scholarly journals Advances in Heavy Metal Bioremediation: An Overview

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ali Sayqal ◽  
Omar B. Ahmed
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Contamination ◽  
Ex Situ ◽  
Toxic Heavy Metals ◽  
Heavy Metal Remediation ◽  
Land Farming ◽  
Biological Methods ◽  
Metal Bioremediation

The pollution of toxic heavy metals is considered one of the most important environmental issues which has accelerated dramatically due to changing industrial activities. This review focuses on the most common methods, strategies, and biological approaches of heavy metal bioremediation. Also, it provides a general overview of the role of microorganisms in the bioremediation of heavy metals in polluted environments. Advanced methods of heavy metal remediation include physicochemical and biological methods; the latter can be further classified into in situ and ex situ bioremediation. The in situ process includes bioventing, biosparging, biostimulation, bioaugmentation, and phytoremediation. Ex situ bioremediation includes land farming, composting, biopiles, and bioreactors. Bioremediation uses naturally occurring microorganisms such as Pseudomonas, Sphingomonas, Rhodococcus, Alcaligenes, and Mycobacterium. Generally, bioremediation is of very less effort, less labor intensive, cheap, ecofriendly, sustainable, and relatively easy to implement. Most of the disadvantages of bioremediation relate to the slowness and time-consumption; furthermore, the products of biodegradation sometimes become more toxic than the original compound. The performance evaluation of bioremediation might be difficult as it has no acceptable endpoint. There is a need for further studies to develop bioremediation technologies in order to find more biological solutions for bioremediation of heavy metal contamination from different environmental systems.

scholarly journals Heavy metal composition of maize and tomato grown on contaminated soils

2018 ◽  
Vol 3 (1) ◽  
pp. 414-426
Author(s):  
A.O. Adekiya ◽  
A.P. Oloruntoba ◽  
S.O. Ojeniyi ◽  
B.S. Ewulo
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Contaminated Soils ◽  
Heavy Metal Contamination ◽  
Mining Area ◽  
Atomic Absorption Spectrophotometry ◽  
Toxic Heavy Metals ◽  
Mining Site ◽  
Solanum Lycopersicum L ◽  
Sources Of Pollution

Abstract The study investigated the level of heavy metal contamination in plants {maize (Zea mays) and tomato (Solanum lycopersicum L.)} from thirty soil samples of three locations (Epe, Igun and Ijana) in the Ilesha gold mining area, Osun State, Nigeria. Total concentrations of As, Cd, Co, Cr, Cu, Ni, Pb and Zn were determined using atomic absorption spectrophotometry. Spatial variations were observed for all metals across the locations which was adduced to pH and the clay contents of the soils of each location. The results showed that heavy metals are more concentrated in the areas that are closer to the mining site and the concentrations in soil and plants (maize and tomato) decreased with increasing perpendicular distance from the mining site, indicating that the gold mine was the main sources of pollution. The mean concentrations of heavy metals in plants (tomato and maize) samples were considered to be contaminated as As, Cd and Pb respectively ranged from 0.6 - 2.04 mg kg-1, 0.8 - 5.2 mg kg-1, 0.8 - 3.04 mg kg-1 for tomato and respectively 0.60 - 2.00 mg kg-1, 1.50 - 4.60 mg kg-1 and 0.90 - 2.50 mg kg-1 for maize. These levels exceeded the maximum permissible limits set by FAO/WHO for vegetables. In conclusion, monitoring of crops for toxic heavy metals is essential for food safety in Nigeria.

scholarly journals Determination of heavy metals and selenium content in chicken liver at Erbil city, Iraq

2020 ◽  
Vol 9 (3) ◽  
Author(s):  
Hoshyar Saadi Ali ◽  
Dhary Alewy Almashhadany ◽  
Hawraz Sami Khalid
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Inductively Coupled Plasma ◽  
Heavy Metal Contamination ◽  
Optical Emission ◽  
Critical Issue ◽  
Chicken Liver ◽  
Poultry Meat ◽  
Emission Spectrometry ◽  
Toxic Heavy Metals

