Level Of Maximum Permissible Concentration Research Articles

DEVELOPMENT OF A MATHEMATICAL MODEL FOR ANALYSING THE HAZARDOUS IMPACT ON THE STATE OF GROUNDWATER IN CITY AGGLOMERATIONS FROM MISSILE AND ARTILLERY ATTACKS

The authors have developed a mathematical model for analysing the hazardous impact on the groundwater in urban agglomerations from missile and artillery attacks. The mathematical model consists of a system of four analytical dependencies. The first analytical dependence describes determining the area of groundwater intake from the groundwater level, considering the presence of artificial coatings, infiltration, evaporation, and transpiration, as well as the effect of evapotranspiration. The second dependence determines the area of influence of the missile and artillery danger from the type of weapon, the explosive charge, calibre (diameter), and territorial conditions, the key indicators of the content of which in the territory of the critical infrastructure object, which suffered damage, are further determined by expert calculation using natural samples of soils and groundwater. The third dependence determines the impact of harmful (polluting) substances on groundwater in the territory of the critical infrastructure object, which suffered damage, depending on the process of groundwater movement in the area of the emergency, taking into account the hydraulic pressure and water yield coefficient; the process of distribution of chemically dangerous substances in groundwater, taking into account the coefficient of hydrodynamic dispersion and the velocity of groundwater; convective diffusion of chemically hazardous substances, taking into account the kinetics of sorption. The fourth dependency allows us to choose an efficient concept for the organisation of groundwater monitoring on the territory of a critical infrastructure object that suffered damage based on the variation of formalised parameters for solving individual problems. The initial conditions of the mathematical model are related to the presence of chemically dangerous compounds in groundwater at the maximum permissible concentration level. The boundary conditions of the mathematical model relate to the non-overgrowth of consequences beyond the object level in terms of the number of victims. Keywords: mathematical model, groundwater, missile and artillery damage, critical infrastructure object, emergency prevention.

Purification of surface water by using the corona discharge method

Purpose. The primary objective of this research is to develop a technology for achieving water quality at the level of Maximum Permissible Concentrations (MPC) required by sanitary regulations and norms. Methods. To meet these regulatory requirements, experimental studies were conducted to analyze the chemical and microbiological composition of water, focusing on parameters such as the total microbial count (quantity/ml), coliform bacteria (quantity/ml), coliphages (quantity/100 ml), clostridia (cl/20 ml), and other harmful substances. The research also examined water disinfection processes depending on the autumn and winter seasons of the year. Findings. To assess the device’s effectiveness, the research determined the optimal ozone concentration and contact time in the disinfection chamber. The findings indicate that 0.6 grams per hour (G = 0.6 g/hour) of ozone (O3) per cubic meter of surface water is sufficient for the removal of harmful microbiological substances. Originality. The primary innovation in this research lies in the establishment of parameters for an ozone generator utilizing a novel corona discharge method. The study introduces both theoretical frameworks and practical methodologies for effectively disinfecting surface waters using this innovative technique. Practical implications. This case study offers insights that can be applied and replicated in regions facing similar water quality challenges.

PUBLIC HEALTH RISK FROM CONTAMINATION OF DRINKING WATER WITH CARCINOGENIC CHEMICALS IN CENTRALIZED WATER SUPPLY SYSTEMS

The paper presents the results of assessing the carcinogenic risk to public health from consuming drinking water contaminated with priority chemicals at the level of their hygienic standards. A comparative analysis of SanPiN 1.2.3685-21 “Hygienic Standards and Requirements for Ensuring the Safety and (or) Harmlessness of Environmental Factors for Humans” and repealed SanPiN 2.1.4.1074-01 “Drinking Water and Water Supply to Populated Areas. Drinking Water. Hygienic Requirements for Water Quality of Centralized Drinking Water Supply Systems. Quality Control” valid since March 01, 2021, is carried out. Maximum allowable concentrations of carcinogenic chemical substances and values of slope factors and risk potential factors have been analyzed. A comparative analysis of SanPiN 1.2.3685-21 that is currently in force and the US EPA “2018 Edition of the Drinking Water Standards and Health Advisories Tables” has been conducted. The average daily intake doses of each studied substance in drinking water at the level of maximum permissible concentrations were determined. It has been found that, despite the tightening of standards for some substances, the content of many carcinogens in water at the maximum allowable concentrations or below can lead to high values of potential carcinogenic risk, and a list of activities is needed to complement the current standards regarding the quality of water.

