Dr John Todd has figured out and demonstrated a method to remediate DDT-contaminated water without the use of electrolysis, or other energy inputs. He was able to decontaminate one of the top superfund sites. The method is broadly versatile, and requires even lower tech than electrolysis. His methods can also sequester heavy metals. It involves introducing organisms across all of the kingdoms so that they self-organize on the contaminant.

More narrowly, Paul Stamets has worked a lot on mycroremediation — remediating with fungi.