Total petroleum hydrocarbon (TPH) concentrations and their fractional composition (medium fraction: n-alkane chain-length C15 to C27, heavy fraction: >C27) were determined at distances from 1 to 60 m from roads and at soil depths from 0.5 to 15 cm. The traffic intensities were up to 25000 vehicles per day. Soil TPH concentrations were highest within 15 m distance (665 and 3198 mg kg−1at the windward and leeward sides, resp.), followed by a rapid drop to background values beyond (196 and 115 mg kg−1in 60 m distance at the windward and leeward sides, resp.). The data variability was lowest at distances of 1 m and highest within tree plantations at distances of 15 m from the road. The TPH concentrations decreased with depth but were significantly higher than the background at all depths investigated. A principal component analysis revealed a positive relation between the medium-to-heavy fraction ratio and soil depth. A fractional differentiation of hydrocarbons with distance from road was not observed. It was concluded that the assessment of the potential of hydrocarbons to translocate, accumulate, or degrade in soil necessitates their subdivision into fractions based on their physicochemical and metabolic properties.

Total petroleum hydrocarbon (TPH) deposition rates were determined along various roads using the natural snow cover as deposition trap. Daily deposition rates decreased with distance from the roads, which coincided with long-term TPH accumulation in roadside soils. Scanning electron microscopy (SEM-EDX) of the snow meltwater sediment revealed occurrence of carbon-rich plaques, which were identified as hydrocarbons using FTIR-microscopy. GC-MS revealed that the compounds extracted from the sediment consisted of an unresolved complex hydrocarbon mixture (UCM). Individual n-alkanes could not be resolved in the sediment extract, whereas TPHs extracted from soils contained a series of n-alkanes peaking at C25-C27. The proportion of UCM compounds from TPHs decreased with distance from road. We conclude that high-boiling hydrocarbons bind to coarse mineral dust and/or to splash water and vehicle spray, which preferentially deposit within a 10 m roadside strip.

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Rhodium(III) extraction from hydrochloric solutions using bis-acylated triethylenetetramine has been studied. Optimal conditions for rhodium(III) recovery have been determined. It was found that, at a contact time to 5 min, the extraction occurred by an ion-association mechanism. At a contact time longer than 5 min, rhodium(III) was extracted by a mixed mechanism with the insertion of an extractant into the inner coordination sphere of the rhodium(III) ion. The composition of the extracted compound was determined using electronic, IR spectroscopy and functional analysis, and the structure of this compound was proposed.

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Petroleum hydrocarbons (PHs) are the most widespread organic pollutants of roadside soils, the reclamation of which is costly due to large areas affected, and natural PHs biodegradation is the only way of mitigating negative ecological consequences. This study aimed to investigate the microbial response to PHs in roadside soils and to identify soil organic matter (SOM) and PHs involved in biodegradation processes. To address this aim, soil respiration is related to light (chain‐length ≤C14) medium (C15–C27), and heavy fractions (≥C28) of total PHs, and to SOM components: carbohydrates, proteins, lignin, aliphates, carbonyl/carboxyl, and char amounts of soils sampled at distances of up to 100 m from three roads in Kharkiv, Ukraine. A close relation between soil respiration and ratio of the light fraction to the sum of medium and heavy alkane fractions indicate the preferential mineralization of more biodegradable light PHs fractions. A positive relation between soil respiration and carbohydrate C, as well as negative correlation with aliphatic C, indicate preferred degradation of carbohydrates compared to more recalcitrant aliphates. Carbohydrate content increased and aliphatic C decreased with distance from the roads, and carbohydrates decreased with PHs concentration, indicating increased degradation of carbohydrates at high PHs concentrations (positive priming). It is concluded that microorganisms generate the energy required for PHs degradation by enhanced oxidation of native SOM where carbohydrates were of paramount importance.

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Experimental works are devoted to research the efficiency of deamonization and de-nitrogenation of wastewater during treatment in a biodisk installation. Working hypothesis - immobilization of the microbiocenosis can provide simultaneous deep treatment of wastewater from organic compounds and inorganic nitrogen-containing compounds. The purpose of this work is to assess the efficiency of purification of highly concentrated organic pollutants and mineralized wastewater from nitrogen compounds in a biodisk installation and to determine the main ecological-trophic groups of microorganisms included in the immobilized nitrogen-transforming microbiocenosis. Methods of research of immobilized microbiocenosis - microbiological. physiological, biochemical (inhibitory experiments), natural and model wastewater - hydrochemical. It has been established that in microbiocenosis immobilized on disks conditions that allow heterotrophic and autotrophic microorganisms to actively metabolize organic and inorganic compounds under aerobic and anoxidic conditions are created. The quantitative indicators of the influence on the kinetics of the processes of the concentration of organic substances in the treated wastewater have been determined. On the basis of microbiological, physiological and biochemical studies in the immobilized microbiocenosis, ammonium-acid bacteria (and, possibly, archaea) nitrite-acid and denitrifying bacteria were found, and in the absence of organic substances in the environment - anammox bacteria. Moreover, in the biofilm that was formed in the absence of organic substances in the environment, the activity of anammox bacteria in deamonization significantly exceeded the activity of ammonium oxidizing bacteria and archaea. The obtained results and quantitative requirements were used in the organization of real wastewater treatment in a biodisc plant in industrial conditions.