We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Aging microplastic aggravates the pollution of heavy metals in rhizosphere biofilms
Summary
Researchers found that aging microplastics aggravate heavy metal pollution in rhizosphere biofilms, with weathered MPs accumulating more metals and altering microbial community structure in the root zone, potentially increasing contaminant transfer to plants.
Heavy metals (HMs) and microplastics (MPs) are ubiquitous in agricultural soils. Rhizosphere biofilms are important sites for HM adsorption, and biofilms are easily disturbed by soil MPs. However, the adsorption of HMs on rhizosphere biofilms induced by aged MPs is not clear. In this study, the adsorption behavior of Cd(II) on biofilms and pristine/aged polyethylene (PE/APE) was analyzed and quantified. The results showed that the adsorption amount of Cd(II) on APE was greater than that on PE, in which the oxygen-containing functional groups of APE could provide binding sites to increase the adsorption of HMs. Density functional theory (DFT) calculations revealed that the binding energy of Cd(II) onto APE (-6.00 kcal·mol) was much stronger than that of PE (7.11 kcal·mol) due to hydrogen bonding interactions and oxygen atom-metal interactions. For HM adsorption on MP biofilms, APE increased the adsorption capacity of Cd(II) by 4.7 % relative to PE. The pseudo-second-order kinetic and Langmuir models suitably described the adsorption kinetics and isothermal adsorption of Cd(II), respectively (R2 > 80 %), indicating that monolayer chemisorption dominated. However, the hysteresis indices of Cd(II) in the Cd(II)-Pb(II) system (< 1) were higher than those in the single system (> 1) due to the competitive adsorption of HMs. Overall, this study clarifies the effect of MPs on the adsorption of HMs in rhizosphere biofilms and will help researchers assess the ecological risks of HMs in soils.
Sign in to start a discussion.
More Papers Like This
Influencing mechanisms of microplastics existence on soil heavy metals accumulated by plants
This review summarizes existing research on how microplastics in soil affect the uptake of heavy metals by plants. Microplastics can change soil chemistry and microbial communities in ways that alter how much toxic metals plants absorb through their roots. This is concerning for human health because microplastic-contaminated agricultural soil could lead to crops that contain higher levels of dangerous heavy metals.
How aging microplastics influence heavy metal environmental fate and bioavailability: A systematic review
This systematic review found that environmental aging (UV, weathering) degrades microplastics into smaller particles with higher surface reactivity, increasing their capacity to adsorb heavy metals. These aged microplastic-heavy metal complexes bioaccumulate through the food chain, posing greater ecological and human health risks than either pollutant alone.
Potential impacts of polyethylene microplastics and heavy metals on Bidens pilosa L. growth: Shifts in root-associated endophyte microbial communities
Researchers found that polyethylene microplastics in soil contaminated with heavy metals significantly stunted plant growth, reducing root length by nearly 49% and increasing harmful reactive oxygen species in plant tissues. The microplastics also shifted the soil's microbial communities toward stress-resistant species, demonstrating how plastic pollution can disrupt the soil ecosystem that supports our food supply.
Interaction of microplastics with heavy metals in soil: Mechanisms, influencing factors and biological effects
This review summarizes how microplastics and heavy metals interact in soil, where microplastics can absorb and carry toxic metals through the food chain and into the human body. Aging and weathering of microplastics changes their surface properties, making them better at picking up heavy metals, which raises concerns about combined exposure through contaminated crops and water.
Effects of combined microplastics and heavy metals pollution on terrestrial plants and rhizosphere environment: A review
This review summarizes how microplastics and heavy metals interact in soil to affect plant growth and the surrounding ecosystem. When present together, these pollutants cause significantly more harm than either alone, reducing plant weight by up to 87.5% and altering how heavy metals accumulate in crops -- raising concerns about food safety and human exposure through contaminated agricultural products.