Reclamation Efficiency Research Articles

Improving mine reclamation efficiency for farmland sustainable use: Insights from optimizing mining scheme

Underground coal mining inevitably causes ground subsidence, especially in the coal-grain composite area with a high groundwater table (HGT) in eastern China, where mining subsidence causes waterlogging of arable land and threatens regional food security. Concurrent Mining and Reclamation (CMR) of underground coal mines emphasizes the implementation of reclamation measures in the subsidence process, so it is necessary to simulate and analyze dynamic subsidence to optimize reclamation planning. In this paper, the Guqiao coal mine, one of the HGT coal mining areas in eastern China, is used as a research area. First, the New Water Index (NWI) method and Otsu image segmentation algorithm were adopted to quantitatively analyze the spatial distribution and expansion of surface ponding caused by underground coal mining from 2008 to 2020 based on Landsat remote sensing images. Second, Fast Lagrangian Analysis of Continua in three Dimensions (FLAC3D) was used to invert the law of surface subsidence and the evolution characteristics of surface water caused by different mining schemes. Finally, each simulated mining scheme's reclamation timing, earthwork allocation, and reclamation rate were compared. The results show that: (1) the waterlogging area increases yearly with coal mining, reaching 1049 hm2 in 2020; (2) compared with the traditional reclamation (TR) rate of 32%, the reclamation rate of CMR could be increased to 65%; (3) the best mining scheme for CMR was up-warding skip mining with a reclamation duration of three years in this case. Optimization of mining schemes could control the temporal and spatial distribution of surface subsidence and determine the land reclamation plan. Meanwhile, the land use planning feedback could guide the mining scheme's design and realize sustainable land use during the mining life cycle in other similar areas.

Activated Carbon-Loaded Titanium Dioxide Nanoparticles and Their Photocatalytic and Antibacterial Investigations

Activated carbon doping TiO2 nanoparticles were synthesised by zapota leaf extract using the co-precipitation method. The bio-constituents of plant compounds were used in the reactions of stabilization and reductions. The carbon loading on the TiO2 nanoparticles was characterised by XRD, FTIR, UV-DRS, SEM with EDX, and TEM analysis. The loading of activated carbon onto the TiO2 nanoparticles decreased the crystallite size and optical bandgap, and their doping improved the surface structure of AC/TiO2 nanoparticles. Mesoporous/microporous instability was remodified from the activated carbon, which was visualised using SEM and TEM analysis, respectively. The photocatalytic dye degradation of Rh-B dye was degraded in TiO2 and AC/TiO2 nanoparticles under visible light irradiation. The degradation efficiencies of TiO2 and AC/TiO2 nanoparticles were 73% and 91%, respectively. The bacterial abilities of TiO2 and AC/TiO2 nanoparticles were examined by E. coli and S. aureus. The water reclamation efficiency and bactericidal effect of TiO2 and AC/TiO2 nanoparticles were examined via catalytic dye degradation and bacterial efficiency of activated carbon-doped titanium dioxide nanoparticles.

Checking of the condition of transformers and the efficiency of oil regeneration with RVM (return voltage measurement)