Assessment of the safety of priority carcinogenic substances at the level of hygienic regulations in atmospheric air

The aim of this work was to assess the risk of carcinogenic substances with a proven danger to humans at the level of current maximum permissible concentrations (MPC). The results were obtained on the basis of the collection and analysis of data on chemical carcinogenic compounds that are included in the national regulatory base of permissible content in the atmospheric air of populated areas, as well as the base of Directives of EU countries and the International Agency for the Study of Cancer using bibliosemantic, bibliographic and hygienic research methods. At the same time, the chemical substances classified by experts from International Agency for Research on Cancer in terms of carcinogenicity to humans were taken into consideration: definitely carcinogenic (group 1), probably (group 2A) and possibly carcinogenic to humans (group 2B). As a result, 52 compounds were identified in the list of carcinogenic substances normalized in atmospheric air, of which 12 substances are assigned to group 1, 13 to group 2A, and 27 to group 2B. In this work, only substances of the first group were subject to in-depth analysis. To assess the danger of substances’ concentrations at the level of maximum permissible concentrations, risk indicators according to the recommended methodical documents were determined. Calculations of the carcinogenic risk caused by the concentrations of these substances at the level of hygienic regulations for the atmospheric air of populated areas proved that only for two compounds (benzo/a/pyrene and formaldehyde) the risk is acceptable and meets the international standards recommended by EU and WHO. For other substances of this group, the carcinogenic risk of exposure is excessive. A conclusion was made regarding the need to review the existing hygienic standards from the standpoint of risk and consider them in the future as annual averages. In order to solve this issue, the criterion scale "concentration - carcinogenic risk" was highlighted in the work, with the help of which it was proposed to determine the maximum permissible concentrations according to the indicators of risk acceptable for the conditions of Ukraine.

Deep eutectic solvents-based headspace single-drop microextraction for the chromatographic determination of phenols and aliphatic alcohols in atmospheric air

In this work, the possibility for gas chromatography determination of volatile organic compounds in atmospheric air with preliminary microextraction into single drop of a deep eutectic solvent is presented for the first time. Highly toxic compounds (phenol, o-cresol) and aliphatic alcohols (methanol, n-butanol, n-pentanol) were selected as analytes for which low MPCs in the atmospheric air were established. A eutectic mixture of natural, environmentally friendly substances menthol and thymol was used as an extractant. The resulting eutectic solvent forms a stable drop that allows the rapid extraction of analytes from the gas phase. 30 min of sampling is enough to achieve sensitivity at the level of maximum permissible concentrations of these analytes in atmospheric air. At the same time, the volatility of the components of the eutectic compound themselves made it possible to introduce this solvent directly into the gas chromatograph without dilution. The developed procedure was used to analyze real air samples and standard gas mixtures. The limits of detection for analytes were in the range 0.001–0.01 mg L−1. The RSD for all analytes was <5 %. This sample preparation method can be easily and efficiently combined with subsequent chromatographic detection.

