We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Adsorption behaviour of microplastics on the heavy metal Cr(VI) before and after ageing
Summary
Researchers studied how UV aging affects the adsorption of hexavalent chromium onto PE, PS, and PA microplastics, finding that aged microplastics had significantly enhanced adsorption capacity due to increased surface area and functional group changes from weathering.
As the important carriers of environmental pollutants, microplastics have a significant impact on the migration, transformation and toxicology of heavy metals. In this paper, the adsorption behavior of Cr(VI) on PE/PS/PA microplastics under UV irradiation was studied. The research results show that the adsorption capacity of original PA is the strongest, followed by PS and PE. The specific surface area of the aged microplastics increased and new functional groups were formed, so the adsorption of three microplastics for Cr(VI) was stronger than that before aging. The average saturation adsorption of Cr(VI) by PA/PS/PE increased respectively from 730.69 μg/g, 146.11 μg/g and 75.61 μg/g to 736.31 μg/g, 318.75 μg/g and 136.78 μg/g. The Langmuir and Freundlich models showed that the adsorption is more consistent with the Freundlich model, indicating that adsorption is mainly based on multi-molecular layer adsorption on non-homogeneous surfaces. In the Cu-Cr polluted water, Cu has different effects on the adsorption behavior. Cu can promote the adsorption of Cr(VI) by PE and PS, while inhibited the adsorption by PA. In addition, environmental conditions such as temperature, pH and dissolved organic matter also have significant effects on adsorption behavior. Mechanistic analysis confirmed that electrostatic interaction plays an important role. Secondly, based on the surface physicochemical properties of the microplastics, surface complexation and van der Waals forces also significantly enhance the adsorption of Cr(VI) on the aged microplastics.
Sign in to start a discussion.
More Papers Like This
Microplastics as an emerging vector of Cr(VI) in water: Correlation of aging properties and adsorption behavior
Researchers studied the correlation between aging properties and adsorption of hexavalent chromium Cr(VI) onto polyethylene microplastics under accelerated UV aging conditions, finding that aging-induced changes in surface chemistry increased the adsorption capacity. Aged microplastics may act as more effective vectors for toxic heavy metals in aquatic environments.
Adsorption and Desorption Behavior of Cr(VI) on Two Typical UV-Aged Microplastics in Aqueous Solution
Researchers examined how UV weathering changes the ability of two common microplastic types (polyethylene and polystyrene) to adsorb and release chromium(VI) from contaminated water. UV aging altered surface chemistry and significantly increased adsorption capacity for the toxic heavy metal.
Aging amplifies synergistic adsorption and reduction of Cr(VI) by polyamide microplastics
Researchers found that UV and chemical aging of polyamide microplastics amplified their adsorption and reduction of hexavalent chromium Cr(VI), increasing oxygen-containing functional groups while reducing amide bonds, with Cr(VI) binding driven by electrostatic forces and hydrogen bonds and the aged microplastics able to reduce Cr(VI) to less toxic Cr(III) even under UV light and oxygen-depleted conditions.
Polyamide microplastics as better environmental vectors of Cr(VI) in comparison to polyethylene and polypropylene microplastics
Researchers found that polyamide microplastics adsorb more hexavalent chromium (Cr(VI)) than polyethylene or polystyrene microplastics, with UV aging increasing adsorption capacity, making polyamide particles potentially more dangerous environmental vectors for this toxic heavy metal.
Adsorption mechanism of hexavalent chromium on electron beam-irradiated aged microplastics: Novel aging processes and environmental factors
Researchers used electron beam irradiation as a novel method to age polypropylene microplastics and then studied how these aged particles adsorb hexavalent chromium from water. They found that aging dramatically increased the microplastics' ability to bind chromium by generating oxygen-containing functional groups on their surfaces. The study highlights that weathered microplastics in the environment may have a significantly greater capacity to concentrate heavy metal pollutants than fresh plastic particles.