BIOREMEDIATION OF CONTAMINATED SOIL WITH PETROLEUM PRODUCTS
Authors: Pisarenko p. , Samoilik M. , Taranenko A. , Tsova Yu , Sereda M. 
Published: January 2022

Petroleum products are recognized as one of the most environmentally hazardous soil contaminants. The sources of this pollution are the enterprises of petroleum and chemical industry, transport, landfills. Soil has the ability to absorb many chemicals and retain them in the surface, fertile layer. Petroleum products change the mechanical, chemical, biochemical and physico-chemical characteristics of the soil, which can lead to the destruction of plants and microorganisms and affects on the soil self-cleaning. The degree of petroleum products impact on plants and microorganisms depends on many factors: temperature and humidity of the air and soil, the amount of nutrients, soil type, the concentration of pollutants. The effect of petroleum products on plants is due direct toxic effects and transformation of the soil environment. At the cellular and physiological level, the effect of petroleum hydrocarbons on plants is appeared in the violation of the structure of chloroplasts and photosynthesis. Hydrocarbons damage the membranes of chloroplasts, mitochondria, root cell membranes. Plants that grow in conditions of petroleum pollution of the soil contain more substances with stress-protective properties. The impact of soil contamination on plants can be direct and indirect. Direct impact - is the impact of petroleum components on plants, indirect impact - are changes in morphological, physicochemical and biological properties of the soil. Moreover, petroleum pollution can have negative and stimulating effects on plants. Therefore, determination the phytotoxic effect in soils contaminated with petroleum products, for selection the optimal methods of soil remediation is relevant today. The question of probiotics uses for remediation contaminated soil is not enough studied in Ukraine. Wide use of probiotic is prevented by insufficient study of this area: deficiency of scientific and scientific-practical base, comparative studies of different probiotics, methods of calculating the required doses to obtain a given cleansing effect and more. Thus, there is a need for further studies of effects of petroleum products on plants and methods of remediation of contaminated soils with probiotics. The article evaluates the phytotoxicity of contaminated soil with petroleum products before and after cleaning with probiotics. To assess the phytotoxic effect of petroleum products were used indicators: seedling height, root length, phytomass of seedlings and phytomass of plants root system. In the experiment were used test-plants: peas (Pisum sativum), oats (Avéna satíva). Remediation of contaminated soil was performed by biological method using probiotic Sviteko-Agrobiotic-01 (dilution 1: 100). The probiotic was applied on the second day after petroleum contamination. The obtained results showed that petroleum products pollution has a different effect on peas and oats in different periods from the moment of pollution. Contaminated soil with petroleum products hadn’t significant phytotoxic effect on Pisum sativum seeds on the 2nd day after contamination. Оn the 30th day after contamination research results showed clear toxic effect on Pisum sativum seeds by concentration of petroleum products of 5000 and 10000 mg/kg; Оn the 180 days after contamination research results showed toxic effect on Pisum sativum seeds at all research concentrations. Contaminated soil with petroleum products had phytotoxic effect on Avéna satíva seeds on the 2nd day after contamination starting from the concentration of petroleum products 5000 mg/kg (such as decreasing the length of the roots and the ground part of plants). On the 30th and 180 th day after contamination petroleum products hadn’t toxic effect on Avéna satíva seeds in the all range of the studied concentrations. It was found that contaminated soil for Pisum sativum becomes toxic mostly on 30th day after the introduction of petroleum products and soil toxicity increase over the time. For Avéna satíva, the soil becomes toxic from the moment of contamination at concentrations of petroleum products 5000 mg/kg and the toxicity of the soil decreases over time. The research results confirmed the effectiveness of biological method (use probiotics) of cleaning the soil from petroleum products. It is established that probiotics clean the soil up to the 5th class of toxicity (no toxicity) at almost all concentrations of petroleum products. Only in the variant with Pisum sativum at concentration of petroleum products 20,000 mg/kg the phytotoxic effect was more than 20% (low toxicity). The average value of the efficiency of soil remediation from petroleum products by probiotics at sowing Pisum sativum was 75%, at Avéna satíva - 74%. Therefore, the experiment showed high efficiency of bioremediation from petroleum products in comparison with soil self-cleaning. On the basis of research results it is planned to develop methodical bases of complex system of remediation of technogenic polluted soils by the way of application of newest environmentally benign methods (using probiotic).