Cadmium In Solution Research Articles

Cadmium in bone cement induces necrosis and decreases the viability of residual osteosarcoma cells: A xenograft study.

The aim of this study was to show whether local application of cadmium-impregnated bone cement can induce apoptosis and decrease the viability of residual osteosarcoma (OS) cells in nude mice. K7M2 tumorigenic OS cell line was cultivated in vitro. The xenograft tumor model was formed by subcutaneously adding the tumor cells to athymic nude mice. Tumor was formed within 1 month. Then, mice were randomly assigned to five groups, each containing seven nude mice: control (group 1), wide resection (group 2), intralesional resection (group 3), intralesional resection + bone cement (group 4), and intralesional resection + cadmium embedded in bone cement (group 5). Tumor resection with 1 cm surgical margins was performed in the wide resection group. In intralesional resection groups, tumor tissue was resected with positive margins aiming to leave 15 mm3 of macroscopic tumor tissue. In group 3, the defect was left empty; groups 4 and 5 received bone cements prepared with saline and cadmium solutions, respectively. After the resection, mice were observed for 15 days and sacrificed. Next, surgical resection sites were evaluated histopathologically in each group. Recurrent tumor was formed in all mice in the wide resection group, and apparent progression of residual tumor was observed in groups 3 and 4. On the contrary, only a thin layer of residual tumor was observed around the bone cement in group 5. Histological evaluation revealed remarkable necrosis in group 5 and lowest viability compared to other groups. No systemic toxic effect related to cadmium was observed. Our data suggest that local application of cadmium in bone cement has a significant potential to increase tumor necrosis and decrease the viability of residual OS cells.

The Formation of Sediments of Porous Metals during the Radiation–Chemical Reduction of Pb2+ and Cd2+ Ions in Water Solution

When accelerated electrons were irradiated with aqueous solutions of cadmium and lead salts containing methyl alcohol, metal precipitates with densities of 1.17 and 1.1 g/cm3 were obtained and porosities of 86.5 and 90.3%, respectively, and greater surface area. The process of metal deposition was studied and the radiation–chemical yields were calculated, which amounted to (1.7 ± 0.2) × 10–2 and (3.4 ± 0.3) × 10–2 g per 1 kGy for cadmium and lead, respectively, and 1.56 ± 0.05 metal atoms per 100 eV of absorbed radiation energy. The developed method can be promising for obtaining precipitation of pure and amorphous metals from aqueous solutions of their salts, for developing technologies for treating water effluents containing toxic metals, as well as for using porous cadmium and lead in the manufacture of electrical devices.

Application of response surface methodology for optimization of cadmium removal by Aloe Vera/carboxylated carbon nanotubes nanocomposite-based low-cost adsorbent

In this research, Aloe Vera leaf powder (OAMP) was modified with carboxylated carbon nanotubes (CNTs-COOH) and the prepared nanocomposite was used as a novel low cost adsorbent for the removal of cadmium ions from aqueous solutions. The prepared OAMP/CNTs-COOH nanocomposite was characterized by fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Energy-dispersive x-ray spectroscopy (EDS) and Brunauer–Emmett–Teller (BET) analysis. The influence of operation parameters such as initial concentration of adsorbate, adsorbent dosage, contact time and pH of the cadmium solution on the cadmium adsorption process was studied by response surface methodology (RSM) optimization. The solid phase extraction (SPE) using OAMP/CNTs-COOH based-adsorbent was performed for the pre-concentration and matrix separation and inductively coupled plasma–mass spectrometry (ICP-MS) detector was used for measurement of cadmium ions concentration. The empirical adsorption data were fitted by Langmuir isotherm model. The value of maximum adsorption capacity was 46.95 mg g−1, indicating high efficiency of OAMP/CNTs-COOH nanocomposite in the adsorption process of Cd(II). The kinetic of the Cd(II) adsorption process was followed by Elovich kinetic model. The reported thermodynamic parameters designated that the adsorption of Cd(II) on the OAMP/CNTs-COOH was an endothermic and spontaneous process. The results revealed that OAMP/CNTs-COOH demonstrate enhanced adsorption performance in comparison with non-treated Aloe Vera.

