Colloidal Water Research Articles

DYNAMICS OF TRANSFORMATION OF IRON COLLOIDS IN MIRE WATERS UNDER THE INFLUENCE OF BIOTA AND INSOLATION

In the work the influence of biota and irradiation on the stability of iron colloids in mire waters is studied. The dynamics of the processes of photo- and biotransformation of colloidal iron has been studied. It is shown that the mechanisms of these changes are different: during insolation, the decrease in the iron content in the colloidal fraction occurs due to the formation of larger poorly soluble hydroxide particles (>0.22 μm), and in the presence of biota, a part of iron passes into a fraction of a smaller size (<1.4 nm).

Distribution of trace and rare earth elements in the estuary of Ría de Huelva (SW Spain): Field data and geochemical modeling

The geochemistry of the Ría de Huelva estuary (Spain) has been widely studied owing to its unique conditions due to mixing of acid mine drainage (AMD), river water and seawater, which have been aggravated by the existence of an adjacent phosphate fertilizer plant and its associated phosphogypsum stack.To better understand the complex geochemistry of the overall estuarine system, we make use of (1) measured concentrations of relevant trace elements (rare earth elements (REEs) and metal(loid)s) in the sediments and waters of the estuary and (2) geochemical modeling which combines mixing and adsorption processes.Our study sheds light on the elemental distribution in the sediments and water in the water-mixing area. As seawater neutralizes the acidity of the river water (pH increases to 6.2) colloids of Fe- and Al-oxyhydroxysulphates (schwertmannite and basaluminite, respectively) precipitate as concentrations of aqueous Fe and Al increase. These phases have a high adsorption capacity and play a critical role in the geochemistry of the aquatic system by retaining Cu, Pb, Cr, As, P, REEs and smaller amounts of Zn, Co, Ni and Mn. The geochemical model reproduces the behaviour of the aqueous REEs, requiring high S/L ratios at pH ≥ 3.5 and participation of sediments and colloids in the reactions to match the field data.The evaluation of the effect of the adjacent phosphogypsum stack on the estuarine geochemistry shows that the stack has a notorious impact on the geochemistry of the surrounding estuarine environment owing to the release of high quantities of phosphate.

Formation conditions of Jixian System cherts in the Qishan area, Ordos Basin: Implications for marine redox conditions and paleoecology

Abundant chert bands and nodules are discovered throughout the Mesoproterozoic Jixian System in the Ordos Basin. These cherts faithfully record the Jixian period oceanic conditions and paleoecology. However, the diagenetic mechanism of the cherts remains unclear and controversial. To understand the origin of these cherts, we performed a multitracer study by combining field reconnaissance, petrological analyses, Si isotope analysis, and major and trace element analysis of chert samples from the Qishan section. The results show that Jixian cherts had a high Al/(Al + Fe + Mn) value (~0.48), showed a flat distribution of rare earth elements in seawater, and most of the Fe/Ti values are <20. A weak negative Ce anomaly (~0.97) indicates the contribution of REY to weakly oxygenated seawater. The high isotopic composition of silicon (δ30Si = 0.74 ‰-1.35 ‰) and the average Siex value of 37.52 indicate that there is a source of biological silica, and the relationship between Eu/Eu* and Y/Ho and δ30Si shows that the hydrothermal and volcanic influences were less and correlated with seawater. The chert bands were closely related to biological activities. The chert nodules were influenced by hydrothermal activity. Secondary cherts were related to diagenesis, but the nature of siliceous fluids remains unchanged, still characterized by biogenic activity origins. The sea oxygen concentration in the Jixian period had increased, with periodic variations in the intensity of biological activities affecting the pH of the water body, or biological photosynthesis binding SiO2 colloid in water, affecting chert sediments, leading to frequent interlayering between dolomite and chert bands. Episodic hydrothermal fluids and late-stage diagenetic processes jointly influenced the formation of cherts. This study bears significant significance in enhancing our understanding of the sedimentary environment and the origin of cherts during the Jixian period in the Ordos Basin.

