Liquid Contaminants Research Articles

An overview of MXene-Based nanomaterials and their potential applications towards hazardous pollutant adsorption

With the massive development of industrialization, multiple ecological contaminants in gaseous, liquid, and solid forms are vented into habitats, which is currently at the forefront of worldwide attention. Because of the possible damage to public health and eco-diversity, high-efficiency clearance of these environmental contaminants is a serious concern. Improved nanomaterials (NMs) could perform a significant part in the exclusion of contaminants from the atmosphere. MXenes, a class of two-dimensional (2D) compounds that have got tremendous consideration from researchers for a broad array of applications in a variety of industries and are viewed as a potential route for innovative solutions to identify and prevent a variety of obstreperous hazardous pollutants from environmental compartments due to their exceptional innate physicochemical and mechanical features, including high specific surface area, physiological interoperability, sturdy electrodynamics, and elevated wettability. This paper discusses the recent progress in MXene-based nanomaterials' applications such as environmental remediation, with a focus on their adsorption–reduction characteristics. The removal of heavy metals, dyes, and radionuclides by MXenes and MXene-based nanomaterials is depicted in detail, with the adsorption mechanism and regeneration potential highlighted. Finally, suggestions for future research are provided to ensure that MXenes and MXene-based nanomaterials are synthesized and applied more effectively.

Impact of Fabric Construction on Adsorption and Spreading of Liquid Contaminations.

A contamination on a textile material is defined as an undesirable, local formation that deviates in appearance from the rest of the material. In this paper the relationship between the shape and surface of liquid contaminations and the firmness factor of woven fabric is investigated. The interdependence of constructional and structural parameters of raw and bleached cotton fabrics were analysed. The results show that selected contaminations are distributed differently, primarily depending on the construction characteristics of the fabric, type of contamination and hydrophilicity of cotton fabric.

Versatile nonfluorinated superhydrophobic coating with self-cleaning, anti-fouling, anti-corrosion and mechanical stability

It remains a great challenge to design and achieve fluorine-free superhydrophobic materials for multifunctional applications through facile and substrate-independent approaches. Herein, environmental-friendly superhydrophobic composite coating was fabricated with the combination of nano zinc oxide (nano-ZnO) and polydimethylsiloxane (PDMS) via a versatile spray-coating method. The surface wettability, micro-nano morphologies and chemical compositions of the superhydrophobic ZnO@PDMS coating were investigated through contact angle meter, FE-SEM, AFM, EDS, XPS and FTIR techniques. The optimal superhydrophobic ZnO@PDMS coating with water contact angle (WCA) of 158.3 ± 1.7° and sliding angle of 6.2 ± 1.8° can be achieved with the nano-ZnO/PDMS mass ratio of 1.5:1. The self-cleaning and anti-fouling ability was evaluated based on the solid and liquid contaminants. The electrochemical impendence spectroscopy (EIS) results verified that the superhydrophobic ZnO@PDMS coating exhibits a larger capacitive arc diameter, enhanced charge transfer resistance and |Z|0.01 Hz value at the low frequency, suggesting an improvement of anti-corrosion performance. Besides, the mechanical robustness and stability of the superhydrophobic ZnO@PDMS coating were evaluated through tape-peeling and sandpaper abrasion tests, which provides potential applications towards real-world applications.

Prevention of coronavirus contamination from the environment using an air-cleaning closed system drug-transfer device.