Utilization of Hydroxyapatite from Tuna Fish Bone Waste as Adsorbent for Cadmium from Aqueous Solutions

This study aims to determine the performance of hydroxyapatite adsorbents from tuna bone waste against cadmium metal ion removal. Hydroxyapatite adsorbents have been activated physically (calcined at 500°C and 700°C) and chemically (using H3PO4). The adsorbent was then characterized using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). A batch experiment was conducted to study the effect of initial concentration and contact time on cadmium adsorption. The results of SEM and FTIR analysis showed that the best adsorbent was obtained from calcination results at 700°C. The observation shows that the contact time and initial concentration affect the efficiency of adsorption. The highest removal efficiency of cadmium was 86.28% with an adsorption capacity of 44.62 mg/g obtained at the contact time of 150 minutes and an initial concentration of cadmium 100 mg/L. The results of the isotherm study show that the adsorption equilibrium in the cadmium solution follows the Freundlich isotherm model with values R2 = 0.923, N = 9.4339, and KF = 7.92. The adsorption kinetics of cadmium adsorption followed the pseudo-second-order equation with values of K2 and qe at 0.021534 g.mg−1.min−1 and 47.61 mg/g, respectively. The results obtained indicate that hydroxyapatite from tuna bone waste is a promising alternative for cadmium adsorption.

Adsorption of lead and cadmium from aqueous solution by Gunungkidul zeolitic tuff, Indonesia

This study focuses on utilizing zeolitic tuff as a novel adsorbent for lead and cadmium solution. Two zeolitic tuff samples were obtained from Tegalrego and Bantengwareng village, Gunungkidul, Yogyakarta, Indonesia. Zeolitic tuff sample characterization was carried out by conducting microscopic and X-ray diffraction analysis, cation exchange capacity, and chemical measurement. Batch adsorption tests were carried out for the study of isotherms with the Langmuir model. The results of characterization showed that the Bantengwareng and Tegalrejo zeolitic tuff sample consist dominantly of mordenite mineral and other impurities. Bantengwareng zeolitic sample revealed had higher mordenite and smectite content compared to Tegalrejo zeolitic tuff sample which effects to the adsorption capacity. The batch adsorption test showed the adsorption ability of the Bantengwareng zeolitic tuff sample achieved for 76% of lead and 69% of cadmium; however, the Tegalrejo zeolitic tuff sample achieved for 51% of lead and 26% of cadmium. The result of isotherm study based on Langmuir equation revealed that the adsorption capacity of Bantengwareng and Tegalrejo zeolitic tuff samples has a value of 416.67, 384.61 and 277.77, 243.91 mg/g for lead and cadmium, respectively. The correlation coefficient based on Langmuir model varied from 0.866 to 0.956, which suggests that isotherm models fit very well. The reusability study revealed that the efficiency decreased reduce up to 30% after third cycles; however, the zeolitic tuff samples in study area are considered as part of its adsorption potential for lead and cadmium solution.

In Russian

The aim of this work is to study the influence of the chemical nature of grafted β-cyclodextrins side functional groups on chemically modified silica gels sorption affinity for cadmium, lead, and copper cations as the most typical water pollutants. Two organo-inorganic sorbents that differ only in the chemical nature of side functional groups of grafted β-cyclodextrin molecules wide edge were synthesized by chemical immobilization of mono-(6-O-(toluenesulfonyl))-β-cyclodextrins on the granular mesoporous silica gel surface. The obtained functionalized silica gels were characterized by IR and UV spectroscopy, chemical, elemental and derivatographic analysis, pH-metry, low-temperature nitrogen adsorption-desorption as well as sorption measurements. The results of studying the sorption of cadmium, lead, and copper cations from nitrate buffer solutions with pH = 2.0 were analyzed using the Lagergren kinetic model for pseudo-first and pseudo-second order processes, and the equilibrium sorption results were analyzed using the Langmuir and Freindlich models for homogeneous and heterogeneous surfaces. It has been found that only β-cyclodextrin-containing surface centers of chemically modified silica gels participate in the sorption of metal cations. The simultaneous formation of inclusion complexes of grafted β-cyclodextrin molecules with nitrate anions of the solution and mixed complexes of metal cations with side functional groups of the wide edge of immobilized cyclic oligosaccharides occurs during the interaction of synthesized silica gels with buffer solutions of cadmium, lead and copper nitrates. The sorption affinity of β-cyclodextrin-containing silica gel with secondary alcohol groups in the structure increases in the order Cd 2+ < Pb 2+ < Cu 2+ . The cation sorption sequence is opposite – Cu 2+ < Pb 2+ < Cd 2+ – for β-cyclodextrin-containing silica gel with side thiosemicarbazidoethyl groups. The change in the sorption specificity of functionalized silica gels to metal cations is interpreted from the standpoint of the theory of “soft” and “hard” acids and bases. The formation of “β-cyclodextrin ‒ nitrate-anion” inclusion complexes with a composition of 1:1 on the surface of chemically modified silica gels promotes metal cations sorption. The results obtained make it possible to predict the sorption specificity of β-cyclodextrin-containing silica materials and its directed change using various functional derivatives of β-cyclodextrin.