Pulsed‐Laser‐Driven CO2 Reduction Reaction for the Control of the Photoluminescence Quantum Yield of Organometallic Gold Nanocomposites

Over the last decade, the CO2 reduction reaction (CO2RR) has been increasingly exploited for the synthesis of high‐value raw materials in gaseous or liquid form, although no examples of CO2 fixation in nanoparticle systems have been demonstrated. Herein, CO2 fixation into solid nanomaterials by laser synthesis and processing of gold colloids in water, traditionally considered a green approach leading to ligand‐free nanoparticles without the formation of by‐products, is reported. If carbon monoxide‐rich gold nanoparticles are observable even after synthesis in deionized water, the presence of CO2 derivatives in alkaline water environment leads to C2 and C3 coupling with the production of carboxylic acids as a typical CO2RR fingerprint. While laser processing of preformed gold colloids is selective for C2 coupling, both C2 and C3 coupling to lactic acid are observed during pulsed laser ablation of a gold target. In the latter case, it is demonstrated that it is possible to synthesize photoluminescent organometallic nanocomposites in the blue spectral region with a quantum yield of about 20% under adequate experimental conditions. In this research, new pathways are offered to be explored in energetics, photonics, catalysis, and synthesis at the nanoscale.

Colloidal Filterable Bacteria Enhance Ammonia Nitrogen Enrichment in River Colloids under Different Turbidity Conditions: Bacterial Diversity, Assembly Mechanism, and Nitrogen Transformation

Turbidity has been one of the most typical problems in urban rivers, accompanied by eutrophication. Though the colloid is a nonnegligible factor associated with turbidity and nutrient enrichment in urban rivers, the characteristics of nitrogen enrichment and bacterial communities of colloids under different turbidity conditions of urban rivers have not been well understood. In this study, colloids of low and high molecular weights (LMW, 30 kDa–0.2 μm, and HMW, 0.2–1 μm) were separately collected from the bulk water (&lt;1 μm) of several typical urban rivers in China. Since the colloidal concentration presented the significantly highest correlation with turbidity, colloidal characteristics were further explored under three turbidity gradients with two cutoffs of 10 and 30 NTU. Results showed that colloidal organic matter in medium and high turbidity rivers was mainly sourced from the release of endogenous plankton and the proportion of colloidal organic carbon in dissolved organic carbon increased from 33% to 38% with increased turbidity. Colloidal ammonia nitrogen in medium turbidity accounted for the highest proportion (an average of 60%) in bulk water, which could be explained by the significantly positive correlation of colloidal ester groups and ammonia nitrogen (R2 = 0.47). Bulk water, HMW, and LMW colloids presented different dominant bacterial genera and LMW colloids also contained three unique dominant filterable genera: Flavobacterium, Acinetobacter, and Limnohabitans. LMW colloidal filterable bacteria under medium and high turbidities presented the greatest potential for dissimilatory nitrate reduction to ammonium, which might further enhance the enrichment of ammonia nitrogen in colloids. This study provides a primary understanding of the characteristics of colloids and colloidal bacterial communities in urban rivers from the perspective of turbidity and puts a new insight on the remediation of rivers under medium turbidity.

Experimental modelling of heating and local field enhancement by iron oxide nanoparticles upon laser excitation

SignificanceLocal determination of the iron oxide nanoparticles (IONPs) temperature during laser heating is important in the aspect of laser phototherapy. ApproachWe have carried out theoretical modeling of local EM field enhancement and heating under the laser action near individual IONPs and ensembles of NPs with different sizes of the magnetic core and different content of iron oxide in them. To experimental determine the temperature of IONPs water colloids, we used fluorescence thermometry based on rhodamine B (RhB) fluorescence lifetime. ResultsLocal EM field enhancement and heating strongly depend on the NPs shape and distance between them. In the case of anisotropic NPs, a significant change in the spatial distribution of the EM field near the NPs surface was observed. The local heating of NPs in an ensemble reaches sufficiently higher values, the relative change was about 35°С for Fe2O3 NPs. Nevertheless, all the studied IONPs water colloids showed heating by no more than 15°C. ConclusionsSignificant enhancement of the local field occurs in IONP pairs and ensembles. The heating temperature of the ensemble depends on the thermal conductivity of the medium, in which the heat dissipation depends.

Synthesis, structural and spectroscopic investigation of Nd3+,Y3+ codoped CaF2 nanoparticles as water colloids: Exploiting emission in the near infrared region for nanothermometry

Nd3+,Y3+ codoped CaF2 nanoparticles (NPs) have been synthesized by a microwave-assisted hydrothermal method, using citrate moiety as capping agent. Y3+ ions have been introduced in the crystal structure to declusterize the Nd3+ ions and improve the emission properties. After a structural and morphological characterization of the obtained NPs, the optical properties of colloidal dispersions have been analyzed in the near infrared (NIR) range. The emission spectra reveal several transitions associated with different sites where the Nd3+ ions are accommodated in the crystal structure. Some bands show a marked dependence on the temperature, and a thermometric investigation reveals good thermal relative sensitivities in the physiological temperature range (20–60 °C), proving the applicability of the investigated colloidal NPs as optical nanothermometers.

