Removal Of Microplastics Research Articles

Removal of Microplastics from Laundry Wastewater Using Coagulation and Membrane Combination: A Laboratory-Scale Study

Microplastic (MP) pollution has recently emerged as a critical global environmental issue. Laundry wastewater is a significant contributor to MP pollution, containing high concentrations of MPs. Although coagulation has recently been widely applied to remove MPs from such wastewater, its efficiency remains poor, and the removal mechanisms are not yet fully elucidated. In this study, the occurrence and characteristics of MPs in raw domestic laundry wastewater were investigated. The coagulation process was combined with ultrafiltration (UF) membrane filtration to enhance MP removal. The results showed that the concentrations of MPs in laundry wastewater ranged from 9000 to 11,000 particles/L, with fibrous particles constituting the majority (42.6%) and polyester accounting for 68.2% of detected MPs. Using aluminium chloride and ferric chloride as coagulants, maximum removal efficiencies of 91.7 and 98.3% were achieved, respectively. Mechanistic analysis revealed that charge neutralization played a dominant role during coagulation. Fourier transform infrared spectroscopy further demonstrated the formation of new functional groups, substituted benzene rings, and the presence of Fe-O and Al-O bonds, indicating the interaction between MPs and coagulants. Furthermore, the UF membrane was used to remove fibrous MPs and MPs with low densities. These MPs had not been removed with pre-coagulation. The removal efficiency of these MPs reached 96 ± 2%, reducing their concentration to only 60 particles/L in the UF permeate. These findings highlight the synergistic potential of coagulation and UF membrane filtration for effective MP removal and provide a valuable reference for advancing wastewater treatment technologies targeting MP pollution.

Technical and Economic Feasibility Investigation for the Treatment of Microplastic-Contaminated Marine Sediments Through an Environmentally Sustainable Separation Process

This work provides a comprehensive study of a density separation treatment through sucrose solution for the removal of microplastics (MPs) from marine sediments. The theoretical determination of flotation velocities for 1.0 mm diameter spherical MPs with a density of 1.3 g/cm3 at various solution temperatures and sucrose contents was performed. An optimal velocity of 1.03 m/h was observed with a 70% sucrose solution at 50 °C. The validation of theoretical velocities was carried out through experimental tests at optimal operating conditions for polypropylene (PP), high-density polyethylene (HDPE), polylactic acid (PLA), and polyvinyl chloride (PVC) as target MPs. The results showed an experimental floating velocity slightly lower than the theoretical predictions for PP, HDPE, and PLA. PVC, instead, characterized by a higher density than the separation solution, showed a settling velocity 42% lower than the theoretical one. Further tests were performed to assess the solid-to-liquid (S/L) ratio effect on MPs’ separation efficiency. The results showed an optimal S/L of 75 kg/m3 with 80% PVC removal and total PP, HDPE, and PLA removal. Finally, the design and cost optimization of a longitudinal settling tank were proposed for the pilot/real-scale treatment. The observed outcomes provided in-depth details useful for the development of an environmentally sustainable treatment for the preservation of marine areas.

Towards sustainable microplastic cleanup: Al/Fe ionotropic chitosan hydrogels for efficient PET removal.

Chitosan (CHI) was modified with iron and aluminum salts to create ionotropic beads, Fe-CHI and Al-CHI, for the removal of polyethylene terephthalate microplastics (PET-MP) from water. Infrared spectroscopy revealed reduced hydrogen bonding associated with N-H vibration of CHI (3500-3100cm-1) due to the interaction with the metal ions, and absorption peaks between 500 and 916cm⁻1 predominantly due to metal-oxygen stretching vibrations. The swelling behavior of the beads increased with temperature but decreased as pH and metal doping concentration increased. Conductivity and PET-MP removal efficiency improved with higher metal ion concentrations, with Al-CHI exhibiting greater swelling and conductivity compared to Fe-CHI. The highest efficiency for MP remediation was recorded at low pH levels. MP adsorption decreased with rising temperatures and varied with pH changes due to protonation and deprotonation reactions of CHI, along with the various cationic and anionic species formed by the metals. At pH 7, MP removal by Fe-CHI beads declined as the doping concentration increased, attributed to specific Fe species that emerged at this pH. The zeta potential measurements showed that both the beads and the MP were in an unstable range at low pH but shifted towards stability at higher pH levels. Re-adsorption efficiencies exceeded 70% for both low and high-doped Fe-CHI and Al-CHI beads when tested with ~ 40 MP/mL of MP suspension over three different cycles. Overall, the use of ionotropic CHI beads offers a promising, eco-friendly method for effectively reducing PET-MPs in water.

