Adsorbent For Removal Of Cadmium Research Articles

Microwave-assisted synthesis of γ-alooh nanoflowers as an adsorbent for cadmium removal from domestic wastewater.

In this study, cadmium ions were effectively removed from domestic wastewaters using an adsorptive treatment strategy based on γ-AlOOH nanoflowers. A novel, rapid, and simple procedure was developed for the synthesis of the nanoflowers. Characterization studies were performed using X-ray powder diffraction patterns and scanning electron microscope images. The synthesized nanoflowers were utilized as adsorbent in the batch adsorption experiments. The influential parameters of the adsorption process were optimized, and a flame atomic absorption spectrophotometry (FAAS) system was used to determine maximum percent removal of cadmium ions. Matrix-matched calibration strategy, in which the calibration plot was developed in wastewater medium, was utilized for the accurate and precise quantification of cadmium in the effluent samples. The percentage removal efficiency values were calculated between 84 and 98% for different concentrations of cadmium ions in the wastewater samples. Equilibrium data was fitted to the four different linearization methods of the Langmuir isotherm model, as well as the Freundlich isotherm model and Elovich isotherm model. The best fitting was achieved for the Langmuir model with a high R2 value of 0.9956 and maximum adsorption capacity was calculated as 6.23mg/g.

Experimental design of polymer synthesis applied to the removal of Cd2+ ions from water via adsorption

Cadmium is a highly toxic metal, and its presence can have adverse effects on both human health and aquatic ecosystems. The efficient removal of cadmium from wastewater is therefore of crucial importance, but traditional methods have proved to be inadequate. Thus, technologies for the treatment of wastewater containing cadmium, including adsorption, have been developed. The aim of this study was the preparation of a polymeric material by the grafting reaction of κ-carrageenan and its use as an adsorbent for cadmium removal. This was performed to study the removal capacity of cadmium ions in synthetic solutions, as well as the effects of pH and ions on adsorption capacity, adsorption kinetics, isotherms, and reusability. Additionally, the disinfectant potential of the solution was evaluated for the inactivation of total coliforms and E. coli in river water. The best adsorption capacity was 75.52 ± 1.325 mg g−1, with the kinetics described by the pseudo-second order model. Maximum adsorption capacity (127.6 ± 1.833 mg g−1) and RL (0.0113) were determined using the Langmuir model, the Freundlich model was the one that best fits the experimental data and indicated cooperative adsorption, and the Dubinin-Radushkevich isotherm was used to obtain the adsorption energy and identify that it is physical. The presence of ions K+, Na+, Mg2+, and Ca2+ in a concentration of 0.5% decreased the adsorption capacity, and that at pH 2.0, the adsorption capacity was drastically reduced. The study indicates that the polymer has potential as an adsorbent for removing cadmium from aqueous solutions and exhibits self-disinfecting properties.

Adsorptive removal of cadmium from electroplating wastewater using hybrid composite of thiol-grafted seed gum of Tamarindus indica and Teff hay biocarbon

Abstract This study examined the methods for preparing biocarbon from Teff hay (TBC) and thiol-grafted seed gum of Tamarindus indica (TH@TI-TBC) with the purpose of removing cadmium (Cd) from polluted electroplating waste water. To improve biocarbon adsorption, seed gum and thiol were added in a two-step combination. At a pH of 5.5, the most effective Cd adsorption was seen with TH@TI-TBC (261.47 mg g−1). While comparing to the Freundlich and Temkin models, the Langmuir and pseudo-second-order kinetic models found to be the best fit to the obtained adsorption data. After being treated with electroplating wastewater having 30 mg−1 L of cadmium, TH@TI-TBC was able to remove up to 89 % of the Cd, proving its effectiveness in dealing with adsorptive removal of Cd. Experimental studies and computational analyses revealed that electrostatic interaction and surface complexation were the principal underlying processes for Cd removal by TH@TI-TBC. In addition, an innovative material that can transform the waste into a product for environmental remediation must be developed using the vast amounts of Teff hay that are generated as agro-residue. So, this work proved that TH@TI-TBC can be made from Teff hay biocarbon could be a potential candidate for removing Cd from industrial wastewater.