Up to now the insulation in HV power transformers has been made from oil/paper therefore the diagnosis of this kind of insulation will be also important in the next forty-fifty years. The lifetime of this equipment strongly depends on the condition of the insulation system. The ageing process of oil/paper insulating systems is a very complex and complicated phenomenon. In order to get a well-supported decision on the further operation of aged transformers, relevant information would be necessary on the condition of the oil-paper insulation. We also know that the oil-paper insulation has almost always inhomogeneous condition considering the temperature, moistening and ageing processes. The classical methods (insulation resistance, loss tangent, etc.) characterise the insulation by single measured value. This single value is not sufficient for relevant characterisation and diagnosis of such a complex system with lots of tons of insulation and with almost always inhomogeneous distribution of temperature, moisture and ageing product. If we measure the polarization spectra in three states (new insulation in equilibrium and uniform polarization spectrum, new insulation with not uniform distribution of polarization spectrum, later reaching again the uniform distributions) the shape of three polarization spectra will be different. Comparing the polarization and classical methods of this three case we can realize that sometimes the “classical single values” are almost the same but the polarization spectra are different. The three response methods provide very practical information about the insulation system (e.g. moisture, ageing). The moistening and accumulation of ageing by-products change the distribution of interfacial polarisation in the range of long time-constants. These promising response methods measure the polarisation distribution in the range of long time-constant (with other words, in the low frequency range). The three test methods were: Return Voltage measurement (RVM), the C and tgδ measurement in range of some tens of mHz to 50 Hz (FDS=Frequency Domain Spectroscopy), and the measurement of DC charging and discharging currents (PDC=polarisation and depolarization currents) up to some thousands of sec. These equivalent methods (RVM, FDS and PDC) are able to follow the changing of condition of insulation contrary to classical methods. Therefore a little bit surprising that until now the convenient standards is missing considering the polarization methods. In an earlier Hungarian research work (Budapest University of Technology) almost all the necessary measurements have been realized, consequently we are in possession of fundamental data considering the polarization methods. This paper would like to show a short review about the RVM technique, the correct interpretation of RVM data and a case study for the checking of the efficiency of the oil reclamation with RVM technique.

Expression Regulation of Water Reabsorption Genes and Transcription Factors in the Kidneys of Lepus yarkandensis.

Lepus yarkandensis is a desert-dwelling animal that has various adaptations to cope with drought. The kidney maintains water and acid-base balance mainly through the vasopressin-regulated water reabsorption pathway and proximal tubular bicarbonate reabsorption pathway. In this study, we compared the differentially expressed genes (DEGs) and transcription factors in the kidneys of L. yarkandensis and Oryctolagus cuniculus to explore the relationship between the DEGs in kidneys and the animals’ adaptations. Transcriptome sequencing data were used to predict the differentially-expressed water reabsorption genes and their transcription factors. Quantitative real-time PCR, immunohistochemistry, and western blotting were used to detect and verify the expression of DEGs in the kidney at mRNA and protein levels. Transcriptome analysis of the kidney of L. yarkandensis and O. cuniculus showed that 6,610 genes were up-regulated and 5,727 genes down-regulated in data shared by both species. According to the data, 232 transcription factors and their corresponding target genes were predicted, from which genes and transcription factors related to renal water reabsorption were screened. Quantitative RT-PCR results showed AQP1, AQP2, ADCY3, HIF1A, CREB3, and NFATc1 had higher expression in the L. yarkandensis kidney; in comparison, FXYD2 mRNA expression levels were lower. In western blotting, transcription factors HIF1A, NFATc1, NF-κB1, and critical genes ADCY3, ATPA1, and SLC4A4, were highly expressed in the kidneys of L. yarkandensis. Immunohistochemical results showed that the ADCY3 protein was in the basolateral membrane of the collecting duct, the ATP1A1 protein was in the basolateral membrane and medulla of proximal tubules, and the SLC4A4 protein was in the basolateral membrane of proximal tubules. According to these results can be inferred that HIF1A, NFATc1, and NF-κB1 play a certain role in regulating the expression of genes related to water reabsorption in the kidney of L. yarkandensis, thus improving the water reclamation efficiency of L. yarkandensis, so as to adapt to the arid desert environment.

Life cycle assessment as decision support tool for water reuse in agriculture irrigation

This study presents a decision support tool that evaluates the environmental efficiency of water reclamation for agricultural irrigation, among other options. The developed tool is published as open source at https://doi.org/10.18167/DVN1/YLP1BA. The objective of this decision support tool is to facilitate the interpretation of the Life Cycle Assessment (LCA) results. This framework was applied to a representative case of reuse of reclaimed water for vine irrigation at the Murviel-Les-Montpellier experimental site (Hérault, France). It was then generalized through modeling assumptions to consider different reuse scenarios.To highlight situations in which the supply of recycled water for irrigation may or may not provide significant environmental benefits, three main parameters were varied: (i) tertiary treatment technologies, (ii) availability of conventional water sources, (iii) energy mix composition.The results show that the environmental impact of reclaimed water depends directly on the type of tertiary treatment technology and the location of the treatment plant in relation to the field and other water sources. The decision support tool has identified where wastewater reuse is clearly an environmentally beneficial source of irrigation among surface and groundwater sources (e.g., WWTP closer to field than river, groundwater too deep, tertiary treatment environmentally beneficial). However, there are many situations where the decision support process cannot distinguish between water reuse for agricultural irrigation and conventional water sources, especially when the nutrient content of treated municipal wastewater is insufficient to offset the negative effects of high energy requirements and chemicals of tertiary treatment.

