The review presents relevant data on polycyclic aromatic hydrocarbons (PAHs): physical and chemical characteristics,
sources of release into the environment, impact on human health, sanitary and hygienic regulation, methods of sample
preparation and detection. PAHs are found everywhere in nature: in geological sediments, soil, air, water, snow, plant
and animal tissues. Many of the PAHs exhibit carcinogenic, mutagenic, and teratogenic activity. The content of PAHs,
as a class of organic pollutants with a complex mechanism of action, should be mainly controlled during environmental
monitoring. All measures to reduce the level of environmental pollution in Russia are based on control over the content
of harmful substances, which is regulated by sanitary and hygienic standards.
The wide distribution of PAHs in trace concentrations and their ability to accumulate in various objects necessitates
the development of effective methods for their control. Special attention in the review is paid to modern spectroscopic
methods for the determination of PAHs in environmental objects: spectrophotometry, low-temperature Shpol’skii luminescence, molecular fluorescence analysis, micellar-stabilized and solid-phase luminescence, phosphorescence at room
temperature, and fluorescence resonance energy transfer. A comparative analysis of the methods allows us to conclude
that the sensitivity of the methods of molecular luminescence analysis, as a rule, exceeds the methods of spectrophotometry. The main limitations of the methods of molecular luminescence analysis are associated with insufficiently high
versatility and selectivity.
Further studies to improve spectroscopic control methods aimed at eliminating interfering influences and improving
the selectivity and sensitivity of methods for analyzing multicomponent PAH mixtures in environmental monitoring
are promising.
Keywords: polycyclic aromatic hydrocarbons (PAHs), sources of PAHs, effect on human health, spectroscopic methods, absorption, luminescence
Article published in number 4 for 2021 DOI: 10.25750/1995-4301-2021-4-012-019
Views: 52
Possibility of disposal of plastic waste using micromycetes Fusarium solani and Trichoderma lignorum
The effect of micromycetes (MM) Fusarium solani and Trichoderma lignorum on the biodegradation of plastics (sevilene, polystyrene, polyethylene, polyamide, polycarbonate, fluoroplast-4) after 10 years of exposure in an aqueous medium in a closed system was investigated. Differential scanning calorimetry showed that destruction was most complete in the case of polyamide, and less intense in the case of sevilen.
The cultivation of MM with these polymers led to a significant alkalization of the medium, an increase in the specific electrical conductivity and the concentration of inorganic ions in the aqueous suspension, which is associated with the vital activity of microbial cells. In a suspension of three polymers (polyamide, polystyrene, and polycarbonate) favorable conditions are created for the life of MM, especially for T. lignorum, which may indirectly indicate the possibility of using the products of destruction of these polymers by fungi as nutrients.
The maximum values of the content of suspended solids and the minimum coefficient of light transmission in the suspension, which indirectly indicate a greater mass of mycelium, are established for the variants of polyamide, polycarbonate and polystyrene with micromycetes.
The maximum content of organic substances in suspensions, determined by the COD index, was noted for samples of sevilene, polystyrene and polyethylene (control and with MM), the minimum – for samples of fluoroplast-4.
The proof of the MM viability after 10 years of exposure was the powerful growth of mycelium on the surface of the nutrient medium in all variants during their microbiological inoculation, which indicates that the studied polymers served as a carbon source for fungi for a long time.
The results of the study showed that the polymers most utilized by the studied types of ММ were polyamide, polycarbonate and polystyrene. To accelerate the biodegradation of polymers, it is necessary to optimize the conditions, in particular, to carry out the process with the introduction of certain nutrients that accelerate the growth of MM.
