The fourth rail transit is an interesting topic to be shared and accessed by the community within that area of expertise. Several ongoing works are currently being conducted especially in the aspects of system technical performances including the rail bracket component and the sensitivity analyses on the various rail designs. Furthermore, the lightning surge study on railway electrification is significant due to the fact that only a handful of publications are available in this regard, especially on the fourth rail transit. For this reason, this paper presents a study on the electrical performance of a fourth rail Direct Current (DC) urban transit affected by an indirect lightning strike. The indirect lightning strike was modelled by means of the Rusck model and the sum of two Heidler functions. The simulations were carried out using the EMTP-RV software which included the performance comparison of polymer-insulated rail brackets, namely the Cast Epoxy (CE), the Cycloaliphatic Epoxy A (CEA), and the Glass Reinforced Plastic (GRP) together with the station arresters when subjected by 30 kA (5/80 µs) and 90 kA (9/200 µs) lightning currents. The results obtained demonstrated that the GRP material has been able to slightly lower its induced overvoltage as compared to other materials, especially for the case of 90 kA (9/200 µs), and thus serves better coordination with the station arresters. This improvement has also reflected on the recorded residual voltage and energy absorption capacity of the arrester, respectively.
Microplastics (MPs) are a pervasive pollutant in the marine environment. Pantai Teluk Likas in Sabah, Malaysia is one of the most visited beaches where tourism, recreational, and fisheries activities are high in this area. Hence, the area suffers from severe pollution, particularly from plastics. This study aims to quantify the microplastic composition in terms of color, shapes, and polymer types in marine bivalves (Anadara granosa, Glauconome virens, and Meretrix lyrata) and water column samples from Pantai Teluk Likas. All samples were digested using sodium hydroxide (NaOH) and incubated in the oven for at least 48 h. Serial filtration was done for each sample before they were observed under the dissecting microscope. The microplastics were identified and counted based on their physical attributes which were colors and shapes. The functional group of the polymers was determined using FTIR spectroscopy. Microplastics were found present in all samples collected. G. virens had the highest abundance of microplastics at 113.6 ± 6.5 particles/g followed by M. lyrata at 78.4 ± 3.7 particles/g. On the contrary, A. granosa had the least microplastics with an abundance of 24.4 ± 0.6 particles/g. Meanwhile, 110.0 ± 36.2 particles/L of microplastics were found in water column samples from Pantai Teluk Likas. Based on the analysis, fibers were the most common shape in bivalves, while fibers and films were common in the water column. In terms of colors, black, blue, and red were a few of the most abundant colors observed in both samples. The most common polymer detected in all bivalve species and water column samples is polycarbonate (PC), followed by polymethyl methacrylate (PMMA). Future study that focuses on the correlation between microplastic abundance in the marine biota and the water column is recommended to better understand microplastic availability and exposure.
This study aims at investigating the distortion of poly(dimethylsiloxane) (PDMS) nanostructures in a soft lithography demolding process using molecular dynamics simulation. Experimental results show that after peeling, PDMS nanopillars became 10-60% longer in height than the mold size. Molecular dynamics simulations have been employed to plot the stress-strain curve of the nanopillars when subjected to uniaxial stress. Three force fields (COMPASS, CVFF, and PCFF) were used for modeling. The demolding process in soft lithography and nanoimprint lithography causes significant deformation in replication. The experimental results show clear signs of elongation after demolding. Molecular dynamics simulations are employed to study the stress-strain relationship of the PDMS nanopillars. The results from the simulation show that a PDMS nanopillar at temperature T = 300 K under tensile stress shows characteristics of flexible plastic under tensile stress and has a lower Young's modulus, ultimate tensile stress, and Poisson's ratio.