Developing a sorptive material of cadmium from pyrolysis of hen manure

A large amount of manure is generated from concentrated animal feeding operations (CAFOs), leading to serious environmental issues and hazardous risks from pathogens, such as methicillin-resistant Staphylococcus aureus. Therefore, developing an effective method for manure disposal is essential. Thus, in this study, we suggest the use of CO2 in pyrolysis of hen manure (HM) as an effective method to convert the carbon in HM into syngas (especially carbon monoxide (CO)). HM was used and tested as the model compound. From the results of thermo-gravimetric analysis, the decarboxylation of CaCO3 in HM in the presence of N2 was realized at temperatures ranging from 638 to 754 °C. The Boudouard reaction was observed at ≥ 664 °C in the presence of CO2. Despite the lack of occurrence of the Boudouard reaction, more CO formation was observed in the presence of CO2 at ≥ 460 °C. This was deemed as a homogeneous reaction induced by CO2. Considering the high Ca content of HM, HM biochar in N2 and CO2 were used as adsorbent for removal of Cadmium (Cd), which is toxic heavy metal. The adsorption capacities of HM_N2 and HM_CO2 were 302.4 and 95.7 mg g−1, respectively. The superior performance of HM_N2 is mainly attributed to the presence of Ca(OH)2, which provides favorable (alkaline) conditions for precipitation and ion exchange. Our results indicate the environmental benefits from using CO2. Specifically, CO2 (representative greenhouse gas) converted into fuel. Given this, pyrolysis of HM in the presence of CO2 was achieved at ≤ 640 °C, and the atmospheric condition should be switched from CO2 to N2 at ≥ 640 °C to ensure the decarboxylation of CaCO3.

Bolivian natural zeolite as a low-cost adsorbent for the adsorption of cadmium: Isotherms and kinetics

Population growth in recent years has led to increased wastewater production and pollution of water resources. This situation also heavily affects Bolivia, so wastewater treatment methods and materials suitable for Bolivian society should be explored. This study investigated the natural Bolivian Zeolite (BZ) and its NaCl-modified structure (NaBZ) as adsorbents for cadmium removal from water. The natural BZ and the modified form NaBZ were investigated by different physicochemical characterization techniques. Furthermore, XPS and FT-IR techniques were used to investigate the adsorption mechanisms. The cadmium adsorption on BZ and NaBZ was analyzed using various mathematical models, and the Langmuir model provided a better description of the experimental adsorption data with cadmium adsorption capacities of 20.2 and 25.6 mg/g for BZ and NaBZ, respectively. The adsorption followed the pseudo-second order kinetics. The effect of different parameters, such as initial cadmium concentration and pH on the adsorption was studied. In addition, the results of the regeneration test indicated that both BZ and NaBZ can be regenerated by using hydrochloric acid (HCl). Finally, the adsorption experiment of BZ and NaBZ on a real water sample (brine from Salar de Uyuni salt flat) containing a mixture of different heavy metals was carried out. The results obtained in this study demonstrate the effectiveness of natural BZ and modified NaBZ in the removal of heavy metals from wastewater.

Effective and Stable Adsorptive Removal of Cadmium(Ii) and Lead(Ii) Using Selenium Nanoparticles Modified by Microbial Smta Metallothionein

Effective and Stable Adsorptive Removal of Cadmium(Ii) and Lead(Ii) Using Selenium Nanoparticles Modified by Microbial Smta Metallothionein

Modeling and optimization of porous aerogel adsorbent for removal of cadmium from crab viscera homogenate using response surface method and artificial neural network

The purpose of this study was to establish an efficient modern strategy for the reduction and control of cadmium (Cd) content in the crab viscera homogenate. To this end, the coupling of an artificial neural network (ANN) technique with the genetic algorithm (GA) method and compared the performance of GA-ANN with response surface methodology (RSM) were demonstrated in the prediction and optimization of the ultrasonic-assisted adsorption of Cd using a aerogel adsorbent. On the basis of single factor test, the data sample was established by Box–Behnken Design, and the effects of ultrasonic time, temperature, the addition amount of aerogel, and pH on the removal rate of Cd were researched. The results revealed that the RSM and GA-ANN models had relative errors and coefficients of determination R2 values of 3.90%, 0.8440, and 1.79%, 0.9283, respectively, suggesting that GA-ANN is more accurate than RSM. The maximum percentage of Cd extracted (79.13%) was obtained using GA-ANN model as ultrasonic time of 87 min, temperature of 81 °C, adsorbent dosage of 0.07 g, pH of 3.20. In conclusion, the present results provide an effective method for optimizing multi-technology coupling to reduce the toxic heavy metal content in aquatic products.