Simultaneous removal of diclofenac, triclosan, and microplastics using graphene oxide-chitosan sponges

Simultaneous removal of diclofenac, triclosan, and microplastics using graphene oxide-chitosan sponges

Biodegradable sponges made from chitin-cellulose nanofibers for sustainable removal of microplastics from aquatic environment

Biodegradable sponges made from chitin-cellulose nanofibers for sustainable removal of microplastics from aquatic environment

Efficient tetracycline hydrochloride degradation via peroxymonosulfate activation by N doped coagulated sludge based biochar: Insights on the nonradical pathway.

Coagulation could effectively remove microplastics (MPs). However, MPs coagulated sludge was still a hazardous waste that is difficult to degrade. Nitrogen-doped carbon composite (N-PSMPC) was prepared by carbonizing MPs coagulated aluminum sludge (MP-CA) doped with cheap urea in this study. Compared with the carbon material (PSMPC) produced by direct carbonization of MP-CA, N-PSMPC had a higher degree of defects, which could provide more active sites for peroxymonosulfate (PMS) activation. And then, the N-PSMPC was applied to the degradation of tetracycline hydrochloride (TC). The results showed that the N-PSMPC/PMS system exhibited excellent TC degradation performance at the pH range of 3-9, and the coexistence of CO32- and HCO3- inhibited the TC degradation. Moreover, the graphite N, pyridine N and carbonyl group were identified as the primary catalytic active sites. Three TC degradation pathways were speculated based on the intermediates detected by liquid chromatography-mass spectrometry, and the degradation mechanism was dominated by the nonradical pathway. In addition, the analysis of TC and intermediates by toxicity assessment software showed that N-PSMPC/PMS system could mitigate the TC toxicity. This study will provide a novel approach for the resourceful utilization of MP-CA and provide technical support for the removal of MPs and TC in water.

Modeling and optimization study for microplastic removal from aquatic medium using Chroococcidiopsis species

Modeling and optimization study for microplastic removal from aquatic medium using Chroococcidiopsis species

Development and Efficiency Evaluation of Microplastic Removal Filter for Laundry Machines

Microplastics contained in laundry wastewater are identified as the main cause of marine microplastics, accounting for approximately 35% of marine microplastics. In this study, a four-stage microplastic filter for laundry wastewater was developed and the removal rates of microplastics, COD, SS, and turbidity were checked through 50 tests to confirm the efficiency of the filter. The microplastic removal rate was confirmed using μFTIR with a high efficiency of 98.5% on average for 50 tests. The microplastics contained in laundry wastewater were identified as 57% PE, 9% PET, 9% PA, 8% PU, 8% PP, 6% PPMA, and 3% PAN. COD was measured using the COD manganese method, and the COD removal rate of the laundry wastewater filter was an average of 92% for 50 times. SS was verified by filtration using a vacuum pump and the average removal rate was 80% during 50 tests. Turbidity was confirmed with an average removal rate of 88% using a turbidity meter. As a result of the experiment, it was confirmed that when the developed filter was installed in laundry wastewater, not only microplastics but also various water pollutants were reduced. In addition, the water quality pollution index showing the highest correlation with microplastics in laundry wastewater was SS, and the p-value was confirmed to be 0.000.

Microplastic removal in aquatic systems using extracellular polymeric substances (EPS) of microalgae

Microplastic removal in aquatic systems using extracellular polymeric substances (EPS) of microalgae

Microplastics in aquatic environments: detection, abundance, characteristics, and toxicological studies.

Microplastics (MPs) are fragments with a diameter of less than 5 mm that have been directly manufactured or formed by the degradation of plastic waste. MPs are not only prone to bioaccumulation in the environment, but they also lead to the spread of micropollutants in the environment, thereby threatening human health ecological environment. The useful detection method of MPs and understanding their abundance, characteristics and toxicity are great essential for MPs removal and control. This work presented the current methods of MPs' detection, compared the abundance and characteristics of MPs in water, and reviewed MPs' toxicity to organisms. Furthermore, detailed policies intervention for plastics and MPs' mitigation have been focused which delineate for application of science and policy together with scientific evidence. Lastly, this study suggests more attention should be paid to the content of MPs in freshwater and organisms closely related to human life, as well as the toxicological toxicity of MPs in mammals.