Background:Closed system drug-transfer devices (CSTD) allow the reconstitution of hazardous drugs into infusion bags, while preserving the sterility of the product and preventing the escape of liquids and aerosols into the environment. Air-cleaning technology CSTD is based on an activated carbon filter and a membrane which enable maintaining the drug sterile by filtration of air entering the vial during pressure equalization.Objective:The study aimed to investigate if an air-cleaning CSTD can prevent liquid viral contamination by human coronavirus OC43 (HCoV-OC43).Methods:Chemfort™ CSTD with (intact) or without (control) a Toxi-Guard system was used to transfer liquids between an IV bag and an empty vial (a total of 5 liquid transfers) inside a sealed glove box contaminated by HCoV-OC43 aerosols. In addition, the vial adaptor was challenged by direct spray of HCoV-OC43 solution on the septum and filter areas. HCoV-OC43 RNA was extracted from samples of the transferred liquid and compared between the devices with or without a Toxi-Guard system.Results:Use of a CSTD with the Toxi-Guard system resulted in non-detectable cycle threshold (CT) values, indicative of no detectable HCoV-OC43RNA in the transferred liquid, even when the septa and filter areas were directly sprayed with HCoV-OC43 stock solution. In contrast, use of the CSTD with no Toxi-Guard system resulted in a detectable CT value of the transferred liquid.Conclusions:Using Chemfort CSTD with integral Toxi-Guard technology can prevent the introduction of microbial and airborne contaminants into the fluid path, thus potentially protecting patients from infection.

GET A LIST OF FEATURE EXTRACTORS BASED ON FEATURE IMPORTANCE TECHNIQUES

It is well-known, we live in the digital industrial era and we have a lot of accumulated volumes of structured and unstructured data. The accumulated data, actually, can help us make our solutions more efficient in different areas of human activities. That is why we are trying to recognize which kind of data can resolve which kind of problem. For this purpose, we have a lot of useful techniques for assessment of the data feature importance. We are more confident in feature importance techniques when we work with numerical values of structured data because the detected objects are described by particular values. Alas, when extracting the features from unstructured data, like from images, it is still a question of how feature importance techniques are useful because it is either a question of how we are going to describe a detected object or which set of features might be an optimal one. Of course, it is a good case when we can extract a lot of different features of a detected object but how it is enough if we want to recognize it from a list of other possible objects? This problem we are going to resolve this by an approach where we describe the nature of the detected object via its unique features either than feature importance techniques. In the article, we consider the state of art feature importance methods, feature extraction algorithms and methodology of how to create the optimal set of feature extractors. Keywords: Computer vision, object detection, feature importance, machine learning, water pollution, liquid contamination.

Analysis of Dense Non-aqueous Phase Liquid Contaminants Effects on Soil Permeability by Response Surface Methodology

Soil contamination is considered a controversial issue in most countries. Nowadays, it is important to clearly understand how pollutants influence the soil from different sources. Today, hydrocarbons are one of the most important sources of soil contaminants, which is considered as a fundamental issue at the global level. The current study aims to analyze and model the effect of simultaneous parameters (time and concentration) of phenols and naphthalene with different percentages (10, 15, 20 and 25%) together with the amount of bentonite in fine-grained sandy soil. The designed experiments made use of response surface methodology (RSM) and Design-Expert software to carry out a computer-based simulation. According to the proposed model, the amount of bentonite is most affected by the permeability of the soil. The obtained results also showed that the permeability significantly decreases in the light of increasing the percentage of phenol and naphthalene coupled with the amount of bentonite and the age of contamination. On average, an 80% reduction of permeability was observed in contaminated soil, which was found in the soil contaminated with naphthalene. According to the results of the synergistic effects of time, the considerable impacts of both the percentage of hydrocarbon pollutants and the amount of bentonite on the reduction of permeability are quite evident.

Rapid and Robust Surface Treatment for Simultaneous Solid and Liquid Repellency.

A wide range of liquid and solid contaminants can adhere to everyday functional surfaces and dramatically alter their performance. Numerous surface modification strategies have been developed that can reduce the fouling of some solids or repel certain liquids but are generally limited to specific contaminants or class of foulants. This is due to the typically distinct mechanisms that are employed to repel liquids vs solids. Here, we demonstrate a rapid and facile surface modification technique that yields a thin film of linear chain siloxane molecules covalently tethered to a surface. We investigate and characterize the liquid-like morphology of these surfaces in detail as the key contributing factor to their anti-fouling performance. This surface treatment is extremely durable and readily repels a broad range of liquids with varying surface tensions and polarities, including water, oils, organic solvents, and even fluorinated solvents. Additionally, the flexible, liquid-like nature of these surfaces enables interfacial slippage, which dramatically reduces adhesion to various types of solids, including ice, wax, calcined gypsum, and cyanoacrylate adhesives, and also minimizes the nucleation of inorganic scale. The developed surfaces are durable and simple to fabricate, and they minimize fouling by both liquids and solids simultaneously.

