A review on green remediation techniques for hydrocarbons and heavy metals contaminated soil

Organic pollutants cause many environmental problems to our environment because of their toxicity, non-degradation and ability to long-range transport. The most common organic pollutants are known as persistent organic pollutants (POPs) and are known as hydrocarbons. Effective techniques for the removal of hydrocarbons and heavy metals from soil have drawn great attention. Remediation techniques represent one of the most important of these techniques because of their gentle impact on the environment. The study highlights numerous methods for Physical and chemical remediation techniques with explanation of the ability of some plants and agricultural wastes for remediation.

Green Remediation And Physiological Responses of Plants To Metal-Contaminated Soils In Jinchang Mining Areas, Western Desert, China

Jinchang mining area, as a metal mine with a long history of arid and semi-arid mining in western China, has brought a great risk of heavy metal pollution to the local environment. In this experiment, tailings, slag and native soil are mixed in equal proportions for the pot experiment settings. 9 species of sand plants unique to the arid region of the western inland were planted to screen the varieties with green remediation value. After six months of plant growth, the concentration of Zn in the plant was the highest, ranging from 103.27 to 467.63mg/kg, followed by Cu, ranging from 25.07 to 200.35mg/kg. In the early stage (2 months), POD was the main defense, and in the later stage (4\6 months), SOD and CAT were the main defense, accompanied by unknown proteins up-regulated. The results of net photosynthetic rate showed that it was inhibited by metal stress in the early stage, and it was high in the late stage to provide material basis for the accumulation and secretion of adaptable and resistant substances. Seven species of plants, such as Suaeda glauca, Bassia scoparia, Halogeton glomeratus, Kalidium foliatum, Medicago falcata, Atriplex canescens, Artemisia desertorum can be used as enrichment materials for Zn and Cu. While, Atriplex canescens has the highest metal enrichment potential, and can be used as a planting variety to enrich Cd, Ni and Pb in a broad spectrum of metals including Zn and Cu. This study lays a solid scientific foundation for green remediation of contaminated soil in arid desert area of western China.

Port Sediments: Problem or Resource? A Review Concerning the Treatment and Decontamination of Port Sediments by Fungi and Bacteria

Contamination of marine sediments by organic and/or inorganic compounds represents one of the most critical problems in marine environments. This issue affects not only biodiversity but also ecosystems, with negative impacts on sea water quality. The scientific community and the European Commission have recently discussed marine environment and ecosystem protection and restoration by sustainable green technologies among the main objectives of their scientific programmes. One of the primary goals of sustainable restoration and remediation of contaminated marine sediments is research regarding new biotechnologies employable in the decontamination of marine sediments, to consider sediments as a resource in many fields such as industry. In this context, microorganisms—in particular, fungi and bacteria—play a central and crucial role as the best tools of sustainable and green remediation processes. This review, carried out in the framework of the Interreg IT-FR Maritime GEREMIA Project, collects and shows the bioremediation and mycoremediation studies carried out on marine sediments contaminated with ecotoxic metals and organic pollutants. This work evidences the potentialities and limiting factors of these biotechnologies and outlines the possible future scenarios of the bioremediation of marine sediments, and also highlights the opportunities of an integrated approach that involves fungi and bacteria together.