Distinct chemical adsorption behaviors of sulfanilamide as a model antibiotic onto weathered microplastics in complex systems

Plastisphere-hosted viruses: A review of interactions, behavior, and effects

Microbial communities, including bacteria, diatoms, and fungi, colonize plastic surfaces, forming biofilms known as the "plastisphere." Recent research has revealed that plastispheres also host a wide range of viruses, sparking interest in microbial ecology and virology. This shared habitat allows viruses to replicate, interact, infect, and spread, potentially impacting the environment and human health. Consequently, viruses attached to microplastics are now recognized to have broad effects on cellular and immune responses. However, the ecology and implications of viruses hosted in plastisphere habitats remain poorly understood, highlighting their fundamental importance as a subject of study. This review explores various pathways for virus attachment to plastispheres, factors influencing these interactions, their impacts within plastisphere and host-associated environments, and associated issues. It also summarizes current research and identifies knowledge gaps. We anticipate that this paper will help improve our predictive understanding of plastisphere viruses in natural settings and emphasizes the need for more research in real-world environments to advance the field.

Interaction and mechanistic studies of thiram and common microplastics in food and associated changes in hazard

Microplastics (MPs), an emerging pollutant in the environment and food, may adsorb other contaminants such as pesticide due to particles' properties. The adsorption behavior and their hazardous changes of four common types of MPs to thiram was investigated. The adsorption kinetics and isotherm models were fitted well using the pseudo-second-order model and the Langmuir model respectively, indicating forces such as van der Waals forces dominate, and the maximum adsorption capacity at pH values of 6-7 also indicates that electrostatic forces play a smaller role. The adsorption thermodynamic studies showed that the adsorption was a spontaneous and exothermic process. The decrease in the adsorption capacity as the concentration of MPs increases and more adsorption by aged MPs demonstrate that the adsorption process is related to the sites on the surface of MPs. Due to the influence of ionic strength, the adsorption capacity of MPs for thiram increases significantly when the adsorption process takes place in solutions with salinity or in orange and apple juices. The bioavailability of thiram adsorbed by PVC and PET increased significantly. This study highlights the strong role of MPs in food as carriers of pesticide residues in food systems and that the combined hazard should also be of concern.

Effects and applications of surfactants on the release, removal, fate, and transport of microplastics in aquatic ecosystem: a review

Microplastics (MPs) and surfactants (STs) are emerging pollutants in the environment. While many studies have focused on the interactions of STs with MPs, there has not been a comprehensive review focusing on the effect of STs on MPs in aquatic ecosystems. This review summarizes methods for removal of MPs from wastewater (e.g., filtration, flotation, coagulation/flocculation, adsorption, and oxidation-reduction) and the interactions and effects of STs with MPs (adsorption, co-adsorption, desorption, and toxicity). STs can modify MPs surface properties and influence their removal using different wastewater treatments, as well as the adsorption-desorption of both organic and inorganic chemicals. The concentration of STs is a crucial factor that impacts the removal or adsorption of pollutants onto MPs. At low concentrations, STs tend to facilitate MPs removal by flotation and enhance the adsorption of pollutants onto MPs. High ST concentrations, mainly above the critical micelle concentrations, cause MPs to become dispersed and difficult to remove from water while also reducing the adsorption of pollutants by MPs. Excess STs form emulsions with the pollutants, leading to electrostatic repulsion between MPs/STs and the pollutant/STs. As for the toxicity of MPs, the addition of STs to MPs shows complicated results, with some cases showing an increase in toxicity, some showing a decrease, and some showing no effect.

Interaction between microplastic biofilm formation and antibiotics: Effect of microplastic biofilm and its driving mechanisms on antibiotic resistance gene