Distinct stabilization characteristics of organic carbon in coastal salt‐affected soils with different salinity under straw return management

AbstractStraw returning effectively promotes the soil organic carbon (SOC) pool, but the straw‐induced change in SOC quality (C fraction) remains unclear, particularly in saline soil. Here, we investigated how straw returning and soil salinity (low, medium, and high) affect SOC fractions, including easily oxidized and particulate organic C (EOC and POC) and mineral‐associated organic C (MOC) at aggregate scales, including macroaggregates (MA), microaggregates (MI), and silt + clay particles. The results revealed that SOC fraction contents in the whole soil decreased with increasing soil salinity, and straw returning increased the total organic C (TOC) in both low‐ and medium‐salinity soils. In low‐salinity soil, straw returning induced decreases of 12.1% and 30.6% in MI‐associated EOC and POC, respectively, and promoted significant increases of MI‐associated MOC, indicating that 'hierarchical aggregation' theory (i.e., single soil particles gradually form clusters, MI and MA) dominated during soil aggregate formation. In medium‐salinity soil, straw application increased all SOC fraction contents in MA, and raised the POC/TOC of the whole soil by 56.6%, suggesting that the 'macroaggregate turnover' theory (MI is formed within MA) played a more important role in forming aggregates. Our results demonstrated that low‐ and medium‐salinity soils had different C‐increasing strategies under straw returning: MA contributed more to the increased SOC than MI in low‐salinity soil, whereas the reverse was true in medium‐salinity soil. These findings suggest that higher soil salinity would weaken the C sequestration potential of straw returning, and that targeted measures should be applied to enhance reclamation efficiency.

Efficiency of Vegetative Reclamation of Coal Spoil Heaps

Efficiency of Vegetative Reclamation of Coal Spoil Heaps

ЭКОЛОГИЧЕСКИЕ ОСНОВЫ МЕЛИОРАЦИИ ЗЕМЕЛЬ

The analysis of the current state of agricultural land reclamation in Russia is carried out. It is noted that over the past 20 years, more than 85% of reclaimed lands are degraded; the intensity of degradation has increased almost 2 times compared to the previous 20 years. This was due to the lack of a systematic analysis of the cause-and-effect relationships of the concept of «LAND» as a natural object and natural resource, which includes a number of interacting and interdependent components, such as atmosphere, biota, soil, surface and groundwater. Ways to improve the efficiency of agricultural land reclamation are proposed and substantiated, based on the rational use of the natural resource potential of the territories and the elimination of contradictions between the agricultural use of the lands and the environment protection. The proposed approaches make it possible to remove the main contradictions between agriculture, land reclamation and environment protection.

Surfactants attached thin film composite (TFC) nanofiltration (NF) membrane via intermolecular interaction for heavy metals removal