Urban areas worldwide are in the race to become smarter, and the Kingdom of Saudi Arabia (KSA) is no exception. Many of these have envisaged a chance to establish devoted municipal access networks to assist all kinds of city administration and preserve services needing data connectivity. Organizations unanimously concentrate on sustainability issues with key features of general trends, particularly the combination of the 3Rs (reduce waste, reuse and recycle resources). This paper demonstrates how the incorporation of the Internet of Things (IoT) with data access networks, geographic information systems and combinatorial optimization can contribute to enhancing cities' administration systems. A waste-gathering approach based on supplying smart bins is introduced by using an IoT prototype embedded with sensors, which can read and convey bin volume data over the Internet. However, from another perspective, the population and residents' attitudes directly affect the control of the waste management system. The conventional waste collection system does not cover all areas in the city. It works based on a planned scheme that is implemented by the authorized organization focused on specific popular and formal areas. The conventional system cannot observe a real-time update of the bin status to recognize whether the waste level condition is 'full,' 'not full,' or 'empty.' This paper uses IoT in the container and trucks that secure the overflow and separation of waste. Waste source locations and population density influence the volume of waste generation, especially waste food, as it has the highest amount of waste generation. The open public area and the small space location problems are solved by proposing different truck sizes based on the waste type. Each container is used for one type of waste, such as food, plastic and others, and uses the optimization algorithm to calculate and find the optimal route toward the full waste container. In this work, the situations in KSA are evaluated, and relevant aspects are explored. Issues relating to the sustainability of organic waste management are conceptually analyzed. A genetic-based optimization algorithm for waste collection transportation enhances the performance of waste-gathering truck management. The selected routes based on the volume status and free spaces of the smart bins are the most effective through those obtainable towards the urgent smart bin targets. The proposed system outperforms other systems by reducing the number of locations and smart bins that have to be visited by 46% for all waste types, whereas the conventional and existing systems have to visit all locations every day, resulting in high cost and consumption time.
This study investigates the Covid-19 driven indiscriminate disposal of PPE wastes (mostly face mask and medical wastes) in Chittagong metropolitan area (CMA), Bangladesh. Based on the field monitoring, the mean PPE density (PPE/m2± SD) was calculated to be 0.0226 ± 0.0145, 0.0164 ± 0.0122, and 0.0110 ± 0.00863 for July, August, and September 2021, respectively (during the peak time of Covid-19 in Bangladesh). Moreover, gross information on PPE waste generation in the city was calculated using several parameters such as population density, face mask acceptance rate by urban population, total Covid-19 confirmed cases, quarantined and isolated patients, corresponding medical waste generation rate (kg/bed/day), etc. Moreover, the waste generated due to face mask and other PPEs in the CMA during the whole Covid-19 period (April 4, 2020 to September 5, 2021) were calculated to be 64183.03 and 128695.75 tons, respectively. It has been observed that the negligence of general people, lack of awareness about environmental pollution, and poor municipal waste management practices are the root causes for the contamination of the dwelling environment by PPE wastes. As a result, new challenges have emerged in solid waste management, which necessitates the development of an appropriate waste management strategy. The ultimate policies and strategies may help to achieve the SDG goals 3, 6, 11, 12, 13, and 15, and increase public perception on the use and subsequent disposal of PPEs, especially face masks.
The present study focuses on the indiscriminate disposal of personal protective equipment (PPEs) and resulting environmental contamination during the 3rd wave of COVID-19-driven global pandemic in the Chittagong metropolitan area, Bangladesh. Because of the very high rate of infection by the delta variant of this virus, the use of PPEs by the public is increased significantly to protect the ingestion/inhalation of respiratory droplets in the air. However, it is a matter of solicitude that general people throw away the PPEs to the dwelling environment unconsciously. With the increase of inappropriate disposal of PPEs (i.e., mostly the disposable face masks made from plastic microfibers), the possibility of transmission of the virus to the general public cannot be neglected completely. This is because this virus can survive for several days on the inanimate matter like plastics and fibers. At the same time, the result of environmental contamination by microplastic/microfiber has been widespread which eventually creates the worst impact on ecosystems and organisms. The present results may help to increase public perception of the use and subsequent disposal of PPEs, especially the face masks.
The conversion of plastic waste into fuel by pyrolysis has been recognized as a potential strategy for commercialization. The amount of plastic waste is basically different for each country which normally refers to non-recycled plastics data; consequently, the production target will also be different. This study attempted to build a model to predict fuel production from different non-recycled plastics data. The predictive model was developed via Levenberg-Marquardt approach in feed-forward neural networks model. The optimal number of hidden neurons was selected based on the lowest total of the mean square error. The proposed model was evaluated using the statistical analysis and graphical presentation for its accuracy and reliability. The results showed that the model was capable to predict product yields from pyrolysis of non-recycled plastics with high accuracy and the output values were strongly correlated with the values in literature.