Heavy metal contamination of poultry meat is a critical issue for human health due to associated risks of cytotoxicity and systemic pathologies after ingestion of such metals. A total of twenty chicken liver samples were collected from markets of Erbil city and analyzed for ten heavy metals contents by Inductively Coupled Plasma Optical Emission Spectrometry. The targeted metals were cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), mercury (Hg), zinc (Zn) and selenium (Se). The average concentrations (mg/kg) of targeted trace elements were 0.06±0.027, 0.06±0.05, 2.05±0.34, 1.85±0.47, 0.15±0.17, and 33.53±5.24 for Co, Cr, Cu, Mn, Ni, and Zn respectively. Copper (Cu) levels significantly exceeded the maximum permissible limit of WHO. Moreover, the average concentrations of toxic heavy metals and selenium were 0.07±0.037, 0.278±0.10, 0.11±0.083, and 2.01±0.454 mg/kg for Cd, Pb, Hg, and Se respectively. Hg and Pb levels exceeded the permissible limits of WHO. Higher levels of Cu and Hg in poultry may pose a serious threat to consumers which demand countermeasures and precautions to be taken. Iraqi Standards Authority and relevant official institutions are strongly recommended to regulate safe disposal of heavy metal waste in the environment to reduce animal exposure to such metals.

scholarly journals Heavy metal remediation technologies in Latvia: possible applications and preliminary case study results / Technologie remediacji obszarów zanieczyszczonych metalami ciężkimi na Łotwie: możliwe zastosowania i wstępne wyniki badań

2012 ◽  
Vol 19 (4) ◽  
pp. 533-547
Author(s):  
Juris Burlakovs ◽  
Magnuss Vircavs
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Contamination ◽  
Anthropogenic Activities ◽  
Residential Areas ◽  
Territorial Planning ◽  
Heavy Metal Remediation ◽  
Study Results ◽  
Polluted Sites

Abstract Environmental contamination with heavy metals as a result of anthropogenic activities is not a recent phenomenon. Contaminated sites with heavy metals can be found in functioning as well as abandoned industrial (brownfield) territories, landfills, residential areas with historical contamination, road sides and rarely in polluted sites by natural activities. Pollution data on its amount and concentrations is known from historical studies and monitoring nowadays, but it should be periodically updated for the use of territorial planning or in case of a change of the land use. A special attention should be paid to heavy metal contamination, because in many cases this contamination is most problematic for remediation. 242 territories now are numbered as contaminated and fixed in the National Register of contaminated territories - at least 56 of them are known as contaminated with heavy metals in different amount and concentration. Legislative aspects are discussed as well as an overview of soil and groundwater contamination research and the possible remediation technologies in Latvia are given. Two case studies are described in order to give the inside look in pre-investigations done before potential start of heavy metal remediation works.

Heavy Metal Pollution and its Management

2016 ◽  
pp. 27-50 ◽  
Author(s):  
Ashok K. Rathoure
Keyword(s):  
Heavy Metal ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Ex Situ ◽  
Management Tool ◽  
Contaminated Site ◽  
Anthropogenic Activity ◽  
Toxic Heavy Metals ◽  
Metabolic Degradation

Environmental degradation has become a major societal issue thanks to uncontrolled anthropogenic activity, besides natural factors. Entry of toxic heavy metals and minerals in human system mainly through contaminated water, food and air, leads to overt and insidious health problems. Heavy metal pollution, a global concern today, can be managed by using bioremediation, an eco-friendly alternative. Bioremediation is one of the most promising technological approaches to the problem of hazardous waste. It is a technology for removing pollution from environment, restoring contaminated site and preventing future pollution. Bioremediation can be performed in situ or ex situ. Microorganisms directly degrade contaminants rather than merely transferring them from one medium to another, employ metabolic degradation pathways and can be used in situ to minimize disturbance of the cleanup site. Hence, microorganisms can be effective, economical and non-disruptive tools for eliminating hazardous chemicals. Its advantage generally outweigh the disadvantage, therefore may be used as management tool.