Оценка состояния водоохранных зон р. Волги в районе п. Ильинка (Астраханская область)

Anthropogenic pollution of water basins may become a serious threat for ecosystems and human health. Pollutants are transferred through food chains or directly when untreated water is used, released to soil through subsoil waters or during floods. The increased anthropogenic load on rivers’ hydrosystems, especially in their del-tas, is becoming rampant these days. The goal of the research is to study the coastal areas and to assess the state of vegetation. To achieve this goal, standard methods of biotesting and bioindication were applied in the territories of two water-protection zones – those of the Volga River and the Nozhovskiy erik (shallow channel in the Volga delta – translator’s note) near the Ilyinka village. The water quality in the Volga River, within the examined range, is stably characterized as “dirty” (4th class). The exceeded level of maximum permissible concentrations for petroleum products, heavy metals (mercury, zinc, molybdenum), sulfides and phenols is observed. The research has not revealed the impact of the quality of water on phytotoxicity of the soil and indices of abundance of the vegetation that grows in this territory. Toxicity of soils is weak in the area of the Nozhovskiy erik, it is very weak in the area of the Volga River: the germination capacity of the test object (watercress) ranges between 67 and 88%, morpho-metric indices of plants do not differ much from those in control groups. Within the summer period the monitoring sites were characterized by the maximum frequency-abundance indices of typical representatives of the local flora, which are camel thorn (Alhagi pseudalhagi) and greater burdock (Arctium lappa). Vegetation in these areas is abundant, its state is assessed as satisfactory.

Removal of Cr(VI) from wastewater by modified montmorillonite in combination with zero-valent iron

For this study, the authors synthesised a composite sorbent based on montmorillonite: (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2·nH2O denoted by MM, that contains Fe3O4 particles and dodecyldimethylbenzylammonium chloride: C21H38NCl as a cationic surfactant (CS) denoted by MM:Fe3O4:CS. X-ray phase analysis showed that the interlayer distance of montmorillonite expanded by 0.3 Å in the process of modification by Fe3O4, and by another 2.5 Å with further addition of the surfactant. The expansion of the interlayer space of MM acts as evidence of the penetration of the modifying particles into the MM structure and the formation of a composite with properties that differ from the initial MM.This modification promotes an increase in the adsorption efficiency of Cr(VI) ions from their 50 mg/L acidic solutions by more than 5 times compared to the initial MM, and up to 2.8 times when compared to MM:Fe3O4 composite. The adsorption of Cr(VI) on MM:Fe3O4:CS is accurately described by the Langmuir model (r2 > 0.99); the maximum Langmuir capacity at pH = 5 and 290 K is 38.8 mg/g. The authors also investigated the thermodynamics of the sorption process; it has been shown that the process is endothermic, the determining factor in it is the structural changes of the sorbent. It has been shown that complete desorption of chromium is possible using a 2 M NaOH solution.The composite sorbent was tested on removing Cr(VI) from a real wastewater sample. It has been shown that purification to the maximum permissible concentration level in drinking water is possible when using a combination of adsorption with post-purification with zero-valent iron sol. On the basis of this combination, a scheme is proposed in this paper for the utilisation of chromium-containing solutions to obtain water of an acceptable quality that can be discharged into surface water, and a chromium-containing solution for the extraction of pure chromium compounds.

Technological Schemes for Collection, Disposal and Treatment of Surface Run-off and Their Development

The paper focuses on surface wastewater collection and its disposal from railway station tracks. It is described that usually either drainage trays located along the tracks or perforated pipelines arranged in special channels filled with water-permeable material are used to collect and divert surface run-off from the railway track. The analysis reveals the qualitative and quantitative composition of surface run-off. The paper shares data obtained during the investigation of railway stations and enterprises of the Kuibyshev railway and focuses on contamination of the territory of this enterprise with petroleum products and on concentrations surface wastewater contamination with petroleum products, suspended substances and iron. The authors further introduce technological schemes for surface wastewater treatment, which allow achieving the quality of treated wastewater at the level of maximum permissible concentrations for water bodies of fishing purposes.

Өндіріс әсер ететін аумақтағы топырақтың экологиялық жай-күйін бағалау

The article presents data on the study of changes in soil cover under the influence of human activity.&nbsp;&nbsp;&nbsp; The results of the conducted studies on the determination of the humus content and pH level, the content of heavy metals in technogenically disturbed soils in the adjacent territory of the natural gas processing enterprise are presented. The obtained data on the content of gross and mobile forms of heavy metals indicates that the maximum permissible concentration level for these pollutants is not exceeded.

