Acacia nilotica L. Bark Removes Toxic Elements from Solution: Corroboration from Toxicity Bioassay Using Salix viminalis L. in Hydroponic System

The present investigation deals with the advantages and potential of the Acacia nilotica bark as an adsorbent of toxic metals. Bark (1 g) when added to 100 ml of aqueous solution containing 10 μg ml^-1 metal solution exhibited different metal adsorption values for different metals. The order of metal adsorption being Cr ≥ Ni > Cu > Cd > As > Pb. A similar trend of metal adsorption was observed when the bark is reused (1^st recycle) Cr> Ni > Cu > Cd > Pb and also in the column sorption. In order to verify the metal removal property of A. nilotica bark, toxicity bioassay with Salix viminalis stem cuttings in hydroponic system augmented with Cd, Cr, and Pb together with A. nilotica bark powder was carried out. The results of toxicity bioassay confirmed the metal adsorption property of the bark powder. The functions of toxicity studies include leaf area, root length and number of new root primordia produced per stump. The leaf area, root length, and the number of new root primordia increased considerably in the presence of A. nilotica bark. The order of metal toxicity for leaf area and new root primordial is Cd > Cr > Pb. However, for root length the order of metal toxicity is Cr > Cd > Pb. The metal budgets of the leaf and root confirmed that the bark powder had adsorbed substantial amount of toxic metals and thus alleviates the toxicity imposed by the various tested elements. Hence, the utility of A. nilotica bark in developing and designing innovative technology for the clean up of toxic elements in aqueous solutions and possible scope for its use in phytoremediation are discussed.     

Heavy metal uptake capacity of fresh water algae (Oedogonium westti) from aqueous solution: A mesocosm research

The green macroalgae present in freshwater ecosystems have attracted a great attention of the world scientists for removal of heavy metals from wastewater. In this mesocosm study, the uptake rates of heavy metals such as cadmium (Cd), nickel (Ni), chromium (Cr), and lead (Pb) by Oedogonium westi (O. westti) were measured. The equilibrium adsorption capabilities of O. westti were different for Cd, Ni, Cr, and Pb (0.974, 0.418, 0.620, and 0.261 mgg^–1, respectively) at 18°C and pH 5.0. Furthermore, the removal efficiencies for Cd, Cr, Ni and Pb were observed from 55–95%, 61–93%, 59–89%, and 61–96%, respectively. The highest removal efficiency was observed for Cd and Cr from aqueous solution at acidic pH and low initial metal concentrations. However, the removal efficiencies of Ni and Pb were higher at high pH and high concentrations of metals in aqueous solution. The results summarized that O. westti is a suitable candidate for removal of selected toxic heavy metals from the aqueous solutions.     

Impact of Humin on Soil Adsorption and Remediation of Cd(II), Pb(II), and Cu(II)

In situ immobilization constitutes a promising technology for the mitigation of contaminants, through the reduction of metal bioavailability and mobility. This study investigated the adsorption isotherms and kinetic characteristics of humin extracted from peat soils. We also studied the influences of the pH, ionic strengths, and soluble organic matter concentrations of soil solutions on the adsorptive properties of humin, and compared its ability to detoxify potentially toxic metals in both actual and simulated soil solutions. The study results indicated that humin contains a massive population of oxygen-containing functional groups. Its adsorption capacity for Pb(II) was greater than that for Cu(II), which exceeded that for Cd(II). The adsorption of humin for Pb(II) conformed to the Freundlich model, while the adsorption of humin for Cd(II) and Cu(II) followed the Langmuir model. The adsorption kinetics of humin with respect to potentially toxic metals aligned well with second-order kinetics equations. As the pH was elevated, the potentially toxic metal adsorption by humin increased rapidly. Electrolyte ions and tartaric acids in solution both inhibited the adsorption of potentially toxic metals by humin, and its ability to inactivate potentially toxic metals. This was shown to be improved in actual field soil solutions in contrast to simulated soil solutions.     

