater

Conventional direct current electrocoagulation (DC-EC) has disadvantages such as easy passivation of electrodes, high energy consumption, and large sludge production, which limit its use in polyvinyl alcohol (PVA) wastewater. Therefore, alternating pulse current electrocoagulation (APC-EC) has been developed to overcome these problems. In this study, the influencing factors and energy consumption of PVA treatment by APC-EC and DC-EC were explored, and the best operating conditions of APC-EC were obtained via the response surface method (RSM). The best process conditions for APC-EC were determined to be the electrode type of Fe/Fe, current density of 1.0 mA cm⁻², initial pH of 7, electrode distance of 2.0 cm, supporting electrolyte of 0.08 mol L⁻¹ NaCl, initial PVA concentration of 150 mg L⁻¹, duty cycle of 30%, and frequency of 500 Hz. In addition, the floc properties of APC-EC and DC-EC were compared to explore the basic mechanism for the removal of PVA. Adsorption and co-precipitation with hydroxide iron complexes are the main methods for removing PVA from wastewater in the APC-EC process. Compared with DC-EC, the application of APC-EC can reduce electrode passivation and production of sludge and operating costs, and improve electrode stability and PVA removal efficiency. This study provides a new strategy and method for the PVA removal from wastewater by APC-EC with low cost and high efficiency, showing broad prospect for the applications of the APC-EC in removing PVA.

Compared with DC-EC, the application of APC-EC can reduce electrode passivation and production of sludge and operating costs, and improve electrode stability and PVA removal efficiency.

Electrochemical process for simultaneous removal of chemical and biological contaminants from drinking water

Simultaneous management of chemical and biological contaminants in drinking water has been presented through modification in conventional electrocoagulation (EC) process. Traditional EC process using iron and aluminum electrodes removed metals but did not affect microbiological contaminants to a greater extent. Iron anode composition was amended by addition of zinc for desired antimicrobial output. To evaluate the efficiency of this system, samples were spiked with multiple element standard and microbial cultures to human unsafe contamination level. Modified EC process removed both types of contaminants making water safe for human consumption within the prescribed regulatory guidelines set by WHO/NSDWQ within 4 min. This setup removed chemical contaminants up to 100% including nitrates, fluoride, arsenic, beryllium, chromium, copper, mercury, vanadium, zinc, nickel, phosphorus, and lead. A substantial removal in cadmium (89.8%), cobalt (75.7%), and selenium (46.7%) was computed. The treatment could not prove good results for removal of boron, barium, lithium, and strontium from the spiked sample. The compositional analysis of flocs screened after spiked sample treatment confirmed the physical adsorption of metals at floc surface. Treatment technique comprehensively proved equally efficient for disinfection of most common microbiological contaminations including E. Coli, fecal coliforms, total coliforms, total plate count, Staphylococcus auseous, and Pseudomonas aeruginosa within 5 min. In EC process 220V voltage was applied through rectifier at electrodes having 15.6 cm² surface area and 15 mm apart in 1-L water sample batches, where current varied from 0.8 to 1.6 ampere. The outcomes of the current experiment are of novel significance regarding simultaneous removal of metals and microbiological contaminants from drinking water which is not reported in previous treatment studies.

Use of Electrocoagulation for Treatment of Pharmaceutical Compounds in Water/Wastewater: A Review Exploring Opportunities and Challenges

Increasing dependency on pharmaceutical compounds including antibiotics, analgesics, antidepressants, and other drugs has threatened the environment as well as human health. Their occurrence, transformation, and fate in the environment are causing significant concerns. Several existing treatment technologies are there with their pros and cons for the treatment of pharmaceutical wastewater (PWW). Still, electrocoagulation is considered as the modern and decisive technology for treatment. In the EC process, utilizing electricity (AC/DC) and electrodes, contaminants become coagulated with the metal hydroxide and are separated by co-precipitation. The main mechanism is charge neutralization and adsorption of contaminants on the generated flocs. The range of parameters affects the EC process and is directly related to the removal efficiency and its overall operational cost. This process only could be scaled up on the industrial level if process parameters become optimized and energy consumption is reduced. Unfortunately, the removal mechanism of particular pharmaceuticals and complex physiochemical phenomena involved in this process are not fully understood. For this reason, further research and reviews are required to fill the knowledge gap. This review discusses the use of EC for removing pharmaceuticals and focuses on removal mechanism and process parameters, the cost assessment, and the challenges involved in mitigation.

