Hydrogen peroxide as a biodegradation stimulator in remediation processes of soils heavily contaminated with petrochemicals

Abstract

The soil contaminated with petroleum products must be excluded from the crops and treated to reclamation processes. Natural processes of decomposition of hydrocarbon compounds go very slow, so it is necessary to use bioaugumentation or stimulation in order to accelerate the return of the soil to high culture. In this study the effect of hydrogen peroxide on the process of cleaning soil strongly contaminated with pertochemicals was investigated. For this purpose, a pot experiment lasting 60 days was carried. The dynamics of changes in the population of fi lamentous fungi, yeasts and bacteria were examined and also content of aliphatic hydrocarbons (n-alkanes), monoaromatic and polycyclic aromatic hydrocarbons (PAHs). Experimental use of hydrogen peroxide in the process of biodegradation of petroleum compounds assisted in the analyzed soil led to an increase of the number of grampositive bacteria during the test. Stimulation of oil products biodegradation by hydrogen peroxide also increased by 35% decomposition effi ciency of aliphatic hydrocarbons (C8-C40) and about 50% PAH's in comparison to control samples without hydrogen peroxide. There was no infl uence of hydrogen peroxide on the content of monoaromatic hydrocarbons (BTEX) with respect to controls, although in the end of experiment, the total concentration decreased by about 50% compared to the initial content.Keywords: soil, remediation, petrochemicals, hydrogen peroxide. INTRODUCTIONCrude oil products (petrochemicals) may transform in the environment as a result of physico-chemical as well as biological processes. Attenuation (natural processes to decrease concentrations of contaminants in soil) consists in degradation of petrochemicals by autochthonic microorganisms which use them as a main source of carbon . The process may take even several hundred years 5. The fi nal attenuation products are typically carbon dioxide, inorganic substances and biomass.Biodegradation of soil-contaminating petrochemicals depends on site specifi c conditions such as physical and chemical properties of soil, concentration and structure of the petrochemical contamination, concentration of biogenic compounds, temperature, oxygen content, humidity, soil reaction and activity of the microbial consortia 6, 7. Soil bioremediation processes may be enhanced by the use of such techniques as bioaugmentation and/or biostimulation 5, 8 with oxygen or/and correcting soil reaction and enrichment with biogenic compounds facilitating the development of autochthonic microbial communities.The rate of the biodegradation process is to a large extent determined by oxygen delivery to the soil. It can be applied either directly to subsurface (oxygen injection) or in a form of chemical compounds such as ozone or hydrogen peroxide. Due to its properties and decomposing to yield only oxygen and water, hydrogen peroxide is considered environmentally friendly powerful oxidizer, often applied in chemical clean-up processes of soils with pH 3-5 (Fenton reaction) 9, 10, 11, 12. Reactive forms of oxygen r...

From oil spills to barley growth – oil‐degrading soil bacteria and their promoting effects

“…Using these microorganisms bioremediation of soils can be achieved by natural attenuation, biostimulation, and bioaugmentation [4][5][6][7][8][9][10]. To enhance the efficiency of bioremediation the use of microbes has been combined with a number of other techniques such as addition of surfactants [11][12][13][14], sorbents [15][16][17], oxidants [18] or special slow-release fertilizers [19], peat moss hybrid immobilization [20], application of jet air flows [21], and methods of electrochemical stimulation [22][23][24][25][26]. On the other hand, stimulation of microbial action can be augmented by the presence or action of other living organisms such as earthworms [27][28][29], various plants [30], or through the action of domestic animal droppings [31,32].…”

Unconventional yeast in the degradation of hydrocarbons in contaminated soil

“…Local desorption and diffusion from different soil layers, causing the increase of contamination, can be additional problem [3,4,11]. The use of Y. lipolytica yeast inoculum may change the soil microbiota [3,4].…”

“…Local desorption and diffusion from different soil layers, causing the increase of contamination, can be additional problem [3,4,11]. The use of Y. lipolytica yeast inoculum may change the soil microbiota [3,4]. The ratio of Gram-positive to Gram-negative bacteria may be recognized as a microbiological index of the degree of contamination with petroleum-derived substances, as well as bioaugmentation efficiency [3,18].…”

“…Petroleum-derived compounds are reduced in the soil in consequence of chemical oxidation and photolysis, sorption, precipitation, volatilization and biodegradation [1,2]. Natural bioremediation processes take place in contaminated soil due to microorganisms abilities to assimilate petroleum-derived hydrocarbons and use them as the source of carbon and energy [3,4] or in co-metabolism [5]. Recognition of microorganisms capable of degrading petroleum pollutants and their metabolic pathways allowed the use of the activity of selected strains to bioaugmentation of contaminated soil [6,7].…”

The Influence of Stimulation Techniques on the Microbiological Changes and n-Alkane Transitions in the Soil Contaminated of Petroleum-Derived Substances

“…The processes of contamination removal or precipitation of hydrocarbons' decay deriving from crude oil are conducted with the use of different techniques and with different effectiveness. By these, chemical, physicochemical, and biological methods are meant, which include photodegradation as well as biodegradation in the in situ or ex situ conditions (Ziółkowska and Wyszkowski 2008;Lal et al 2010;Rosik-Dulewska et al 2015;Azubuike et al 2016). Biodegradation of petroleum substances hydrocarbons can be limited by many factors, among others are autochthonous microbiota, the accessibility of biogenic compounds, the environment reaction, temperature, humidity, the accessibility of oxygen, physicochemical properties of soil, and by a type as well as the contamination intensity (Pala et al 2006).…”