Rhamnolipid: nature-based solution for the removal of microplastics from the aquatic environment

Abstract Over the past two decades, research into the accumulation of small plastic particles and fibers in organisms and environmental settings has yielded over 7,000 studies, highlighting the widespread presence of microplastics in ecosystems, wildlife, and human bodies. In recent years, these contaminants have posed a significant threat to human, animal, and environmental health, with most efforts concentrated on removing them from aquatic systems. Given this urgency, the purpose of this study was to investigate the potential of rhamnolipid, a biosurfactant, for the removal of microplastics from water. Specifically, this study evaluates the effects of water matrix, initial pH of the solution (7.0, 7.5, 8.0, 8.5, 9.0, 9.5, and 10.0), concentrations of alum (5, 10, 20, 30, 40, and 50 mg/L), and concentrations of rhamnolipid (1, 5, 10, 20, 40, 80, and 100 mg/L). Optimum removal was achieved at alum and rhamnolipid concentrations of 5.0 mg/L and 1.0 mg/L, respectively, with a solution pH of 8.0. In both types of water tested, a removal efficiency of about 74% was determined, indicating the potential of rhamnolipid as a nature-based solution to control microplastic pollution in surface waters.

A Review of Sources, Hazards, and Removal Methods of Microplastics in the Environment

The prevalence of microplastics in a wide range of environmental media has attracted increasing attention worldwide. This review article provides a comprehensive and systematic review of the nature, sources, hazards, and removal methods of microplastics in the environment. In contrast to previous studies focusing on the sources and risks of microplastics in a single environment, this article comprehensively analyses atmospheric, terrestrial runoff, marine and freshwater sources of microplastics and explores the hazards they pose to the environment and the health of humans and other organisms. Microplastics cause multiple adverse effects on aquatic and terrestrial organisms through accumulation, including growth inhibition, oxidative stress, inflammation, organ damage, and germ cell abnormalities. They may also enter the food chain and affect human health. This article summarizes the latest research progress on microplastic removal technologies from biological, physical, and chemical perspectives, with high efficiency, sustainability, and degradability for biological removal and adsorption and filtration being more effective for physical removal. This provides valuable information for future research related to microplastics. We advocate for a reduction in the use of microplastics and provide references for solving the problem of microplastic pollution.

Investigation of microplastics in community well water in Banda Aceh, Indonesia: a separation technique using polyethersulfone-poloxamer membrane

<p>Microplastics (MPs) pose a substantial challenge to the environment and have life-threatening implications for organisms, including humans. To overcome this challenge, several investigations have been conducted, including adsorption with a specific absorbent, manual and modified sand filtration columns, and ultrafiltration using polymers. However, microplastic removal using these methods remains limited in certain cases; hence, an optimal method is required to separate MPs from water. The aim of this study was to remove MPs from community water wells in Banda Aceh, Indonesia, using a polyether sulfone (PES) membrane modified with poloxamer surfactants and patchouli oil. Membranes were created using the phase inversion method to form an asymmetrical structure with a top-to-bottom pore distribution. Community well water samples were collected from numerous points in Banda Aceh City. This was followed by analysis before and after filtration using a microscope and FTIR spectroscopy to determine the shape and type of MPs. The results revealed fiber- and film-shaped MPs detected in the well water of each community examined in this study. The FTIR analysis demonstrated that MP contamination was dominated by polyethylene and polypropylene plastics, consistent with the trend observed across Asia. Nonetheless, MP contamination could be eliminated by an ultrafiltration process using a membrane. In this study, the removal of MPs using the membrane delivered significant results. Pure PES membranes can eliminate up to 87.5% of MPs from water samples. However, the PES membrane containing poloxamer and patchouli oil delivered 100% rejection.</p>

Microplastic removal by ozone oxidation in cooling wastewater of food packaging industry

Microplastic removal by ozone oxidation in cooling wastewater of food packaging industry

Environmental impact of microplastic emissions from wastewater treatment plant through life cycle assessment.