Heavy metals are well-known pollutant in the water body, which can threaten our health in various ways. Since size exclusion and electrostatic repulsion play a significant role in heavy metals removal for membrane technology, hereon, a positively charged nanofiltration membrane with a dense polyamide (PA) layer and a surfactant functionalized layer (SFL) was successfully developed. The optimization of the PA layer was achieved by adjusting the concentration of piperazine (PIP) and trimesoyl chloride (TMC) during interfacial polymerization and the thin film composite (TFC) membrane formed by 0.4% (w/v) PIP and 0.01% (w/v) TMC was selected for further study due to its gratifying performance. Then, the membrane was developed by attaching surfactants in which cetyl trimethyl ammonium bromide (CTAB) endowed a superior positively charged surface whereas sodium dodecyl sulfate (SDS) intensified negative charge compared to the original membranes. Furthermore, the SFL attached membrane was successfully obtained by attaching CTAB with various concentration and grafting time. The feed concentration of all metal ions and salts adopted for evaluating NF performances were 500 mg‧L−1. The best performance showed a high water permeability of 21.5 ± 0.6 L‧m−2‧h−1‧bar−1 and 96.6 ± 1.4% rejection for MgCl2. Overall, the as-developed SFL attached membrane has found its potential application in heavy metal removal in which the separation efficiency was over 98% against Zn2+, Ni2+, 96%–98% against Cu2+, >94% against Ca2+ and >85% against Pb2+ with a high efficiency of water reclamation simultaneously.

Economic Evaluation of Ecological Restoration of Degraded Lands through Protective Afforestation in the South of the Russian Plain

The latest international climate documents emphasize the great importance of protective forest stands in ensuring the sustainable development of agriculture, and the main requirement is the use of the forest-forming factor by landowners in the interests of improving the environment. In Russia, until recently, the ecological significance of forest plantations was underestimated, which created the ground for discussions about their effectiveness. In this regard, a new approach is proposed that emphasizes the positive impact of forests, including sustainable development, environmental security of the agricultural sector and reducing the degradation of agricultural land. The purpose of the work was an economic assessment and regularities of the dynamics of humus-regulating and nitrogen-phosphorus-potassium (NPK)-regulating efficiency of protective forest plantations on lands with deflation-hazardous soils. By means of a system analysis, the change in the soil cover of land use due to the influence of forest plantations on the balance of soil fertility elements in forested cells is comprehensively analyzed. The different spatial placement of trees from each other under different degrees of deflation in semiarid conditions is modeled. These models are used to determine the nature of the dynamics of soil nutrients in forested areas: in protection zones and outside protection. It is established that the anti-deflationary effect of agroforestry depends on the indicator of the protective forest cover of the land, the level of deflationary danger, and the operational life of the plantings. In semiarid conditions, it increases in proportion to the increase in the protection of land and amounts to EUR 376–EUR 4222 ha−1. With an increase in the intensity of deflation to the level of dust storms, the prevented damage from the loss of soil nutrients increases almost four times. In systems of plantings from early-maturing fast-growing rocks, the anti-deflationary effect is 6–7% higher on an average annual basis than in systems of plantings from long-lasting, slow-growing rocks. The greatest efficiency of forest reclamation in ensuring a positive balance of humus and NPK substances in the soil (EUR 1002–EUR 4222 ha−1) is achieved when placing plantings after 15 H. The study will confirm the need to subsidize the integration of trees into farm systems.

Reclaiming degraded mixed monoethanolamine and N-methyldiethanolamine solvent in carbon dioxide capture process

In this work, the effect of thermosiphon on vacuum distillation of degraded amine solutions was investigated for the amine reclamation process. A detailed analysis of the feed, the recovered solvent, and the waste streams showed that this novel reclamation process modified with thermosiphon was able to remove most of the undesirable impurities and degradation products and to restore the single degraded solvent to almost its original purity at a high recovery efficiency compared with the original process. Therefore, the thermosiphon was found to increase the recovery efficiency of degraded single amine reclamation at a steady-state. The average rate of products obtained from the enhanced unit was 2.64 mL/min, 6.28 times higher than the rate of product collected from the original unit (0.42 mL/min) at a temperature of 140 °C and vacuum pressure of 20 kPa. However, due to heavy amine in formulated mixed amines, the phenomenon of hindered circulation in thermosiphon occurred to make reclamation efficiency decline considerably. In order to maintain the original recovery efficiency in case of mixed solvents, after eliminating the thermosiphon part, the vacuum distillation temperatures were increased to a maximum of 170 °C close to heavy amine boiling point, by our new feeding mode of opening and closing feed valve intermittently in equal interval of 10 min to increase the evaporation rate of heavy amine at unsteady state. The analysis results showed that most of the undesired degradation products and impurities were removed, and the recovered product had a high weight ratio of MDEA/MEA in the range of 0.45–0.6. The total solvent concentration of the product was close to the feeding solvent concentration. These data will benefit for commercial reclaiming system design for blended amine solvents.