Reversible valves on centrifugal microfluidic platforms facilitate the automation of bioanalytical assays, especially of those requiring a series of steps (such as incubation) in a single reaction chamber. In this study, we present fixed elastic reversible (FER) valves and tunable elastic reversible (TER) valves that are easy to fabricate, implement and control. In the FER valve the compression of an elastic barrier/patch against a microchamber's outlet prevents the release of liquid. The valve sealing pressure was determined by adjusting the engraving depth of the valve-seat at which the elastic patch was located, this allows to set the sealing pressure during disc fabrication. In the TER valve, the patch compression value and sealing pressure is controlled by the penetration depth of a plastic screw into the valve-seat. The ER valves prevent liquid flow until the centrifugal force overcomes their sealing pressure. Moreover, at a constant spin speed, turning the screw of a TER valve reduces its sealing pressure and opens the valve. Therefore, the TER valve allows for controlling of the liquid transfer volume at various spin speeds. The FER and TER valves' behavior is mathematically described and equations for the prediction of their operation under centrifugal forces are provided. As a point-of-care (POC) application of ER valves, we have developed a microfluidic disc with a series of TER valves and peptide microarrays for automated multiplexed detection of five different proteins from a single serum sample.
The focus of this study is to analyze the level of knowledge, awareness, and attitude toward plastic waste and to distinguish the key drivers that encourage the households in Kuala Lumpur, Malaysia, to participate in "No plastic campaign," This study used the logistic regression model to explain the factors that may affect the willingness to participate (WTP) of households in the campaign. In this study, it is found that 35 % of households are willing to participate in the campaign. The results of the study also indicate that people who are more informed and more convinced of their knowledge have a more positive attitude toward recycling than their counterparts do. Furthermore, this study provides additional evidence of the level and classification of importance of motivating factors for plastic recycling, using the modified average and coefficient of variation of the models. From the analysis, the factor "helps reduce landfill use" is found as the most important factor and the factor of "raising money for charity" is found as the least important factor that motivates households to participate in recycling. The determinations of the study suggest some strategies that could hold implications for government and households to boost them to participate in the campaign "No Plastic Bag."
Marine debris, defined as any persistent manufactured or processed solid material discarded, disposed of or abandoned in the marine and coastal environment, has been highlighted as a contaminant of global environmental and economic concern. The five main categories of marine debris comprise of plastic, paper, metal, textile, glass and rubber. Plastics is recognised as the major constituent of marine debris, representing between 50% and 90% of the total marine debris found globally. Between 4.8 and 12.7 million metric tonnes of consumer plastics end up in the world oceans annually, resulting in the presence of more than 100 million particles of macroplastics in only 12 regional seas worldwide, and with 51 trillion particles of microplastic floating on the ocean surface globally. The impacts of marine debris can be branched out into three categories; injury to or death of marine organisms, harm to marine environment and effects on human health and economy. Marine mammals often accidentally ingest marine debris because of its appearance that can easily be mistaken as food. Moreover, floating plastics may act as vehicles for chemicals and/or environmental contaminants, which may be absorbed on to their surface during their use and permanence into the environment. Additionally, floating plastics is a potential vector for the introduction of invasive species that get attached to it, into the marine environment. In addition, human beings are not excluded from the impact of marine debris as they become exposed to microplastics through seafood consumption. Moreover, landscape degradation owing to debris accumulation is an eyesore and aesthetically unpleasant, thus resulting in decreased tourism and subsequent income loss. There are a wide range of initiatives that have been taken to tackle the issue of marine debris. They may involve manual removal of marine debris from coastal and aquatic environment in form of programmes and projects organised, such as beach clean-ups by scientific communities, non-governmental organizations and the removal of marine litter from Europe's four regional seas, respectively. Other initiatives focus on assessment, reduction, prevention and management of marine debris under the umbrella of international (the United Nations Environment Programme/Mediterranean Action Plan, the Oslo/Paris Convention) and regional organisations - that is, the Helsinki Commission. There are also a number of international conventions and national regulations that encourage mitigation and management of marine debris. However, it is argued that these initiatives are short-term unsustainable solutions and the long-term sustainable solution would be adoption of circular economy. Similarly, four of the sustainable developmental goals have targets that promote mitigation of marine debris by efficient waste management and practice of 3R. As evident by the Ad Hoc Expert Group on Marine Litter and Microplastics meeting, tackling the marine debris crisis is not a straightforward, one-size-fits-all solution, but rather an integrated and continuous effort required at local, regional and global level.
