Experimental Study on the Influencing Factors of Treatment of Landfill Sludge Using Vacuum Preloading with the Fenton Reagent

At present, there is a lack of necessary technical parameters for sludge vacuum reinforcement. To explore the effects of the drain board type on sludge vacuum reinforcement, the Fenton reagent was used to pretreat the landfill sludge in a sludge landfill area in Shanghai, and then, vacuum preloading contrast tests of different prefabricated vertical drainage types were carried out. During the test, the discharge and settlement of sludge were recorded. After the test, the moisture content, shear strength, and appearance of PVD were measured and analysed. The main conclusions are as follows: (1) the optimum ratio of H2O2 and Fe2+ is 2 for the landfill sludge; (2) the total displacement and accumulated settlement of the test group with integral prefabricated vertical drainage are 1.7 times and 1.2 times those of the separate prefabricated vertical drainage, respectively; (3) the type of prefabricated vertical drainage has no effect on the distribution of water content and shear strength; and (4) when the sludge is vacuum strengthened, the integral prefabricated vertical drainage should be preferred.

The Study of Subsurface Land Drainage Optimal Design Model

This paper focused on choosing the best design of subsurface land drainage systems in semiarid areas. The study presented three different soil layers with different hydraulic conductivity and permeability, all layers are below the drain level, and the permeability is increasing with depth. A mathematical model was formulated for the horizontal and vertical drainage optimal design. The result was a nonlinear optimization problem with nonlinear constraints, which required numerical methods for its solution. The purpose of the mathematical model is to find the best values of pipes and tubewells spacing, groundwater table drawdown, and pumps operating hours which leads to a minimum total cost of the subsurface drainage design. A computer code was developed in MATLAB environment and applied to the case study. Results show that the vertical drainage was economically better for the case study drainage network design. And the main factor affecting the mathematical model for both pipe and well drainage was the distance between pipes and tubewells. In addition, considering the lifespan of vertical drainage project, the optimal design involves the minimum possible duration of pumping stations. It is hoped that the proposed optimal mathematical model will present a design methodology by which the costs of all alternative designs can be compared so that the least-cost design is selected.

Numerical Study of the Process of Unsteady Filtration of a Fluid in Interacting Porous Pressure Layers

A review of the fundamental studies conducted in 2010 - 2020 is given in the article to develop a mathematical model related to the fluid and gas filtration processes in porous media. To conduct a comprehensive study of the process of unsteady filtration of fluid in multi-layer porous pressure media and to make a management decision, a mathematical model described by a system of partial differential equations with corresponding initial and boundary conditions and a conservative numerical algorithm were developed. On the basis of the developed software of the problem posed, computational experiments were conducted on a computer; the calculation results were presented in the form of tables and graphical objects. The schemes of location and capacity of vertical drainage wells to protect irrigated and non-irrigated areas from flooding were proposed on the basis of the developed software. Using the proposed mathematical tool, it is possible to obtain the prognostic groundwater levels for any area for the required period of time, considering a number of factors, for example, the formation heterogeneity in plan, the gradient of the permeability barrier, and other hydrogeological, hydro-technical, and natural conditions; to calculate the capacity and optimal drilling pattern of vertical drainage wells to protect the territory and to develop oil and gas fields.

Analysis of the Smear Zone Effect due to PVD Installation on the Embankment Consolidation Process with 2D and 3D Plaxis

The method of preloading and vertical drainage is one of the popular methods used to increase shear strength of soft soil. Initial loading is carried out with the aim of consolidating the soil layer with a large or equal load greater than the load that will be carried by the ground both during and after construction. While vertical drainage can speed up the evaluation process. The development of a vertical drainage system is the use of PVD (Prefebricate Vertical Drain). PVD is installed to drain the air that is dissipated in the preparation process. Analysis to compare the settlement that occurred in the Reklamasi Peti Kemas Belawan Fase II project with modeling on Plaxis 2D and 3D with and without using the smear zone effect. From the analysis, the settlement that occurred on consolidation process with Plaxis 2D modeling with and without the effect of the smear zone effect was 2,288 meters and 1,922 meters while the 3D Plaxis modeling obtained 2,077 meters for analysis without changing the effect of the smear zone and 1,930 meters for analysis with calculate the effect of the smear zone.

