Enhanced Techniques of Soil Washing for the Remediation of Heavy Metal-Contaminated Soils

Soil contaminated with Cd and Pb has caused sharp decrease of cultivatable soil and has been attracting increasing attention. Biosurfactants are efficient in solving the problem. However, little information is available about the influence of sophorolipids (SLs) on the remediation of Cd- or Pb-contaminated soil. The sophorolipids produced by Starmerella bombicola CGMCC 1576 were used to study the effects of Cd and Pb removal in batch soil washing from artificially contaminated soil. The removal efficiency of crude total SLs was better than both distilled water and synthetic surfactants. Furthermore, 83.6% of Cd and 44.8% of Pb were removed by 8% crude acidic SLs. Acidic SLs with high water solubility were more effective than lactonic SLs in enhancing remediation of heavy metal-contaminated soils. The complexation of Cd with the free carboxyl group of the acidic SLs was observed by Fourier-transform infrared spectroscopy study, and this complexation was effective in heavy metal removal from the soil. The fermentation broth of S. bombicola, without further preparation, removed 95% of Cd and 52% of Pb. These results suggested that SLs produced by S. bombicola could function as potential bioremediation agents for heavy metal-contaminated soil.

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Heavy Metals in Contaminated Soils: A Review of Sources, Chemistry, Risks and Best Available Strategies for Remediation

ISRN Ecology ◽

10.5402/2011/402647 ◽

2011 ◽

Vol 2011 ◽

pp. 1-20 ◽

Cited By ~ 848

Author(s):

Raymond A. Wuana ◽

Felix E. Okieimen

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Land Tenure ◽

Contaminated Soils ◽

Soil Washing ◽

Land Resource ◽

Land Use Pattern ◽

Advantages And Disadvantages ◽

Zinc Cadmium ◽

Scale Down

Scattered literature is harnessed to critically review the possible sources, chemistry, potential biohazards and best available remedial strategies for a number of heavy metals (lead, chromium, arsenic, zinc, cadmium, copper, mercury and nickel) commonly found in contaminated soils. The principles, advantages and disadvantages of immobilization, soil washing and phytoremediation techniques which are frequently listed among the best demonstrated available technologies for cleaning up heavy metal contaminated sites are presented. Remediation of heavy metal contaminated soils is necessary to reduce the associated risks, make the land resource available for agricultural production, enhance food security and scale down land tenure problems arising from changes in the land use pattern.

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New-Generation Washing Agents in Remediation of Metal-Polluted Soils and Methods for Washing Effluent Treatment: A Review

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17176220 ◽

2020 ◽

Vol 17 (17) ◽

pp. 6220 ◽

Cited By ~ 2

Author(s):

Zygmunt M. Gusiatin ◽

Dorota Kulikowska ◽

Barbara Klik

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Contaminated Soils ◽

Metal Removal ◽

Heavy Metal Removal ◽

Soil Washing ◽

Effluent Treatment ◽

Chemical Pollution ◽

Polluted Soils ◽

Soil Flushing

Soil quality is seriously reduced due to chemical pollution, including heavy metal (HM) pollution. To meet quality standards, polluted soils must be remediated. Soil washing/soil flushing offers efficient removal of heavy metals and decreases environmental risk in polluted areas. These goals can be obtained by using proper washing agents to remove HMs from soil. These washing agents should not pose unacceptable threats to humans and ecosystems, including soil composition. Currently, it is desirable to use more environmentally and economically attractive washing agents instead of synthetic, environmentally problematic chemicals (e.g., ethylenediaminetetraacetic acid (EDTA)). The usefulness of novel washing agents for treatment of heavy metal-contaminated soils is being intensively developed, in terms of the efficiency of HM removal and properties of washed soils. Despite the unquestionable effectiveness of soil washing/flushing, it should be remembered that both methods generate secondary fluid waste (spent washing solution), and the final stage of the process should be treatment of the contaminated spent washing solution. This paper reviews information on soil contamination with heavy metals. This review examines the principles and status of soil washing and soil flushing. The novel contribution of this review is a presentation of the sources and characteristics of novel washing agents and chemical substitutes for EDTA, with their potential for heavy metal removal. Methods for treating spent washing solution are discussed separately.

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Using poly-glutamic acid as soil-washing agent to remediate heavy metal-contaminated soils

Environmental Science and Pollution Research ◽

10.1007/s11356-017-9235-7 ◽

2017 ◽

Vol 25 (6) ◽

pp. 5231-5242 ◽

Cited By ~ 10

Author(s):

Zong-Han Yang ◽

Cheng-Di Dong ◽

Chiu-Wen Chen ◽

Yih-Terng Sheu ◽

Chih-Ming Kao

Keyword(s):

Heavy Metal ◽

Glutamic Acid ◽

Contaminated Soils ◽

Soil Washing

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Chemical Properties of Heavy Metal-Contaminated Soils from a Korean Military Shooting Range: Evaluation of Pb Sources Using Pb Isotope Ratios

Applied Sciences ◽

10.3390/app11157099 ◽

2021 ◽

Vol 11 (15) ◽

pp. 7099

Author(s):

Inkyeong Moon ◽

Honghyun Kim ◽

Sangjo Jeong ◽

Hyungjin Choi ◽

Jungtae Park ◽

...

Keyword(s):

Heavy Metals ◽

Heavy Metal ◽

Contaminated Soils ◽

Management Strategies ◽

Chemical Properties ◽

Heavy Metal Concentration ◽

Soil Samples ◽

Shooting Range ◽

Geochemical Properties ◽

Mineral Phases

In this study, the geochemical properties of heavy metal-contaminated soils from a Korean military shooting range were analyzed. The chemical behavior of heavy metals was determined by analyzing the soil pH, heavy metal concentration, mineral composition, and Pb isotopes. In total, 24 soil samples were collected from a Korean military shooting range. The soil samples consist of quartz, albite, microcline, muscovite/illite, kaolinite, chlorite, and calcite. Lead minerals, such as hydrocerussite and anglesite, which are indicative of a transformation into secondary mineral phases, were not observed. All soils were strongly contaminated with Pb with minor concentrations of Cu, Ni, Cd, and Zn. Arsenic was rarely detected. The obtained results are indicated that the soils from the shooting range are contaminated with heavy metals and have evidences of different degree of anthropogenic Pb sources. This study is crucial for the evaluation of heavy metal-contaminated soils in shooting ranges and their environmental effect as well as for the establishment of management strategies for the mitigation of environmental risks.

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