Solid-state recycling, which involves the direct recycling of scrap metal into bulk material using severe plastic deformation, has emerged as a potential alternative to the conventional remelting and recycling techniques. Hot press forging has been identified as a sustainable direct recycling technique that has fewer steps and maintains excellent material performance. An experimental investigation was conducted to explore the hardness and density of a recycled aluminum-based metal matrix composite by varying operating temperature and holding time. A mixture of recycled aluminum, AA6061, and aluminum oxide were simultaneously heated to 430, 480, and 530 °C and forged for 60, 90, and 120 min. We found a positive increase in microhardness and density for all composites. The hardness increased approximately 33.85%, while density improved by about 15.25% whenever the temperature or the holding time were increased. Based on qualitative analysis, the composite endures substantial plastic deformation due to the presence of hardness properties due to the aluminum oxide embedded in the aluminum matrix. These increases were significantly affected by the operating temperature; the holding time also had a subordinate role in enhancing the metal matrix composite properties. Furthermore, in an effort to curb the shortage of primary resources, this study reviewed the promising performance of secondary resources produced by using recycled aluminum and aluminum oxide as the base matrix and reinforcement constituent, respectively. This study is an outline for machining practitioners and the manufacturing industry to help increase industry sustainability with the aim of preserving the Earth for our community in the future.
Carbon fibre-reinforced polymer (CFRP) composite materials play an increasingly important role in modern manufacturing, and they are among the more prominent materials used in aircraft manufacturing today. However, CFRP is highly prone to delamination and other damage when drilled due to it being extremely strong with a good strength-to-weight ratio and high thermal conductivity. Because of this problem and CFRP's growing importance in aircraft manufacture, research has focused on the entry and exit holes as indicators of damage occurrence during drilling of screws, rivets, and other types of holes. The inside of the hole was neglected in past research and a proper way to quantify the internal side of a hole by combining the entry and exit hole should be included. To fill this gap and improve the use of CFRP, this paper reports a novel technique to measure the holes by using the extension of the adjusted delamination factor (SFDSR) for drilling thick CFRP composites in order to establish the influence of machining input variables on key output measures, i.e., delamination and other damages. The experimental results showed a significant difference in interpretation of the damage during the analysis. Improvement was made by providing better perspectives of identifying hole defects.
Composites from carbon fibre reinforced polymers (CFRPs) play a significant role in modern manufacturing. They are typically used in aerospace and other industries that require high strength-to-weight ratios. Composite machining, however, remains a challenging job and sometimes is hampered by poor efficiency. Despite considerable research being conducted over the past few years on the machining of composite materials, the material nevertheless suffers from delamination, fibre loss, and imperfect finishing of the fuselage. Laser technology is becoming increasingly popular as an alternative approach to cutting and drilling composites. Experiments have been conducted with a CFRP thickness of 25.4 mm using fibre laser to test the effect of the machining parameters on the primary performance measurements. In this study, different machining criteria are used to assess the fibre laser ability of thick CFRP composites for drilling operation. The experimental findings revealed that a fibre laser is capable of penetrating a thick CFRP to a depth of 22 mm by using a novel drilling procedure.
The present project investigated the potential of utilizing corncobs and sugar cane waste as viscosivier in drilling fluid. For this purpose, the synthetic-based drilling fluid, Sarapar 147, was used as the base fluid. Both the materials were subjected to pre-treatment of drying, dehumidifying, grinding and sieving process prior to rheological tests. The rheological tests were conducted in accordance with the API 13B specifications to measure mud density, plastic viscosity, yield point, 10-second and 10-minute gel strength. The study found that plastic viscosity and yield point had a direct relationship with the amount of materials added. To drill fluid additive with corn cobs, the density, plastic viscosity and yield point were increased when the amount of additives were increased. Based on these experiments, both additives were found to have the potential to be used as additive in drilling fluid. In particular, they were able to improve its rheological properties by increasing the density, plastic viscosity and yield point. The suitable concentration for the corn cobs and sugar cane is 6.45 lb/bbl and 9.43 lb/bbl, respectively.
