Degradation of ibuprofen in field groundwater matrices extracted from (a) TAL and (b) MIT Superfund sites of Puerto Rico, and in natural surface water matrices collected from local (c) JAM and (d) WAR ponds of Boston, Massachusetts. Conditions: Fe(II)/sulfite process – 10 μM ibuprofen, 0.2 mM Fe(II), 2 mM sulfite, initial pH 7; electro/sulfite process – 10 μM ibuprofen, 2 mM sulfite, 200 mA, initial pH 7; electro/Fe(II)/sulfite process – 10 μM ibuprofen, 0.2 mM Fe(II), 2 mM sulfite, 200 mA, initial pH 7. Note: TAL, Tallonal Superfund site; MIT, Pozo Mita Superfund site; JAM, Jamaica pond; WAR, Wards pond.