Article published in number 4 for 2021 DOI: 10.25750/1995-4301-2021-4-193-202
Views: 29
Problems of legal regulation of medical waste disposal
E.D. Vetoshkina, E.S. Koshcheeva, M.A. Smirnov
Section: Social ecology
The article is devoted to an urgent problem in the field of environmental safety – legal regulation of medical waste
management at the level of federal legislation, as well as trends in the normative consolidation of the medical waste
disposal system being created. The selected legislative mechanism for special regulation in the field of medical waste
disposal is the most optimal model of legal regulation. Exemption of the specified category from the scope of Federal Law
No.89-FZ “On Production and Consumption Waste” of June 24, 1998 contributes to the environmental safety on issues
of medical waste disposal. On the other hand, a serious problem of legal regulation has been identified. The result of the
study is a recommendation on the need for special legal regulation of the medical waste management system at the level
of the law. The normative model of special regulation on the example of the draft law “On conducting experiments on the
organization and centralized management of medical and biological waste in the Moscow region and on amendments to
certain legislative acts of the Russian Federation” is assessed by the authors positively in terms of differentiating the
concepts of “medical waste” and “biological waste”, but the idea of introducing a regional operator and the principles of
public-private partnership (by analogy with the model of solid waste disposal) is criticized.
Keywords: medical waste, regulation, liability in the field of medical waste circulation, legal regulation model
Article published in number 4 for 2021 DOI: 10.25750/1995-4301-2021-4-224-229
Views: 29
Technological solutions and experience of industrial processing of liquid acid-alkaline waste
Section: Methodology and research methods. Models and forecasts
At industrial enterprises, there are remnants of materials and raw materials that were formed during production and lost their initial properties. These materials are commonly referred to as man-made waste. The analysis of waste of hazard classes I and II from the list of Federal Classification Catalog of Waste showed that it is necessary to process such liquid waste as spent acids (sulfuric, hydrochloric, nitric, phosphoric), residues of alkaline reagents (potassium and sodium hydroxides), spent solutions for treating metal surfaces (phosphating, oxidation, degreasing, passivation, etching, etc.), spent electrolytes (nickel plating, galvanizing, cadmium, etc.), etc. A characteristic feature of this type of waste is a significant content of toxic ions of heavy metals, petroleum products, an increased salt background. The listed wastes are close to those that are formed in electroplating industries and in the production of inorganic materials. This made it possible to prepare proposals for technological solutions for the integrated processing of liquid waste of hazard classes I and II.
The paper presents the data of laboratory studies and industrial tests of the process of purification of acid-base wastewater and waste technological solutions from poorly soluble metal compounds, as well as organic compounds of various nature. The high efficiency of the combined use of the reagent method, electroflotation, membrane filtration and sorption methods for wastewater treatment from metal ions and organic pollutants is shown. The following technological indicators of purification efficiency have been achieved: the efficiency of extraction of metal ions in the form of poorly soluble compounds is 96–99%, the efficiency of extraction of petroleum products, industrial oils and surfactants is more than 90%.
Article published in number 4 for 2021 DOI: 10.25750/1995-4301-2021-4-034-042
Views: 19
Ecology and sustainable development: priorities of science and education
D.S. Ermakov
Section: Chronicle
We present results of the discussion about the state and prospects of scientific research in the field of ecology and sustainable development at the All-Russian scientific and practical seminar "Ecology and sustainable development: priorities of science and education" (May 31, 2021, A. N. Severtsov Institute of ecology and evolution of Russian academy of sciences, Moscow), which was attended by employees of research institutes and environmental institutions, teachers of schools and universities, representatives of executive and legislative authorities, public organizations. Experts in the field of ecology, geography, sociology, economics, political science, pedagogy discussed the importance of studying and solving problems of sustainable development, which are currently considered mainly in the socio-economic aspect, primarily from an environmental point of view. We need special research which will link the mechanisms of ensuring the sustainability of natural systems of different levels and societies, as well as to implement them in practice with the active assistance of the education and enlightenment system, the interested participants which are decision-makers, and the general population. The necessity of greening the economy and nature management, improving legislation, state, and local governance, preserving biological diversity and the environmental functions of natural ecosystems, mitigating and preventing the negative effects of climate change, providing reliable information about the state of the environment and overcoming "scientific myths" about sustainable development, training qualified personnel and developing talents in the field of ecology is emphasized. According to the results of the seminar, it was noted that at the global plan we need new meanings and development priorities. At the same time, current scientific results and expert assessments should be involved in the process of making political and socio-economic decisions, developing state, regional and municipal programs; they should be brought to the attention of the general public (particularly, in a popular form, through the mass media) and used for implementation of training courses and educational projects.