Computer Simulation of Ventilation During Electric Welding Operations

The article considers the construction of an integrated ventilation system that combines local exhaust ventilation of welders’ workplaces and general exchange ventilation of premises. Using the method of computer simulation, the air movement fields, air temperature and concentration of harmful impurities are calculated. A comparative analysis of the main types of stationary devices for local exhaust ventilation of electric welding workplaces, such as exhaust hoods, welding panels, as well as air-blow exhaust devices, is carried out. The conditions for the effective use of lift-and-turn exhaust devices have been determined. The factors influencing the efficiency of their operation have been identified, and combinations of influencing factors that ensure the maximum permissible concentrations of harmful emissions in the welders’ working areas have been established. The conditions under which the general exchange effect of local exhaust is sufficient to maintain the concentration in the room at the level of maximum permissible concentrations (MPC) have been determined. The results obtained can be used to develop engineering methods for calculating and optimizing ventilation devices and systems, as well as to analyze structural and design solutions for the ventilation of electric welding productions.

Computer modeling of ventilation when performing electric welding

The design of an integrated ventilation system, which combines local exhaust ventilation of welders' workplaces and general ventilation of premises, is considered. Thefields of air mobility, its temperature and concentration of harmful impurities are calculated using the method of computer modeling. A comparative analysis of the main types of stationary devices for local exhaust ventilation of electric welding workstations (exhaust hoods, welding panels, as well as blowers) is performed. The conditions for the effective use of lift-and-turn suction pumps have been determined. The factors influencing the efficiency of their work have been identified, and combinations of influencing factors have been established that ensure the maximum permissible concentration of harmful emissions in the working areas of welders. The conditions under which the general exchange effect of local suction is sufficient to maintain the concentration in the room at the level of maximum permissible concentrations (MPC) have been determined. The results obtained can be used to develop engineering methods for calculating and optimizing ventilation devices and systems, as well as to analyze structural and design solutions for the ventilation device of electric welding industries.

ПРОСТРАНСТВЕННОЕ РАСПРЕДЕЛЕНИЕ ХИМИЧЕСКИХ ЭЛЕМЕНТОВ В ВОДОТОКЕ ШТОЛЬНИ 504 ПЛОЩАДКИ «ДЕГЕЛЕН»