Thermal degradation of hard alloys of the niobiumcadmium system at low pressure

Due to the lack of data on the double film Nb-Cd system thermal stability, the effect of thermo-vacuum treatment of cadmium solid solutions in niobium, in intermetallic compound NbCd2 and in cadmium-based alloys on the structure of materials was studied. A step-by-step isochronous annealing at a temperature of 300 and 500°C and a pressure of 1·10-3 Pa was used as the research method followed by tracking changes in the composition and structure by comparing the diffractometric data before and after heat treatment. The amount of cadmium in the coating, the sublimation (evaporation) rate of cadmium from film coatings was determined based on the previously established dependence of the lattice parameter of the body-centered cubic lattice of solid solutions on the composition. As a result, the heating of film coatings (49.0 - 64.5 at % Cd) represented by solid solutions in high vacuum up to 300°C was founded to be accompanied by the onset of intense degradation of the crystalline niobium-cadmium system due to the diffusion of cadmium atoms to the solid phase-vapor interface and its subsequent sublimation. Coatings from the NbCd2 intermetallic compound which is a degenerate semiconductor and cadmium-based solid solutions (72.5 and 76.8 at % Cd) including the amorphized phase of the intermetallic compound, after exposure at this temperature are degraded due to the complete transfer of cadmium to the vapor phase by evaporation. Upon thermal exposure to a temperature of 200°C, the structure of solid solutions of cadmium in niobium and the NbCd2 intermetallic compound was stable.

Cadmium foliar application affects wheat Cd, Cu, Pb and Zn accumulation

Cadmium is toxic to plants, easily reaching unsafe levels for animal and human consumption. A greenhouse experiment investigated the effect of foliar-applied Cd on the accumulation and distribution of Cd, Zn, Cu and Pb in wheat (Triticum aestivum) grown in heavy metal-contaminated soil. Cadmium solutions (0, 10, 20, 30 and 40 mg L−1) were repeatedly sprayed on entire aboveground wheat plants during heading stage to medium milk development stage. Plant sample analyses after harvest indicated that both the biomass yield and grain yield were negatively affected by Cd application (p < 0.05); compared to controls, leaf and grain Cd concentrations increased 187–547% and 26.3–91.8%, respectively. However, grain Cd accumulation (concentration × yield) was not affected by Cd treatments (p > 0.05). Stem, leaf and glume Zn concentrations increased by less than 31%, while grain Zn concentrations were negatively affected by Cd treatments (3.4–34.4% lower than the control). Grain Cu concentrations were also negatively affected by Cd treatments, while grain Pb concentrations were similar between treatments. The antagonistic effect of Cd on grain Zn accumulation may mainly be due to competition for transporters and binding compounds in wheat leaves and stems. Preventing excess Cd from entering aboveground plant tissues should lessen negative plant and potentially animal/human health effects.

Carbon dioxide reduction under visible light: a comparison of cadmium sulfide and titania photocatalysts

Photocatalysts based on titania and solid solutions of cadmium and zinc sulfides with deposited metals (Pt, Ag) were compared in CO2 reduction under visible light. In the presence of titania- and cadmium sulfide-based photocatalysts, the dominant reduction products were CH4 and CO, respectively, due to different positions of the conduction band level for these semiconductors. The deposition of metals on the surface of both TiO2- and CdS-based samples increased the molar concentration of methane in the reaction products.