Characterization of Aqueous Pb(II) and Cd(II) Biosorption on Native and Chemically Modified Alstonia macrophylla Saw Dust

This study was conducted in order to understand the mechanism of Cd and Pb adsorption in aqueous solutions by raw and modified saw dust (SD) of Alstonia macrophylla. The biosorbent was characterized by Boehm titration, specific surface area, scanning electron microscopy (SEM), X-ray energy dispersion (EDAX), and Fourier transform infrared (FTIR) analyses. SD was treated using organic acids and bases. Batch studies were conducted for raw and modified SD to determine the effect of initial concentration, pH, ionic strength, and contact time on metal adsorption. The specific surface area and total basic and acidic groups of SD were 77 m²/g and 1521 and 2312 μmol/g, respectively. The adsorption of both metals onto SD was pH dependent. No ionic strength dependency was observed in adsorption of Cd and Pb at pH >6, indicating inner sphere surface complexation. Monolayer adsorption is dominant in both metal sorptions by SD. Furthermore, there is no competition between metals on adsorption and raw SD was found to be suitable for removal of Cd and Pb as compared to organic acid– or base-treated SD. Maximum adsorption capacity of SD for Cd and Pb were 30.6 and 204.2 mg/g, respectively. Results indicate that the A. macrophylla SD can be considered as a potential material for metal ion removal from wastewater.     

Equilibrium isotherm studies for the uptake of cadmium and lead ions onto sugar beet pulp

The adsorption of Cd2+ and Pb2+ on sugar beet pulp (SBP), a low-cost material, has been studied. In the present work, the abilities of native (SBP) to remove cadmium (Cd2+) and lead (Pb2+) ions from aqueous solutions were compared. The (SBP) an industrial by product and solid waste of sugar industry were used for the removal of Cd2+ and Pb2+ ions from aqueous water. Batch adsorption studies were carried out to examine the influence of various parameters such as initial pH, adsorbent dose, initial metal ion concentration, and time on uptake. The sorption process was relatively fast and equilibrium was reached after about 70 min of contact. As much as 70-75% removal of Cd2+ and Pb2+ ions for (SBP) are possible in about 70 min, respectively, under the batch test conditions. Uptake of Cd2+ and Pb2+ ions on (SBP) showed a pH-dependent profile. The overall uptake for the (SBP) is at a maximum at pH 5.3 and gives up to 46.1 mg g(-1) for Cd2+ and at pH 5.0 and gives 43.5 mg g(-1) for Pb2+ for (SBP), which seems to be removed exclusively by ion exchange, physical sorption and chelation. A dose of 8 gL(-1) was sufficient for the optimum removal of both the metal ions. The Freundlich represented the sorption data for (SBP). In the presence of 0.1M NaNO3 the level of metal ion uptake was found to reach its maximum value very rapidly with the speed increasing both with the (SPB) concentration and with increasing initial pH of the suspension. The reversibility of the process was investigated. The desorption of Cd2+ and Pb2+ ions which were previously deposited on the (SBP) back into the deionised water was observed only in acidic pH values during one day study period and was generally rather low. The extent of adsorption for both metals increased along with an increase of the (SBP) dosage. (SBP), which is cheap and highly selective, therefore seems to be a promising substrate to entrap heavy metals in aqueous solutions.     

Synergistic Removal of Pb(II), Cd(II) and Humic Acid by Fe3O4@Mesoporous Silica-Graphene Oxide Composites

The synergistic adsorption of heavy metal ions and humic acid can be very challenging. This is largely because of their competitive adsorption onto most adsorbent materials. Hierarchically structured composites containing polyethylenimine-modified magnetic mesoporous silica and graphene oxide (MMSP-GO) were here prepared to address this. Magnetic mesoporous silica microspheres were synthesized and functionalized with PEI molecules, providing many amine groups for chemical conjugation with the carboxyl groups on GO sheets and enhanced the affinity between the pollutants and the mesoporous silica. The features of the composites were characterized using TEM, SEM, TGA, DLS, and VSM measurements. Series adsorption results proved that this system was suitable for simultaneous and efficient removal of heavy metal ions and humic acid using MMSP-GO composites as adsorbents. The maximum adsorption capacities of MMSP-GO for Pb(II) and Cd (II) were 333 and 167 mg g⁻¹ caculated by Langmuir model, respectively. HA enhances adsorption of heavy metals by MMSP-GO composites due to their interactions in aqueous solutions. The underlying mechanism of synergistic adsorption of heavy metal ions and humic acid were discussed. MMSP-GO composites have shown promise for use as adsorbents in the simultaneous removal of heavy metals and humic acid in wastewater treatment processes.     

