Heavy Metal Toxicity, Health Hazards and their Removal Technique by Natural Adsorbents: A Short Overview

Environmental pollution particularly from heavy metals and minerals in the wastewater is the most severe problem in India. Due to extensive anthropogenic activities such as industrial operations particularly mining, agricultural processes and disposal of industrial waste materials; their concentration has increased to dangerous levels. Heavy metals in industrial effluent include Copper, nickel, chromium, lead, zinc, arsenic, cadmium, selenium and uranium. So far, a number of efficient methods have been reviewed for the removal of heavy metals such as chemical precipitation, ion exchange, reverse osmosis, electro dialysis, ultra filtration, nanofiltration, coagulation, flocculation, floatation, etc. However these methods have several disadvantages such as high reagent requirement, unpredictable metal ion removal, generation of toxic sludge etc. Adsorption process being very simple, economical, effective and versatile has become the most preferred methods for removal of toxic contaminants from wastewater. This paper reviews the use of various readily available natural materials as adsorbents of heavy metals from industrial wastewater. Various natural adsorbents reviewed includes sand, waste tea leaves eggshell, rice husk, activated carbon, zeolites, olive stones, wood sawdust etc.

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Column Study on the Removal of Metals from Industrial Effluents using the Biomass Sargassum sp

International Journal of Applied Research in Mechanical Engineering ◽

10.47893/ijarme.2012.1053 ◽

2012 ◽

pp. 6-9

Author(s):

A. Saravanan ◽

Uvaraja Uvaraja ◽

Nishanth Nishanth ◽

Soundarajan Krishnan

Keyword(s):

Heavy Metals ◽

Metal Ion ◽

Human Life ◽

Industrial Effluents ◽

Chemical Precipitation ◽

Electrochemical Treatment ◽

Chemical Oxidation ◽

Metal Ion Removal ◽

Ion Removal ◽

Oxidation Reduction

Heavy metals are ubiquitous environmental contaminants in industrialized societies. The presence of heavy metals in the environment is of major concern because of their toxicity, bio-accumulating tendency, threat to human life and the environment. Traditional methods have been used to remove heavy metals from effluent include chemical precipitation, chemical oxidation/reduction, ion exchange, electrochemical treatment, evaporation and filtration. Many of these methods are ineffective; resulting in low levels of metal ion removal and can also be economically inefficient. Biomass of brown marine macro algae is a renewable biological resource, which is available in large quantities and can form a good base for the development of biosorbent material. The work considered the parameters of the effluents and the experimental column model for the metal adsorption. Among the experimental model Thomas model fitted the column biosorption data well.

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Isotherm, Kinetics and Thermodynamics of Cu(II) and Pb(II) Adsorption on Groundwater Treatment Sludge-Derived Manganese Dioxide for Wastewater Treatment Applications

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18063050 ◽

2021 ◽

Vol 18 (6) ◽

pp. 3050

Author(s):

Stephanie B. Tumampos ◽

Benny Marie B. Ensano ◽

Sheila Mae B. Pingul-Ong ◽

Dennis C. Ong ◽

Chi-Chuan Kan ◽

...

Keyword(s):

Heavy Metals ◽

Metal Ion ◽

Acid Leaching ◽

Single Layer ◽

Toxic Metal ◽

Ion Concentration ◽

Groundwater Treatment ◽

Toxic Heavy Metals ◽

Solution Ph ◽

Metal Ion Removal

The ubiquitous occurrence of heavy metals in the aquatic environment remains a serious environmental and health issue. The recovery of metals from wastes and their use for the abatement of toxic heavy metals from contaminated waters appear to be practical approaches. In this study, manganese was recovered from groundwater treatment sludge via reductive acid leaching and converted into spherical aggregates of high-purity MnO2. The as-synthesized MnO2 was used to adsorb Cu(II) and Pb(II) from single-component metal solutions. High metal uptake of 119.90 mg g−1 for Cu(II) and 177.89 mg g−1 for Pb(II) was attained at initial metal ion concentration, solution pH, and temperature of 200 mg L−1, 5.0, and 25 °C, respectively. The Langmuir isotherm model best described the equilibrium metal adsorption, indicating that a single layer of Cu(II) or Pb(II) was formed on the surface of the MnO2 adsorbent. The pseudo-second-order model adequately fit the Cu(II) and Pb(II) kinetic data confirming that chemisorption was the rate-limiting step. Thermodynamic studies revealed that Cu(II) or Pb(II) adsorption onto MnO2 was spontaneous, endothermic, and had increased randomness. Overall, the use of MnO2 prepared from groundwater treatment sludge is an effective, economical, and environmentally sustainable substitute to expensive reagents for toxic metal ion removal from water matrices.