Review on current approach for treatment of palm oil mill effluent: Integrated system

Malaysia is one of the countries that is well known for its palm oil based products and exports all over the world. Over the years, palm oil mill has been rising at alarming rate in Malaysia, causing palm oil-based wastes to increase especially palm oil mill effluent (POME). POME in Malaysia are channelled into water bodies such as rivers after treated mostly with conventional biological method. However, with current technologies and knowledge, conventional POME treatments are seen to be outdated and require major improvements as greenhouse gaseous are emitted to the environment as well as being less cost effective. Integrated systems that combine two or more conventional methods are introduced and reviewed to provide insights on the advantages and disadvantages of the system if it is to be implemented in real life plant. Integrated systems that focus on combining conventional methods are compiled and reviewed specifically for POME treatment. Among the integrated methods that are reviewed includes biological with membrane, adsorption with magnetic field exposure, adsorption with membrane and electrocoagulation with membrane. The systems are seen to give excellent color, chemical oxygen demand (COD) and total suspended solids (TSS) removal with average of higher than 90%. Reduction in space utilization, improved treatment time as well as simplified operating system were reported when integrated systems are applied as compared to conventional treatment of POME.

A WO3/PPy/ACF modified electrode in electrochemical system for simultaneous removal of heavy metal ion Cu2+ and organic acid

Heavy metal ions and organic acids are common pollutants in electroplating wastewater. Effective and economic treatment of such wastewater needs novel technologies. In this study, WO₃/PPy-1/ACF electrode was prepared using a hydrothermal modification method and it has large specific area (788.27 m² g^-1), high areal capacitance (2.58 F cm^-2 under 5 mA cm^-2 charge and discharge) and excellent conductivity. The modified electrode was used in an electrochemical system with activated carbon fiber felt (ACF) as counter electrode. The system simultaneously and successfully removed 97.8 % Cu²⁺ and 80.1 % citric acid (CA) from a simulated electroplating wastewater (typically 100 mg L^-1 Cu²⁺ and 800 mg L^-1 CA) in five- hour optimized operation. The influence of operating parameters (circulating inflow rate, applied voltage and influent pH) on the treatment performance was compared. There is interplay between Cu²⁺ reductive deposition and CA oxidation. The synergetic electrochemical treatment mechanism involves formation of hydrogen peroxide, free radicals, and catalytic effect of Cu species was proposed. This electrochemical system which is low-cost, easy to operate and highly efficient, may be applicable in treating acid-wash or electroplating wastewater, containing heavy-metal ions and organic acids.

A comprehensive review on contaminants removal from pharmaceutical wastewater by electrocoagulation process

The pharmaceuticals are emergent contaminants, which can create potential threats for human health and the environment. All the pharmaceutical contaminants are becoming enormous in the environment as conventional wastewater treatment cannot be effectively implemented due to toxic and intractable action of pharmaceuticals. For this reason, the existence of pharmaceutical contaminants has brought great awareness, causing significant concern on their transformation, occurrence, risk, and fate in the environments. Electrocoagulation (EC) treatment process is effectively applied for the removal of contaminants, radionuclides, pesticides, and also harmful microorganisms. During the EC process, an electric current is employed directly, and both electrodes are dissoluted partially in the reactor under the special conditions. This electrode dissolution produces the increased concentration of cation, which is finally precipitated as hydroxides and oxides. Different anode materials usage like aluminum, stainless steel, iron, etc. are found more effective in EC operation for efficient removal of pharmaceutical contaminants. Due to the simple procedure and less costly material, EC method is extensively recognized for pharmaceutical wastewater treatment over further conventional treatment methods. The EC process has more usefulness to destabilize the pharmaceutical contaminants with the neutralization of charge and after that coagulating those contaminants to produce flocs. Thus, the review places particular emphasis on the application of EC process to remove pharmaceutical contaminants. First, the operational parameters influencing EC efficiency with the electroanalysis techniques are described. Second, in this review emerging challenges, current developments and techno-economic concerns of EC are highlighted. Finally, future recommendations and prospective on EC are envisioned.