Environmental pollution is one of the major concerns in the 21st century; where billions of tonnes
of harmful chemicals are produced by industries such as petroleum, paints, food, rubber, and
plastic. Phenol and its derivatives infiltrate the ecosystems and have become one of the top major
pollutants worldwide. This review covers the major aspects of immobilization of phenoldegrading
bacteria as a method to improve phenol bioremediation. The use of various forms of
immobilization matrices is discussed along with the advantages and disadvantages of each of the
immobilization matrices especially when environmental usage is warranted. To be used as a
bioremediation tool, the immobilized system must not only be effective, but the matrices must be
non-toxic, non-polluting and if possible non-biodegradable. The mechanical, biological and
chemical stability of the system is paramount for long-term activity as well as price is an
important factor when the very large scale is a concern. The system must also be able to tolerate
high concentration of other toxicants especially heavy metals that form as co-contaminants, and
most immobilized systems are geared towards this last aspect as immobilization provides
protection from other contaminants.
Skin sampling is a diagnostic procedure based on the analysis of extracted skin tissues and/or the observation of biomarkers in bodily fluids. Sampling using microneedles (MNs) that minimize invasiveness is gaining attention over conventional biopsy/blood lancet. In this study, new MNs for electrochemically assisted skin sampling are reported, specifically tailored for combined skin tissue biopsy and interstitial fluid (ISF) extraction. To overcome risks associated with using metal MNs, a highly electroactive, mechanically flexible, and biocompatible organic conducting polymer (CP) coated onto plastic is chosen as an alternative. Two different variants of doped poly(3,4-ethylenedioxythiophene) are coated on polymethyl methacrylate and used in combination as a MN pair with subsequent testing via a variety of electrochemical techniques to (i) give real-time information of the MN penetration depth into the skin, and (ii) yield new information on various salts present in the ISF. The MN skin sampler shows the ability to extract ions from the hydrated excised skin as a step towards in vivo ISF extraction. The presence of ions was analyzed using X-ray photoelectron spectroscopy. This added chemical information in conjunction with the existing biomarker analysis increases opportunity for disease/condition detection. For example, in the case of psoriasis, information about salt in the skin is invaluable in combination with pathogenic gene expression for diagnosis.
In April and June 2010, coconut seedlings with symptoms of very slow growth, yellowing of leaves, and general abnormal leaf growth were observed in germination beds in Teluk Intan, Perak, Malaysia. The roots were soft, rotten, and brown, extending upward and downward from these lesions. Rhizomorphs and basidiocarps were produced on coconut seeds near the germination eye and identified as Marasmiellus palmivorus according description by Turner (2). Three isolates were obtained by plating surface sterilized symptomatic roots and basidiocarp on malt extract agar (MEA) amended with 85% lactic acid (1 ml added to 11 of the medium). To confirm the identity of the fungus, genomic DNA was extracted from mycelia and basidiocarps of isolates and the large subunit (LSU) region was amplified and sequenced using LR0R/LR7 primers (3). All isolates had identical LSU sequences (GenBank Accession No. JQ654233 to JQ654235). Sequences were identical to each other and 99% similar to a M. palmivorus sequence deposited in the NCBI database (Accession No. AY639434).To confirm pathogenicity, three isolates of M. palmivorus that were obtained from symptomatic plant tissue was inoculated onto seeds of Malaysian Red Dwarf variety. Each isolate was grown in 100 ml of malt extract broth in 250 ml Erlenmeyer flasks and incubated at 27 ± 2°C for 5 days on an orbital shaker (125 rpm). The resulting culture was passed through two layers of sterile cloth. Mycelial suspension was obtained by blending mycelia in 100 ml of sterile water. Seeds were sterilized by soaking in 10% v/v sodium hypochlorite in distilled water for 3 min. The seeds were then rinsed three times over running tap water. The calyx portion of the seed was removed and five holes were made around the germination eye. The seeds were inoculated by injecting 2 ml of suspension into each hole. The control seeds were inoculated with sterile distilled water only. The seeds were transferred to 40-cm diameter plastic pots containing a mixture of sand, soil, and peat in the ratio of 3:2:1, respectively, and steam treated at 100°C for 1.5 h. Pots were placed in the glasshouse with normal exposures to day-night cycles, temperatures of 29 ± 4°C, and high relative humidity (85 to 95%) achieved by spraying water twice daily. After 2 months, 75% of the inoculated seeds failed to germinate. It was speculated that the artificial inoculum was higher than under germination bed conditions. Rhizomorphs and basidiocarps were produced on husk seeds near the germination eye. Seedlings that emerged successfully developed symptoms similar to those observed in the germination bed. No symptoms developed in the noninoculated seeds and seedlings. At 80 days post inoculation, basidiocarps were observed emerging from three diseased seedlings near the germination eye. Three reisolations were made on MEA from root lesions surface sterilized. Pathogenicity tests and LSU sequence analyses indicated that M. palmivorus is the causal agent of the symptoms observed on coconut seedlings. M. palmivorus was first recorded on coconuts and oil palm in the 1920s (1) and attacks the fruit and the petiole on oil palm (2). To our knowledge, this is the first report of M. palmivorus causing post-emergence damping off on coconut seedlings. References: (1) K. G. Singh. A check-list of host and diseases in Malaysia. Ministry of Agriculture and Fisheries, Malaysia, 1973. (2) P. D. Turner. Oil palm diseases and disorders. Oxford University Press. 1981. (3) R. Vilgalys et al. J. Bacteriol. 172:4238, 1990.
Microplastics (MPs) have become a prevalent environmental concern, exerting detrimental effects on marine and terrestrial ecosystems, as well as human health. Addressing this urgent issue necessitates the implementation of coordinated waste management policies and strategies. In this study, we present a comprehensive review focusing on key results and the underlying mechanisms associated with microplastics. We examine their sources and pathways, elucidate their ecological and human health impacts, and evaluate the current state of waste management policies. By drawing upon recent research and pertinent case studies, we propose a range of practical solutions, encompassing enhanced recycling and waste reduction measures, product redesign, and innovative technological interventions. Moreover, we emphasize the imperative for collaboration and cooperation across sectors and jurisdictions to effectively tackle this pressing environmental challenge. The findings of this study contribute to the broader understanding of microplastics and provide valuable insights for policymakers, researchers, and stakeholders alike.
Percolation theory has been used with great interest in understanding the design and characterization of dosage forms. In this study, work has been carried out to investigate the behavior of binary mixture tablets containing excipients of similar and different deformation properties. The binary mixture tablets were prepared by direct compression using lactose, polyvinyl chloride (PVC), Eudragit RS 100, and microcrystalline cellulose (MCC). The application of percolation theory on the relationships between compactibility, Pmax, or compression susceptibility (compressibility), gamma, and mixture compositions reveals the presence of percolation thresholds even for mixtures of similar deformation properties. The results showed that all mixture compositions exhibited at least one discreet change in the slope, which was referred to as the percolation threshold. The PVC/Eudragit RS100 mixture compositions showed significant percolation threshold at 80% (w/w) PVC loading. Two percolation thresholds were observed from a series of binary mixtures containing similar plastic deformation materials (PVC/MCC). The percolation thresholds were determined at 20% (w/w) and 80% (w/w) PVC loading. These are areas where one of the components percolates throughout the system and the properties of the tablets are expected to experience a sudden change. Experimental results, however, showed that total disruption of the tablet physical properties at the specified percolation thresholds can be observed for PVC/lactose mixtures at 20-30% (w/w) loading while only minor changes in the tablets' strength for PVC/MCC or PVC/Eudragit RS 100 mixtures were observed.
Microplastic (MP) is an emerging contaminant of concern due to its abundance in the environment. Wastewater treatment plant (WWTP) can be considered as one of the main sources of microplastics in freshwater due to its inefficiency in the complete removal of small MPs. In this study, a column-based MP removal which could serve as a tertiary treatment in WWTPs is evaluated using granular activated carbon (GAC) as adsorbent/filter media, eliminating clogging problems commonly caused by powder form activated carbon (PAC). The GAC is characterized via N2 adsorption-desorption isotherm, field emission scanning electron microscopy, and contact angle measurement to determine the influence of its properties on MP removal efficiency. MPs (40-48 μm) removal up to 95.5% was observed with 0.2 g/L MP, which is the lowest concentration tested in this work, but still higher than commonly used MP concentration in other studies. The performance is reduced with further increase in MP concentration (up to 1.0 g/L), but increasing the GAC bed length from 7.5 to 17.5 cm could lead to better removal efficiencies. MP particles are immobilized by the GAC predominantly by filtration process by being entangled with small GAC particles/chips or stuck between the GAC particles. MPs are insignificantly removed by adsorption process through entrapment in GAC porous structure or attachment onto the GAC surface.