Design of Bridge Type C-Band Planar RF Sensor for Detection of Solute Concentration Level in Water

In this paper, a planar Micro-strip-based bridge topology CSRR is proposed for the detection of various solute concentrations in water sample. The designed bridge topology CSRR (B-CSRR) sensors resonates at 5.18 GHz with a Q-factor of 170, which exhibits a fractional sensitivity (10.17%). To avoid the contamination of test liquids, use of the thin Teflon layer is incorporated on top of the sensor region. The numerical analysis of the sensors for various scenarios including the sensor loaded with several lossy samples are carried out and accordingly shift in resonant frequency is recorded. The optimized design topology helps to attain better electric field confinement at the resonant frequency, which eventually leads to improved dielectric sensitivity. In the next part, an equivalent circuit of the proposed sensor is developed using the Advanced Design System (ADS) software. Afterwards, the designed sensor is fabricated on 0.8mm thick Taconic TLY-5 substrate ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\boldsymbol {\varepsilon }_{r}$ </tex-math></inline-formula> = 2.2). Finally, the measurement of B-CSRR sensor is carried out for different solute concentration in pure water, which is in present scenario are salt and detergent concentration, respectively. The developed sensor is found to be quite sensitive which produces a substantial change in the measured insertion loss even for small variation in solute concentration. For instance, a typical 2% variation in detergent, and salt concentration leads to nearly 1.5 dB, and 2.0 dB, change in measured S21.

Predictions of terminal rising velocity, shape and drag coefficient for particle-laden bubbles

The motion of particle-laden bubbles is common in the gas–liquid-solid three-phase process like flotation. In this study, the motion of particle-laden bubbles in the stagnant deionized water was obtained by high-speed dynamic imaging. The experimental ranges of the mean bubble diameter and particle diameter were 2.76–3.95 mm and 58.2–196.35 μm, respectively. Results show that the terminal rising velocity decreases with the increase in the diameter of covering particles and the decrease in bubble diameter. For the coverage below 50%, the terminal rising velocity decreases sharply as coverage increases; while for 50% to nearly 100%, decreases slowly. The sharp decrease is mainly because particles immobilize the bubble surface and increases the drag, which is similar to the effect of contaminants in liquid on bubble motion. When the coverage exceeding 50%, the interface mobility of particle-laden bubbles is completely retarded. The slow decrease is attributed to the decreasing net buoyancy caused by decreasing density difference between water and the particle-laden bubble. Based on the impact of particle coverage on bubble behavior, the measured data were compared with predictions by the available models of the terminal rising velocity and drag coefficient for the bare bubble in the contaminated liquid. Comparison results show that the terminal rising velocity model given by Zheng et al. (2020) and the drag coefficient model given by Wang et al. (2019) can be extended to particle-laden bubbles with a mean error of 4.8% and 0.6%, respectively. The aspect ratio of particle-laden bubbles is negatively correlated to the terminal rising velocity like that of bare bubbles. A new aspect ratio prediction model for particle-laden bubbles related to the ratio between coverage and the Eo number was introduced to facilitate direct prediction of the terminal rising velocity. The comprehensive prediction models of particle-laden bubbles behaviors given in this study are helpful for the design and optimization of equipment that contains bubble-particle aggregates.