A novel hydrogel for highly efficient adsorption of Cu(II): synthesis, characterization, and mechanisms

Among the Cu(II) removal methods, adsorption is a favorable technique and has attracted large attention because of its effectiveness and low cost. In quest of seeking for a favorable adsorbent with a high Cu(II) adsorption capacity and excellent reusability, researchers have paid much attention to hydrogels with three-dimensional networks. In this study, a novel hydrogel (P(AMPS-co-VDT) hydrogel) based on free-radical polymerization was synthesized with ionic monomer sodium 2-acrylamido-2-methylpropane sulfate (AMPS-Na⁺) and 2-vinyl-4, 6-diamino-1, 3, 5-triazine (VDT) and applied for Cu(II) adsorption in aqueous solutions. The hydrogel was characterized for swelling performance, surface morphology, functional groups, thermal gravimetric behavior, and elements. The maximum Cu(II) adsorption capacity (175.75 mg/g) was relatively high compared with other hydrogels. The P(AMPS-co-VDT) hydrogel also was found to have a relatively good Cu(II) desorption and reuse behavior. The adsorption mechanism could be chelation and ion exchange. This work provides a new hydrogel for effective Cu(II) removal in the future.

Optimization of Mn removal from aqueous solutions through electrocoagulation

Manganese (Mn) was removed from aqueous solutions through electrocoagulation using Al electrodes. Effects of initial Mn concentration (185-405 mg l^-1), the input voltage (1-11 V), inter electrode distance (1-5 cm), and initial pH (2-11) on Mn removal were investigated. Experiments were designed with an orthogonal central composite design on the four variables using the response surface methodology. Analysis of variance was applied and the final Mn concentration was expressed by a mathematical equation. Optimum values of the four factors to get the highest removal were also obtained. As the results showed, electrocoagulation using Al electrodes was able to remove Mn from aqueous solutions efficiently. An equilibrium state was achieved within 195 min. The mathematical model was appropriate to describe experimental data with a high regression coefficient. Kinetics and isotherm data were described appropriately by pseudo-second-order and Langmuir models, respectively. The optimum operating conditions were obtained as pH 9, initial Mn concentration 360 mg l^-1, inter electrode distance 2 cm, and input voltage 10 V. The highest removal efficiency was 92% which is considered a high value.

Simultaneous removal of cadmium, zinc and manganese using electrocoagulation: Influence of operating parameters and electrolyte nature

In the present study, the influence of operating parameters and electrolyte nature on the simultaneous removal of toxic metals (cadmium, zinc and manganese) from synthetic smelting wastewater by batch electrocoagulation was investigated. This wastewater contained high concentrations of anion-cation electrolytes. Results indicated that the efficiency of heavy metals removal can be enhanced by increasing the solution pH and current density. The Fe-Fe electrode combination is more effective than the other combinations (Al-Al, Al-Fe and Fe-Al). The interaction of heavy metal ions showed that the increase of initial Zn²⁺ concentration adversely affects on Cd²⁺ removal. In addition, the single chloride system exhibits the optimum removal efficiency on Mn²⁺. Single sulfate and binary anion systems exert a more positive effect on Cd²⁺ and Zn²⁺ removal because of the stronger charge neutralization and destabilization of iron hydroxide flocs. Increases of Ca²⁺ and Mg²⁺ ions exert a significant negative effect on metal removal. However, the addition of a small amount of sodium chloride into a high sulfate and hardness solution can accelerate the removal of heavy metals. Finally, the sludge samples generated from electrocoagulation were characterized by XRD and SEM-EDS analyses.

Recent trends in removal and recovery of heavy metals from wastewater by electrochemical technologies

Heavy metal-laden water and wastewater pose a threat to biodiversity, including human health. Contaminated wastewater can be treated with several separation and purification methods. Among them, electrochemical treatment is a notable clean technology, versatile and environmentally compatible for the removal and recovery of inorganic pollutants from water and wastewater. Electrochemical technology provides solution for the recovery of metals in their most valuable state. This paper analyses the most recent electrochemical approaches for the removal and recovery of metal ions. Various current works involving cell design and electrode development were addressed in distinguished electrochemical processes, namely, electrodeposition, electrocoagulation, electroflotation, and electrosorption. Cathodic reduction of metal ions has been proven in result to metal deposit on the metal, metal oxide, stainless steel, and graphite electrode. However, little progress has been made toward electrode modification, particularly the cathode for the purpose of cathodic reduction and deposition. Meanwhile, emerging advanced materials, such as ionic liquids, have been presented to be prominent to the technological advancement of electrode modifications. It has been projected that by integrating different priorities into the design approach for electrochemical reactors and recent electrode developments, several insights can be obtained that will contribute toward the enhancement of the electrochemical process performance for the effective removal and recovery of heavy metals from water and wastewater in the near future.

