We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Aging of polylactic acid microplastics during hydrothermal treatment of sewage sludge and its effects on heavy metals adsorption
Summary
Researchers examined how hydrothermal treatment of sewage sludge causes polylactic acid microplastics to age, and how this aging changes their heavy metal adsorption capacity. Hydrothermal treatment accelerated PLA-MP degradation, increasing surface oxygen groups and enhancing adsorption of copper, cadmium, and lead compared to untreated particles.
Microplastics' (MPs) aging process and environmental behavior have attracted extensive attention due to the potential long-term ecological impact. MPs enriched in sludge may accelerate aging during sludge treatment and the affecting environmental behavior, i.e., adsorption performance for pollutants. However, the related studies have not been well researched, especially for the biodegradable MPs. This study revealed the influences of hydrothermal treatment on the characteristics of polylactic acid microplastics (PLA-MPs) and the consequences on heavy metals adsorption. The changes in PLA-MPs' physiochemical properties were characterized and compared. PLA-MPs' surface became irregular, and the oxygen-containing functional groups increased through FTIR and XPS analysis. Meanwhile, the molecular weight and crystallinity of PLA-MPs decreased significantly with the rising in hydrothermal temperature. Accordingly, the adsorption capacity of PLA-MPs for Pb increased from 93.97 μg g for the raw PLA-MPs to 1058.03 μg g for the aged PLA-MPs. Multiple adsorption kinetics and isotherms were discussed for the Pb adsorption onto PLA-MPs with different aging of the PLA-MPs. The adsorption mechanisms of Pb relate to electrostatic interaction and complexation. The main difference is that the adsorption for raw PLA-MPs is dominated by physical and chemical adsorption, whereas the adsorption for the aged PLA-MPs prefers chemical adsorption. In addition, we carefully evaluated the influences of pH, dissolved organic matter, and ionic strength on the PLA-MPs adsorption. The present study highlighted the significance of hydrothermal treatment on the MPs aging and the adsorption performance.
Sign in to start a discussion.
More Papers Like This
The Effect of Different Aging Methods on the Heavy Metal Adsorption Capacity of Microplastics
Polystyrene and polylactic acid microplastics were aged under UV and high-temperature conditions, and aged microplastics showed altered surface properties that affected their adsorption capacity for heavy metals cadmium, copper, and zinc.
Exploring the influence of sludge dewatering agents on Microplastic aging under hydrothermal treatment: Insights from Polylactic Acid microplastics
This study examined how industrial wastewater sludge treatment chemicals (dewatering agents) interact with hydrothermal processing to alter the physical and chemical properties of polylactic acid (PLA) microplastics in sludge. The findings matter because different treatment chemistries transform microplastic surfaces in distinct ways — affecting their porosity, reactivity, and persistence — which has implications for how microplastics behave after leaving wastewater treatment facilities.
Aging properties of polyethylene and polylactic acid microplastics and their adsorption behavior of Cd(II) and Cr(VI) in aquatic environments
Researchers compared how polyethylene and polylactic acid (PLA) microplastics age in the environment and how that aging affects their ability to absorb heavy metals like cadmium and chromium from water. They found that aging changed the surface chemistry of both plastic types, increasing their capacity to pick up these toxic metals. The findings matter because aged microplastics in the environment may concentrate and transport more pollutants than fresh plastic particles.
Aging characteristics of polylatic acid microplastics and their adsorption on hydrophilic organic pollutants: mechanistic investigations and theoretical calculations
Researchers characterized how polylactic acid microplastics undergo UV and thermal aging in aquatic environments, finding that aging altered surface chemistry, increased hydrophilicity, and enhanced adsorption of heavy metal pollutants—raising concerns about aged biodegradable plastics as carriers of co-contaminants.
Impacts of poly(lactic acid) microplastics on organic compound leaching and heavy metal distribution during hydrothermal treatment of sludge
Biodegradable poly(lactic acid) microplastics (PLA-MPs) introduced into sewage sludge during hydrothermal treatment release lactic acid and other organic breakdown products that lower pH and alter the distribution of heavy metals like cadmium and copper. This means that PLA — often promoted as an environmentally safe plastic — can still mobilise toxic contaminants during waste treatment, complicating assumptions about its safety relative to conventional plastics.