Current state and prospects for the development of legal support for hydrotechnical land reclamation

The article is devoted to the analysis of the current state of Ukrainian legislation in the field of hydrotechnical land reclamation, as well as highlighting the prospects for the development of legal support for a certain area of public relations. It has been established that hydrotechnical land reclamation contributes to an increase in the soil fertility, increase in the productivity and sustainability of agriculture, and the creation of a guaranteed food fund of state. However, in recent years, the efficiency of hydrotechnical land reclamation has been declining, which is explained by a number of objective and subjective reasons: insufficient material and technical support and shortcomings in usage of hydrotechnical structures, the deterioration of ecological and reclamation state of agricultural land, insufficient interest and responsibility of the landowners and land users. These factors include the incomplete use of scientific developments, insufficient information support, imperfect and outdated legal and regulatory framework. Considering the great importance of hydrotechnical land reclamation for the development of the country’s agriculture, these relations require proper legal regulation. It has been concluded that it is impossible to solve the following problems through the organization of land reclamation: combating desertification, providing resources and food for the state in years with adverse weather conditions, providing agriculture with water. All this due to the fact that this problem is complex. To achieve the goals of irrigation and drainage strategy in Ukraine for the period up to 2030 within certain priority directions, it is necessary to ensure the effective interaction of legal, organizational, economic and financial mechanisms for the restoration of irrigation and drainage in Ukraine.

Regeneration of the Disturbed Lands: Identified Trends

The generalized and analyzed experience of reclamation in various federal areas of our country has been presented, as well as this in the Urals Federal District with the lowest percentage of disturbed land regeneration. There has been identified a gradual increase of reclaimed lands, the interconnection of the biggest percentage of reclaimed and disturbed lands in the Urals, Siberian, Far Eastern and Volga Federal Districts, the ratio of disturbed and reclaimed lands by categories with details of reclamations. The information has been analyzed for a long period of time – 1995–2018 to possibly consider the identified trends as reliable. Taking them into account while making management decisions to increase the efficiency of reclamation.

THE EFFECT OF FULLER’S EARTH AND DIFFERENT ACID SOLVENTS ON USED ENGINE OIL THROUGH ACID-CLAY TREATMENT FOR RENEWABLE ENERGY

In this study, the fuller’s earth (FE) and different acid solvents on used engine oil (UEO) using acid-clay treatment were investigated. The reclamation efficiency of different acids paired with FE was measured through several analyses. All the UEO samples showed positive water content. The treated oils’ density was improved to 0.718 g/ml compared to UEO of 0.855 g/ml. The FT-IR did not enhance components due to alkene, aldehyde, and methane with similar wavelengths to untreated EO. Copper (Cu) and lead (Pb) content in treated EO were not detected.
 Keywords: Used engine oil, fuller’s earth, acid-clay treatment, adsorption

Effects of land use types and environmental factors on spatial distribution of soil total nitrogen in a coalfield on the Loess Plateau, China

Soil total nitrogen (TN) is one of the most important nutrients for plant and crop growth. It is essential to estimate the spatial distribution of TN to evaluate soil productivity, land reclamation efficiency, and agricultural management. This study was performed to investigate the spatial distribution of TN and its influencing factors in a coalfield in the Loess Plateau, China. A total of 143 topsoil samples were collected from five land use types and different slope positions. Classical statistical and geostatistical methods were used to quantify the spatial variation in TN. Redundancy analysis (RDA) was used to detect correlations between environmental factors and TN, whereas the random forest (RF) algorithm and LightGBM were applied to simulate the correlations. The results showed that the degree of spatial dependence ranged from 31.7%–45.2%, indicating moderate spatial variability in TN. Land use type significantly affected TN. The highest TN contents were found in the conservation tillage lands, followed by conventional tillage land, shrub land, grassland, and coal mining areas. The spatial distribution of the TN was also influenced by the slope position. The sites located downslope had higher TN than those located on the upper and middle slopes. RDA indicated that available potassium (AK) and soil organic matter (SOM) significantly affected the spatial distribution of TN. It was also demonstrated by LightGBM and RF that the TN content could be simulated by AK, SOM, normalised vegetation index, elevation, and available phosphorus. These results are helpful in understanding the effects of anthropogenic and natural factors on soil TN in coalfield areas.