scholarly journals Bioavailability Assessment of Heavy Metals Using Various Multi-Element Extractants in an Indigenous Zinc Smelting Contaminated Site, Southwestern China

2021 ◽  
Vol 18 (16) ◽  
pp. 8560
Author(s):  
Jun-Xian Wang ◽  
Da-Mao Xu ◽  
Rong-Bing Fu ◽  
Jia-Peng Chen
Keyword(s):  
Heavy Metals ◽  
Risk Assessment ◽  
Heavy Metal ◽  
Heavy Metal Contamination ◽  
Release Kinetics ◽  
Contaminated Sites ◽  
Contaminated Site ◽  
Toxic Heavy Metals ◽  
Zinc Smelting ◽  
Metal Fractions

Despite recent studies have investigated the strong influences of smelting activities on heavy metal contamination in the soil environment, little studies have been conducted on the current information about the potential environmental risks posed by toxic heavy metals in smelting contaminated sites. In the present study, a combination of the bioavailability, speciation, and release kinetics of toxic heavy metals in the indigenous zinc smelting contaminated soil were reliably used as an effective tool to support site risk assessment. The bioavailability results revealed that the bioavailable metal concentrations were intrinsically dependent on the types of chemical extractants. Interestingly, 0.02 mol/L EDTA + 0.5 mol/L CH3COONH4 was found to be the best extractant, which extracted 30.21% of Cu, 31.54% of Mn, 2.39% of Ni and 28.89% of Zn, respectively. The sequential extraction results suggested that Cd, Pb, and Zn were the most mobile elements, which would pose the potential risks to the environment. The correlation of metal bioavailability with their fractionation implied that the exchangeable metal fractions were easily extracted by CaCl2 and Mehlich 1, while the carbonate and organic bound metal fractions could be extracted by EDTA and DTPA with stronger chelating ability. Moreover, the kinetic modeling results suggested that the chemical desorption mechanism might be the major factor controlling heavy metal release. These results could provide some valuable references for the risk assessment and management of heavy metals in the smelting contaminated sites.

Phytoremediation of Cadmium Contaminated Soils: Advances and Researching Prospects

2013 ◽  
Vol 743-744 ◽  
pp. 732-744 ◽  
Author(s):  
Hui Su ◽  
Zhang Cai ◽  
Qi Xing Zhou
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Soil Contamination ◽  
Contaminated Soils ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Low Cost ◽  
Organic Contamination ◽  
Metal Organic

More and more attention has been paid to soil contamination by heavy metals in recent years. Heavy metal contamination includes heavy metal - heavy metal contamination, heavy metal - organic contamination, and heavy metal nutrient contamination. In particular, soil contamination by cadmium (Cd) is the most typical one. In terms of the current remediation technologies, phytoremediation of Cd contaminated soil remains popular due to its low cost, environmental aesthetics and in-situ effective treatment. Therefore, screening-out and identification of Cd hyperaccumulators becomes a hotspot in this researching domain. In order to further improve the efficiency of phytoremediation, we have developed a variety of joint remediation technologies. Based on these work at home and abroad, we summed up the studying progress in this field. Some main researching contents and directions of phytoremediation for Cd contaminated soils were also proposed.

scholarly journals Overview of leaching remediation of heavy metal contamination in soil

2021 ◽  
Vol 245 ◽  
pp. 02005
Author(s):  
Cui Shuang ◽  
Han Qing ◽  
Zhang Tianyi
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Contaminated Soil ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Chelating Agent ◽  
Soil Leaching

The remediation methods of heavy metal contaminated soil can be divided into bioremediation, physical remediation and chemical remediation. Chemical remediation mainly includes soil leaching and chemical curing. There are two kinds of soil leaching remediation methods: in situ soil leaching remediation and ectopic leaching remediation. The eluent of heavy metals in soil includes inorganic eluent, chelating agent, surfactant and so on. Soil leaching can be applied to the remediation of contaminated soil alone or combined with other remediation methods.