Contaminants in biochar and suggested mitigation measures – a review

Biochars produced by pyrolysis at high temperatures under oxygen limited conditions can contain both well-known contaminants (polycyclic aromatic hydrocarbons (PAHs), potentially toxic elements (PTEs), dioxins, volatile organic compounds (VOCs)) and emerging contaminants (e.g., persistent free radicals, metal cyanide). Their potential to induce phytotoxicity, cytotoxicity, and neurotoxicity highlight the need to establish effective strategies to control and eliminate contaminants for sustainable biochar use. Although some articles have reviewed the ecotoxic potential of biochar in relation to some of these contaminants, strategies to mitigate the whole suite of contaminants potentially present in biochar have not been systematically reviewed so far. This review discusses (i) the formation mechanism of such contaminants and (ii) evaluates their potential risk to ecosystems, a prerequisite (iii) to understand and explore effective control strategies for producing biochars with minimum contamination. A pyrolysis unit design where pyrolysis liquids and solids are fully separated following the pyrolysis zone and optimization of pyrolysis parameters ensures organic contaminants in the pyrolysis liquids do not condense onto the biochar. Post-production treatments, such as thermal treatment or natural and artificial ageing help organic contaminant removal and breakdown. Co-pyrolysis of metal-rich feedstock with metal-free biomass is the only way of reducing total PTE levels, though available PTE levels are low in biochars and decrease further with pyrolysis temperature. More specific strategies for reducing the concentration of individual contaminants are discussed in the review. With our proposed recommendations, biochars with little risk for the environment can be produced.

Monitoring water-immiscible organic liquid contaminations on water via stable sensing silicone rubber composites

Sensor technology is significant to monitor organic contaminations on water for the present industries. In this letter, highly sensitive carbon nanotube (CNT) based silicone rubber composites (CNTRs) are used as the candidate for sensing materials, which yet display unstable liquid sensing outputs owing to poor dispersion of CNTs. As hybrid carbon blacks (CBs) are added, CNT/CB composites are prepared to solve bad distribution of CNTs. CNT/CB composites achieve a better conductivity, larger sensing capacity and more stable sensing response on singular chemical liquids than CNTR. Importantly, growing resistance responsivities are discovered as CNT/CB composites circularly contact toluene and water. We therefore design the sensing application to monitor toluene suspensions on water.

Fabrication of a wearable directional moisture-transfer cotton by clean technology of wet plasma, without fluoride consumption

A cleaner wearable cotton which has the properties of one-way water transfer and resisting external liquid contamination was fabricated in this study. Wet plasma combined with fluorine-free hydrophobic agent (WP-FfHA) was used as an environmental-friendly technology in the preparation process. Other than the attribute of environmental protection, it was proved that wet plasma can not only reduce the consumption of water-repellent agent by 25 %, but also significantly improve the waterproofness of fabric through contact angle measurement. Water-drip test was used to determine the asymmetric wettability of the fabric. The results display that the water droplets were transferred from the undersurface to the top surface within less than 3 s through wicking zones, even under the condition of reverse gravity. Meanwhile, the liquids on the upper surface were not able to reverse-penetrate to the bottom. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were employed to analyze the micro-topography and chemical construction of the wicking and non-wicking areas on the fabric surface. Tests for fastness showed that the fabric maintained a contact angle of 145 ° after 5 times of regular soaping. Investigation of breathability and mechanical property confirmed that the wearability of the cleaner directional moisture-transfer fabric was not adversely affected by this novel modification approach.

Investigation of gas gathering pipelines operation efficiency and selection of improvement methods