A boundary model of terrain reconstruction in a coal-mining subsidence waterlogged area

Mining of coal resources in an area with a high groundwater level causes large-scale water accumulation on the surface, which brings great difficulties to land reclamation. To improve the reclamation efficiency, a boundary mathematical model of terrain reconstruction in the subsidence waterlogged area was established based on the Probability Integral Method (PIM) and the principle of equal amounts of digging and filling. The terrain reconstruction curve of deep-digging and shallow-filling was calculated through the linear combination of the surface’s predicted subsidence curve and the designed elevation line. The dividing boundary, inner boundary, and outer boundary of deep-digging and shallow-filling were defined. Finally, the whole subsidence area was divided into four different regions according to inflection points of the terrain reconstruction curve, and the ecological reconstruction schemes of agriculture, forestry, and fishery were put forward. The engineering practice of the 1013 panel in Wugou Coal Mine showed that 54.69%, 31.55%, and 13.76% of the subsided land were reclaimed for cultivated land, slope cultivated land, and aquaculture area, respectively, and all the subsided land was reasonably utilized. This method provides a new technology for eco-environment treatment in the subsidence area with a high groundwater level.

Variability of Silvicultural Characteristics of Forest Shelterbelts in Krasnodar Krai

Modern shelterbelts of Krasnodar Krai do not fully protect arable land and often have different sanitary state. Under these conditions, the preservation of forest shelterbelts and their protective functions in the system of agroforestry and other complex continues to be relevant. The research was carried out in the main and auxiliary forest shelterbelts within the boundaries of the Ust-Labinsk district of Krasnodar Krai. The purpose of the research was to determine the ecological state of the forest shelterbelts by identifying their integrity and implementation of forestry and land reclamation assessment. In order to obtain more complete information on their state, a remote assessment of the tree canopy integrity of the shelterbelts was carried out. It follows from the remote assessment analysis that about 42.5 % of the area surveyed in the key plots of plantations has an average degree of integrity of tree canopy, high – 22.3 %, low and very low – 35.2 %. Lower indicators of the tree canopy integrity are observed in the auxiliary forest shelterbelts. The percentage participation of each group of forest shelterbelts allowed us to rank the ranges of integrity corresponding to a certain forestry and land reclamation assessment (units). The range of the tree canopy integrity from 0 to 25 % corresponds to grade 1, from 25 to 50 % – 2, from 50 to 70 % – 3, from 70 to 100 % – 4. Based on this, the shelterbelts were devided into 4 groups: norm, risk, crisis and disaster. The results of determining the ecological state of the forest shelterbelts by ground and remote methods in the Ust-Labinsk district of Krasnodar Krai showed that a significant part of the surveyed plantations has a dense structure and requires silvicultural care. The group of the forest shelterbelts “disaster” needs reconstruction. This will significantly improve the environmental condition and reclamation efficiency, as well as increase the service life of the systems of forest sheltebelts.

Evaluation of the disturbed lands recultivation projects in the Republic of the Crimea

The development of the extractive industry on the territory of the Crimean Peninsula leads to an increase in the number of quarries and, consequently, to an increase in the area occupied by disturbed lands requiring recultivation. The reclamation of such land plots on the basis of creating the necessary conditions for the development on them of regenerative successions of zonal vegetation and ultimately the formation of soils is much cheaper for land users. Therefore, studies of the rates of soil formation, including using the methods of mathematical modeling of the processes of formation of the humus horizon of the soil over time, become relevant. Based on the example of the Alexandrovsky field of saw limestone in the Black Sea region of the Republic of the Crimea, the economic efficiency of reclamation of disturbed land was calculated. The results of the calculation showed that in terms of cost-effectiveness, it is more rational to use the mining engineering model with further self-overgrowing of the sites to be reclaimed when it comes to reclaiming disturbed lands of the Alexandrovsky career.