As two pollutants with similar transport pathways, microplastics (MPs) and antibiotics (ATs) inevitably co-exist in water environments, and their interaction has become a topic of intense research interest for scholars over the past few years. This paper comprehensively and systematically reviews the current interaction between MPs and ATs, in particular, the role played by biofilm developed MPs (microplastic biofilm). A summary of the formation process of microplastic biofilm and its unique microbial community structure is presented in the paper. The formation of microplastic biofilm can enhance the adsorption mechanisms of ATs on primary MPs. Moreover, microplastic biofilm system is a diverse and vast reservoir of genetic material, and this paper reviews the mechanisms by which microplastics with biofilm drive the production of antibiotic resistance genes (ARGs) and the processes that selectively enrich for more ARGs. Meanwhile, the enrichment of ARGs may lead to the development of microbial resistance and the gradual loss of the antimicrobial effect of ATs. The transfer pathways of ARGs affected by microplastic biofilm are outlined, and ARGs dependent transfer of antibiotic resistance bacteria (ARB) is mainly through horizontal gene transfer (HGT). Furthermore, the ecological implications of the interaction between microplastic biofilm and ATs and perspectives for future research are reviewed. This review contributes to a new insight into the aquatic ecological environmental risks and the fate of contaminants (MPs, ATs), and is of great significance for controlling the combined pollution of these two pollutants.

An ultra-light sustainable sponge for elimination of microplastics and nanoplastics

The currently established tools and materials for elimination of the emerging contaminants from environmental and food matrices, particularly micro- and nano-scale plastics, have been largely limited by complicated preparation/operation, high cost, and poor degradability. Here we show that, crosslinking naturally occurring corn starch and gelatin produces ultralight porous sponge upon freeze-drying that can be readily enzymatically decomposed to glucose; The sponge affords capture of micro- and nano-scale plastics into its pores by simple pressing in an efficiency up to 90% while preserving excellent mechanical strength. Heterogeneous diffusion was found to play a dominant role in the adsorption of microplastics by the starch-gelatin sponge. Investigations into the performance of the sponge in complex matrices including tap water, sea water, soil surfactant, and take-out dish soup, further reveal a considerably high removal efficiency (60%∼70%) for the microplastics in the real samples. It is also suggested tiny plastics in different sizes be removable using the sponge with controlled pore size. With combined merits of sustainability, cost-effectiveness, and simple operation without the need for professional background for this approach, industrial and even household removal of tiny plastic contaminants from environmental and food samples are within reach.

Interaction behaviors of sulfamethoxazole and microplastics in marine condition: Focusing on the synergistic effects of salinity and temperature

Microplastics and antibiotics are two common pollutants in the ocean. However, due to changes of salinity and temperature in the ocean, their interaction are significantly different from that of fresh water, and the mechanism remains unclear. Here, the interactions of sulfamethoxazole (SMZ) and microplastics were studied at different temperatures and salinities. The saturation adsorption capacity of SMZ in polypropylene (PP), polyethylene (PE), styrene (PS), polyvinyl chloride (PVC), and synthetic resins (ABS) were highest at the temperature of 20 °C, with 0.118 ± 0.002 mg·g^-1, 0.106 ± 0.004 mg·g^-1, 0.083 ± 0.002 mg·g^-1, 0.062 ± 0.007 mg·g^-1 and 0.056 ± 0.003 mg·g^-1, respectively. The effect of temperature reduction is more significant than temperature rise. The intraparticle diffusion model is appropriate to PP, when film diffusion model suited for PS. The salinity has a more significant effect than temperature on different microplastics, due to the electrostatic adsorption and iron exchange. With the increase in salinity from 0.05% to 3.5%, the adsorption capacity of microplastics on SMZ fell by 53.3 ± 5%, and there was no discernible difference of various microplastics. The hydrogen bond and π-π conjugation of microplastics play an important role in the adsorption of SMZ. These findings further deepen the understanding of the interaction between microplastics and antibiotics in the marine environment.

Isolation and characterization of microplastics from skin care products; interactions with albumin proteins and in-vivo toxicity studies on Artemia salina

Skincare products are a significant source of primary microplastics (MPs). This study isolates and characterizes microplastic from two skin care products: face wash (FW-MPs) and face scrub (FS-MPs). Microplastics extracted were around 660 µm in size. The extracted MPs, designated as unground MPs (UG-MPs), were smooth surface and spherical. Ground ones were denoted as the ground MPs (G-MPs) that varied in size and surface shape. G-MPs interacted with bovine serum albumin (BSA) and human serum albumin (HSA). BSA adsorption on FW-MPs was 29%, whereas HSA adsorption was 47%. Contrarily, FS-MPs displayed 17% and 31%. Fluorescence spectroscopy and FE-SEM images showed HSA adsorption on G-MPs was greater than BSA. G-MP interaction changed the life cycle of Artemia salina. UV-Vis and fluorescence spectroscopy were used to study protein adsorption and desorption on G-MPs. A. salina treated to 2.5 mg/mL G-MPs delayed hatching and development and internalized microplastics in the gut at 144 h exposure.