Актуальность работы обусловлена необходимостью получения современных данных о концентрации химических элементов в системе «вода–почва–растения» на припортальном участке штольни 504 площадки «Дегелен» бывшего Семипалатинского испытательного полигона. В период весеннего половодья возможен вынос элементов за пределы площадки штольни 504. Цель: изучение пространственного распределения химических элементов в системе «вода–почва–растения» в водотоке штольни 504. Для достижения данной цели были поставлены следующие задачи: 1) определить уровни концентрации химических элементов в воде; 2) изучить уровни концентрации химических элементов в почве; 3) выявить особенности накопления химических элементов в растениях штольни 504. Методы. Элементный состав воды определялся методами масс-спектрометрии с индуктивно-связанной плазмой (Elan 9000 «Perkin Elmer SCIEX»), атомно-эмиссионной спектрометрии с индуктивно-связанной плазмой («iCAP 6300 Duo» Thermo Scientific). Анализ таких показателей, как общая минерализация, содержание сульфатов, гидрокарбонатов, хлоридов, кальция, магния и натрия, проводился титриметрическими, колориметрическими, потенциометрическими методами в соответствии с ГОСТ. Результаты. Анализ данных, полученных по воде, показал высокое содержание таких элементов, как Li, Be, Al, Mn, Zn, Rb, Sr, Cd, Cs, La, Ce, U, среднее содержание которых в несколько раз превышает показатель кларка в подземных водах аридного климата (сульфатные воды). Также для воды замечено превышение предельно допустимых уровней для таких элементов, как Be (2800 ПДК), Mn (260 ПДК), Al (76 ПДК), U (70 ПДК) и Cd (50 ПДК). По последним данным выявлено, что содержание таких элементов, как Li, Be, Al, в воде увеличилось в 2 раза, тогда как Co, Ni и Cu – в десятки раз. Пространственное распределение исследуемых элементов в почве штольни 504 неоднородно, большая часть элементов концентрируется в грунте севернее русла водотока. На данном участке выявлено повышенное содержание таких элементов, как Be, Mn, Cu, Zn, Мо, Cd, Cs, Pb и U, превышающих показатель кларка литосферы. Индекс превышения значения кларка литосферы составил для концентрации урана 1000 раз. Сравнение полученных данных на загрязненных участках со значением предельно-допустимых концентраций химических элементов для почвы выявило превышение у Pb (26 ПДК), Mn и Cu (9 ПДК). Химический состав воды и почвы штольни 504 является уникальным по содержанию редкоземельных элементов. Среднее содержание РЗЭ в воде в тысячу раз превышает показатель кларка в подземных водах аридного климата и подземных водах СИП. Замечено превышение предельно допустимого уровня концентрации для самария в воде. Характерным является преобладание группы легких РЗЭ с ярко выраженной церий-лантановой специализацией. Для большинства видов растений штольни 504 на загрязненном участке выявлено повышенное содержание Be, Сd, Cs, Pb, U и ряда РЗЭ. Концентрация исследуемых элементов в таких видах растений, как тростник и вейник, на сравниваемых участках менялась незначительно, что, видимо, обусловлено наличием физиолого-биохимических механизмов, препятствующих их поступлению. Исходя из вышеизложенного, можно сделать вывод, что пространственное распределение элементов на площадке штольни 504 связано, прежде всего, с выносом химических элементов штольневыми водами. В воде штольни 504 выявлено порядка десяти элементов, превышающих значения кларка и предельно допустимые уровни.

PURIFICATION OF WATER FROM PHENOL BY BACTERIA OF THE GENUS PSEUDOMONAS IMMOBILIZED ON NATURAL AND SYNTHETIC CARRIERS

Aim. Optimization of the process of water purification from phenol using bacteria of the genus Pseudomonas (P. cepacia ONU327, P. fluorescens ONU328, P. maltophilia ONU329) immobilized on natural and synthetic carriers. Methods. The concentration of phenol in water was determined by extraction-photometric method using 4-aminoantipyrin. For purification of water from phenol (with a concentration of 200 mg / l) non-pathogenic individual strains of bacteria P. fluorescens ONU328, P. maltophilia ОNU329, P. cepacia ОNU327, immobilized on carriers of different nature (zeolite, mussel doors, river sand, ceramic rings, activated carbon, high peat, synthetic carrier type "VIYA"). Results. There were experimentally confirmed that adhesion of cells of the bacterial strains of P. cepacia ONU327, P. fluorescens ONU328, P. maltophilia ONU329 to zeolite, river sand (which practically do not sorb phenol) contributed to the effective biodegradation of phenol by 96–100% (depending on the selected strain bacteria). The residual concentration of phenol in water during its treatment (for 11 days) by cells of P. fluorescens ONU328 strain or P. maltophilia ONU329 strain immobilized on zeolite decreased from 200 mg / l to 8.0±0.95 mg / l (water purification from phenol (α) – 96%) and up to 2.0±0.14 mg / l (α = 99%) – when using immobilized cells of the strain P. cepacia ONU327. It was established that when river microorganisms-destructors were immobilized on the river sand, the residual concentration of phenol in water on the 11th day of treatment was 6.0 ± 0.55 mg / l (α = 97%) and 2.0±0.14 mg / l (α = 99%) – respectively for the strains of P. maltophilia ONU329 and P. fluorescens ONU328; and reached the level of maximum permissible concentration (MPC = 0.001 mg / l) – in the case of river cells of strain P. cepacia ONU327 immobilized in the sand of the river. It was established experimentally that the acceleration of water purification from phenol occurred when using cells of bacteria of the genus Pseudomonas (P. cepacia ОNU327, P. fluorescens ONU328) immobilized on ceramic tubes and a fibrous nozzle of the “VIYA” type. Within 5 days of exposure, the degree of water purification from phenol immobilized on the fibrous attachment of the VIYA type by destructive microorganisms, taking into account the control correction (native unmodified sorbent of the VIA type) reached 97% – as a result of the action of the strain P. cepacia ONU327; and 99% – as a result of the strain P. fluorescens ONU328. Conclusion. To accelerate the purification of water from phenol (for 5 days) by 97–99%, it is recommended to use the strains of the bacteria P. cepacia ONU327 and P. fluorescens ONU328 immobilized on a fibrous nozzle of the type "VIYA". Full dephenolization of water is observed when it is treated with the strains of bacteria P. cepacia ONU327, P. fluorescens ONU328, which are immobilized separately on activated carbon, river sand (for the strain P. cepacia ONU327) and on the mussel doors (for the strain P. fluorescens ONU328), respectively.