Raman, UV-Vis, MS, and IR characterization of molecular-colloidal solution of hydrated fullerenes C60 obtained using vacuum-sublimation cryogenic deposition method. Is the C60 molecule truly highly hydrophobic?

Vacuum-sublimation cryogenic deposition (VS-CD) method is successfully applied to produce fullerene water colloidal solution (FWCS): the melting of the solid phase of the mixture obtained by joint condensation of C60 fullerene and water vapors onto a surface cooled with liquid nitrogen results in formation of a stable colloidal solution. The results of the FWCS characterization by means of Raman, IR, and UV-Vis spectroscopy and their comparison with known literature data on hydrated fullerenes give the authors an opportunity to make conclusion that the FWCS contains C60@{H2O}n complexes of hydrated C60 fullerene. Transmission electron microscopy shows that the VS-CD-produced material contains predominantly small C60 clusters of about 2–5 nm size, while mass spectrometry with laser desorption/ionization has demonstrated the presence of pure fullerene C60 and the absence of any products of its transformation. The performed analysis reveals a close similarity of the stable C60@{H2O}n complexes generated by VS-CD with the previously known highly hydrophilic hydrated fullerene obtained by ultrasonication method.

Kinetic and Thermodynamic Control of Supramolecular Aggregation of Near Infrared Pyrrolopyrrole Cyanine Fluorophores Confined in Colloidal Nanoparticles.

Control of the intermolecular aggregation of organic π-conjugated molecules as chromophores is crucial for tuning their physical properties such as light absorption/emission, and energy and charge transfer. Lots of advances have been achieved in control of intermolecular aggregation of organic chromophores in solid states where an indefinitely large number of molecules are involved. However, much less understanding has been gained at a mesoscale of aggregates formed by well-defined organization of a deterministic number of chromophores, which has been realized in natural photosynthetic systems but still remains rare in manmade materials. Here, we report both the kinetic and the thermodynamic control of the supramolecular aggregation of a near-infrared cyanine dye, PPcy, and its derivatives confined in colloidal nanoparticles stabilized by surfactants in aqueous media. Our results demonstrate that both the aggregation number, the aggregation state and the optical properties of the PPcy chromophores are controllable through optimization of the alkyl and polymer chains tethered from PPcy, the effective concentration of the chromophore inside each particle, and the surfactants utilized to stabilize the colloids in water.

Lyotropic Liquid Crystals of Colloidal Gibbsite Nanoplatelets: Phase Transition, Kinetic Characterization, and Confinement Effect

Abstract2D gibbsite nanoplatelets, [γ‐Al(OH)3], are widely used as an inorganic mineral platform for 2D lyotropic liquid crystal (LC) colloids. These particles are synthesized and enlarged using an improved hydrolysis method, resulting in highly crystalline (96.5%), low polydispersity (15.1%), and readily dispersible colloids in water. The aqueous mesomorphic system is characterized for the isotropic‐to‐nematic phase transition by analyzing number density and shear viscosity. Thermal stability is assessed through thermogravimetric analysis. Additionally, kinetic and thermodynamic parameters for 2D gibbsite nanoparticles are determined for the first time using three models (Coats‐Redfern, Friedman, and Kissinger). In particular, the activation and Gibbs free energies for the first dehydration stage of gibbsite yield ranges of 98‒128 kJ mol−1 and 135‒161 kJ mol−1, respectively. To investigate the confinement effect of colloidal gibbsite‐LCs, an isotropic gibbsite dispersion is introduced into a tube, leading to the uniform formation of gibbsite‐LC layers along two distinct pathways: tangential to the liquid‐air interface and as concentric circles along the tube walls. These findings offer valuable insights into potential applications, particularly in the domain of gas barrier inorganic films across various specialized fields.