Efficiency of eggshell as a low-cost adsorbent for removal of cadmium: kinetic and isotherm studies

Eggshell (ES) is an alternative source of calcium carbonate that efficiently removes heavy metals in aqueous solution. The adsorption capacity of ES depends on their physico-chemical properties and the influence of experimental conditions, but in the majority of reports, not all the reaction parameters related to adsorption process of heavy metals are available, and the adsorption mechanism is not systematically studied. In this contribution, the use of ES waste is reported to establish an overall performance trend of the experimental parameters on cadmium ion (Cd2+) adsorption from an aqueous solution. Different physicochemical techniques Brunauer–Emmett–Teller (BET), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) are used to characterize the physico-chemical properties of ES and the adsorption performance is studied as a function of contact time, pH, concentration, and adsorbent dosage. The highest adsorption capacity, 217.4 mg.g−1, obtained in 10 min at an initial pH = 5 with an adsorbent dose of 0.8 g.L−1, is mainly attributed to the high specific surface area of the eggshell used in this work. Adsorption kinetics are described by the pseudo-second-order model, in good agreement with the experimental data, and the sorption mechanism follows the isotherm model of Langmuir, characterized by the chemical adsorption of a homogeneous monolayer of Cd2+ on the surface of ES adsorbents. The desorption efficiency of cadmium ions is efficient in the presence of nitric acid. The outcomes provided by the study confirm the use of eggshell as an effective and inexpensive material, offering high efficiency for cadmium removal.

Aluminium Tertiary Industry Waste and Ashes Samples for Development of Zeolitic Material Synthesis

Wastes generated in large amounts have been recognized as sustainable sources of raw materials for the synthesis of adsorbents. The synthesis of zeolite through wastes recycling of two different ash sources (coal bottom ash and sugarcane waste ash) and industrial aluminum waste was evaluated. The molar ratio of SiO2/Al2O3 for zeolite 4A formation was achieved by the addition of aluminum waste from tertiary industry as aluminum source. Coal bottom ash and sugarcane waste ash were used as a source of both silica and alumina. The synthesized materials were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and cation exchange capacity (CEC). The analysis of the properties of the products demonstrates that the by-products can be used to produce zeolite A. The utilization of synthesized zeolites as adsorbent for cadmium removal from aqueous solution was conducted following the concept of implementation of utilization of waste materials as a component of the circular economy in the wastewater sector.

Evaluation of cadmium biosorption property of de-oiled palm kernel cake

Cadmium contamination is a global concern because of its widespread nature of polluting both biotic and abiotic components of ecosystem. Though many natural, chemical/synthetic components have been researched for remediation of cadmium, development of an eco-friendly, economic biosorbent still remains a challenge. Deoiled palm kernel cake (DOPC), a byproduct from palm-oil mills was investigated in the present study for its cadmium remediating capacity. DOPC was immobilized using sodium alginate polymer and biosorption studies were carried out using DOPC as adsorbent for removal of cadmium. Research revealed biosorption potential of DOPC and the optimum conditions for maximum biosorption of cadmium have been identified as 120 min of contact time, 150 rpm of agitation speed, pH 6 and 15 mg/L of initial cadmium concentration. Maximum percentage of adsorption was 99% by using 1.5 g/100 ml of adsorbent. The adsorption equilibrium data Biosorbent was characterized before and after adsorption by FTIR which showed the involvement of carboxyl, hydroxyl and amino-groups. Statement of novelty Cadmium pollution and the leading environmental problems is a global concern. Despite various attempts for development of different matrices for remediation of cadmium from contaminated samples, application of deoiled palm kernel cake (DOPC) as a biosorbent is not being explored. Present study provides quantitative data relating the richness of phytochemical repertoire DOPC possess, its resulting radical scavenging potential and its applications as an efficient, eco-friendly and economic alternative as a biosorbent matrix material for cadmium bio-remediation.