Emulsion Stability Tes and Effect of HNO3 Concentration in the Internal Phase on Cadmium Ion Extraction using Liquid Membrane Emulsion Technique

Study on the emulsion stability and cadmium ion extraction tests was performed using the liquid membrane emulsion technique. This study aimed to determine the emulsion stability between the membrane phase and the internal phase with the variation of the ratio (2:1, 1:1, 2:3, and 1:2), and to determine the maximum conditions of cadmium ion extraction in a solution including the various concentration of HNO3 solution 1, 1.5, 2, and 2.5 M. This study is a laboratory experimental method using benzoyl acetone compound as cation carrier, kerosene as membrane phase, HNO3 solution as the internal phase, span-20 and span-80 as surfactants, and cadmium solution as the sample solution. Cadmium ion concentration in the external phase was determined by UV-VIS spectrophotometer. The result showed that the emulsion stability test which produced the most stable emulsion was in the ratio of the membrane phase and the internal phase 1:1. In addition, the concentration of the HN03 solution resulted in a maximum extraction percentage of 1.5 M with an extraction percentage was 95.28%.

Porphyrin-based metal-organic framework and polyvinylchloride composites for fluorescence sensing of divalent cadmium ions in water

Toxic metal contamination of Earth’s scarce fresh water sources creates a persistent necessity for the development of new materials and techniques to detect metal ions in water. Cadmium in particular is released into the environment by ubiquitous phosphate fertilizers, and chronic cadmium exposure can lead to internal organ damage and bone weakening. The present study shows that NU-902, a water stable zirconium porphyrin-based metal-organic framework (MOF), is fluorescent and undergoes a detectable change in photoluminescent emission properties in the presence of divalent cadmium ions. The MOF displays detectable fluorescence quenching in the presence of cadmium at levels of 0.3 ppb, far below concentrations deemed acceptable by most regulatory agencies, indicating its potential as a fast, reliable chemosensor for cadmium in drinking water. After establishing the fluorescent properties of the powder MOF, it was immobilized within plasticized polyvinylchloride (PVC) to create a membrane with potential for easy in field use as a sensor. The MOF-PVC composite displayed fluorescence quenching within five minutes of exposure to an aqueous cadmium solution. This study shows the potential use of a water stable porphyrin-based MOF for fast, sensitive detection of metal ion contamination in water in powder form, as well as in a polymer composite.

Geochemical behavior and stabilization of spent sulfate-reducing biofilter mixtures for treatment of acid mine drainage

Sulfate-reducing biofilters operated in semi-passive or passive modes constitute an approach of choice for treatment of acidic mining effluents. The aim of the present study involved examining the behavior of biofilters after use based on two modes of management, namely in unsaturated and saturated media. Two acidophilic biofilters were investigated following their mixing with different alkaline industrial residues (i.e., 25% fly ash biomass or 30% aluminum red mud, or 10% kiln dust). Percolation column tests for a 330-d period indicated that aluminum red mud and lime kiln dust (to a lesser extent) are efficient materials for maintaining the pH neutrality of biofilter leachate and to reduce release of metals (i.e., Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in spent biofilters. The storage of biofilters in saturated mode also makes it possible to preserve the reducing conditions of the environment and neutrality of the pH and to limit the dissolution of the solution of cadmium, nickel and zinc. Conversely, increased iron release is noted under saturated conditions. Finally, the results indicated that a mixture of biofilters and lime kiln dust is preferable to surface addition of these to reduce the loss of metals in leachates.

Alleviation of aluminum and cadmium toxicity by biochar and its potential toxicity to sorghum

Biochar has been used as an alternative in organic wastes management and to alleviate trace elements toxicity. The aim of this research was to use a rapid and simple test to detect the potential toxic effects of biochar and its ability to alleviate aluminum and cadmium toxicity to seeds and seedlings of Sorghum bicolor L. Two experiments were carried out in Petri dishes with two different biochars where sorghum seeds were exposed to aluminum (experiment 1) and cadmium (experiment 2) solutions. The experimental designs were completely randomized, with five doses of aluminum or cadmium in aqueous solution (0, 0.5, 1, 2, and 4 mmol/L of Al or Cd), combined with or without the addition of 0.25 g of biochar from sugarcane bagasse or from sewage sludge. Compared to treatments without biochar, in the treatments with biochar, higher seed germination rate and growth of sorghum seedlings were obtained. Moreover, the biochars were not toxic to sorghum and they decreased the toxicity of aluminum and cadmium, mainly the biochar from sewage sludge that presented higher pH and greater occurrence of functional groups in its particles.