Purpose: The article implies theoretical and experimental studies of the liquid pollution accumulations impact on the efficiency of gathering gas pipelines operation at the Yuliivskyi oil and gas condensate production facility (OGCPF). Research of efficiency of gas pipelines cleaning by various methods. Design/methodology/approach: The research methodology consists of determining the hydraulic efficiency of gathering gas pipelines before and after cleaning of their internal cavity by different methods and comparing the obtained results, which allows to objectively evaluate the efficiency of any cleaning method. CFD simulation of gas-dynamic processes in low sections of gas pipelines with liquid contaminants. Findings: Experimental studies of cleaning efficiency in the inner cavity of the gas gathering pipelines of the Yuliivskyi OGCPF by various methods, including: supply of surfactant solution, creating a high-speed gas flow, use of foam pistons were performed. It was established that cleaning the inner cavity of gas gathering pipelines by supplying a surfactant solution leads to an increase in the coefficient of hydraulic efficiency by 2%-4.5%, creating a high-speed gas flow by 4%-7%, and under certain conditions by 8%-10 % and more. However, for two gas pipelines the use of foam pistons allowed to increase the coefficient of hydraulic efficiency from 5.7 % to 10.5 % with a multiplicity of foam from 50 to 90. be recommended for other deposits.The results of CFD simulation showed that the accumulation of liquid contaminants in the lowered sections of gas pipelines affects gas-dynamic processes and leads to pressure losses above the values provided by the technological regime. With the increase in liquid contaminants volume the pressure losses occur. Moreover, with a small amount of contamination (up to 0.006 m3), liquid contaminants do not have a significant effect on pressure loss. If the contaminants volume in the lowered section of the pipeline is greater than the specified value, the pressure loss increases by parabolic dependence. The increase in mass flow leads to an increase in the value of pressure loss at the site of liquid contamination. Moreover, the greater the mass flow, the greater the impact of its changes on the pressure loss. The CFD simulation performed made it possible not only to determine the patterns of pressure loss in places of liquid contaminants accumulation in the inner cavity of gas pipelines, but also to understand the gas-dynamic processes in such places, which is an unconditional advantage of this method over experimental. Research limitations/implications: The obtained simulation results showed that the increase in the volume of liquid contaminants in the inner cavity of gas gathering pipelines leads to an increase in pressure losses above the value provided by the technological regime. To achieve maximum cleaning of gas gathering pipelines, it is necessary to develop a new method that will combine the considered. Practical implications: The performed experimental results make it possible to take a more thorough approach to cleaning the inner cavity of gas gathering pipelines and to forecast in advance to what extent the hydraulic efficiency of gas gathering pipelines can be increased. Originality/value: The obtained results of CFD simulation of gas-dynamic processes in lowered sections of gas pipelines with liquid contaminants, experimental studies of the effectiveness of various methods of cleaning the inner cavity of gas gathering pipelines has original value.

Development of a 3D Printed Double-Acting Linear Pneumatic Actuator for the Tendon Gripping.

The lack of standardization in tissue testing procedures results in a variety of custom-made devices. In the case of the determination of the mechanical properties of tendons, it is sometimes necessary to adapt the existing laboratory equipment for conducting experiments when specific commercial equipment is not applicable to solve issues such as proper gripping to prevent tendon slipping and rupturing, gripping control and manoeuvrability in case of tendon submerging and without contamination of the testing liquid. This paper presents the systematic development, design, and fabrication using 3D printing technology and the application of the double-acting linear pneumatic actuator to overcome such issues. It is designed to do its work submerged in the Ringers’ solution while gripping the tendon along with the clamps. The pneumatic foot valve unit of the Shimadzu AGS-X tensile testing machine controls the actuator thus preventing Ringers’ solution to be contaminated by the machine operator during specimen set-up. The actuator has a length of 60 mm, a bore of 50 mm, and a stroke length of 20 mm. It is designed to operate with an inlet pressure of up to 0.8 MPa. It comprises the cylinder body with the integrated thread, the piston, the piston head, and the gripper jaw. Fused deposition modeling (FDM) has been used as the 3D printing technique, along with polylactic acid (PLA) as the material for 3D printing. The 3D printed double-acting linear pneumatic actuator was developed into an operating prototype. This study could open new frontiers in the field of tissue testing and the development of similar specialized devices for medical purposes.

Designing shoe tread for friction performance: a hierarchical approach

Falls are the leading cause of emergency department visits. Slipping on liquid contaminants is a common cause of falls. Footwear has demonstrated promise in preventing these slips.The mechanics of ...