Possible Approaches to Studying the Influence of Magnetic Fields and Mechanical Effects on the Physicochemical Properties of Aqueous IgG Colloids

The influence of various mechanical influences (transfusion, stirring, vibration, shaking, etc.) and magnetic installations (used in the application of spin chemistry methods) on colloidal solutions of protein and water, which are often used in pharmaceutical production, was studied. It has been shown that when mechanical influences are applied, physical and chemical properties of water and aqueous colloids of the IgG protein are changed. Magnetic fields do not have a significant effect on water; however, variation in a number of physical and chemical characteristics is observed in protein colloids. Moreover, the effect after exposure to magnetic fields with a frequency of 8 Hz is higher compared to the effect after exposure to magnetic fields with a frequency of 50 Hz. This effect persists even at extremely low concentrations of IgG protein molecules. The measurement system proposed in this work makes it possible to monitor the state of protein molecules in a non-invasive mode. In the future, optical and potentiometric methods built into flow systems can be used at all stages of the production of protein pharmaceuticals.

Oxygen evolution from extremophilic cyanobacteria confined in hard biocoatings.

Biocoatings, in which viable bacteria are immobilized within a waterborne polymer coating for a wide range of potential applications, have garnered greater interest in recent years. In bioreactors, biocoatings can be ready-to-use alternatives for carbon capture or biofuel production that could be reused multiple times. Here, we have immobilized cyanobacteria in mechanically hard biocoatings, which were deposited from polymer colloids in water (i.e., latex). The biocoatings are formed upon heating to 37°C and fully dried before rehydrating. The viability and oxygen evolution of three cyanobacterial species within the biocoatings were compared. Synechococcus sp. PCC 7002 was non-viable inside the biocoatings immediately after drying, whereas Synechocystis sp. PCC 6803 survived the coating formation, as shown by an adenosine triphosphate (ATP) assay. Synechocystis sp. PCC 6803 consumed oxygen (by cell respiration) for up to 5 days, but was unable to perform photosynthesis, as indicated by a lack of oxygen evolution. However, Chroococcidiopsis cubana PCC 7433, a strain of desiccation-resistant extremophilic cyanobacteria, survived and performed photosynthesis and carbon capture within the biocoating, with specific rates of oxygen evolution up to 0.4 g of oxygen/g of biomass per day. Continuous measurements of dissolved oxygen were carried out over a month and showed no sign of decreasing activity. Extremophilic cyanobacteria are viable in a variety of environments, making them ideal candidates for use in biocoatings and other biotechnology. IMPORTANCE As water has become a precious resource, there is a growing need for less water-intensive use of microorganisms, while avoiding desiccation stress. Mechanically robust, ready-to-use biocoatings or "living paints" (a type of artificial biofilm consisting of a synthetic matrix containing functional bacteria) represent a novel way to address these issues. Here, we describe the revolutionary, first-ever use of an extremophilic cyanobacterium (Chroococcidiopsis cubana PCC 7433) in biocoatings, which were able to produce high levels of oxygen and carbon capture for at least 1 month despite complete desiccation and subsequent rehydration. Beyond culturing viable bacteria with reduced water resources, this pioneering use of extremophiles in biocoatings could be further developed for a variety of applications, including carbon capture, wastewater treatment and biofuel production.

Research Progress on Colloid Pump Effect of Micro- and Nanoplastics in Drinking Water

Currently, micro- and nanoplastics are the most concerning pollutants, which have been confirmed to exist in every stage of drinking water treatment process. Micro- and nanoplastics in drinking water have large specific surface areas, which could adsorb inorganic matter, organic matter, and microorganisms, thereby increasing their risk to human health. The adsorption and agglomeration behavior of micro- and nanoplastics on typical pollutants is called the "colloid pump effect." Focused on the micro- and nanoplastics in drinking water, the occurrence, colloid pump effect, and toxic effect on the human body and the effect of colloid pumps on the removal of micro- and nanoplastics were summarized and described. The results revealed that micro- and nanoplastics existed widely in source water, treated water, pipe network water, and tap water. The colloid pump effect of micro- and nanoplastics promoted their agglomeration with inorganic matter, organic matter, and microorganisms, which not only intensified the toxic effect of micro- and nanoplastics but also affected the removal effect. There were different viewpoints on the effect of coagulation and sedimentation on the removal of micro- and nanoplastics, and the removal effect of sand filters was limited. The advanced treatment was an efficient process to remove micro- and nanoplastics with a particle size smaller than 5 μm. The removal rate of micro- and nanoplastics could be effectively improved by exploring the mechanism of the colloid pump effect and its initiation conditions. Finally, from the perspective of the drinking water treatment process and colloid pump effect, the control of micro- and nanoplastics in drinking water was prospected in order to provide reference for reducing the occurrence and toxicity of micro- and nanoplastics in drinking water, ensuring drinking water quality safety and human health.