Management of land reclamation quality for agricultural use in opencast mining

Purpose. Theoretical substantiation of principles and development of recommendations for the choice of technological variant to form the quality of lands of technogenic origin, which would ensure rational spending of funds allotted for reclamation and preservation of the reclaimed lands suitability for agricultural use with the highest requirements for agrophysical soil characteristics. Methods. The following methods were used in the process of the research: the method of theoretical generalization and systematization (to determine the characteristics peculiar to the formation of qualitative characteristics of man-made soil using mechanization of reclamation works), analytical (to determine the factors influencing the effectiveness of land reclamation in opencast mining), comparison (to analyze the efficiency of different versions of reclamation works mechanization). Findings. The influence of technical means of reclamation works mechanization on the quality of lands subject to restoration in conditions of opencast mining is analyzed. A methodological approach to the choice of mechanization of land reclamation works in respect to the indicators of the formed quality of technogenic agricultural lands as a factor of their monetary valuation and the level of costs for their reproduction is proposed. Recommendations for quality management of man-made lands by technical support of the process of their consumer properties formation, aimed at achieving a favorable ratio between quality and, accordingly, monetary valuation of man-made lands, on the one hand, and, on the other, – the cost of their reclamation. Originality.A scientific and methodological approach to the choice of technical equipment for reclamation works is proposed, where two factors are considered: reclamation costs and quality of man-made lands, which allows to determine the priority of cost savings or land quality improvement according to the target criterion of reclamation works efficiency. Practical implications. The obtained results are aimed at improving the methodological bases for management of the man-made lands reclamation process based on the choice of its mechanization means. Keywords: land quality, reclamation costs, monetary valuation of lands, reclamation technology, reclamation efficiency

ПРИВОДОХРАНИЛИЩНЫЕ РЫБОВОДНО-МЕЛИОРАТИВНЫЕ КОМПЛЕКСЫ КАК ОБЪЕКТЫ РЫБОВОДСТВА И ЭКОЛОГИЧЕСКОГО ОЗДОРОВЛЕНИЯ ФИТОЗАГРЯЗНЕННЫХ ИРРИГАЦИОННЫХ ВОДОЕМОВ

Purpose: development of a layout-structural solution and technology for fish-breeding and reclamation complex operation for ecological improvement of phyto-contaminated reservoirs and fish farming in them. One of the urgent environmental problems typical for river and lake reservoirs is the overgrowth of their shallow waters with higher aquatic vegetation. Phyto-contamination of water bodies leads to a depletion of their ecological biodiversity, displacement of valuable species of aquatic flora and fauna, the decrease in their biological productivity and deterioration of conditions for various environmental management (water supply, fish farming, recreation, etc.). Rational and efficient use of natural resources cannot be ensured without ecological improvement of such objects. One of the directions of phyto-contaminated water bodies treatment is to carry out their biological reclamation by the introduction of herbivorous fish species into them. To increase the efficiency of such reclamation, it is proposed to create and use reservoir fish-breeding and reclamation complexes. Materials and Methods. The experimental and theoretical basis for the development of layout-structural solutions and technologies for the operation of such complexes was provided by known information and author's observations of the stocking of reservoirs. Results. The established shortcomings of the applied technologies led to the need to create the complexes that ensure the cultivation of fish stocking material adapted to the conditions of the stocking reservoir and the implementation of acclimatization measures for introducing herbivorous fish into the water body. Conclusions. The layout-constructive scheme and technology of fish-breeding and reclamation complex operation are proposed, which makes it possible to carry out the ecological improvement of phyto-contaminated reservoirs and, in general, to improve conditions, to increase the complexity, efficiency of using their resource potential and fulfillment of nature management.