Increase in Efficiency of Processes of Purification of Gases of Aluminous Production

Technical actions for decrease in harmful effects on the surrounding environment from the rotating furnaces of agglomeration of JSC RUSAL Achinskare offered. Additional technical solution on tertiary treatment of flue gases of the furnace of agglomeration in a scrubber electric precipitators and the direction of purified gases on repartition of carbonization of the aluminous shop is developed. the providing decrease in harmful emissions in the atmosphere to the level of maximum-permissible concentration. The carried-out trial tests of the offered technology confirmed that except effective purification of flue gases of furnaces of agglomeration of inorganic dust and carbon dioxide the high extent of decomposition of alyuminatny solution necessary for technology of receiving alumina is provided.

Water Purification from Hydroxo-Compounds of Iron by Ceramic Membranes Based on Clay Minerals

The high efficiency of the process of water purification from Fe(III) hydroxo-compounds by microfiltration tubular ceramic membrane based on clay minerals has been shown. This water purification process was developed by Dumanskii Institute of Colloid and Water Chemistry (ICWC), National Academy of Science of Ukraine. The effect of the initial solution concentration, its pH, working pressure, the process duration, and the presence of Cl, SO42− HCO3−, Ca2+ and Na+ ions on the separation properties of membrane was studied. The total salt content of the solution did not exceed the maximum permissible concentration (MPC) of the total mineralization of drinking water. It was established that Fe(III) solutions with Fe(III) initial concentration of up to ∼170 mg/dm3 could be purified to the Fe(III) MPC level in drinking water at pHini 5.0–7.5 and P = 1.0 MPa during the whole process when the membrane specific performance varied in the range 0.28–0.43 m3/(m2·h). As a result of dynamic modification by Fe(III) hydroxo-compounds at the minimum solution pHini 2.8, the membrane retained 33.8% of Ca2+ ions, i.e. acquired the ultrafiltration properties. The presence in solution of Cl−, SO42−, and HCO3− ions, each in the amount of 200 mg/dm3, and Ca2+ and Na+ ions in the amount of 150 and 236 mg/dm3, respectively, practically did not affect the retention of Fe(III) hydroxo-compounds by ceramic membrane. Since such membranes are cheaper than similar membranes based on oxide ceramics and not inferior to them in terms of the efficiency and can work in most severe conditions, they can be used in practice for the purification of the surface and underground natural waters from Fe(III) hydroxo-compounds, including compounds of various classes, such as chloride, sulfate, hydrocarbonate (carbonate), and mixed type. In addition, they can be applied in local installations for pretreatment of drinking water.

