0
Article Tier 2 Environmental Sources Sign in to save

Influence of Different Microplastic Forms on pH and Mobility of Cu2+ and Pb2+ in Soil

Molecules 2022 92 citations

AI summary Read the abstract

Researchers investigated how different microplastic forms influence soil pH and the mobility of copper and lead ions, finding that microplastics' surface properties and electrostatic interactions can modify heavy metal sorption and alter the soil microenvironment.

Microplastics, due to their surface properties, porosity and electrostatic interactions have a high affinity for cations sorption from the aqueous phase. As soil is a complex matrix, interactions between microplastics, soil constituents and heavy metals (HM) may modify the soil microenvironment for heavy metal mobilization/immobilization processes. In order to better understand the problem, three commonly found forms of microplastics in soil (fibers, fragments and microbeads) were mixed with Cu2+- or Pb2+-contaminated soil and incubated at 22 °C for 180 days. In soil samples pH and the content of water and acid exchangeable species of metals were analyzed. The results of this study showed that the presence of microplastics in HM-contaminated soil affected metal speciation, increasing the amount of easily exchangeable and potentially bioavailable forms of Cu2+ or Pb2+ in the tested soil. Soil pH also increased, confirming that microplastic particles affect soil properties relevant to the sorption/desorption process of metal cations. Overall, the smallest microplastic particles (≤1 mm), such as fibers or glitter microbeads, had a greater impact on the change in the sorption and desorption conditions of metals in tested soil than larger particles. The findings of our study show that microplastic form, shape and size should be considered as important factors that influence the soil properties and mobility of heavy metals in soil.

More Papers Like This

Article Tier 2

Influence of polyethylene-microplastic on environmental behaviors of metals in soil

AI summary Read the abstract

Researchers investigated how polyethylene microplastics affect the adsorption, desorption, and bioavailability of heavy metals in soil. They found that adding microplastics altered how metals bind to soil particles and increased the mobility of certain metals like cadmium and lead. The study suggests that microplastic contamination in soils may change the environmental behavior of heavy metals, potentially increasing their availability to plants and soil organisms.

Article Tier 2

Metal adsorption by microplastics in aquatic environments under controlled conditions: exposure time, pH and salinity

AI summary Read the abstract

Scientists systematically varied pH, salinity, and exposure time during metal adsorption experiments on different microplastic types, finding that pH had the greatest influence on metal uptake, with higher pH favoring adsorption of copper, lead, and cadmium onto most tested polymers.

Article Tier 2

Response of soil heavy metal forms and bioavailability to the application of microplastics across five years in different soil types

AI summary Read the abstract

Researchers conducted a five-year experiment examining how microplastics affect the chemical forms and bioavailability of heavy metals across five different soil types. They found that microplastics generally reduced the readily available forms of heavy metals while increasing the mineral- and organic-bound forms, and that the bioconcentration of chromium and lead decreased substantially. The study suggests that soil type and exposure duration both play important roles in how microplastics influence heavy metal behavior in soils.

Article Tier 2

Microplastic-induced changes in soil properties and microbial communities promote Cd and Pb release from soil aggregates

AI summary Read the abstract

A lab study of soil mixed with microplastics found they lowered soil acidity levels and made toxic metals cadmium and lead more available, especially in the smallest soil particles. Microplastics also changed soil nutrients and microbial communities, and these changes were linked to the increased release of cadmium and lead.

Article Tier 2

Effects of soil environmental factors and UV aging on Cu2+ adsorption on microplastics

AI summary Read the abstract

Laboratory experiments and modeling showed that copper adsorption onto microplastics was significantly influenced by soil environmental factors (pH, organic matter, ionic strength) and the degree of UV aging of the plastic particles. Understanding these context-dependent sorption behaviors is important for predicting how microplastics transport heavy metals in real agricultural soils.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper