Bioremediation approaches for oil contaminated soils in extremely high-mountainous conditions

Abstract

Pollution of soil ecosystems by petroleum-based contaminants is a global problem that requires urgent measures to resolve it, especially the pollution of soils in the subarctic and high-mountain regions (Filler et al. 2009, McDonald and Knox 2014, Adipah 2019. Petroleum pollution causes oxidative stress, changes in soil chemistry and low nutrient availability. Petroleum-based contaminants reduce the number and metabolic activity of aerobic soil microorganisms and affect plant growth and germination, creating an impermeable membrane that impedes water and oxygen circulation. Especially high molecular weight petroleum hydrocarbons negatively influence soils organisms for a long time (Chen and Zhong 2019).Sites in cold climatic zones experience temporally variable temperatures, and these variations may have an impact on the local soil microbial activity (Chang et al. 2011). Implementation of bioremediation techniques to accelerate natural biodegradation rates is an economically and ecologically effective method (Kumar et al. 2019). Nowadays bioremediation approaches have been studied by many researchers in numerous laboratory and field experiments, and approved as simple to maintain, applicable over large areas, cost-effective and environmentally friendly technologies to remediate oil contaminants (Adams et al. 2015, Koshlaf and Ball 2017, Wu et al. 2019. There are in-situ and ex-situ techniques, the first one involves treatment the contaminated soil without excavation whilst the latter does. In-situ soil remediation techniques are rare in many countries due to uncertainty about their effectiveness of this technique and possible adverse environmental impacts, especially in cold regions due to lack of knowledge