In situ and ex situ bioremediation of radionuclide-contaminated soils at nuclear and norm sites

Author(s):  
A.J. Francis ◽  
Y.V. Nancharaiah
Keyword(s):  
Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4664
Author(s):  
Israel Gonçalves Sales da Silva ◽  
Fabíola Carolina Gomes de Almeida ◽  
Nathália Maria Padilha da Rocha e Silva ◽  
Alessandro Alberto Casazza ◽  
Attilio Converti ◽  
...  

Petroleum hydrocarbons, heavy metals and agricultural pesticides have mutagenic, carcinogenic, immunotoxic and teratogenic effects and cause drastic changes in soil physicochemical and microbiological characteristics, thereby representing a serious danger to health and environment. Therefore, soil pollution urgently requires the application of a series of physicochemical and biological techniques and treatments to minimize the extent of damage. Among them, bioremediation has been shown to be an alternative that can offer an economically viable way to restore polluted areas. Due to the difficulty in choosing the best bioremediation technique for each type of pollutant and the paucity of literature on soil bioremediation enhanced by the use of specific additives, we reviewed the main in situ and ex situ methods, their current properties and applications. The first section discusses the characteristics of each class of pollutants in detail, while the second section presents current bioremediation technologies and their main uses, followed by a comparative analysis showing their respective advantages and disadvantages. Finally, we address the application of surfactants and biosurfactants as well as the main trends in the bioremediation of contaminated soils.


Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4309 ◽  
Author(s):  
Maiara Barbosa Ferreira ◽  
Aline Maria Sales Solano ◽  
Elisama Vieira dos Santos ◽  
Carlos A. Martínez-Huitle ◽  
Soliu O. Ganiyu

In recent years, due to industrial modernization and agricultural mechanization, several environmental consequences have been observed, which make sustainable development difficult. Soil, as an important component of ecosystem and a key resource for the survival of human and animals, has been under constant contamination from different human activities. Contaminated soils and sites require remediation not only because of the hazardous threat it possess to the environment but also due to the shortage of fresh land for both agriculture and urbanization. Combined or coupled remediation technologies are one of the efficient processes for the treatment of contaminated soils. In these technologies, two or more soil remediation techniques are applied simultaneously or sequentially, in which one technique complements the other, making the treatment very efficient. Coupling anodic oxidation (AO) and soil remediation for the treatment of soil contaminated with organics has been studied via two configurations: (i) soil remediation, ex situ AO, where AO is used as a post-treatment stage for the treatment of effluents from soil remediation process and (ii) soil remediation, in situ AO, where both processes are applied simultaneously. The former is the most widely investigated configuration of the combined processes, while the latter is less common due to the greater diffusion dependency of AO as an electrode process. In this review, the concept of soil washing (SW)/soil flushing (SF) and electrokinetic as soil remediation techniques are briefly explained followed by a discussion of different configurations of combined AO and soil remediation.


2017 ◽  
pp. 90
Author(s):  
Marcia Marques ◽  
Jorge Antonio Lopes ◽  
Marcelo Alarsa ◽  
Marcos F. Ferrari ◽  
Graciane Silva ◽  
...  

Remediation of soils contaminated with petroleum and its products became a major issue in all regions of the world where on-shore and off-shore exploitation, refining transportation and storage of these products are carried out intensively. Many techniques for remediation of contaminated areas have been developed and tested during decades, being bioremediation both in-situ and ex-situ tow of the available options that require further development, which are currently capturing the attention of different sectors involved with the problem in Brazil. This paper presents the historical perspective of the increasing problem that initially appeared in the most traditional industrialized countries and currently has been intensified in countries with growing economy and technological development such as Brazil. Technological options for remediating the areas, variables relevant to the cleaning process, as well as the most recent trends in Brazil regarding the use of different techniques, with focus on biopiles are briefly presented.


2020 ◽  
Vol 166 ◽  
pp. 01007
Author(s):  
Vasyl Savosko ◽  
Aleksandr Podolyak ◽  
Irina Komarova ◽  
Aleksey Karpenko

Object of research: to systematize (taking into account the possible consequences to biosphere) the known technologies for ecological restoration of soils contaminated by heavy metals and radionuclides. Only a healing technology should be recognized as one possible methodology for solving any soil problems. For soils contaminated by heavy metals and radionuclides healing patterns is conceptually ordered into the following levels: mission, strategy, technology. The mission of healthy soil should be aimed at maintaining the chemical elements content within the optimum interval. The strategy of healthy soil involves the regulation of individual elements content in the soil. Ex-situ a soil healing technology is implemented outside the original pollution site. In-situ, a soil healing technology is carried out directly on the original pollution site. Excavation of the contaminated soil layer is the first stage for ex-situ soil restoration. In the future it will be possible: 1) storage of contaminated soil at special landfills, 2) treatment of contaminated soil at a special reactor. All technologies for in-situ healthy of heavy metals contaminated soils can be ordered as: 1) localization, 2) deconcentration, 3) inactivation, 4) extraction.


