Written by Preetika Preetika, Staff Writer and John Nicholson, M.Sc., P.Eng., Editor

The search for effective solutions to remediate contaminated groundwater, especially groundwater impacted by emerging contaminants, has fueled a rising interest in new and emerging remediation methods, marking a departure from traditional pump and treat approaches.

In situ methods are becoming more common in groundwater treatment due to their potential cost-effectiveness and diminished environmental impact. According to the Superfund Remedy Report, 47% of the 118 groundwater remedies available in 2018–2020 were selected for in situ treatment, while 31% were selected for ex situ treatment (EPA, 2023).

This article looks into several innovative technologies and approaches that have surfaced to address groundwater contamination, illustrating a promising flow path toward sustainable and efficient remediation strategies.

Permeable Reactive Barriers (PRBs)

Permeable Reactive Barriers (PRBs) involve the strategic installation of barriers containing reactive materials. These materials catalyze the degradation, adsorption, or precipitation of contaminants as groundwater flows through them.

Permeable Reactive Barrier Schematic

What makes PRBs particularly attractive is their cost-effectiveness, versatility, and scalability, especially when implemented as a multi-barrier system. This approach enables the simultaneous treatment of multiple pollutants, showcasing its potential as a comprehensive and adaptable solution.

Microalgae

The utilization of microalgae-based systems, has demonstrated remarkable efficacy in addressing emerging contaminants in groundwater. Microalgae, known for their ability to absorb and transform various pollutants, offer a sustainable and efficient in situ
remediation option. This innovative approach holds promise for tackling the challenge of remediating emerging contaminants such as .

Photo Credit: https://doi.org/10.1016/j.scitotenv.2020.144918

The use of microalgae for the bioremediation of emerging contaminants stands out because of significant advances in terms of treatment efficiency and potential use of biomass for the production of high added value products. Microalgae removes contaminants through a combination of bioadsorption, bioaccumulation, and biodegradation.

Integrated Remediation Approaches

Integrated remediation approaches, which involve combining aquatic plants with microorganism-strengthening remediation technology, are actively being developed for both surface and groundwater environments. These holistic methods aim to combine natural attenuation processes, enhancing the overall effectiveness of in situ remediation. By making use of the strengths of various
components within an ecosystem, these integrated approaches showcase the potential for a harmonized and enhanced remediation strategy.

Microbial remediation and plant-microbe interaction under arsenic pollution (Photo Credit: https://doi.org/10.1016/j.scitotenv.2022.160972)
Microbial remediation and plant-microbe interaction under arsenic pollution (Photo Credit: https://doi.org/10.1016/j.scitotenv.2022.160972)

Looking ahead: Integration of Cutting-Edge Technologies

The future of groundwater remediation holds exciting possibilities with the integration of
cutting-edge technologies. The adoption of artificial intelligence for “big data” analysis and drone surveys
represents a forward-looking approach to addressing contamination in situ. These technologies not only
enhance the efficiency and accuracy of remediation efforts but also signify a commitment to staying at the
forefront of scientific and technological advancements.

Ongoing research and development of new technologies and methods for groundwater remediation offer promising avenues for more sustainable and cost-effective treatment approaches. The combination of PRBs, emerging treatment technologies, integrated remediation approaches, and innovative policies reflects a holistic and dynamic approach to tackling the complex challenges associated with groundwater contamination.