Complex processing of phosphatic ores enrichment waste
D.Y. Turaev, I.A. Pochitalkina
Section: Ecologization of industry
The production of high-quality phosphate fertilizers, in particular calcium acid phosphates, requires the use of ore
rich in phosphates (above 28 wt.% P2O5
) and containing a minimum amount of impurities, including harmful ones.
The absence of such large natural deposits leads to the need to enrich the existing phosphate ore containing an average
amount of phosphates (14–23% P2O5
) and contaminated with various impurities. Enrichment of polymineral phosphate
ores leads to the production of their concentrates and waste (sludge). Sludge is a mixture of clay impurities, iron compounds, phosphate substances contained in the original ore, as well as toxic surfactants used in its flotation enrichment.
This prevents the use of sludge as a secondary source of raw materials in any industry and its return to waste deposits.
The lack of methods for processing sludge leads to their accumulation and environmental pollution: the area of
fertile land is shrinking, pollution of nearby natural water bodies increases. The proposed integrated physicochemical
technology for processing phosphate ore dressing wastes using nitric acid is aimed at improving the environmental
situation in the regions producing phosphate raw materials and obtaining a number of valuable products important for
the national economy: glauconite sand, clay, hydrogen phosphate and calcium nitrate. The yield of sludge processing
products was experimentally established, which amounted to: 68.6% glauconite, 6.91% clay, 12.9% technical calcium
hydrogen phosphate, 18.2% technical calcium nitrate. Processing products – clay and glauconite sand are most widely
used in the construction industry, in particular, in the production of bricks and concrete. Glauconite sand and clay are used in the production of sorbents, paints and primers. Hydrophosphate and calcium nitrate are used in agriculture as
phosphorus and nitrogen fertilizers, respectively.
Keywords: phosphatic ore, slimes, the nitric-acid method, glauconitic sand, clay, hydrophosphate of lime, nitrocalcite
Section: Methodology and research methods. Models and forecasts
The article is devoted to the problem of neutralization of industrial wastewater containing highly toxic chlorides,
sulfates, nitrates, ions of heavy and non-ferrous metals. Wastewater, as a rule, has an acidic reaction, and the first stage
of its neutralization consists in the use of alkaline reagents (NaOH, Na2
CO3
, Ca(OH)2
) to neutralize and form hybrid
sediments of iron, aluminum and other metals. The total concentration of salt components in technological solutions
ranges from 10 to 100 g/L, most often it is a mixture of Na2
SO4
, NaCl, NaNO3
, less often other salts. The technology of
deep processing of mineralized water consists in softening, filtration on pressure filters and microfiltration of industrial waste. The peculiarity of the proposed scheme lies in the use of the reverse osmosis method of desalting, according to
which it is concentrated by 3–5 times and evaporated to a salt content of 200–300 g/L. This scheme allows you to obtain
concentrate and fresh water that meets environmental requirements. After water demineralization, the concentrate goes
to isohydric crystallization with Na2
SO4 · 10H2
O by cooling to 0 о
С. After centrifugation of the pulp, the mother liquor is
mixed with the initial stream and sent to a reverse osmosis unit, and the crystalline hydrate is sent to drying to obtain
anhydrous technical salt.
On the example of a model technological solution that simulates liquid industrial waste from mining enterprises, with
the help of computational and experimental studies, the fundamental possibility of obtaining anhydrous sodium sulfate
by means of intracycle isohydric crystallization of a concentrate after a reverse osmosis plant has been shown. A schematic diagram of the neutralization of liquid inorganic waste of I and II hazard classes with the production of a secondary
product, Na2
SO4
, is proposed; the possibility of isomorphic capture of impurities during its crystallization is estimated
Section: Methodology and research methods. Models and forecasts
Membrane technology is a crucial tool toward technological process intensification in chemical industry. In addition
to its undeniable contribution to desalination and reuse of water, the spread of separation applications in industry could
save great part of the energy. Beyond the contribution to the environmental and economic improvement of separation
processes, the membrane manufacturing industry itself needs to minimize environmental and occupational risks, that
means meet principles of “green” chemistry. Membrane manufacturing should be developed with the reduction or elimination of hazardous compounds. The chemical processes of membrane production are linked with the use of a wide range of
solvents. A lot of organic solvents required for membrane production are classified as toxic or hazardous substances and
their use is strictly limited by law. One of the promising environmentally friendly methods of production of membranes
is the applying of “green” solvents.