This study aimed to quantify the environmental impact of microplastic (MP) emissions from wastewater treatment plants (WWTPs) using life cycle assessment (LCA). The investigation comprehensively evaluated the contribution of MPs to overall WWTP midpoint and endpoint impacts, with a detailed analysis of the influence of particle size, shape, polymer type, and the environmental costs and benefits of individual wastewater treatment processes on MP removal. The LCA model was developed using SimaPro software, with impact assessments conducted via the USEtox framework and the IMPACT World+ methodology. Results showed that at the midpoint level, MPs accounted for 1.24E+05 CTUe (94% of the total plant impact), representing the potential harm to aquatic species per cubic meter of discharged wastewater-surpassing the impacts of other contaminants (e.g., heavy metals, nutrients) by at least two orders of magnitude. At the endpoint level, the damage of 8.39E-02 PDF·m2·yr (1.7% of the total) indicated the potential loss of species diversity, comparable to other pollutant contributions. Polyethylene, polystyrene, and polypropylene were identified as the most impactful polymer types. In terms of environmental costs and benefits, secondary, tertiary, and primary treatments demonstrated decreasing environmental benefits, directly correlated with their respective MP removal efficiencies. These findings underscore the critical role of MP emissions in WWTP life cycle inventories and highlight the urgent need for targeted environmental policies and advanced treatment technologies to address MP contamination in both natural and engineered aquatic systems.

Reduced graphene oxide membrane with small nanosheets for efficient and ultrafast removal of both microplastics and small molecules.

The clogging of sieving pores due to the complex sewage system of mixed molecules and nanoparticles of different scales is a difficulty in the membrane-based separation process. When the holes are reduced to the point where they can repel small molecules in the contaminants, large-molecule contaminants can adsorb to the holes and decrease the permeability. A similar question remains in new promising graphene oxide (GO) membranes. In this study, we prepared a small lateral-sized reduced graphene oxide (S-rGO) membrane with short Z-type water transport pathways and a lower adsorption energy for pollutant molecules. The S-rGO membrane presented an ultrahigh permeability for large size microplastics (MPs) of 236.2 L m-2 h-1 bar-1 (99.9 % rejection rate) and small dye molecules of 234.2 L m-2 h-1 bar-1, which was 40 and 25 times higher than the permeability of traditional GO membranes with larger sized sheets, respectively. We evaluated the long-term stability of the membrane in cross-flow system. The membrane maintained more than 212.8 L m-2 h-1 bar-1 permeability and a 99.9 % rejection rate under 16 h. Our findings provided a new strategy to address the difficulty of efficient membrane use for complex water pollutants.

Ni-MOF-doped superhydrophobic sponge with photothermal conversion properties for enhanced removal of oil pollutants and microplastics from aqueous environments

Ni-MOF-doped superhydrophobic sponge with photothermal conversion properties for enhanced removal of oil pollutants and microplastics from aqueous environments

Biophysics-guided uncertainty-aware deep learning uncovers high-affinity plastic-binding peptides.

Plastic pollution, particularly microplastics (MPs), poses a significant global threat to ecosystems and human health, necessitating innovative remediation strategies. Biocompatible and biodegradable plastic-binding peptides (PBPs) offer a potential solution through targeted adsorption and subsequent MP detection or removal from the environment. A challenge in discovering plastic-binding peptides is the vast combinatorial space of possible peptides (i.e., over 1015 for 12-mer peptides), which far exceeds the sample sizes typically reachable by experiments or biophysics-based computational methods. One step towards addressing this issue is to train deep learning models on experimental or biophysical datasets, permitting faster and cheaper evaluations of peptides. However, deep learning predictions are not always accurate, which could waste time and money due to synthesizing and evaluating false positives. Here, we resolve this issue by combining biophysical modeling data from Peptide Binder Design (PepBD) algorithm, the predictive power and uncertainty quantification of evidential deep learning, and metaheuristic search methods to identify high-affinity PBPs for several common plastics. Molecular dynamics simulations show that the discovered PBPs have greater median adsorption free energies for polyethylene (5%), polypropylene (18%), and polystyrene (34%) relative to PBPs previously designed by PepBD. The impact of including uncertainty quantification in peptide design is demonstrated by the increasing improvement in the median adsorption free energy with decreasing uncertainty. This robust framework accelerates peptide discovery, paving the way for effective, bio-inspired solutions to MP remediation.

Treatment of unregulated open dumping site soil by combined Aloe vera gel washing and electrocoagulation for the removal of microplastics and heavy metals

Treatment of unregulated open dumping site soil by combined Aloe vera gel washing and electrocoagulation for the removal of microplastics and heavy metals

Efficient microplastic removal in aquatic environments using iron–nitrogen co-doped layered biocarbon materials

Efficient microplastic removal in aquatic environments using iron–nitrogen co-doped layered biocarbon materials