Interaction of radionuclide 131I and cadmium chloride in an alternative bioassay with Artemia franciscana evaluated by a digital record

The interaction of radionuclide 131I and cadmium chloride was investigated by an alternative bioassay using the crustaceans Artemia franciscana. Fifty individuals were placed in each Petri dish. Due to radiation protection, evaluation of the experiment was performed using digital recordings taken by a camera. In the group containing a cadmium solution with an added radionuclide with a volumetric activity of 32 MBq·l-1, the lethality was significantly lower than in the group containing only a cadmium solution of 0.250 mmol·l-1. In the cadmium solution group and higher volumetric activity of radionuclide 131I (370 MBq·l-1), the lethality was significantly higher than in the control group, which demonstrated a synergistic effect. It was found that lethality was lower in the group containing only radionuclide 131I with a volumetric activity of 138 MBq·l-1 than in the control group. This result supports the theory of radiation hormesis.

Effects of cadmium toxicity on sesame seed germination explained by various nonlinear growth models

This experiment was conducted to evaluate the effects of cadmium toxicity on the seed germination properties of sesame cultivars (Halil, Nazok Shakhei, Oltan, and Yellow White) using non-linear growth models. Seeds were germinated in petri dishes (90 mm diameter), with a double layered of filter paper soaked in distilled water as control treatment or cadmium (CdSO4) solutions in concentrations of 0, 100, 200, 400, 600, 800 and 1000 ppm. Each treatment was replicated four times and included 50 seeds in each petri dishes. Hyperbolastic growth models for the description of seed germination data were compared to Richards, Weibull, Logistic and Gompertz models. Our results revealed that all studied cultivars were germinated at the cadmium-polluted germination medium to a maximum of 200 ppm without reduction in germination fraction, while seed germination rate was decreased at this concentration compared to 0 and 100 ppm. Increasing cadmium concentration resulted in the germination fraction reduction from 1 to 0.4 at the 400 ppm. The recommended hyperbolastic growth model was type III or (H3) as it provided the best model with the lowest Corrected Akaike Information Criterion for cv. Halil (AICc = −14.6) and cv. Nazok Shakhei, (AICc = −14.2).

Application of fuzzy modeling and response surface methodology for optimization of cadmium uptake by colpomenia sinosa

The optimum conditions for the removal of cadmium as heavy and toxic metals via a biomass were investigated in this program. The biomass was prepared from an eco-friendly, native, and low-cost algae microorganism, e.g., Colpomenia sinuosa. The cadmium uptake involved the biosorption process onto the cell wall of the Colpomenia sinuosa. The experiments were carried out on the five different parameters of temperature, algae biomass dosage, the initial cadmium concentration, pH of the cadmium solution, and contact time for interval times of cadmium of the biomass surface. The design of the experiment (DOE) was done for different conditions. The optimum conditions were compared via two optimization methods. Both the response surface methodology (RSM) and fuzzy modeling were treated with experimental data. The contour maps were planned for understanding the effects of two interactive factors. The combined effects of pH-temperature, pH-contact time, and algae biomass dosage-temperature were plotted for cadmium uptake.

Acceleration and centralization of a back-diffusion process: Effects of EDTA-2Na on cadmium migration in high- and low-permeability systems

Pollutant accumulation in the low-permeability zones (LPZs) in groundwater systems is regarded as a secondary source, and its consequent back-diffusion can extend the timeframe of pump-and-treat remediation. However, the bioavailability and mobility of heavy metals and the medium characteristics can be changed during the process. This study investigated the accumulation and back-diffusion law of toxic metals and the effects of ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) on them by implementing a series of tank experiments. In these experiments, a cadmium solution was injected first, and deionized water or EDTA-2Na constantly washed the system consisting of different medium layers. The experimental results showed that the cadmium breakthrough curves had some concentration gradient reverse points where the curves fluctuated with elution by deionized water, which did not exist when EDTA-2Na was the eluent. In these scenarios, the mass of accumulated cadmium in the media before elution was large, with a value of 931 mg (153 mg/kg), when the low-permeability medium was clay. However, when EDTA-2Na was injected together with cadmium, the value dropped to 319 mg (52.3 mg/kg), greatly reducing the cadmium accumulation. Additionally, the use of EDTA-2Na as an eluent resulted in the appearance of a secondary peak in the breakthrough curve, showing that EDTA-2Na accelerated and centralized the back-diffusion. Notably, the reduced cadmium accumulation in LPZs with the elution by EDTA-2Na was partly due to a reduced adsorption capacity of the clay minerals. The above results can advance the technology related to pump-and-treat remediation.