Adsorption of antibiotics on different microplastics (MPs): Behavior and mechanism

MPs can adsorb antibiotics to coexist and accumulate in the aquatic environment in the form of complexes, resulting in unforeseeable adverse consequences. The adsorption behavior and mechanism of three antibiotics amoxicillin (AMX), ciprofloxacin (CIP), and tetracycline (TC) by four MPs Polyvinyl chloride (PVC), polystyrene (PS), polypropylene (PP), and polyethylene (PE) were studied. Results showed that the adsorption of antibiotics onto MPs follows the pseudo-second-order kinetic and the Freundlich isotherm model, indicating a multilayer chemical adsorption. Combined with FTIR, XRD, and SEM analyses, the adsorption behavior was simultaneously governed by physical processes. Additionally, the equilibrium adsorption capacity was inhibited in the research concentration range of NaCl from 10 mg/L to 10 g/L. The higher the salt concentration, the more pronounced the inhibition phenomenon was. The high (9) and low (3) pH also inhibited the adsorption of antibiotics to MPs. The humic acid (HA) concentration in the range of 0-20 mg/L generally inhibited the MPs-antibiotics adsorption, but the higher HA concentration showed less inhabitation than the lower one. The adsorption inhibition of TC on the four MPs by SA also followed the above rule. However, the adsorption inhibition of sodium alginate (SA) on AMX and CIP on the four MPs was enhanced with its concentration (0-50 mg/L).

UV and chemical aging alter the adsorption behavior of microplastics for tetracycline

This study evaluates the "vector" effects of different microplastics (MPs) on coexisting pollutants. The adsorption of tetracycline was studied on biodegradable plastics poly(butylene adipate-co-terephthalate) (PBAT) and non-biodegradable plastics polystyrene (PS), polypropylene (PP), and polyethylene (PE) after UV aging and chemical aging. The physicochemical properties of PBAT changed more obviously after UV radiation and chemical aging comparing to PS, PP and PE. Pores and cracks appear on the surface of aged PBAT. The crystallinity increased from 29.2% to 52.62%. In adsorption experiments, pristine and aged PBAT had strong vector effects on the adsorption of tetracycline than PS, PP and PE. The adsorption capacity of tetracycline on PBAT was increased from 0.7980 mg g^-1 to 1.2669 mg g^-1 after chemical aging. The adsorption mechanism indicated that electrostatic interactions and hydrogen bonds contribute to the adsorption process. In addition, for the adsorption of tetracycline on PS, π-π interaction was the main cause, and the adsorption mechanism was not considerably changed by aging. In conclusion, this study demonstrates that biodegradable plastics have substantial vector effect on coexisting pollutants at the end of their life cycle, this contributes to assessment of the risk from microplastic pollution.

Evaluation of ciprofloxacin (CIP) and clarithromycin (CLA) adsorption with weathered PVC microplastics

The sorption kinetics of two of the most frequently used antibiotics onto recycled (weathered) polyvinyl chloride (PVC) was investigated, using Freundlich and Langmuir isotherm models. Various experimental conditions were set, including pH, contact time, rotational speed, temperature, and initial concentration. The batch experimental results indicated that Freundlich model was better fitted than Langmuir (R²: 98.7 and 84.7, for CIP and CLA respectively). Maximum adsorption capacity is 45.9 mg/g and 22.0 mg/g for CIP and CLA, respectively. Enthalpy (ΔH), and entropy (ΔS) values were negative for CIP, indicating that the reaction was exothermic and spontaneous, respectively. It was vice versa for CLA. Field emission scanning electron microscope (FESEM) and Fourier transform infrared spectrometer (FT-IR) analysis confirmed the physical adsorption mechanism. The results demonstrated that the recycled PVC microplastic has a good capacity for adsorption for both antibiotics.