Improved recovery of cadmium from aqueous medium by alginate composite beads filled by bentonite and phosphate washing sludge

Alginate (AL)-based composite beads filled with bentonite (BE) and phosphate washing sludge (PS) have been prepared and used as low-cost adsorbents for removal of cadmium (Cd) from aqueous solution. Such composite beads were prepared by solvent mixing technique followed by a crosslinking reaction. The obtained humid beads were dried using two approaches, namely air drying (AD) and freeze-drying (FD) and then separately used as adsorbents. All the materials investigated in this study were analyzed in terms of their structural, textural, morphological, thermal properties as well as their chemical composition and size distribution. The adsorption capacities of the as-prepared freeze-dried and air-dried composite beads toward Cd ions were evaluated in batch experiments. To optimize the adsorption conditions, the effect of adsorbent dosage, equilibrium time, Cd concentration, initial pH and temperature was evaluated and compared. It was found that the adsorption capacities of BE- and PS-filled composite beads are higher than those determined with BE and PS. The performed adsorption studies showed that the adsorption equilibrium was reached within 180 min. The pseudo-second order model can be effectively used to evaluate the adsorption kinetics and the adsorption isotherms can also be well described by the Langmuir isotherm model with a maximum adsorption capacity of 54.27 and 53.24 mg/g for PS- and BE-filled composites, respectively. Moreover, Cadmium recovery was enhanced with temperature increase and the thermodynamics studies revealed that the adsorption processes were spontaneous and endothermic in nature.

Enhanced sorption capacity of a metal-dye system from water effluents by using activated industrial waste.

Activated coal fly ash (FA) treated with NaOH and hexadecyltrimethylammonium bromide (HDTMABr) was used as adsorbent for removal of cadmium(II) ions and rhodamine B (RB) from an aqueous solution. Characterization of fly ash and FA-HDTMABr were done using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The sorption equilibrium in the system was analysed using isotherm models, such as Freundlich, Langmuir, generalized Langmuir-Freundlich, Redlich-Peterson, Jovanović, extended Jovanović, Tóth, Frumkin-Fowler-Guggenheim, Fowler-Guggenheim-Jovanović-Freundlich, Temkin, Dubinin-Radushkevich, Halsey, Brunauer, Emmett and Teller. The evaluation of the fit of the isotherms studied experimentally was carried out by means of the reduced chi-square test and the coefficient of determination. The maximum monolayer adsorption capacity of the FA-HDTMABr was found to be 744 mg·g-1 and 666 mg·g-1 for Cd(II) and RB, respectively. The PFO, PSO, Elovich mass transfer, liquid film diffusion and intra-particle diffusion models were analysed. Sorption kinetics data were well fitted by the PSO model. The Elovich and intra-particle model also revealed that there are two separate stages in the sorption process, namely, external diffusion and intra-particle diffusion.

Schiff Base Anchored with Silver Nanoparticles as Effective Adsorbent for Removal of Cadmium(II) Heavy Metal from Industrial Wastewater

The current study deals with the examination of the capacity of Schiff base anchored with silver nanoparticles for removal of cadmium(II) ions from industrial wastewater. Schiff base was synthesized using refluxing of salicylaldehyde and 4-aminoantipyrine in alcoholic medium. The characterization of Schiff base were studied by elemental analysis, FTIR, NMR, UV-visible and mass spectral studies. The silver nanoparticles were synthesized using the chemical reduction method and characterized. Then, silver nanoparticles anchored to the Schiff base by suitable method and again characterized. Peanut shells were used as solid phase for removal of Cd(II) ions. The effects of several parameters to optimize the adsorption of Cd(II) ions on solid phase, including pH, contact time, initial metal ion concentration and adsorbent weight were investigated. The maximum removal efficiency of Cd(II) ions on solid phase using Ag nano@Schiff base was achieved under experimental conditions of pH 6 (% removal = 81%), contact time of 15 min (% removal = 93%), initial metal ion concentration of 0.5 ppm (% removal = 95%) and adsorbent weight of 3 mg (% removal = 89%). The results showed that extraction of Cd2+ on AgNPs@Schiff base follows Freundlich adsorption isotherm.