Irrigation of the cultivated area with groundwater from vertical drainage wells

In recent years, there has been a shortage of water resources in the basins of the Amu Darya and Syrdarya rivers, which is the result of the development of new lands for irrigation and the inappropriate use of water and land resources. A side effect of irrigation and land reclamation is the increasing flow of collector-drainage waters every year, which leads to a deterioration in the land reclamation state and pollution of water resources, which can lead to the ecological disaster of land and water resources. Currently, in the Republic of Uzbekistan, from the total volume of water resources of the Amu Darya and Syrdarya rivers, up to 68% is used for irrigation. Of this volume on the Republic territory, about 12% of collector-drainage waters of deteriorated quality are formed. With a shortage of water resources, they are used for irrigation. But irrigation with saline waters can lead to a deterioration in the land reclamation state. In this regard, new irrigation technologies are proposed, which can save both irrigation water and it is advisable to use underground pumped water for irrigation. Field experiments were carried out in the farm "Khozhilkhon-hozhi" in the farm named after A. Niyazov, Kuva district, Fergana region. A feature of the soil conditions in this farm is the small thickness of the covered fine earth, underlain by highly permeable gravel, strong and increased water permeability, with a deep groundwater level (GWL> 3 m). Large water losses are observed during irrigation. The calculation task was to determine how many hectares of land can be irrigated from one vertical drainage well, taking into account the irrigation time, inter-irrigation period, etc. The water-salt balance of the reclaimed lands for 2017-2019 was compiled. The water-salt balance showed that water supply and filtration from canals and atmospheric precipitation play the main role in the inlet part. In the consumable part, the main place is occupied by evapotranspiration and drainage flow. In general, a negative balance is formed on the territory annually by the type of a small salt carryover within 2.85 t / ha. On the territory of the farm and the experimental plot, cotton of the S-6524 variety was sown, the flow rate of the well is 30 l / s, the furrow consumption is 0.5 l / s. The composition of hypothetical salts in the pumped-out waters is calculated After the first irrigation of our field, the pumped-out water is diverted to the neighboring fields, while the first inter-irrigation period is 20 days. In the interval of these 20 days until the second irrigation of the cotton of the original field, it is possible to irrigate the same fields 5 hectares 8 times, in total 40 hectares of land. The experiments showed that irrigation with pumped water from vertical drainage wells did not have a negative impact on the yield of cotton. And the use of the recommended irrigation technology will reduce the shortage of irrigation water and improve the ecological situation of water resources.

Construction of vertical drainage wells using corrosion resistant materials

Vertical drainage wells in terms of construction technology and design do not differ from wells for irrigation. They are not deeper in-depth than irrigation wells and are generally 40-70 m. The main task of vertical drainage wells is land reclamation. They, depending on natural and economic conditions, serve on 5-120 hectares of area. In many areas, vertical drainage wells serve a dual purpose; land reclamation and irrigation of agricultural crops. Water intake wells, including vertical drainage wells, are characterized by a decrease in their flow rates during operation. To ensure the stable operation of the irrigation and drainage system, where water intake wells are operated, repair and restoration work is carried out on them, aimed at increasing flow rates. For the construction of vertical drainage wells in the Sirdarya river basin, steel pipes and filters are mainly used, which corrode in an aggressive environment. In the water intake zone of the well and the metal corrosion process, the colmatation process also occurs. All of them are the main reasons for the decline in well production rates. The carried out repair and restoration measures are aimed at destroying the structure of corrosion and clogging products. In practice, mechanical, physical, biological, and chemical methods are used to clean the filters of water intake wells. They all have their own technology and equipment. However, all these works do not exclude the repeatability of the process. Repetitive workover will come to ineffective, the stage of good concertation is approaching. It is known that polymeric materials do not corrode. They work steadily in aggressive environments. To prevent the corrosion process, polymeric-seam pipes were used as a filter frame and a casing for the construction of vertical drainage wells. Two pilot wells were built on the territory of the Chiyili district of the Kyzylorda region of the Republic of Kazakhstan. The wells were drilled with a rotary drilling unit with backwash. Pure water (irrigation) was used as drilling fluid. To form a gravel pack in the annular zone of the casing, gravel-sand material from the Jailma quarry was used. The material was brought by rail and road transport. Pipe sections were prepared on the surface of 10 meters. Steel rings were put on the pipe from both ends of each section; their connection in the barrel was made by electric welding. The results showed that in the initial period of operation, a decline process was observed. In further exploitation, the well flow rate stabilized. As a result of construction using pipes and filters made of polymer material, the effect was achieved in terms of water volume more than 3 times and in terms of service life 4.2 times compared to a metal filter well.

Numerical study of fluid filtration in three-layer interacting pressure porous formations

A mathematical model was developed to numerically study the process of fluid and gas filtration in three-layer interacting pressure porous formations. It is based on the reviews related to the mathematical modeling developed in recent years; it describes a system of partial differential equations with boundary and initial conditions and a conservative numerical algorithm for conducting a computational experiment (CE) on a computer. In this article, to analyze and make managerial decisions, the results of numerical calculations are presented in the form of graphical objects, which can be used to propose schemes for the location and capacity of vertical drainage wells to protect irrigated and non-irrigated areas from flooding. Using the proposed mathematical tool, it is possible to obtain the predicted groundwater levels of any area for the required period of time, taking into account some factors, such as the inhomogeneity of the reservoir in a plan, the slope of the confining layer, and other hydrogeological, hydro-technical, and natural conditions, or to calculate the thickness and the optimal location of vertical drainage wells to protect the territory, and to develop oil and gas fields and increase their oil and gas recovery. Analysis of the results of a numerical study of the process made it possible to establish the degrees of influence of the elastic filtration regime in a weakly permeable layer on the overflow into adjacent layers.