蛋白核小球藻对Pb(Ⅱ)和Cd(Ⅱ)的生物吸附及其影响因素

藻类吸附作用影响重金属在水生生态系统中的迁移过程及其环境行为。同时,利用藻类吸附能力是修复重金属污染水体和重金属废水处理的一项清洁、廉价和高效的技术。测定了蛋白核小球藻对Pb2+和Cd2+的吸附和脱附动力学,表明吸附是快速表面过程,吸附4 h后基本达到平衡,不易脱附。研究了蛋白核小球藻对Pb2+和Cd2+的吸附热力学,绘制了吸附等温线,并用Langmuir模型进行拟合,相关系数R2分别为0.9906和0.9827,计算得到最大吸附量分别为0.373 mmol Pb/g和0.249 mmolCd/g。考察了pH值、离子强度和温度等环境因素对蛋白核小球藻吸附Pb2+和Cd2+的影响。结果表明,蛋白核小球藻对Pb2+和Cd2+的吸附量在pH值5.0—6.0之间达到最大值,并随着溶液离子强度的增加而降低,随着溶液温度的升高而增加。温度的影响还表明,蛋白核小球藻对Pb2+和Cd2+的吸附是吸热过程。实验还考察了水体环境中普遍存在的溶解性有机质主要成分-富里酸的影响,表明富里酸会抑制蛋白核小球藻对Pb2+和Cd2+的吸附,重金属离子浓度较低时的抑制效果更明显,最大抑制率分别达到了34.2%和34.9%。由于其对重金属的较高吸附量和吸附本身快速完成的特性,蛋白核小球藻有望成为较理想的生物吸附剂,在重金属污染水体的生物修复及废水处理中发挥重要作用。     

Heavy metal biosorption by biomass of Ochrobactrum anthropi producing exopolysaccharide in activated sludge

The removal of chromium, cadmium and copper, toxic metals of high environmental priority due to their toxicity, from dilute aqueous solutions has been studied in the present work, applying a dead exopolysaccharide producing bacterium, Ochrobactrum anthropi, isolated from activated sludge. Particularly, the effect of pH, metal concentration and the effects of contact time were considered. Optimum adsorption pH values of chromium(VI), cadmium(II) and copper(II) were 2.0, 8.0 and 3.0 respectively. Experimental results also showed the influence of initial metal concentration on the metal uptake for dried biomass. Both the Freundlich and Langmuir adsorption models were suitable for describing the short-term biosorption of chromium(VI), cadmium(II) and copper(II) by O. anthropi.     

Biosorption of lead(II), cadmium(II), copper(II) and nickel(II) by anaerobic granular biomass

Biosorption is potentially an attractive technology for treatment of wastewater for retaining heavy metals from dilute solutions. This study investigated the feasibility of anaerobic granules as a novel type of biosorbent, for lead, copper, cadmium, and nickel removal from aqueous solutions. Anaerobic sludge supplied from a wastewater treatment plant in the province of Quebec was used. Anaerobic granules are microbial aggregates with a strong, compact and porous structure and excellent settling ability. After treatment of the biomass with Ca ions, the cation exchange capacity of the biomass was approximately 111 meq/100 g of biomass dry weight which is comparable to the metal binding capacities of commercial ion exchange resins. This work investigated the equilibrium, batch dynamics for the biosorption process. Binding capacity experiments using viable biomass revealed a higher value than those for nonviable biomass. Binding capacity experiments using non-viable biomass treated with Ca revealed a high value of metals uptake. The solution initial pH value affected metal sorption. Over the pH range of 4.0-5.5, pH-related effects were not significant. Meanwhile, at lower pH values the uptake capacity decreased. Time dependency experiments for the metal ions uptake showed that adsorption equilibrium was reached almost 30 min after metal addition. It was found that the q(max) for Pb2+, Cd2+, Cu2+, and Ni2+ ions, were 255, 60, 55, and 26 mg/g respectively (1.23, 0.53, 0.87, and 0.44 mmol/g respectively). The data pertaining to the sorption dependence upon metal ion concentration could be fitted to a Langmiur isotherm model. Based on the results, the anaerobic granules treated with Ca appear to be a promising biosorbent for removal of heavy metals from wastewater due to its optimal uptake of heavy metals, its particulate shape, compact porous structure, excellent settling ability, and its high mechanical strength.     