3D dynamic model empowering the knowledge of the decontamination mechanisms and controlling the complex remediation strategy of a contaminated industrial site

Knowledge of the geology and hydrogeology of the polluted site emblematize a key requirement for environmental remediation, through assembling and synthesizing findings from various sources of physical evidence. In an increasingly virtual era, digital and geo-referenced metadata may serve as tools for collecting, merging, matching, and understanding multi-source information. The main goal of this paper is to emphasize the significance of a 3D hydrogeochemical model to the portrayal and the understanding of contamination dynamics and decontamination mechanisms at a highly contaminated industrial site. Some remediation measures are active on-site, due to the evidence-based presence of chlorinated solvents in groundwater. These are attributable to a slow-release source of pollutants in the saturated zone associated with very low permeability sediments. Therefore, in this research, a new technique for the remediation of secondary sources of dense non-aqueous phase liquid (DNAPL) contamination was investigated for the first time on a full-scale application. The combination of groundwater circulation wells (IEG-GCW®) and a continuous electron donor production device was set up to boost in situ bioremediation (ISB). A multi-phase approach was followed handling and releasing data during various remediation stages, from site characterization via pilot testing to full-scale remediation, thus allowing users to monitor, analyze, and manipulate information in 3D space-time. Multi-source and multi-temporal scenarios reveal the impact of ongoing hydraulic dynamics and depict the decontamination mechanisms in response to the interventions implemented over time, by quantifying the overall performance of the adopted strategies in terms of removal of secondary sources of pollution still active at the site.

A strong basis for friction as the origin of size effect in cutting of metals

A study has been made of the phenomenon of size effect in cutting of metals, namely increase in the specific energy with decreasing chip thickness, in the absence of edge radius effects and under ideal two-dimensional cutting conditions. Freshly cleaved glass knives are used to achieve cutting edges that are sharp on an atomic level. An instrumented ultramicrotomy apparatus is described in which it is possible to achieve two-dimensional orthogonal cutting at small cutting depths in the range of 100 nm to 3 micrometers. Based on observations with three metals (aluminum, copper and zinc), new evidence is presented in support of tool-chip friction as the primary source of the size effect. It is shown that size effect arises as a result of non-proportional decrease of the friction component with the underlying length scale. Calculation of the shear flow stress during cutting showed that this was approximately constant for a given material, independent of the depth of cut. Size dependence of tool-chip friction and contact size is interpreted in terms of the junction growth and adhesion models. Cutting experiments are also carried out with tools covered with solid and liquid contaminants. These results show that contaminant films effectively diminish adhesion and lead to a drastic reduction in the size effect, suggesting practical benefits for industrial manufacturing processes.

Effect of moisture condensation on vapour transmission through porous membranes.

Porous membranes find natural application in various fields and industries. Water condensation on membranes can block pores, reduce vapour transmissibility, and diminish the porous membranes' performance. This research investigates the rate of water vapour transmission through microporous nylon and nanofibrous Gore-Tex membranes. Testing consisted of placing the membrane at the intersection of two chambers with varied initial humidity conditions. One compartment is initially set to a high (water vapour concentration and the other low (, with changes in humidity recorded as a function of time. The impact of pore blockage was explored by pre-wetting the membranes with water or interposing glycerine onto the membrane pores before testing. Pore blockage was measured using image analysis for the nylon membrane. The mass flow rate of water vapour (ṁv) diffusing through a porous membrane is proportional to both its area (A) and the difference in vapour concentration across its two faces (, such that where K is defined as the moisture diffusion coefficient. Correlations are presented for the variation of K as a function of . Liquid contamination on the porous membrane has been shown to reduce the moisture diffusion rate through the membrane due to pore blockage and the subsequent reduced open area available for vapour diffusion. Water evaporation from the membrane's surface was observed to add to the mass of vapour diffusing through the membrane. A model was developed to predict the effect of membrane wetting on vapour diffusion and showed good agreement with experimental data.