Polyhydroxylated Fullerene C60(OH)40 Nanofilms Promote the Mesenchymal-Epithelial Transition of Human Liver Cancer Cells via the TGF-β1/Smad Pathway.

The various growth factors change the phenotype of neoplastic cells from sedentary (epithelial) to invasive (mesenchymal), which weaken intercellular connections and promote chemotaxis. It can be assumed that the use of anti-inflammatory polyhydroxyfull nanofilms will restore the sedentary phenotype of neoplastic cells in the primary site of the tumor and, consequently, increase the effectiveness of the therapy. The studies were carried out on liver cancer cells HepG2, C3A and SNU-449, and non-cancer hepatic cell line THLE-3. Transforming growth factor (TGF), epidermal growth factor and tumor necrosis factor were used to induce the epithelial-mesenchymal transition. C60(OH)40 nanofilm was used to induce the mesenchymal-epithelial transition. Obtaining an invasive phenotype was confirmed on the basis of changes in the morphology using inverted light microscopy. RT-PCR was used to confirm mesenchymal or epithelial phenotype based on e-cadherin, snail, vimentin expression or others. Water colloids at a concentration of 100 mg/L were used to create nanofilms of fullerene, fullerenol, diamond and graphene oxide. The ELISA test for the determination of TGF expression and growth factor antibody array were used to select the most anti-inflammatory carbon nanofilm. Mitochondrial activity and proliferation of cells were measured by XTT and BrdU tests. Cells lost their natural morphology of cells growing in clusters and resembled fibroblast cells after adding a cocktail of factors. Among the four allotropic forms of carbon tested, only the C60(OH)40 nanofilm inhibited the secretion of TGF in all the cell lines used and inhibited the secretion of other factors, including insulin-like growth factor system. Nanofilm C60(OH)40 was non-toxic to liver cells and inhibited the TGF-β1/Smad pathway of invasive cells treated with the growth factor cocktail. The introduction of an anti-inflammatory, nontoxic component that can induce the mesenchymal-epithelial transition of cancer cells may represent a future adjuvant therapy after tumor resection.

Plasma‐enhanced immobilization of cerium oxide nanoparticles on a fluorocarbon‐based nanofibrous membranes

AbstractFluorocarbon‐based (CF) nanofibrous membrane has been prepared by electrospinning of a source polyvinylidene fluoride and its surface was modified by CeOx nanoparticles by immersion in a water colloidal solution with CeOx nanoparticles (CeOx NPs). Two ways of the deposition of CeOx nanoparticles on the CF nanofiber membrane were used: (1) deposition of CeOx NPs on the pristine electrospun membrane and (2) the immediate deposition CeOx NPs on the plasma treated electrospun membrane. We investigated the effect of plasma treatment on the amount of CeOx NPs deposited on CF nanofiber surfaces and on the Ce3+/Ce4+ ratio in CeOx NPs deposited on CF. The amount of CeOx on nanofiber surfaces was determined by XPS (X‐ray photoelectron spectroscopy) and SEM analysis. Results showed a significant increase of CeOx NPs amount on the plasma treated CF membrane, accompanied by slight decrease of Ce3+/Ce4+ ratio in CeOx NPs adherent on plasma treated CF surface in comparison with pristine CF surface. Detailed analysis of XPS spectra – C1s, O1s, and Ce3d indicated a possibility of the chemical bonding of CeOx NPs on the plasma treated CF surface.

Fluorescent Microscopy of Hot Spots Induced by Laser Heating of Iron Oxide Nanoparticles

Determination of the iron oxide nanoparticles (IONPs) local temperature during laser heating is important in the aspect of laser phototherapy. We have carried out theoretical modeling of IONPs local electromagnetic (EM) field enhancement and heating under the laser action near individual IONPs and ensembles of IONPs with different sizes, shapes and chemical phases. For experimental determination of IONPs temperature, we used fluorescence thermometry with rhodamine B (RhB) based on its lifetime. Depending on the IONPs shape and their location in space, a significant change in the spatial distribution of the EM field near the IONPs surface is observed. The local heating of IONPs in an ensemble reaches sufficiently high values; the relative change is about 35 °C for Fe2O3 NPs. Nevertheless, all the studied IONPs water colloids showed heating by no more than 10 °C. The heating temperature of the ensemble depends on the thermal conductivity of the medium, on which the heat dissipation depends. During laser scanning of a cell culture incubated with different types of IONPs, the temperature increase, estimated from the shortening of the RhB fluorescence lifetime, reaches more than 100 °C. Such “hot spots” within lysosomes, where IONPs predominantly reside, lead to severe cellular stress and can be used for cell therapy.