Microbial and plant derived biomass for removal of heavy metals from wastewater

Discharge of heavy metals from metal processing industries is known to have adverse effects on the environment. Conventional treatment technologies for removal of heavy metals from aqueous solution are not economical and generate huge quantity of toxic chemical sludge. Biosorption of heavy metals by metabolically inactive non-living biomass of microbial or plant origin is an innovative and alternative technology for removal of these pollutants from aqueous solution. Due to unique chemical composition biomass sequesters metal ions by forming metal complexes from solution and obviates the necessity to maintain special growth-supporting conditions. Biomass of Aspergillus niger, Penicillium chrysogenum, Rhizopus nigricans, Ascophyllum nodosum, Sargassum natans, Chlorella fusca, Oscillatoria anguistissima, Bacillus firmus and Streptomyces sp. have highest metal adsorption capacities ranging from 5 to 641 mg g(-1) mainly for Pb, Zn, Cd, Cr, Cu and Ni. Biomass generated as a by-product of fermentative processes offers great potential for adopting an economical metal-recovery system. The purpose of this paper is to review the available information on various attributes of utilization of microbial and plant derived biomass and explores the possibility of exploiting them for heavy metal remediation.     

Removal of heavy metals from industrial wastewaters by adsorption onto activated carbon prepared from an agricultural solid waste

Activated carbon was prepared from coirpith by a chemical activation method and characterized. The adsorption of toxic heavy metals, Hg(II), Pb(II), Cd(II), Ni(II), and Cu(II) was studied using synthetic solutions and was reported elsewhere. In the present work the adsorption of toxic heavy metals from industrial wastewaters onto coirpith carbon was studied. The percent adsorption increased with increase in pH from 2 to 6 and remained constant up to 10. As coirpith is discarded as waste from coir processing industries, the resulting carbon is expected to be an economical product for the removal of toxic heavy metals from industrial wastewaters.     

Assessment of willow (Salix sp.) as a woody heavy metal accumulator: field survey and in vivo X-ray analyses

Trees that accumulate metals are important plants for restoring contaminated soil because of their high biomass. In our previous study, we discovered that Salix miyabeana has the capability to take up high levels of Cd, and identified the several accumulation sites of the endogenous metals in the leaf parts of plants. To analyze the detailed localization of Cd in apoplastic and symplastic compartments in S. miyabeana, synchrotron radiation-based micro X-ray fluorescence (SR-μ-XRF) analysis and micro X-ray absorption near edge structure (μ-XANES) measurements were performed on beam line 37XU of the SPring-8 (Hyogo, Japan). The two-dimensional metal distribution of segments of young stems was obtained by μ-XRF with approximately 2 μm(2) X-ray beams and showed the predominant localization of Cd in the apoplastic region. μ-XANES analyses suggest that the apoplastic detoxification of Cd in willow depends on Cd-oxygen, but not on Cd-sulfur, interaction. S. miyabeana growing near an old mining site in Japan was then examined to evaluate the metal accumulating ability of this plant in the field. The metal concentration in the leaves of the plants was compared to that in the soil and enrichment factors (EFs) were calculated for Cu, Zn, Cd and Pb. Results showed efficient removal of Cd and Zn from the contaminated sites by the willow plants. In order to discuss the combined and long-term effect of multiple heavy metals on S. miyabeana grown in soil, variable-pressure scanning electron microscopy fitted with energy dispersive X-ray analysis (VPSEM-EDX) and SR-μ-XRF was used to characterize the serration of leaves. The combination of 2D elemental images revealed metal accumulation in the tip cells in serrations without any exudation of heavy metals from the hydathodes.     

Cadmium, Zinc, Copper, Silver and Chromium(III) removal from wastewaters by Sphaerotilus natans

Living cells of Sphaerotilus natans are used for heavy metal's (Cd, Zn, Cu, Ag, and Cr) removal from aqueous solutions simulating the polluting power of acid industrial wastewaters. At low metal concentrations (<25?mg/l) this microorganism is able to remove within 8–15 days Cd, Zn, Cu, and Ag with excellent yields (from 81 to 99%) often increasing with starting metal concentration. The yield observed for Cr(III) removal, never exceeding 60%, is not appreciably influenced by the starting biomass level; in addition, the time necessary to reach the equilibrium concentration is always remarkably longer (>30 days) than for the other metals. At much higher concentrations, the removal of all the metals is strongly affected in terms of both yield reduction and increase in the time necessary to reach the equilibrium concentrations. Under the hypothesis of mass transfer limitation, the kinetic study of batch runs suggests that metal diffusion from the bulk to the surface of S. natans clumps could be responsible not only for the simple biosorption of the tested metallic micronutrients or abiotic metals, but even for the cell penetration by ions of biological significance, like Mg²⁺ and Fe³⁺.     

