Reviewing the Bioremediation of Contaminants in Groundwater: Investigations over 40 Years Provide Insights into What's Achievable

Biodegradation and biotransformation of contaminants in groundwater commonly occurs naturally. However, natural biodegradation rates can be slow leading to elongated contaminant plumes prolonged risks that demand greater remedial intervention. Enhancement the induced by addition amendments change geochemical conditions those are more favorable for indigenous or added biota. Enhancing requires collocation concern with ‘right’ microbial communities under conditions, so microbiota thrive bio-transform, degrade lock up interest. This is most easily achievable at laboratory bench scale where mixing performed, mass transfer limitations minimized. inducing such changes field aquifers non-trivial - do not mix into because it a laminar (non-turbulent) low-energy flow environment. Bioaugmentation cultured genetically modified organisms have also been considered add enhance degradation rates. Here we provide an overview research studies over approximately 40 years highlight progression understanding from active bioremediation efforts variably successful scale. Investigated providing insights include petroleum hydrocarbons, chlorinated brominated ammonium, metals, munition compounds, atrazine per- polyfluorinated alkyl substances. The redox electron acceptor/donor inducive range highlighted. challenged availability donors/acceptors core on plume fringes. Cases bioaugmentation identified. A long history investigations provides examples importance amendment delivery mechanisms, scale-up field, field-scale demonstration effectiveness technologies. Advantages disadvantages approaches tabulated. value contributions integrative modelling advances literature review example cases deep what might plumes. Limitations strategies outlined here will help direct future efforts. Addressing sources as well itself achieve effective outcomes. Twelve ‘lessons learnt’ synthesized review.