Press perturbations of microplastics and antibiotics on freshwater micro-ecosystem: Case study for the ecological restoration of submerged plants

Microplastics (MPs) can adsorb antibiotics to form complex pollutants, which seriously threatens the health of freshwater ecosystems. Few studies have examined the combined pollution characteristics of microplastics (MPs) and antibiotics in restored freshwater ecosystems and their effects on the growth traits of the aquatic primary producers. We studied both the ecotoxicological effects of polyethylene (PE) MPs and the antibiotics sulfanilamide (sulfa, SA) on the structural (diversity etc.,) and functional (nutrient cycling etc.,) properties of water-plant-sediment ecosystems. The synergistic toxic effects of PE and SA resulted in a reduction in the chlorophyll content and chloroplast fluorescence. Meanwhile, PE and SA single/combined pollution stress inhibits the radial oxygen loss in roots, and activates the antioxidant defense system in leaves. The change in the growth response characteristics of Vallisneria natans (V. natans) under oxidative stress induced by single/combined pollution showed a dosage effect. The microbial compositions of the overlying water and sediment were significantly changed by the pollution exposure, as evidenced by the increased microbial diversity and altered microbial taxa distribution. An increase in the total concentrations of sulfa in the overlying water was accompanied by an increase in the relative abundances of resistance genes. PE-MPs significantly affected the removal of total nitrogen and antibiotics from the overlying water. The interaction between PE and SA affects ammonia and nitrite nitrogen exchange in water-sediment systems. Thus, this study investigated the effects of combined MP and antibiotics pollution on the growth state, metabolic function, microbial community structure and microbial diversity of the freshwater ecosystems. The mechanism underlying of the combined polyethylene-sulfanilamide (PE-SA) effect on the V. natans was revealed. In addition, the correlation between different environmental factors was analyzed, and a structural equation model was constructed. This study provides primary data for evaluating the ecological and environmental effects of combined PE-SA pollution and its possible risks. Moreover, it provides a reference index for the study of ecological wetland environments and phytoremediation.

Microplastics exposure as an emerging threat to ancient lineage: A contaminant of concern for abnormal bending of amphioxus via neurotoxicity

Growing inputs of microplastics into marine sediment have increased significantly the needs for assessment of their potential risks to the marine benthos. A knowledge gap remains with regard to the effect of microplastics on benthos, such as cephalochordates. By employing amphioxus as a model benthic chordate, here we show that exposure to microplastics for 96 h at doses of 1 mg/L and 100 mg/L results in evident accumulation of the polyethylene microplastics. The accumulated microplastics are as much as 0.027% of body weight upon high-dose exposure, causing an abnormal body-bending phenotype that limits the locomotion capability of amphioxus. Mechanistic insight reveals that microplastics can bring about histological damages in gill, intestine and hepatic cecum; In-depth assay of relevant biomarkers including superoxide dismutase, catalase, glutathione, pyruvic acid and total cholesterol indicates the occurrence of oxidative damage and metabolic disorder; Further, microplastics exposure depresses the activity of acetylcholinesterase while allowing the level of acetylcholine to rise in muscle, suggesting the emergence of neurotoxicity. These consequences eventually contribute to the muscle dysfunction of amphioxus. This study rationalizes the abnormal response of the vulnerable notochord to microplastics, signifying the dilemma suffered by the ancient lineage under the emerging threat. Given the enrichment of microplastics through marine food chains, this study also raises significant concerns on the impact of microplastics to other marine organisms, and eventually human beings.

Adsorption of Different Pollutants by Using Microplastic with Different Influencing Factors and Mechanisms in Wastewater: A Review

The studies on microplastics are significant in the world. According to the literature, microplastics have greatly specific surface areas, indicating high adsorption capacities for highly toxic pollutants in aquatic and soil environments, and these could be used as adsorbents. The influencing factors of microplastic adsorption, classification of microplastics, and adsorption mechanisms using microplastics for adsorbing organic, inorganic, and mixed pollutants are summarized in the paper. Furthermore, the influence of pH, temperature, functional groups, aging, and other factors related to the adsorption performances of plastics are discussed in detail. We found that microplastics have greater advantages in efficient adsorption performance and cost-effectiveness. In this paper, the adsorptions of pollutants by microplastics and their performance is proposed, which provides significant guidance for future research in this field.