A new biopreparation is developed to clean soils from oil pollution in the arid climate of the Republic of Kazakhstan. The biopreparation includes bacterial strains R. qingshengii F2-1, R. qingshengii F2-2, and P. alloputida BS3701. When using the biopreparation in a liquid mineral medium with 15% crude oil, laboratory studies have revealed degradation of 48% n-alkanes and 39% of PAHs after 50 days. The effectiveness of the biopreparation has been demonstrated in field experiments in the soil contaminated with 10% crude oil at the K-Kurylys landfill, Republic of Kazakhstan. During the six-month field experiment, the number of oil degraders reached 107 CFU/g soil, which degraded 70% of crude oil by the end of the experiment.
The problem of eliminating petroleum pollution and its consequences is currently very relevant for Kazakhstan, which is among the ten largest oil-producing countries. The specifics of natural conditions—the sharply continental arid climate—necessitate the development and application of adequate technologies for the restoration of oil-contaminated territories and the Caspian seashore. The key factors (temperature, moisture, alkalinity, salinity, low mineral and organic matter content) affect the self-purification processes and microbiological status of oil-contaminated soils of Kazakhstan. The assessment of taxonomic diversity and characteristics of oil-degrading microorganisms isolated from samples of soils and reservoirs contaminated with hydrocarbons are given. The review of biopreparations and biotechnologies developed and used in Kazakhstan for cleaning environments from oil pollution is made, and their effectiveness is shown. The analysis of the current state of research in the field of biodegradation of hazardous pollutants and bioremediation of oil-contaminated areas allows us to identify promising areas of further work and approaches to the development and improvement of technologies for environmental protection.
In the Republic of Kazakhstan (one of the top 10 oil-producing countries in the world), the remediation of oil pollution found in unproductive soils under the conditions of a sharply continental arid climate is a highly relevant problem. The aims of this work are to study the biodegradation capacity of the gray soil of the ‘Daulet Asia’ landfill, assess the degradative potential of indigenous oil-degrading strains and changes in the composition of the soil microbial community. Analytical chemistry methods, distillation and chromatographic mass spectrometry were used for oil analysis; gravimetry and IR spectroscopy were used to evaluate oil degradation. Standard microbiological techniques were employed to isolate and cultivate microorganisms and metagenomic sequencing was carried out using Oxford Nanopore technology. Raw data processing and subsequent analysis were performed using modern software packages. Three isolated strains of interest were identified based on the analysis of 16S rRNA gene fragment sequences. The studied soil has low biodegradation capacity (oil loss was 6.2% on day 60), possibly due to the low abundance and weak activity of indigenous hydrocarbon-oxidizing microorganisms. The taxonomic composition of the microbiome in the studied soil suggests some potential for oil degradation. Assessment of the effectiveness of oil degradation by the indigenous microbiome indicates that this potential can be realized only marginally in situ. Isolated oil-degrading strains were identified as belonging to the Rhodococcus and Kocuria genera. Effective oil removal from the studied soil requires the introduction of active microorganisms (e.g., as part of biopreparations). Considering the characteristics of the hot arid climate, for bioremediation of contaminated sierozems of Southern Kazakhstan, it is advisable to use halotolerant oil-degrading microorganisms with a wide temperature range that are capable of degrading hydrocarbons under moisture deficiency.
The article presents the results of gas chromatographic studies of the oil sludge hydrocarbon composition, physical and chemical and heat-producing properties, which enabled to assess the potential of oil sludge as raw materials, their assortment predisposition and possible manufacturability. It has been established that the main physical and chemical characteristics of the organic part from the averaged samples of oil sludge are similar in properties to raw materials for the production of kerosene-diesel fractions. The expediency of the use of oil sludge and weakly bloating clay materials in the production technology of the popular construction material - expanded clay is substantiated. The results of experimental studies on the development of light and porous heat insulating material by granulation method are presented herein. It is shown that oil sludge from a high viscous state is transferred to a loose conglomerate with a moisture content of 12-15% by co-mixing with finely dispersed sand dune, which ensures uniform distribution when mixed with the basic mass. The peculiarities of granules burning according to a specially developed mode without preliminary drying are considered. It has been established that the addition of oil sludge increases the organic content in the mixture, thereby intensifying the process of combustion, gas generation and bloating of the ceramic body, which will positively affect the technological parameters of obtaining. product. It is found that the proposed technology allows to obtain marketable products, which can be used efficiently. At the same time, the unconditional priority is given to waste-free technologies, as the most environmentally friendly.
15 October 2020 in SERIES CHEMISTRY AND TECHNOLOGY
The article presents the results of gas chromatographic analysis method of the organic part of oil bituminous rock and the results from the analysis of the molecular weight distribution of atactic polypropylene carried out using reverse gel-permeation chromatography. The research results of the structural and mechanical properties of the bitumen part of oil bituminous rock (OBR) of the Iman-Kara deposit, atactic polypropylene (APP) and compositions based on them, carried out on the instrument Reotest 2.1, are also presented herein. It has been determined that the organic part of OBR of the Iman-Kara deposit mainly consists of oxygen-containing organic compounds with additions of heteroatomic structures (sulfur, haloids and nitrogen) with a weight fraction of 53.97%. According to the chromatogram of the molecularly-mass distributed atactic polypropylene, it is found that the average time of fraction maximum yield is 11.4 minutes, the corresponding value of logarithm of the average molecular weight Lg(M) equals to 5.5. Accordingly, the average molecular weight of fraction M is 400. The change patterns of the rheological properties of the organic part of OBR, atactic polypropylene and compositions based on them are described. It has been established that the addition of APP to the organic part of OBR creates a disperse system in which the particles of a polymer additive that are swollen due to oily components are dispersed in the bitumen medium. At the same time, mechanical properties such as elasticity and heat resistance of the organic part of oil bituminous rock are improved. These properties can be shown only with the optimum quantity of APP, when their concentration is such that they form an uninterrupted net structure. The influence patterns of APP on the structure of the organic part of OBR defined in the process of experiments can also be used in further experiments during development of various types of waterproofing materials and coatings.
Background/Objectives: The development of antitumor agents possessing low toxicity against non-cancerous cells is still a challenge in medicinal chemistry. In this paper, we report the antitumor activity of “hybrid structures” derived from the amino acid taurine. We have synthesized 26 compounds, structures of which were confirmed using NMR, X-ray diffractometry, and other techniques. Cytotoxicity of the obtained compounds has been evaluated using three human cancer cell lines. Pyrrolidine 4p has exhibited the strongest antiproliferative activity against HL-60 cells with an IC50 of 76.7 μM, while IC50 against normal cells was 176.3 μM. Water-soluble derivatives of taurine have been tested for antileukemia activity in mice of the BDF1 line. Compound 4p has been identified as the leading compound, which increases the mean survival time of mice from 40 to 100% as compared to the control group. Together, these results prove that taurine-based hybrid structures can be a promising scaffold for the discovery of potential antiproliferative agents.