Heavy Metal Pollution and its Management

2020 ◽  
pp. 1013-1036 ◽  
Author(s):  
Ashok K. Rathoure
Keyword(s):  
Heavy Metal ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Ex Situ ◽  
Management Tool ◽  
Contaminated Site ◽  
Anthropogenic Activity ◽  
Toxic Heavy Metals ◽  
Metabolic Degradation

Environmental degradation has become a major societal issue thanks to uncontrolled anthropogenic activity, besides natural factors. Entry of toxic heavy metals and minerals in human system mainly through contaminated water, food and air, leads to overt and insidious health problems. Heavy metal pollution, a global concern today, can be managed by using bioremediation, an eco-friendly alternative. Bioremediation is one of the most promising technological approaches to the problem of hazardous waste. It is a technology for removing pollution from environment, restoring contaminated site and preventing future pollution. Bioremediation can be performed in situ or ex situ. Microorganisms directly degrade contaminants rather than merely transferring them from one medium to another, employ metabolic degradation pathways and can be used in situ to minimize disturbance of the cleanup site. Hence, microorganisms can be effective, economical and non-disruptive tools for eliminating hazardous chemicals. Its advantage generally outweigh the disadvantage, therefore may be used as management tool.

ASSESSMENT OF HEAVY METAL CONCENTRATION IN COCONUT WATER

1970 ◽  
pp. 07-10
Author(s):  
MdDidarul Islam, Ashiqur Rahaman, Aboni Afrose
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Heavy Metal Concentration ◽  
Coconut Water ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Toxic Heavy Metal ◽  
Low Concentration ◽  
Wet Ashing ◽  
Aas Method

This study was based on determining concentration of essential and toxic heavy metal in coconut water available at a local Hazaribagh area in Dhaka, Bangladesh. All essential minerals, if present in the drinking water at high concentration or very low concentration, it has negative actions. In this study, fifteen samples and eight heavy metals were analyzed by Atomic Absorption Spectroscopy (AAS) method which was followed by wet ashing digestion method. The concentration obtained in mg/l were in the range of 0.3 to 1.5, 7.77 to 21.2, 0 to 0.71, 0 to 0.9, 0 to 0.2, 0.9 to 17.3, 0.1 to 0.9, 0 to 0.9 and 0 to 0.7 for Fe, Ni, Cu, Cd, Cr, Zn, Pb and Se respectively. From this data it was concluded that any toxic heavy metals like Cd, Cr, Pb and Ni exceed their toxicity level and some essential nutrients were in low concentration in those samples. 

A brief Survey of Assessment models to Predict stress Level of Heavy Metals in Soils

2020 ◽  
Vol 13 ◽  
Author(s):  
Sangeetha Annam ◽  
Anshu Singla
Keyword(s):  
Economic Growth ◽  
Heavy Metals ◽  
Heavy Metal ◽  
Ecological Risk ◽  
Stress Level ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Human Life ◽  
High Stress ◽  
Heavy Metal Stress

Abstract: Soil is a major and important natural resource, which not only supports human life but also furnish commodities for ecological and economic growth. Ecological risk has posed a serious threat to the ecosystem by the degradation of soil. The high-stress level of heavy metals like chromium, copper, cadmium, etc. produce ecological risks which include: decrease in the fertility of the soil; reduction in crop yield & degradation of metabolism of living beings, and hence ecological health. The ecological risk associated, demands the assessment of heavy metal stress levels in soils. As the rate of stress level of heavy metals is exponentially increasing in recent times, it is apparent to assess or predict heavy metal contamination in soil. The assessment will help the concerned authorities to take corrective as well as preventive measures to enhance the ecological and hence economic growth. This study reviews the efficient assessment models to predict soil heavy metal contamination.

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