Removal of cadmium from aqueous system by shelled Moringa oleifera Lam. seed powder

The present study explores the unexploited sorption properties of the plant Moringa oleifera Lam. for decontamination of Cd at laboratory scale. Sorption studies using standard practices were carried out in batch experiments as functions of biomass dosage, contact time, metal concentrations, particle size and pH. Percentage sorption in each case was computed on the basis of Cd estimation using a planar NaI (TI) detector coupled to a 4K MCA (Canberra Accuspec Card with PC-AT 386). The adsorption data accurately in a Freundlich isotherm. Sorption studies resulted in the standardization of optimum conditions for removal of Cd (85.10%) as follows: biomass dosage (4.0 g), metal concentration (25 microg/ml), contact time (40 min) and volume of the test solution (200 ml) at pH 6.5. Fourier transform infrared (FTIR) spectrometry highlighted amino acid-Cd interactions responsible for sorption phenomenon. The findings open up new avenues in the removal of toxic metals by shelled Moringa oleifera seeds (SMOS) from water bodies as low cost, domestic and environmentally friendly safe technology.     

Spontaneous Cr(VI) and Cd(II) biosorption potential of native pinnae tissue of Pteris vittata L., a tropical invasive pteridophyte

Heavy metal pollution is a prevalent and critical environmental concern. Its rampancy is attributed to indiscriminate anthropogenic activities. Several technologies including biosorption have been continuously researched upon to overcome the limitations of the conventional method of treatments in removal of heavy metals. Biosorption technology involves the application of a biomass in its nonliving form. Pteris vittata L., a pteridophyte, considered as an invasive weed was investigated in the present study as a potential decontaminant of toxic metals, Cr(VI) and Cd(II). The adsorption capacity of the biosorbent for Cr(VI) and Cd(II) under equilibrium conditions was investigated. The morphology, elemental composition, functional groups, and thermal stability of the biosorbent before and after metal loading were evaluated. At 303?K and an equilibrium time of 120?min, the maximum loading of Cr(VI) on the biosorbent was estimated to be 166.7?mg/g at pH 2 and Cd(II) to be 31.3?mg/g at pH 6. Isotherm models, kinetic studies, and thermodynamic studies indicated the mechanisms, chemisorption, ion exchange and intraparticle diffusion, controlling the Cr(VI) and Cd(II) uptake, respectively. The interactive effect of multi-metal ions in binary component systems was synergistic for Cd(II) uptake. The results validate the toxic metal removal potency of the biosorbent.     

The effect of soil type and degree of metal contamination upon uptake of Cd,Pb and Cu in bush beans (Phaseolus vulgaris L.)

Summary Five soils of increasing specific surface area (SSA) were loaded to five levels of contamination with Cd, Pb and Cu, and bean plants (Phaseolus vulgaris L.) were grown on the soils for 30 days. A linear correlation was found between the concentration of Cd in the soil solutions and the amount absorbed by the plant per gram root material for four out of the five soils, and, in the case of Cu, for all five soils. Quantitatively, there was insufficient Cd or Cu in the soil solution to account for plant uptake of these metals. The amount of Cd absorbed by plants could also be related to the adsorption density (concentration/SSA soil) of the metal in four of the five soils, whereas the Cu content of plants could be related to the adsorption density of all five soils. It is thought that the metals were removed from the soil solution by root absorption and replenished by metal cations adsorbed onto surface sites in the soil. Consideration of the adsorption density of these metals in the soil may be a useful means to determine the permissible limits for heavy metal application for a wide range of soils. Lead uptake was significantly correlated to total Pb in soils, but not to the adsorption density or soil solution concentrations. The possible interpretation of the results are discussed.     

An evaluation of phycoremediation potential of cyanobacterium Nostoc muscorum: characterization of heavy metal removal efficiency

The present study relates to the use of cyanobacterium Nostoc muscorum as a model system for removal of heavy metals such as Pb and Cd from aquatic systems. The effects of various physicochemical factors on the surface binding and intracellular uptake of Pb and Cd were studied to optimize the metal removal efficiency of the living cells of N. muscorum. Results demonstrated that a significant proportion of Pb and Cd removal was mediated by surface binding of metals (85 % Pb and 79 % Cd), rather than by intracellular accumulation (5 % Pb and 4 % Cd) at the optimum level of cyanobacterial biomass (2.8 g L^?1), metal concentration (80 μg mL^?1), pH (pH 5.0–6.0), time (15–30 min), and temperature (30–40 °C). N. muscorum has maximum amounts of metal removal (q _max) capacity of 833 and 666.7 mg g^?1 protein for Pb and Cd, respectively. The kinetic parameters of metal binding revealed that adsorption of Pb and Cd by N. muscorum followed pseudo-second-order kinetics, and the adsorption behavior was better explained by both Langmuir and Freundlich isotherm models. The surface binding of both the metals was apparently facilitated by the carboxylic, hydroxyl, and amino groups as evident from Fourier transform infrared spectra.     