β-Cyclodextrin conjugated graphene oxide: A regenerative adsorbent for cadmium and methylene blue

This study describes an eco-friendly approach for the synthesis of β-cyclodextrin functionalized graphene oxide (βCD-GO) and its evaluation as adsorbent for removal of cadmium (Cd2+) and methylene blue (MB) from aqueous medium. Owing to a βCD mass loading of ~15.3% on GO sheets, the as-prepared nanocomposite displayed superior thermal stability. Moreover, in spite of its fairly low Brunauer–Emmett–Teller specific surface area of 14.24 m2 g−1, the βCD-GO composite demonstrated significantly high adsorption capacity toward both Cd2+ (117.07 mg g−1) and MB (323.98 mg g−1). The equilibrium data presented excellent fit to the Langmuir isotherm, implying monolayer adsorption of Cd2+ and MB onto βCD-GO. The molecular mechanisms involved in the uptake of these pollutants were ion-exchange, electrostatic, hydrophobic and π-π interactions. Further, the uptake of Cd2+ and MB on βCD-GO followed the pseudo-second order kinetics, and the rate of Cd2+ removal was faster than that of MB. Additionally, thermodynamic analysis revealed a spontaneous and endothermic nature of the adsorption process. Most importantly, the βCD-GO composite did not show any significant drop in adsorption efficiency even after three adsorption-desorption cycles. Overall, our preliminary findings suggest that βCD-GO merits further consideration for removal of dyes and heavy metals from wastewaters.

Adsorptive removal of cadmium from aqueous solutions using NiFe2O4/hydroxyapatite/graphene quantum dots as a novel nano-adsorbent

In this study, NiFe2O4/hydroxyapatite/graphene quantum dots (NiFe2O4/HAP/GQDs) as nano-adsorbent to remove cadmium (Cd2+) from aqueous solution were synthesized. This nano-adsorbent was depicted by some techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR). Adsorption studies were conducted to investigate the effect of contact time, pH, adsorbent dosage and initial cadmium ion concentration on removal efficiency. To determine the most fitting kinetic model, the suitability of pseudo-first-order and pseudo-second-order models was compared. The adsorption isotherm was described well by the Langmuir isotherm and maximum equilibrium uptake capacity (qe) was 344.83 mg g−1. Studies revealed that adsorption process is not a physical process and formation of complexes (bidentate and monodentate complexes) between—COO− and—OH functional groups on the surface of NiFe2O4/HAP/GQDs and Cd2+ ions may occur. In addition, the adsorbent can simply be removed by an ordinary filtration process.

Efficiency of calcium carbonate from eggshells as an adsorbent for cadmium removal in aqueous solution

Abstract The presence of heavy metals in water resources brings hazard to health and the environment considering that most of these cannot be degraded and may result in bioaccumulation in the food chain. Its removal from aqueous solution can relatively be done through adsorption, a known technique that efficiently reduces heavy metal concentration. This study investigated the applicability and efficiency of waste chicken eggshells as an adsorbent for the removal of Cadmium (Cd) heavy metal in aqueous solution. The adsorbent dose, contact time and initial concentration were the chosen variables of the study that were optimized through the Central Composite Design of the Response Surface Methodology using Design Expert 7.0 software. The result of the study showed that the chicken eggshells as an adsorbent could remove Cd in an aqueous solution up to 73%. The optimum adsorption capacity was 146 mg g−1 obtained at 150 mg L−1 initial concentration, 75 min contact time, 0.75 g adsorbent dose, and pH 6 at room temperature. Heterogeneous adsorption occurred during the process as revealed by isotherm studies with Freundlich model emerged having a higher coefficient of determination (R2 = 0.91) than the Langmuir model (R2 = 0.86). Overall, the study demonstrated that the chicken eggshell that is generally considered as wastes in large quantities could become an economically advantageous raw material for the removal of carcinogenic Cd from the water body.