OPERATION MODE OF VERTICAL DRAINAGE WELLS DURING IRRIGATION AND NONIRRIGATION PERIODS

В статье изложены результаты полевых исследований по разработке режима работы скважин вертикального дренажа при возделывания хлопчатника в оросительный и вневегетационный периоды в условиях Мактааральского массива Туркестанской области. Известно, что по характеру участия грунтовых вод в процессах почвообразования в природных условиях выделяются два основных типа режимов почвообразовательного процесса - гидроморфный и автоморфный и два промежуточных - полугидроморфный и полуавтоморфный. Принято различать и соответствующие им мелиоративные режимы. Вертикальный дренаж в отличие от других видов дренажа позволяет поддерживать (и создавать) полугидроморфный режим, что особенно важно для вновь орошаемых земель с исходно глубоким уровнем грунтовых вод, где необходимо сохранить этот уровень, не допустить его подъема и предотвратить тем самым продвижение солей к зоне аэрации, необходимой для выращивания растений. Установлено, что обеспечения благоприятного мелиоративного состояния орошаемых земель скважины вертикального дренажа в оросительный период (май-август) должны работать на нормальную нагрузку с коэффициентом полезной работы (КПР) в пределах 0,3-0,35, вневегетационный период (сентябрь-октябрь) с КПР равным 0,35-0,50. Ключевые слова: режим работы, вертикальный дренаж, орошаемые земли, мелиоративный режим, грунтовая вода, зона увлажнения

Implementasi Teknologi Pemanen Air Hujan dan Drainase Vertikal untuk Konservasi Sumber Daya Air dan Pemenuhan Kebutuhan Air Rumah Tangga

Open land degradation due to increasing of settlement area effect to water shortage (i.e. water recharging reduction and run off enhancement). Rain harvesting and vertical drainage approach could be an alternative solution. Additionally, rainwater is a potential water source for dometic water. The social empowerement program aim to increase our partner knowledge and ability on water reseource protection. The program was conducted in Kaliori Village, Banyumas Regency, Central Java Province. Some program were applied such as collecting the data of partner profile, counselling, dissemination of technology, and evaluation. Techology dessimination was conducted in one of member located around Kaliori Landfill. The result showed knowledge improvement of partner about water resource conservation including rain harvesting and vertical drainage approach. However, lack of the equipment performance due to longer dry periode during program. It could affect the partner motivation on approach replication. Partner knowledge improvement on water resource and the techonology (i.e. rain harvesting and vertical dranage approach) was expected to better habit on water resource conservation.

THE AMELIORATIVE CONDITION OF THE IRRIGATED LIGHT SEROZEM OF THE TURKESTAN REGION

The relevance of the study is conditioned by the fact that the large-scale irrigation of cotton fields in arid and desert areas of the Turkestan region inevitably leads to the processes of soil salinization. Salinity is a global problem for humanity. Soil salinization is associated with drainage problems, improper use of water resources, growing demand for agricultural products, which leads to increased pressure on agricultural land. In this regard, this paper is directed at investigating the soil salinity of the irrigated light serozem in a cotton farm of Southern Kazakhstan (now Turkestan region) under the vertical drainage, which would provide the necessary background for the reconstruction of the collection-drainage system of the whole region, thus contributing to the increasing the net yield and the quality of the row cotton, as well as preventing soil deterioration. The leading method for studying the issues of the article was the dispersion method, according to which the salinity of soils was determined by seasons. The main objectives were studying the dynamics of salts changes seasonally and timely under the vertical drainage and studying the spatial distribution of salts in the cotton-based farm. The results showed that in 2014 there was recorded a positive dynamic of changes compared to 2012. In spring 2014, the area under medium saline soil in the 0-20 cm layer decreased from 79.5 to 57.7 %; the weakly saline soil area increased from 20.5 to 34.6 %. In the autumn and winter periods, the area of strongly saline soils decreased from 25.6 to 14.1 %. The area of non-saline soils was recorded at 7.7 %. The results showed that changes in the amount of the ions, both vertically and seasonally, occur with the transport of salts along with soil profile under the influence of temperature gradients and the level of groundwater, i.e., in spring from up to down, and in autumn and winter, contrary from down to up. The theoretical and practical value of the study lies in the fact that the material for improving, preventing the salinization of soils will lead to an increase in the general level of ecological safety of the region and country in general.