Cadmium sulfide quantum dots in water media: Enhanced photoluminescence, dispersion and stability

Within the presented study, we have investigated the effect of the ligand shell on the stability and optical properties of cadmium sulfide (CdS) quantum dots in a water colloidal solution stabilized by 3-mercaptopropyltrimethoxysilane (MPS). The correlation between stability and parameters of nanoparticles, namely, hydrodynamic radius, nucleus size and zeta-potential has been established. The optimal synthesis conditions of stable colloidal solutions shown the luminescence have been found. The mechanism of structural organization of the organic MPS shell, its bonding to the semiconductor nanoparticle surface and influence on the agglomeration have been developed. The mechanism of MPS capped CdS QDs luminescence switch on in water solution by pH control was proposed.

Interactions of natural colloids with microplastics in aquatic environment and its impact on FTIR characterization of polyethylene and polystyrene microplastics

The demand for plastics is expected to rise due to the exponential growth of the manufacturing sector. The plastic industries get subsidies from Governments to boost foreign exchange. The mismanagement of plastic waste has contaminated water bodies with macro, micro, and nano plastics ultimately causing varied toxicological impairment to the aquatic and terrestrial environments. We have investigated the interaction of polystyrene (PS) and polyethylene (PE) microplastics with the natural colloids in waters. Eco-corona formation due to adsorption of colloids and dissolved contaminants on the microplastic’s surface was observed upon suspending PS and PE microplastics in natural marine and freshwater tagged with 2 µg ml−1 acridine orange. Fourier transform infrared spectroscopy (FTIR) studies revealed a diminishing intensity in the characteristic peaks of the and the disappearance of minor vibrations in IR spectra of the polymers upon suspension in natural waters for over 40 days. The alterations in the peaks were restored, and PE was recovered upon treatment with 30 % hydrogen peroxide (H2O2). In contrast, the recovery of PS was only partial, denoting the strong interactions of PS with natural colloids. The active groups on the polymer structure interacting with the colloids creates an eco-corona layer absorbing the light. The ecocorona formation hinders light transmission and detection by analytical methods such as FTIR, thereby substantiating the lower quantities of PS isolated and detected from aquatic animals and environmental samples. Eco-coronated microplastics could mimic the natural feed for small fishes and lower marine animals, facilitating their uptake and further transfer across the aquatic food web.

Production of highly stable upconverting nanoparticles modified with xanthan gum and their long-term studies

Upconverting nanoparticles (UCNPs) forming stable water colloids are essential for biology and medicine, where they can be applied for bioimaging, disease detection, and treatment. The stability of UCNPs’ morphology in the form of their water colloids is as crucial as their spectroscopic properties. An appropriate surface modification is usually required to improve the stability of UCNPs in water. This article presents the results of long-term studies under Sr0.54Lu0.36F2.5:Yb3+, Tm3+ UCNPs modified with xanthan gum (XG) used as a colloid stabilizer. XG changes the surface charge and facilitates further bioconjugation to other molecules. Our studies confirmed that the structural properties of Sr0.54Lu0.36F2.5:Yb3+, Tm3+ UCNPs, their composition, and their luminescence do not change for 28 weeks.

Aggregation of microplastics and clay particles in the nearshore environment: Characteristics, influencing factors, and implications

Since nearly half of the world's population lives near the coast, coastal areas have become hotspots for microplastic (MP) pollution due to human activity. The ubiquity of natural colloids in coastal waters plays a critical role in the potential fate of, and risks posed by, MPs. Nevertheless, far less has been known regarding the aggregation of MPs with inorganic natural clay colloids, especially in the complicated nearshore environment. In this study, the aggregation behavior of MPs as well as the interaction between MPs and clay particles were investigated under different nearshore environmental conditions (MP-to-clay ratio, salinity gradient, humic acid concentration, and wave energy). The aggregation behavior was subjected by the repulsive energy barrier between particles and external energy transferred to the system. The low energy associated with mild wave conditions was favorable for the occurrence of aggregation, whereas sustained high energy under intense wave conditions was found to be detrimental to the aggregation behavior, and the aggregates were prone to fragmentation even if particles coalesced into large clusters. The analysis for the environmental fate of MPs demonstrated that the shoreline was likely to be the sink for most MPs ultimately.