Acidification due to microbial dechlorination near a trichloroethene DNAPL is overcome with pH buffer or formate as electron donor: Experimental demonstration in diffusion-cells

► pH drop resulting from microbial dechlorination determined with batch experiment. ► Diffusion-cells to test different pH buffer capacities and electron donor types. ► Acidification reduces bio-enhanced TCE DNAPL dissolution. ► A higher pH buffer capacity results in larger DNAPL dissolution enhancement. ► Formate instead of lactate as electron donor overcomes acidification.