Soil Research ◽  
2011 ◽  
Vol 49 (3) ◽  
pp. 261 ◽  
Author(s):  
Petra J. Sheppard ◽  
Eric M. Adetutu ◽  
Tanvi H. Makadia ◽  
Andrew S. Ball

Bioremediated soils are usually disposed of after meeting legislated guidelines defined by chemical and ecotoxicity tests. In many countries including Australia, ecotoxicity tests are not yet mandatory safety requirements. This study investigated the biotreatment of weathered hydrocarbon-contaminated soils in 12-week laboratory-based microcosms. Monitored natural attenuation resulted in ~43% reduction of total petroleum hydrocarbon contaminant to 5503 mg/kg (C16–C35), making the soil suitable for disposal as waste under current guidelines (pesticide and metal contents within safe limits). 16S rDNA (universal and AlkB) and ITS-based DGGE fingerprints showed stable and adapted microbial communities throughout the experimental period. However, ecotoxicology assays showed 100% mortality of earthworms (Eisena fetida) in potting soils containing ≥50% (≥2751 mg/kg, legally safe in situ concentrations) contaminated soil over 14 days. Up to 70% reduction in radish (Raphanus sativus) seed germination was observed in potting soils containing ≥10% contaminated soil (≥550 mg/kg, legally safe ex situ concentrations for soil disposal into residential areas). The results indicate the toxicity of these soils to soil biota despite meeting legislated Australian safe levels and guidelines for disposal or use in residential areas.


2017 ◽  
Vol 75 (9) ◽  
pp. 2171-2178 ◽  
Author(s):  
Peifang Wang ◽  
Cui Liu ◽  
Yu Yao ◽  
Chao Wang ◽  
Teng Wang ◽  
...  

To assess the capabilities of the different techniques in predicting Cadmium (Cd) bioavailability in Cd-contaminated soils with the addition of Zn, one in situ technique (diffusive gradients in thin films; DGT) was compared with soil solution concentration and four widely used single-step extraction methods (acetic acid, EDTA, sodium acetate and CaCl2). Wheat and maize were selected as tested species. The results demonstrated that single Cd-polluted soils inhibited the growth of wheat and maize significantly compared with control plants; the shoot and root biomasses of the plants both dropped significantly (P < 0.05). The addition of Zn exhibited a strong antagonism to the physiological toxicity induced by Cd. The Pearson correlation coefficient presented positive correlations (P < 0.01, R > 0.9) between Cd concentrations in two plants and Cd bioavailability indicated by each method in soils. Consequently, the results indicated that the DGT technique could be regarded as a good predictor of Cd bioavailability to plants, comparable to soil solution concentration and the four single-step extraction methods. Because the DGT technique can offer in situ data, it is expected to be widely used in more areas.


2021 ◽  
Vol 2 (2) ◽  
pp. 1-7
Author(s):  
Elijah Chibuzo Ugwu ◽  
Bhaskar Sen Gupta ◽  
Adeloye Adebayo ◽  
Nadia Martínez-Villegas

Environmental contamination caused by high contents of toxic metals in the soil is a global concern. Soil washing using chelating agents and saponin can enhance metal removal from contaminated soils through the formation of soluble metal complexes, mobilization, and extraction with the washing solutions. Column experiments were conducted in this study to assess the feasibility of using a chelate (EDTA), a saponin (soapnut) and microbial (rhamnolipid) cleaning agents to enhance the removal of Cd, Cu, Pb and Zn from sandy loam contaminated soils. The cumulative removal of Cd after 10 pore volumes were 74.05 for EDTA, 63.08 for rhamnolipids, and 69.07 for soapnut. The cumulative removals of Cu after washing with 10 pore volumes were 64.72% for soapnut, 61.58% for rhamnolipids and 61.95% for EDTA. Also, the cumulative removals of Pb were 62% for soapnut, 59.65% for rhamnolipids and 59.95% for EDTA after washing with 10 pore volumes. The cumulative removals of Zn after washing with 10 pore volumes were 68.54% for soapnut, 62.65% for rhamnolipids and 66.08% for EDTA. The performance of these experiments demonstrates that the application of these cleaning agents in in-situ soil remediation can be effective alternative to ex-situ remediation.


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