Periodic Reporting for period 1 - NaplaGro (Nanoplastic Transport in Groundwater environments)
Berichtszeitraum: 2023-04-01 bis 2025-05-31
Groundwater is Earth’s largest source of drinking water, supplying 75% of EU residents. Recent studies have documented plastic contamination in drinking water wells. Nanoplastics (NPs, <1000 nm), originating from product use and microplastic degradation, are emerging pollutants of concern. NPs can act as vectors for toxins, disrupt nutrient cycles, and pose risks to human health, including cytotoxicity and oxidative stress. Their presence in groundwater thus represents a serious health threat.
Despite this, NP transport in aquifers remains poorly understood. Key knowledge gaps include the influence of particle shape, flow conditions, and interactions with biofilms and microbial—especially fungal—communities.
This MSCA was carried out to investigate NP transport in complex groundwater systems addressing three core questions:
1) How does NP shape influence transport in groundwater?
2) How do flow rates affect NP mobility in mineral and biogeochemical media?
3) Can fungal communities retain NPs under realistic aquifer conditions?
The outcomes will improve our understanding of NP behavior in subsurface environments, inform predictive models of NP pollution in drinking water, and support future applications in wastewater treatment or NP immobilization strategies.
Despite this, NP transport in aquifers remains poorly understood. Key knowledge gaps include the influence of particle shape, flow conditions, and interactions with biofilms and microbial—especially fungal—communities.
This MSCA was carried out to investigate NP transport in complex groundwater systems addressing three core questions:
1) How does NP shape influence transport in groundwater?
2) How do flow rates affect NP mobility in mineral and biogeochemical media?
3) Can fungal communities retain NPs under realistic aquifer conditions?
The outcomes will improve our understanding of NP behavior in subsurface environments, inform predictive models of NP pollution in drinking water, and support future applications in wastewater treatment or NP immobilization strategies.
Novel nano- and microscale methods combined with traditionally used imaging approaches were used to systematically study the transport behavior of NP in complex mineral and biogeochemical groundwater aquifer laboratory
settings in order to understand the risk of NP contamination in drinking water aquifers.
settings in order to understand the risk of NP contamination in drinking water aquifers.
Objective 1: How does NP shape affect groundwater transport?
The study showed that non-spherical nanoplastics exhibit up to three times higher deposition rates than spherical particles on simple quartz surfaces, indicating reduced transport. However, on more complex minerals like kaolinite, surface functional groups were more influential than particle shape in determining deposition behavior. This pattern remained unchanged in the presence of organic matter. Therefore, in realistic groundwater environments, surface chemistry plays a more significant role in nanoplastic retention than particle shape.
Objective 2: Can flow rates modify NP transport in porous media?
This objective was fully achieved. Using sediment column experiments, it was found that high flow rates (50 m/d), typical of macropores and infiltration zones, significantly enhance nanoplastic transport, regardless of mineral type or interaction conditions. In contrast, low flow rates (1 m/d), representative of typical groundwater velocities, did not support NP transport. These results highlight that NP mobility is primarily enabled in fast-flowing subsurface environments.
Objective 3: Are fungal communities able to retain NP under realistic aquifer conditions?
This objective was fully achieved. While batch and column experiments showed no measurable NP retention by fungal hyphae, microfluidic chip experiments revealed a site-limited adsorption process. Once reactive sites on the hyphae were saturated, no further NP retention occurred. This suggests that fungal hyphae can retain environmentally relevant NP concentrations (<1 ppm) in groundwater systems under flow conditions.
The study showed that non-spherical nanoplastics exhibit up to three times higher deposition rates than spherical particles on simple quartz surfaces, indicating reduced transport. However, on more complex minerals like kaolinite, surface functional groups were more influential than particle shape in determining deposition behavior. This pattern remained unchanged in the presence of organic matter. Therefore, in realistic groundwater environments, surface chemistry plays a more significant role in nanoplastic retention than particle shape.
Objective 2: Can flow rates modify NP transport in porous media?
This objective was fully achieved. Using sediment column experiments, it was found that high flow rates (50 m/d), typical of macropores and infiltration zones, significantly enhance nanoplastic transport, regardless of mineral type or interaction conditions. In contrast, low flow rates (1 m/d), representative of typical groundwater velocities, did not support NP transport. These results highlight that NP mobility is primarily enabled in fast-flowing subsurface environments.
Objective 3: Are fungal communities able to retain NP under realistic aquifer conditions?
This objective was fully achieved. While batch and column experiments showed no measurable NP retention by fungal hyphae, microfluidic chip experiments revealed a site-limited adsorption process. Once reactive sites on the hyphae were saturated, no further NP retention occurred. This suggests that fungal hyphae can retain environmentally relevant NP concentrations (<1 ppm) in groundwater systems under flow conditions.