As an alternative technology, it is proposed to use the freeze method, in which non-toxic dimethyl sulfoxide (DMSO)
is used as a solvent. This technology requires less energy consumption, which also allows implementing the principles
of “green” chemistry.
Microporous membranes based on poly(vinylidene fluoride) (PVDF) with a thickness of 100 to 250 μm was carried
out by freeze method. Dimethylsulfoxide (DMSO) was selected as the most environmentally friendly solvent for some
fluoropolymers. Porosity, permeability, wettability, physical and mechanical characteristics for obtained membranes
and their morphology were investigated.
It has been found that the most optimal concentration of PVDF in the solution is 30 wt.%. In this case the best
combination of technological and operational properties is provided. The efficiency of prepared membranes for microfiltration process was demonstrated by a suspension of the yeast Saccharomyces cerevisiae.
Such technology in comparison with the existing ones, is devoid of some disadvantages like using of complex equipment and high operating temperature. Freeze method does not require high energy consumption and using of toxic solvents.
Article published in number 4 for 2021 DOI: 10.25750/1995-4301-2021-4-064-070
Views: 15
Flotation technologies for purification of filtration waters of solid waste landfills
V.P. Meshalkin, V.S. Kovalenko, G.A. Shcherbakova, A.V. Kolesnikov
Section: Methodology and research methods. Models and forecasts
Comparison of leachate water treatment methods for solid household waste (MSW) landfills is carried out. The experiments were carried out on model solutions and real filtrate from the MSW landfill of the Moscow region. It has been established that electroflotation treatment is an effective method due to high recovery rates, low energy consumption, as well as the possibility of automation and the absence of secondary water pollution. The effect of surfactants (surface-active substances, SAS), flocculants, Ca, Mg, Ba reagents on electroflotation extraction of UltraPAC coagulant in aqueous solutions of NaCl, Na2SO4 is described. It was found that the addition of an anionic surfactant to the system promotes the
adsorption of the surfactant on its surface, which makes it more hydrophobic, increasing the degree of electroflotation extraction to 95–99% in some cases.
The results of measurements of the particle size, surface charge of the dispersed phase of the UltraPAC co-he results of measurements of the particle size, surface charge of the dispersed phase of the UltraPAC coagulant are presented. It was found that the ζ-potential of Al(OH)2Cl in NaCl solutions in a wide range of pH 5–9 is positive, (+5–+33 mV). In Na2SO4 solutions at pH 7 surface recharge is observed, which is explained by the specific adsorption of SO4 2- anions on the surface of the dispersed phase of Al(OH)2Cl. The particle size varies from 38 μm (pH 5) to 12 μm (pH 9) – in Na2SO4 solutions and from 16 μm (pH 5) to 19 μm (pH 9) – in NaCl solutions. It was found that the addition of Ca2+, Mg2+ reagents to the solution for pH adjustment leads to suppression of the electroflotation process. The introduction of an anionic surfactant stabilizes the electroflotation process and increases the degree of extraction of the coagulant to 75% (MgCl2 – 0.1 g/L) and 99% (CaCl2 – 0.1 g/L).
Studies of the sorption process of extracting Fe3+ and Al3+ ions from aqueous solutions of sodium chloride, nitrate and sulfate salts in a static mode on an industrial powder sorbent of the OU-A brand have been carried out. The influence of Cl-, NO3- and SO42- anions on the value of sorption of metal cations was determined. By the nature of the adsorption isotherms of metal ions, an assumption about the mechanisms of the process was made. The values of the electrokinetic potential of coal particles in salt solutions were obtained, on the basis of which flocculants were selected and their effect on the efficiency of the electroflotation process for extracting spent carbon sorbent was evaluated. It was found that the spent sorbent with Fe3+ ions in an amount of up to 1 g/l, and the sorbent with Al3+ ions – up to 1.6 g/l within 10 minutes can be extracted from solutions of nitrate and sodium chloride salts by adding flocculants of cationic and nonionic types. The experimental studies have shown that the use of a combined method, including sorption treatment with subsequent extraction of the spent sorbent in the process of electroflotation, will not only reduce the duration of wastewater treatment, but also provide a high degree of their purification.
ISSN 1995-4301
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