REMOVAL OF PHENOL FROM WATER BY BACILLUS SUBTILIS ONU551 BACTERIA, ADHESIZED ON THE CARRIERS OF DIFFERENT NATURE

Aim. Investigation of the efficiency of removal phenol from water by bacteria Bacillus subtilis ONU551 adhered on the carriers of different nature. Methods. The concentration of phenol in water was determined by extraction-photometric method using 4-aminoantipyrin. The significance of the differences between the mean values of the residual concentration of phenol in water was determined by Student's criterion at a significance level of at least 95% (p ≤ 0.05). Data processing was performed using the program Microsoft Office Excel 2003. Results. The ability of a B. subtilis ONU551 bacterial strain isolated from waste water produced by pharmaceuticals to oxidize phenol was experimentally established. The concentration of phenol in water during its treatment with free cells of the B. subtilis ONU551 bacterial strain in the amount of 5.5×105 CFU/ml for 5 days of exposure decreased from 200.0 to 112.0±5.5 mg/l (by 44% ), reaching maximum on the 15th day – the degree of phenol removal from water was 99-100%. Adhesion of B. subtilis ONU551 bacteria to the surface of natural (zeolite, peat, activated carbon, sand), synthetic (ceramic tubes, fibrous nozzles of the “VIYA” type) of carriers accelerated the removal of phenol from water 1.4–2.5 times , compared to the treatment of water by free bacterial cells. The residual concentration of phenol in water during its treatment with B. subtilis ONU551 bacteria adhered on sand and on “VIYA” type fiber packing decreased for 6 days from 200.0 mg/l to 9.0±0.25 mg/l and 6.0±0.54 mg/l, respectively (by 95–96%) and on the 11th day was at the level of maximum permissible concentration (0.001 mg/l). The degree of removal of phenol from water by B. subtilis ONU551 bacteria adhered on mussel doors, peat and zeolite at the end of cleaning (11 days) ranged from 87% to 99%; and reached 100% – when used as the carriers of activated carbon, ceramic tubes. Conclusion. The use of B. subtilis ONU551 bacteria adhered on natural and synthetic carriers – mussel shutters, peat, sand and fibrous attachment of “VIYA” type ensures 100% removal of phenol from water.

SRS-lidar for environmental monitoring atmospheric surface layers

Background: The development and implementation of new methods of environmental monitoring is an urgent problem due to the technogenic pollution of the Earth's biosphere. The remote control of the gas composition of the surface atmosphere layer in industrial zones of modern metropolis is important for determining penalties for enterprises whose emissions of pollutants exceed established norms. Objectives: Development of an ecological Spontaneous Raman Scattering (SRS) lidar for monitoring the gas composition in the air basin of large megacities. Theoretical verification of the lidar effectiveness for problem solving. Materials and methods: The developed lidar for environmental monitoring of the atmospheric surface layer is based on the SRS method which allows remote monitoring of the atmospheric gas composition at distances up to several kilometers with a fairly high resolution (up to 1 meter). The absolute concentration of detected polluting gases is determined by comparing the intensities of the satellite pollutant and nitrogen lines in the recorded SRS spectra. Results: The choice of the SRS method for remote laser monitoring of the atmosphere ground layer in large industrial centers is substantiated. The block diagram and the main technical characteristics of the developed SRS lidar are presented. Preliminary estimates of the lidar efficiency for the environmental monitoring were carried out. Conclusions: The simulation results have shown that the specifications of the SRS lidar allow detecting of following polluting gases: CO, NO2, SO2, CH4, H2S, C6H6 at distances up to 200 m with the maximum permissible concentration level. The simulation results were obtained when accumulation time varied from 10 s to 4 min. The specification of the SRS lidar allow its using for remote monitoring of air conditions in the cities and near industrial enterprises.

Zinc, copper, cadmium, and lead levels in cattle tissues in relation to different metal levels in ground water and soil.

