Combined Strategies to Prompt the Biological Reduction of Chlorinated Aliphatic Hydrocarbons: New Sustainable Options for Bioremediation Application

Abstract

Groundwater remediation is one of the main objectives to minimize environmental impacts and health risks. Chlorinated aliphatic hydrocarbons contamination is prevalent and presents particularly challenging scenarios to manage with a single strategy. Different technologies can manage contamination sources and plumes, although they are usually energy-intensive processes. Interesting alternatives involve in-situ bioremediation strategies, which allow the chlorinated contaminant to be converted into non-toxic compounds by indigenous microbial activity. Despite several advantages offered by the bioremediation approaches, some limitations, like the relatively low reaction rates and the difficulty in the management and control of the microbial activity, can affect the effectiveness of a bioremediation approach. However, those issues can be addressed through coupling different strategies to increase the efficiency of the bioremediation strategy. This mini review describes different strategies to induce the reduction dechlorination reaction by the utilization of innovative strategies, which include the increase or the reduction of contaminant mobility as well as the use of innovative strategies of the reductive power supply. Subsequently, three future approaches for a greener and more sustainable intervention are proposed. In particular, two bio-based materials from renewable resources are intended as alternative, long-lasting electron-donor sources (e.g., polyhydroxyalkanoates from mixed microbial cultures) and a low-cost adsorbent (e.g., biochar from bio-waste). Finally, attention is drawn to novel bio-electrochemical systems that use electric current to stimulate biological reactions.

Coupled Adsorption and Biodegradation of Trichloroethylene on Biochar from Pine Wood Wastes: A Combined Approach for a Sustainable Bioremediation Strategy

“…To assess whether in situ bioremediation might be a feasible option for CAH-source-zone degradation, a detailed characterization of the site and feasibility studies (combining laboratory studies with field activities) must be performed [14,15]. Subsequently, to reduce the time needed to achieve remediation goals and overcome bioremediation limitations, a recommended strategy may be the combination of several synergistic technologies [16]. Indeed, the combination of abiotic degradation, e.g., by chemical reduction with zero-valent iron (ZVI), and the stimulation of biological metabolism is a diffused approach [17][18][19][20].…”

Evaluation of the Bioelectrochemical Approach and Different Electron Donors for Biological Trichloroethylene Reductive Dechlorination

“…As new sustainable and eco-friendly strategies are gaining attention [7], bioremediation technologies have been of increasing interest to the science community [8][9][10]. These technologies are based on the activity of specific microorganisms, whose metabolism can transform the contaminant into less toxic and hazardous compounds [11].…”

Remediation of chlorinated aliphatic hydrocarbons (CAHs) contaminated site coupling groundwater recirculation well (IEG-GCW®) with a peripheral injection of soluble nutrient supplement (IEG-C-MIX) via multilevel-injection wells (IEG-MIW)

“…Conventional remediation strategies for CAHs-contaminated groundwater comprise physicochemical technologies such as pump and treat, direct-push-injections, reactive permeable barriers, and in situ chemical oxidation/reduction ( Stroo and Ward, 2010 ; Brusseau and Guo, 2014 ; Kueper et al., 2014 ; Rajajayavel and Ghoshal, 2015 ; Niño de Guzmán et al., 2018 ; Guan et al., 2020 ; Ciampi et al., 2021b ). In the last years, bioremediation of CAHs has gained attention in both research and full-scale remediation for its cost-effectiveness and less invasive nature than more traditional physicochemical methods ( Blazquez-Pallí et al., 2019 ; Rossi et al., 2021 ). Microbial degradation of CAHs in an aquifer could occur through anaerobic reductive dehalogenation ( Aulenta et al., 2007 ; Xiao et al., 2020 ).…”