An overview of siderate plants phytoremediation potential for petroleum hydrocarbons contaminated soil using various biological additives
Author | Affiliation | |||
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Meištininkas, Rimas | ||||
Date |
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2021 |
Soil pollution is a widespread problem in the world. In Europe, according to the European Environment Agency, the total number of potentially contaminated sites is around 2.5 million, of which around 350,000 are considered to be highly contaminated. The most common soil pollutants are petroleum hydrocarbons. According to the Lithuanian Geological Survey, more than 12,000 potential pollution spots have been identified in the country, more than 5000 are related with petroleum hydrocarbons pollution. Various physical, chemical and electrokinetic methods are used to reduce soil pollution, but biological methods, in particular phytoremediation, have recently received considerable attention. This method is relatively inexpensive and environmentally friendly, in most cases does not generate new waste and secondary pollution compared to other conventional treatment methods. Assessing all the requirements for phytoremediation, a very promising group of plants are siderate plants, most of which have symbiotic nitrogen – fixing bacteria. Siderates, especially legumes, have an advantage over non – nitrogen fixing plants because of their inherent ability to fix nitrogen, legumes do not have to compete with microorganisms and other plants due to limited soil nitrogen reserves in contaminated areas. Moreover, during the siderates growing soil is decontaminated and at the same time the soil fertility can be restored or improved. The effectiveness of siderates based phytoremediation depends on the species of used plants, the composition of contaminants to be treated, their concentration and environmental factors. Various technological solutions or additives may be used to increase the efficiency of bioremediation, such as growth promoters, nutrients, inoculum of microorganisms. A pilot scale phytoremediation test of fuel oil contaminated soil using Medicago sativa (alfalfa) and oil-oxidizing microorganisms as an additive shows that the use of such an additive [...]