Agricultural waste material as potential adsorbent for sequestering heavy metal ions from aqueous solutions - a review

Heavy metal remediation of aqueous streams is of special concern due to recalcitrant and persistency of heavy metals in environment. Conventional treatment technologies for the removal of these toxic heavy metals are not economical and further generate huge quantity of toxic chemical sludge. Biosorption is emerging as a potential alternative to the existing conventional technologies for the removal and/or recovery of metal ions from aqueous solutions. The major advantages of biosorption over conventional treatment methods include: low cost, high efficiency, minimization of chemical or biological sludge, regeneration of biosorbents and possibility of metal recovery. Cellulosic agricultural waste materials are an abundant source for significant metal biosorption. The functional groups present in agricultural waste biomass viz. acetamido, alcoholic, carbonyl, phenolic, amido, amino, sulphydryl groups etc. have affinity for heavy metal ions to form metal complexes or chelates. The mechanism of biosorption process includes chemisorption, complexation, adsorption on surface, diffusion through pores and ion exchange etc. The purpose of this review article is to provide the scattered available information on various aspects of utilization of the agricultural waste materials for heavy metal removal. Agricultural waste material being highly efficient, low cost and renewable source of biomass can be exploited for heavy metal remediation. Further these biosorbents can be modified for better efficiency and multiple reuses to enhance their applicability at industrial scale.     

Heavy metal-induced accumulation of free proline in a metal-tolerant and a nontolerant ecotype of Silene vulgaris

Accumulation of free proline in response to Cu, Cd and Zn was studied in nontolerant and metal-tolerant Silene vulgaris (Moench) Garcke. In the nontolerant ecotype these metals induced a massive accumulation of proline, especially in the leaves. When compared at equimolar concentrations in the nutrient solution, Cu was the most effective inducer, followed by Cd and Zn, respectively. However, when compared at equal toxic strength, as estimated from the degree of root growth inhibition, proline accumulation decreased in the order Cd > Zn > Cu. The threshold exposure levels for proline accumulation coincided with the highest no-effect-concentrations for root growth. In the metal-tolerant ecotype the constitutive proline concentration in the leaves was 5 to 6 times higher than in the nontolerant ecotype. Exposure to Cu and Zn, however, was without any effect on the leaf proline concentration, even at exposure levels that caused a 50% root growth inhibition. Only Cd, when present at concentrations above the highest no-effect-concentration for root growth, induced a further increase of the leaf proline content. Reducing transpiration by placing the plants under a transparent polyethylene cover almost completely inhibited proline accumulation, even at metal accumulation rates in the leaves that caused a 10-fold increase of the proline level in leaves of uncovered plants. The results demonstrate that metal-induced proline accumulation depends on the development of a metal-induced water deficit in the leaves. Differential metal-induced proline accumulation in distinctly metal-tolerant ecotypes is a consequence, rather than a cause of differential metal tolerance.     

Effect of EDTA and Tannic Acid on the Removal of Cd,Ni, Pb and Cu from Artificially Contaminated Soil by Althaea rosea Cavan

In this study an ornamental plant of Althaea rosea Cavan was investigated for its potential use in the removal of Cd, Ni, Pb and Cu from an artificially contaminated soil. Effect of two different chelating agents on the removal has also been studied by using EDTA (ethylenediaminetetracetic acid) and TA (tannic acid). Both EDTA and TA have led to higher heavy metal concentration in shoots and leaves compared to control plants. However EDTA is generally known as an effective agent in metal solubilisation of soil, in this study, TA was found more effective to induce metal accumulation in Althaea rosea Cavan under the studied conditions. In addition to this, EDTA is toxic to some species and restraining the growth of the plants. The higher BCF (Bio Concentration Factor) and TF (Translocation Factor) values obtained from stems and leaves by the effects of the chemical enhancers (EDTA and TA) show that Althaea rosea Cavan is a hyper accumulator for the studied metals and may be cultivated to clean the contaminated soils.