Single and simultaneous adsorption of heavy metals onto groundnut shell biochar produced under fast and slow pyrolysis

Biochars produced from groundnut shells at the condition of slow and fast pyrolysis (GB350 and GB700) were used as adsorbents for removal of cadmium (Cd2+), mercury (Hg2+) and lead (Pb2+) ions from aqueous solution. Adsorption experiments were carried out at different solution pH, constant biochar dosage and particle size of 2 mm, variant metal ion concentrations, constant contact time and temperature to determine the adsorption efficiency. The removal efficiency of groundnut shell biochar was greater than 99.60% for Cd2+ under the three maximum contaminants limits. The GB700 was able to ascertain 100% removal efficiency for Cd2+ and Pb2+ in binary mixtures with concentrations of 0.04:0.10, 0.08:0.20 and 0.20:0.50 mg/l. The removal efficiency of GB350 was 100% for Pb2+ and Hg2+ except Cd2+ that showed 99.05, 99.46 and 99.69% at folds one, two and five of the ternary system, respectively. The maximum Langmuir capacity for mono-component system was 0.14 for Hg2+ and 0.18 mg/g for Pb2+, 0.09–0.56 mg/g for binary mixtures, 0.05–0.10 mg/g for ternary mixtures by GB350 and GB700, respectively. The results showed groundnut shell biochar can be used as a cost-effective and effective adsorbent for the removal of heavy metals from aqueous environment. Based on the results, further experiments should be carried out to examine the adsorption of the heavy metal contaminants at higher concentrations, a reduced biochar dosage and different contact time.

Retraction Note to: Adsorptive removal of cadmium from aqueous media using Posidonia oceanica biomass: equilibrium, dynamic and thermodynamic studies

Retraction Note to: Adsorptive removal of cadmium from aqueous media using Posidonia oceanica biomass: equilibrium, dynamic and thermodynamic studies

Adsorptive Removal of Cadmium (II) from Aqueous Solution by Multi-Carboxylic-Functionalized Silica Gel: Equilibrium, Kinetics and Thermodynamics

In the present study, the adsorption behavior of cadmium (II) ion from aqueous solution onto multi-carboxylic-functionalized silica gel (SG-MCF) has been investigated in detail by means of batch and column experiments. Batch experiments were performed to evaluate the effects of various experimental parameters such as pH value, contact time and initial concentration on adsorption capacity of cadmium (II) ion. The kinetic data were analyzed on the basis of the pseudo-first-order kinetic and the pseudo-second-order kinetic models and consequently, the pseudo-second-order kinetic can better describe the adsorption process than the pseudo-first-order kinetic model. Equilibrium isotherms for the adsorption of cadmium (II) ion were analyzed by Freundlich and Langmuir isotherm models, the results indicate that Langmuir isotherm model was found to be credible to express the data for cadmium (II) ion from aqueous solution onto the SG-MCF. Various thermodynamics parameters of the adsorption process, including free energy of adsorption (ΔG0), the enthalpy of adsorption (ΔH0) and standard entropy changes (ΔS0), were calculated to predict the nature of adsorption. The positive value of the enthalpy change and the negative value of free energy change indicate that the process is endothermic and spontaneous process.

Punica granatum (pomegranate) carpellary membrane and its modified form used as adsorbent for removal of cadmium (II) ions from aqueous solution

Punica granatum carpellary membrane (PGCM) has been chemically modified with 2,4 dinitrophenylhydrazine by one step reaction process. Pristine PGCM and modified Punica granatum carpellary membrane (MPGCM) have been employed as adsorbents for removal of cadmium (II) ions from aqueous solution. Modification on the surface of PGCM was characterized by Fourier transform infrared, scanning electron microscope, energy dispersive X-ray spectroscopy and X-ray diffraction techniques. Removal of Cd (II) ions was carried out at various optimized conditions i.e. adsorbent dose (20 mg/l), pH (7), contact time (2 h), and temperature (303 K). The Langmuir isotherm model was the best fit with a high value of regression coefficient (R 2 = 0.991–0.999) compared with the Freundlich and Temkin models. Langmuir maximum adsorption capacity for cadmium was found to be 111.11 mg/g for PGCM and 142.85 mg/g for MPGCM. Kinetics of adsorption of cadmium onto MPGCM was best described by pseudo-second-order kinetics model compared with pseudo-first-order. The negative value of free energy change showed that adsorption was highly spontaneous and favorable. Also the positive value of entropy and enthalpy showed that the process of adsorption was associated with increased randomness and endothermic in nature. Mechanism of removal of cadmium ions from water by MPGCM has also been explicated.