We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Enhanced mobility and dynamic retention of nanoplastics in mineral coated porous media.
Summary
Scientists studied how tiny plastic particles move through different types of soil and sand that might be found in groundwater systems. They discovered that these nanoplastics travel much farther and faster through soil than previously thought, especially when water flows quickly. This matters because it suggests that plastic pollution from things like food packaging and cosmetics could spread more widely through our drinking water sources than we realized.
This study examines the transport and retention of carboxylated and amine-modified polystyrene nanoparticles (NP) in quartz-, kaolinite-, and goethite-coated sands under saturated flow. Column experiments at varying flow velocities (1- 50 m d⁻¹), supported by adsorption kinetics, (X)-DLVO modeling, hydrodynamic torque analysis, and advection-dispersion modeling (ADE), were used to identify controlling factors of NP mobility.Increasing flow velocity enhanced NP breakthrough and shifted deposition zones further along the column length, indicating a transition from diffusion- to reaction-limited attachment. Deposition followed the order goethite > kaolinite > quartz. Despite similar surface charge, carboxylated polystyrene NP showed unexpectedly strong retention on kaolinite, attributed to hydrogen bonding between carboxyl and kaolinite hydroxyl groups, as indicated by IR spectroscopy, an interaction not captured by DLVO theory. Force tensiometry showed variations in contact angles between various mineral coatings, yet no evidence for earlier proposed “long range” hydrophobic forces between NP and macroscopic surfaces could be found from Peak Force QNM measurements. ADE simulations incorporating reversible attachment-detachment and site blocking best reproduced observations, highlighting the combined roles of hydrodynamics and mineral surface chemistry. The modelling exercise further suggests that the low density of polymeric nanoparticles limits gravitational settling, challenging the transferability of trends established for denser mineral engineered nanoparticles (ENPs) such as silica.Overall, the results demonstrate greater NP mobility and more dynamic retention in natural, heterogeneous flow systems than inferred from DLVO interactions, as supported by experiments and kinetic ADE modeling.
Sign in to start a discussion.
More Papers Like This
Effects of co-present mineral colloids on the transport of microplastics in porous media: The key role of hydrochemical and hydrodynamic conditions
Scientists studied how tiny plastic particles (microplastics) move through soil and sand when mixed with natural clay particles. They found that the combination of different clay types and water conditions can either help microplastics travel further underground or trap them in place. This research helps us better understand how microplastics might contaminate groundwater sources that provide our drinking water.
The Effect of Polymer Type and Particle Concentration on Microplastic Transport Mechanisms in Saturated Porous Media
Scientists studied how tiny plastic particles move through soil and groundwater by testing different types of plastics at various concentrations. They found that the amount and type of plastic affects how far these particles travel underground, and that bacteria growing on the plastic surfaces can change how they move through soil. This research helps us better understand how microplastics might contaminate our drinking water sources and food supply.
Secondary nanoplastic transport in sand and in soil
Scientists studied how tiny plastic particles called nanoplastics move through sand and soil after being broken down in the environment for many years. They found that different types of plastic particles move differently underground - some get stuck while others travel further - depending on the plastic type and soil conditions. This research helps us better understand how these microscopic plastic pieces might spread through groundwater and potentially reach drinking water sources, which could affect human health.
How soil moisture and flow regime drive microplastic transport in the vadose zone: insight from modelling and column experiments
Scientists studied how tiny plastic particles move through soil toward underground water sources that we use for drinking water. They found that plastic particles travel very differently depending on how wet or dry the soil is - sometimes getting trapped, other times moving quickly through the ground. This research helps us better understand how microplastics might contaminate our groundwater supplies, which is important for protecting drinking water quality.
Microplastics/nanoplastics in porous media: Key factors controlling their transport and retention behaviors
This review examines what controls how microplastics and nanoplastics move through soil and other porous materials like sand and sediment. Factors like particle size, shape, surface charge, water flow speed, and the presence of other pollutants all influence whether plastics stay in place or travel deeper into groundwater. Understanding these transport behaviors is important for assessing the risk of microplastics contaminating underground drinking water sources.