Removal of Pb, Cu, Cd, and Zn Present in Aqueous Solution Using Coupled Electrocoagulation-Phytoremediation Treatment

This study presents the results of a coupled electrocoagulation-phytoremediation treatment for the reduction of copper, cadmium, lead, and zinc, present in aqueous solution. The electrocoagulation was carried out in a batch reactor using aluminum electrodes in parallel arrangement; the optimal conditions were current density of 8 mA/cm2 and operating time of 180 minutes. For phytoremediation the macrophytes, Typha latifolia L., were used during seven days of treatment. The results indicated that the coupled treatment reduced metal concentrations by 99.2% Cu, 81.3% Cd, and 99.4% Pb, while Zn increased due to the natural concentrations of the plant used.

Removal of trace metal contaminants from potable water by electrocoagulation

This study investigated the effects of four operational and environmental variables on the removal of trace metal contaminants from drinking water by electrocoagulation (EC). Removal efficiencies for five metals (arsenic, cadmium, chromium, lead and nickel) were compared under varying combinations of electrode material, post-treatment, water composition and pH. Iron electrodes out-performed aluminum electrodes in removing chromium and arsenic. At pH 6.5, aluminum electrodes were slightly more effective at removing nickel and cadmium, while at pH 8.5, iron electrodes were more effective for these metals. Regardless of electrode, cadmium and nickel removal efficiencies were higher at pH 8.5 than at pH 6.5. Post-EC treatment using membrane filtration (0.45 μm) enhanced contaminant removal for all metals but nickel. With the exception of lead, all metals exhibited poorer removal efficiencies as the ionic strength of the background electrolyte increased, particularly in the very high-solids synthetic groundwaters. Residual aluminum concentrations were lowest at pH 6.5, while iron residuals were lowest in low ionic strength waters. Both aluminum and iron residuals required post-treatment filtration to meet drinking water standards. EC with post-treatment filtration appears to effectively remove trace metal contaminants to potable water standards, but both reactor and source water parameters critically impact removal efficiency.

Adsorptive removal of Ni(ii) ions from aqueous solution and the synthesis of a Ni-doped ceramic: an efficient enzyme carrier exhibiting enhanced activity of immobilized lipase

We report the successful removal of Ni²⁺ from aqueous solution via entrapment by chitosan nanoparticles, followed by calcination with a ceramic matrix to construct a novel carrier for lipase immobilization with enhanced activity.

Aqueous nickel sequestration and release during structural Fe(ii) hydroxide remediation: the roles of coprecipitation, reduction and substitution

SFH has a strong potential for reducing aqueous Ni²⁺ and the release of precipitated Ni(ii) into solution could be controlled.

Enhanced sludge properties and distribution study of sludge components in electrically-enhanced membrane bioreactor

This study investigated the impact of electric field on the physicochemical and biological characteristics of sludge wasted from an electrically-enhanced membrane bioreactor treating medium-strength raw wastewater. This method offers a chemical-free electrokinetic technique to enhance sludge properties and remove heavy metals. For example, sludge volume index (SVI), time-to-filter (TTF), mean sludge particle diameter (PSD), viscosity, and oxidation-reduction potential (ORP) of 21.7 mL/g, 7 min, 40.2 μm, 3.22 mPa s, and -4.9 mV were reported, respectively. Also, X-ray fluorescence (XRF) and X-ray diffraction (XRD) analyses provided mechanisms for heavy metal removal so as to establish relevant pathways for nutrient recovery. Furthermore, variations in dissolved oxygen (DO), conductivity, viscosity, ORP, total suspended solids (MLSS), and volatile suspended solids (MLVSS) were interrelated to evaluate the quality of wasted sludge. A pathway study on the transport and chemical distribution of nutrients and metals in sludge showed great potential for metal removal and nutrient recovery.

Electrocoagulation of colloidal biogenic selenium

Colloidal elemental selenium (Se(0)) adversely affects membrane separation processes and aquatic ecosystems. As a solution to this problem, we investigated for the first time the removal potential of Se(0) by electrocoagulation process. Colloidal Se(0) was produced by a strain of Pseudomonas fluorescens and showed limited gravitational settling. Therefore, iron (Fe) and aluminum (Al) sacrificial electrodes were used in a batch reactor under galvanostatic conditions. The best Se(0) turbidity removal (97 %) was achieved using iron electrodes at 200 mA. Aluminum electrodes removed 96 % of colloidal Se(0) only at a higher current intensity (300 mA). At the best Se(0) removal efficiency, electrocoagulation using Fe electrode removed 93 % of the Se concentration, whereas with Al electrodes the Se removal efficiency reached only 54 %. Due to the less compact nature of the Al flocs, the Se-Al sediment was three times more voluminous than the Se-Fe sediment. The toxicity characteristic leaching procedure (TCLP) test showed that the Fe-Se sediment released Se below the regulatory level (1 mg L(-1)), whereas the Se concentration leached from the Al-Se sediment exceeded the limit by about 20 times. This might be related to the mineralogical nature of the sediments. Electron scanning micrographs showed Fe-Se sediments with a reticular structure, whereas the Al-Se sediments lacked an organized structure. Overall, the results obtained showed that the use of Fe electrodes as soluble anode in electrocoagulation constitutes a better option than Al electrodes for the electrochemical sedimentation of colloidal Se(0).

An intelligent displacement pumping film system: a new concept for enhancing heavy metal ion removal efficiency from liquid waste

A concept of electrochemically switched ion exchange (ESIX) hybrid film system with piston-like proton pumping effect for the removal of heavy metal ions was proposed. Based on this concept, a novel ESIX hybrid film composed of layered alpha zirconium phosphate (α-Zr(HPO4)2; α-ZrP) nanosheets intercalated with a potential-responsive conducting polyaniline (PANI) was developed for the removal of Ni(2+) ions from wastewater. It is expected that the space between α-ZrP nanosheets acts as the reservoir for the functional ions while the intercalated PANI works as the potential-sensitive function element for piston-like proton pumping in such ESIX hybrid films. The prepared ESIX hybrid film showed an excellent property of rapid removal of Ni(2+) ions from wastewater with a high selectivity. The used film was simply regenerated by only altering the applied potential. The ion pumping effect for the ESIX of Ni(2+) ions using this kind of film was proved via XPS analysis. The proposed ESIX hybrid film should have high potential for the removal of Ni(2+) ions and/or other heavy metal ions from wastewater in various industrial processes.

Effective removal of Ni(II) from aqueous solutions by modification of nano particles of clinoptilolite with dimethylglyoxime

In this work an Iranian natural clinoptilolite tuff was pre-treated and changed to the micro (MCP) and nano (NCP) particles by mechanical method. Modification of micro and nano particles and also their Ni-exchanged forms were done by dimethylglyoxime (DMG). The raw and modified samples were characterized by XRD, FT-IR, SEM, BET, TG-DTG and energy dispersive analysis X-ray spectroscopy (EDAX). Removal of Ni(II) by modified and unmodified samples was investigated in batch procedure. It was found that NCP-DMG has higher capacity for removal of Ni(II). The effects of analytical parameters such as pH, dose of DMG, concentration of nickel solution, contact time and selectivity were studied and the optimal operation parameters were found as follows: pHPZC: 7.6, CNi(II): 0.01 M, contact time: 360 min and DMG dosage: 5mM. The results of selectivity experiments showed that the modified zeolite has a good selectivity for nickel in the presence of different multivalent cations. Langmuir and Freundlich isotherm models were adopted to describe the adsorption isotherms. Adsorption isotherms of Ni(II) ions could be best modelled by Langmuir equation, that indicate the monolayer sorption of Ni(II). Comparison of two kinetic models indicates that the adsorption kinetic can be well described by the pseudo-second-order rate equation that indicates that the rate limiting step for the process involves chemical reaction. The negative ΔH and ΔG indicate an exothermic and spontaneously process. The negative ΔS indicates that the adsorption of nickel cations from solution occurs with lower amount ion replacement, thus chemisorptions due to complex formation are dominant process in nickel removal.