A comprehensive study on the removal of Cd(II) from aqueous solution on a novel pentetic acid-clinoptilolite nanoparticles adsorbent: Experimental design, kinetic and thermodynamic aspects

Synergistic effects of ion exchange and complexation in Cd(II) removal was studied by the modification of nanoparticles of clinoptilolite zeolite (NCP) by pentetic acid (diethylenetriaminepentaacetic acid: DTPA) as a family of EDTA. XRD, FT-IR, BET, TG-DTG, and SEM-EDX were used for the characterization of the NCP and NCP-DTPA. The interactions of solution pH, NCP-DTPA dosage, concentration of cadmium solution and contact time were studied by Response Surface Methodology (RSM). The pH- adsorbent dosage and pH-CCd interactions had the most important roles in the Cd(II) removal. Both Langmuir and Freundlich isotherms can model the removal results. The qm and KL were about 138.9 (mg g−1) and 0.0007 (L mg−1) for the Langmuir isotherm. The values of 1.8 and 1.06 were obtained for n and KF as Freundlich constants, respectively. The results can be well modeled by the pseudo-second-order kinetics model (r2 = 0.9986) for describing the kinetics of the process. The best run included the adsorbent dose: 0.2 g L−1, pH: 5.9, CCd: 985 mg L−1 and 205 min contacting time.

Removal of cadmium in wastewater through geopolymeric materials based on pumice.

Heavy metal pollution in the effluent water due to industrial waste product of various economic activities is not adequately regulated in Colombia, this is because the agencies do little control track discharge and easily granting environmental licenses. As a result of this little regulation currently they do not have updated figures that provide real information on the amount of waste that ends up in the resort, causing health effects of living beings. In the tanning industry, in particular, there cadmium residual concentration higher than the maximum allowed by the Ministry of the environment. This work considers the use of a geopolymeric material based on pumice stone, to capture cadmium ions present in wastewater and thus reduce its concentration in the water resource in order to reduce the population’s exposure to diseases that are associated with accumulation of cadmium in the body. The synthesis of geopolymer began from the alkaline activation of pumice stone with commercial sodium silicate, the use of sand:pumice stone in a 1:1 ratio and 31 hours of reaction, these proportions were defined in a previously work by the authors. The morphological and crystallographic characterization of the sorbent geopolymeric material was performed by scanning electron microscopy and X-ray diffraction. To assess the sorption process, a study of the geopolymer’s contact time with a known solution of cadmium was performed. Cadmium concentration was determined using atomic absorption spectroscopy and the geopolymer was characterized after removal.

Adsorption characteristics of Cd(II) and Ni(II) from aqueous solution using succinylated hay

An environmentally friendly organic biosorbent was fabricated using hay by succinylation. Metallic cation adsorption tests were performed using synthetic nickel(II) and cadmium(II) solutions to simulate heavy-metal recovery from aqueous solution. The adsorption efficiency was greater than 98% for both cadmium and nickel ions when the biosorbent concentration was 5.0 g/L and the initial metal concentrations were 50 mg/L. The surface of the biosorbent was characterized using Fourier transform infrared spectroscopy to investigate the changes in the surface functional groups. The functional groups changed according to the surface treatment, resulting in an effective biosorbent. The kinetics of the metals adsorption revealed that the reactions are pseudo-second order, and the adsorption isotherm well followed the Langmuir model. The maximum adsorption capacities predicted by the Langmuir model were 75.19 mg/g and 57.77 mg/g for cadmium and nickel, respectively. The fabricated biosorbent was regenerated using NaCl multiple times, with 2.1% for Cd and 4.0% for Ni in adsorption capacity after three regeneration cycles. The proposed biosorbent can be a good alternative to resin or other chemical adsorbents for heavy-metal recovery in metallurgical processing or municipal water treatment.