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AN ALTERNATIVE APPROACH ON BIOREMEDIATION OF HEAVY METALS IN TANNERY EFFLUENTS WASTE USING STREPTOMYCES SP.

Asian Journal of Pharmaceutical and Clinical Research ◽

10.22159/ajpcr.2017.v10i10.19480 ◽

2017 ◽

Vol 10 (10) ◽

pp. 323

Author(s):

Thirumurugan D ◽

Ibrahim Adamu Karfi ◽

Vijayakumar R ◽

Nithya Tg

Keyword(s):

Heavy Metals ◽

Incubation Period ◽

Metal Ion ◽

Industrial Effluent ◽

Treatment Plant ◽

Ion Concentration ◽

Effluent Treatment ◽

Tannery Effluent ◽

Streptomyces Sp ◽

Reducing Ability

Objective: The present study is conducted to investigate the abilities of microorganisms to degrade heavy metals in industrial tannery effluent sample.Methods: Tannery effluent sample was collected from effluent treatment plant and analyzed for physicochemical parameters. The potential microbes were isolated and identified by morphological and biochemical characterization. The sample was analyzed before and after to assess the heavy metal reducing the ability of the microorganism and the respective percentage of reduction were studied using X-ray fluorescence spectrometry.Results: The samples were initially found to be highly contaminated with chromium, nickel, and cadmium. Out of three potential isolates, the isolate Streptomyces sp. was found to exhibit a better reduction against chromium (25.7%), cadmium (14.6%), and nickel (23.1%) in 50 ppm at longer incubation period. Comparatively, the reduction abilities of all the three isolates against all the three heavy metals increased with the increase in the incubation period but decreased with the increase in initial metal ion concentration except in the case of Streptomyces sp. against nickel where the reducing ability increased with the increase in metal concentration.Conclusion: Apparently, the present study revealed that Streptomyces sp. had a better remediation potential than the indigenous Pseudomonas sp. and Aspergillus sp. Ultimately, the finding of this research has shown that the Streptomyces sp. can be used as a potent bioremediation agent for treating tannery and industrial effluent in an eco-friendly process.

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The Adsorption of Heavy Metal from Aqueous Solutions onto the Porous Biomorphic-Genetic Composite of Hydroxyapatite/Carbon with Eucalyptus and Bamboo Template

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.730.260 ◽

2015 ◽

Vol 730 ◽

pp. 260-264 ◽

Cited By ~ 1

Author(s):

Shuang Cao ◽

Bin Huang ◽

Zong Qiang Zhu ◽

Yi Nian Zhu

Keyword(s):

Heavy Metals ◽

Metal Ion ◽

Contaminated Water ◽

Initial Concentration ◽

Metal Ion Removal ◽

Ion Removal ◽

Adsorbed Amount ◽

Removal Of Heavy Metals ◽

New Material ◽

Ammonia Leaching

This study used two types of plant, eucalyptus and bamboo, to produce sorbents for copper (II), cadmium (II), zinc (II), and lead (II) metal ion removal in a water bath shake. The porous biomorphic-genetic composite of hydroxyapatite/carbon with eucalyptus template (PBGC-Fe/C-E) and the porous biomorphic-genetic composite of hydroxyapatite/carbon with bamboo template (PBGC-Fe/C-B) were prepared using eucalyptus and bamboo as plant templates, and through various processes including ammonia leaching, cyclical impregnation using calcium hydroxide and diammonium solutions, and aerobic firing inside muffle furnaces. Tests were conducted on the HAP/C composites to observe their adsorption effects on Cu (II), Zn (II), Pb (II), and Cd (II). The results show that the prepared composites were able to adsorb heavy metals in water effectively. The results indicated that the adsorbed amount of PBGC-Fe/C-E were found to be 16.4371, 4.6725,24.5528, 17.0194 mg/1 for Cu (II), Zn (II), Pb (II) and Cd (II) ions at initial concentration of 50mg/L (25°C), respectively. The adsorbed amount of PBGC-Fe/C-B were found to be 10.5876, 3.9142,21.2463, 13.4721 mg/1 for Cu (II), Zn (II), Pb (II) and Cd (II) ions at initial concentration of 50mg/L (25°C), respectively. The prepared adsorbent is expected to be a new material for the removal of heavy metals from contaminated water.