Experimental and numerical assessment of Light Non-Aqueous Phase Liquid (LNAPL) subsurface migration behavior in the vicinity of groundwater table

Groundwater contamination by constituents of hydrocarbon fluids may occur from the earth’s surface or subsurface. Key sources of contamination include spills and leakages from oilwells, underground storage tanks (USTs), and oil transport-tankers. These light non-aqueous phase liquid (LNAPL) contaminants pollute the soil and its continuous migration, may even end up contaminating aquifer systems. This highlights the need to understand the fate and migration behavior of LNAPL contaminants in the subsurface, especially in the unsaturated zone – with a view to limiting the contaminants transport. This study presents a numerical approach for describing and predicting the fate of LNAPL contaminant-transport in the subsurface. Multiphase flow concept was adopted, where two LNAPL phases – oil, and gas – were mainly considered. Diesel and crude oil are the hydrocarbon contaminants used, while unconsolidated sand was used as the porous matrix. Two contaminant flow scenarios were simulated experimentally — surface and subsurface imbibition. Mass balance equations and constitutive functions from the several important phenomena that influence LNAPL contaminant flow, in the subsurface, are discussed. Extended Darcy’s law in combination with van Genuchten model were applied in the 2D numerical model description for mass balance equation and constitutive relationship, respectively. The numerical simulation was executed using COMSOL Multiphysics® v. 5.5. The numerical simulation results showed a good correlation with the experimental results, and suggest that exposure time, fluid viscosity, density, contaminant supply, amount released, and the hydraulic properties of the porous matrix, are the most important parameters in LNAPL contaminant subsurface migration. This study thereby concludes that if the fluid thermodynamic properties and the hydraulic properties of the porous matrix are known, the numerical model can accurately predict the migration behavior of hydrocarbon contaminants. In that way, it becomes possible to effectively track oil-spills and leakages propagating into the vicinity of groundwater table and freshwater aquifer. The study outcome is useful in designing and implementing efficient hydrocarbon contamination remediation approaches and saving time by taking the right action.

Experimental effectiveness studies of the technology for cleaning the inner cavity of gas gathering pipelines

Purpose: The purposes of the article are to determine the hydraulic efficiency of two gas gathering pipelines of the Yuliivskyi oil and gas condensate production facility (OGCPF) and develop a set of measures to increase it; to experimentally determine the efficiency of using foams to increase the hydraulic characteristics of the gas gathering pipelines in the Yuliivskyi OGCPF; to develop a set of measures that will help to improve the hydraulic characteristics of gas gathering pipelines. Design/methodology/approach: The research methodology consists in determining the hydraulic efficiency of gas gathering pipelines before and after cleaning their inner cavity with foams with different expansion ratios and comparing the obtained values, which allows to objectively assess the efficiency of this cleaning method. The studies were performed within the framework of research and development work by the specialists of the Ukrainian Scientific Research Institute of Natural Gases. Findings: The pilot testing was carried out to determine the efficiency of cleaning the inner cavity of gas gathering pipelines with foams with different expansion ratios. It showed positive results. It was determined that cleaning the inner cavity of gas gathering pipelines with foams with the expansion ratio from 80 to 90 led to an increase in the hydraulic efficiency coefficient by 10.5%, and with foams with the expansion ratio from 50 to 60 – by 5.7%. The measures taken to clean the inner cavity of gas gathering pipelines from liquid contaminations have proven their efficiency and can be recommended for other fields. Research limitations/implications: The obtained results show that it is reasonable to conduct the experimental studies on the efficiency of cleaning the inner cavity of gas gathering pipelines with the foams with higher expansion ratios. To achieve the maximum quality of cleaning the gas gathering pipelines, it is necessary to develop a new method that will combine the use of foam and gel piston.Practical implications: The performed experimental studies help to take a more reasonable approach to cleaning the inner cavity of gas gathering pipelines with foams and to predict in advance the effect of the foam expansion ratio on the hydraulic efficiency of gas gathering pipelines. Originality/value: The experimental studies on the effect of foam expansion ratios on the hydraulic efficiency of gas gathering pipelines are original.