The objective of the present study was to investigate the interaction between environmental (water and soil) levels of zinc, copper, cadmium, and lead levels, as well as their content in Hereford beef cattle tissues in five districts (D1-western area, D2 and D3-central area, D4 and D5-eastern area) of the Orenburg region. Soil metal levels were assessed using atomic emission spectrometry, whereas water and tissue (liver, kidney, muscle, heart) metal content was studied using inductively coupled plasma-mass spectrometry. The obtained data demonstrate that the highest levels Zn in soil and water (p < 0.001), as well as cattle muscle, liver, and kidney (p < 0.05) were observed in D4 and D5 (eastern area), exceeding the maximum permissible concentration levels (MPCL) for drinking water and muscle for all regions. Similar associations were found for Cu levels. The highest soil and water Cd and Pb content were observed in D2 (central area) and D5 (eastern area), respectively. At the same time, cattle tissue Cd and Pb content did not correspond to the respective environmental levels. Correlation analysis demonstrated that water and soil Zn and Cu content directly correlated with muscle, liver, and kidney, but not heart metal content. At the same time, water Cd levels were negatively interrelated with muscle cadmium content but correlated directly with hepatic metal content. Both water and soil Pb levels positively correlated with renal metal levels in cattle. In turn, soil lead content was inversely associated with muscle metal levels. Regression analysis also demonstrated a significant association between environmental and tissue levels of Zn and Cu. The models adjusted for all studied elements demonstrated a significant effect of metal interaction on tissue metal levels. Hypothetically, excessive environmental Zn, and possibly Cu, levels may affect the uptake of heavy metals including Cd and Pb from the environment.

Investigation of biological destruction of benzo[a]pyrene andpolycyclic aromatic hydrocarbons of biochar in soil

The biological decomposition of benzo[a]pyrene in the concentrations exceeding the MAC (maximum permissible concentration) level in soils by 2, 5 and 10 times was studied in laboratory conditions. The gray forest soil samples were contaminated with benzo[a]pyrene and incubated in optimum for bacterial growth soil moisture for 30 and 60 days. The residual amount of contaminant was monitored by HPLC after extraction with acetone-cyclohexane (2:1). Soil microbial activity was evaluated by measuring basal respiration (BR) and substrate-induced respiration (SID) rates of the soil by gas chromatography. The results of the experiment showed that in 60 days the amount of benzo[a]pyrene in contaminated soils decreased; however, this time was not enough for complete decomposition of pollutant. In this case, benzo[a]pyrene has a negative effect on the BR and SIR rates. Soil contamination affected the BR rate only at high doses (10 MPC), whereas the SIR was a more sensitive indicator of the toxic effect of the pollutant and significantly reacts already at concentrations at the level of 2 MPC. The combination of PAHs isolated from biochar has a strong negative effect on the values of BR and SIR.

Твердофазные биосорбенты для очистки воды от нефтяных углеводородов

In the model solution of dodecane investigated sorbents with immobilized microbial&#x0D; cells genus Pseudomonas (K-5-25, A-2) and Rhodococcus (EriA. 2-4m). Sorbents based&#x0D; on non-woven fabrics made of polypropylene fibers (neutral) and the acrylonitrile&#x0D; fibers containing in their structure of the group of primary and secondary amines, as&#x0D; well as on natural material of the mineral from the group of hydrous layered structure.&#x0D; The efficiency of the sorption and biocatalytic contributions to the study of the degree&#x0D; of water purification. Such self-recovering system, combining physico-chemical and&#x0D; biological removal of petroleum hydrocarbons from solutions with low concentrations&#x0D; of trace and can operate in dynamic mode. Moreover, the sorbent performs one of the&#x0D; most important functions of biological systems, providing delivery and accumulation&#x0D; of oil components from the liquid phase, immobilized cells and carry out selfregeneration&#x0D; biosorbent. Analysis of the comparative effectiveness of these processes&#x0D; with the use of a kinetic model of the results obtained on the solid-phase sorbent with&#x0D; immobilized cells and the initial sorbent without cells, allowed us to determine the&#x0D; degree of physical and chemical removal of dodecane from an aqueous emulsion and&#x0D; the degree of biodegradation, as in liquid, and in solid phase sorption material. The&#x0D; most efficient biological system has shown itself on the basis of non-woven material&#x0D; acrylonitrile, allowing up to 8 days to reduce the concentration of dodecane to the&#x0D; level of maximum permissible concentration and below.