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Removal of Toxic Heavy Metals from Contaminated Aqueous Solutions Using Seaweeds: A Review

Sustainability ◽

10.3390/su132112311 ◽

2021 ◽

Vol 13 (21) ◽

pp. 12311

Author(s):

Edward Hingha Foday Jr ◽

Bai Bo ◽

Xiaohui Xu

Keyword(s):

Heavy Metals ◽

Metal Ion ◽

Heavy Metal Contamination ◽

Removal Rate ◽

Toxic Heavy Metals ◽

Metal Ion Removal ◽

Seaweed Biomass ◽

Multiple Organs ◽

Sorption Material ◽

The Impact

Heavy metal contamination affects lives with concomitant environmental pollution, and seaweed has emerged as a remedy with the ability to save the ecosystem, due to its eco-friendliness, affordability, availability, and effective metal ion removal rate. Heavy metals are intrinsic toxicants that are known to induce damage to multiple organs, especially when subjected to excess exposure. With respect to these growing concerns, this review presents the preferred sorption material among the many natural sorption materials. The use of seaweeds to treat contaminated solutions has demonstrated outstanding results when compared to other materials. The sorption of metal ions using dead seaweed biomass offers a comparative advantage over other natural sorption materials. This article summarizes the impact of heavy metals on the environment, and why dead seaweed biomass is regarded as the leading remediation material among the available materials. This article also showcases the biosorption mechanism of dead seaweed biomass and its effectiveness as a useful, cheap, and affordable bioremediation material.

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Geochemical Mapping, Risk Assessment, and Source Identification of Heavy Metals in Road Dust Using Positive Matrix Factorization (PMF)

Atmosphere ◽

10.3390/atmos12050614 ◽

2021 ◽

Vol 12 (5) ◽

pp. 614

Author(s):

Muhammad Faisal ◽

Zening Wu ◽

Huiliang Wang ◽

Zafar Hussain ◽

Chenyang Shen

Keyword(s):

Heavy Metals ◽

Risk Assessment ◽

Matrix Factorization ◽

Anthropogenic Activities ◽

Contamination Factor ◽

Road Dust ◽

Positive Matrix Factorization ◽

Prevention Measures ◽

Positive Matrix ◽

The City

Heavy metals in road dust pose a significant threat to human health. This study investigated the concentrations, patterns, and sources of eight hazardous heavy metals (Cr, Ni, Cu, Zn, As, Cd, Pb, and Hg) in the street dust of Zhengzhou city of PR China. Fifty-eight samples of road dust were analyzed based on three methods of risk assessment, i.e., Geo-Accumulation Index (Igeo), Potential Ecological Risk Assessment (RI), and Nemerow Synthetic Pollution Index (PIN). The results exhibited higher concentrations of Hg and Cd 14 and 7 times higher than their background values, respectively. Igeo showed the risks of contamination in a range of unpolluted (Cr, Ni) to strongly polluted (Hg and Cd) categories. RI came up with the contamination ranges from low (Cr, Ni, Cu, Zn, As, and Pb) to extreme (Cd and Hg) risk of contamination. The risk of contamination based on PIN was from safe (Cu, As, and Pb) to seriously high (Cd and Hg). The results yielded by PIN indicated the extreme risk of Cd and Hg in the city. Positive Matrix Factorization was used to identify the sources of contamination. Factor 1 (vehicular exhaust), Factor 2 (coal combustion), Factor 3 (metal industry), and Factor 4 (anthropogenic activities), respectively, contributed 14.63%, 35.34%, 36.14%, and 13.87% of total heavy metal pollution. Metal’s presence in the dust is a direct health risk for humans and warrants immediate and effective pollution control and prevention measures in the city.

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