Abstract: Provided are surfactant compositions and their use for deinking various substrates, such as waste paper. The compositions comprise: (a) an alkyldiphenyloxide disulfonate compound of formula (I): wherein R1 at each occurrence is independently C6-C18 alkyl, M+ is H+ or a monovalent cation, p and q are independently 0 or 1 provided that at least one of p and q is 1; and (b) a nonionic surfactant of formula (II): wherein X and Y are independently ethylene oxide or propylene oxide, m and n are independently integers ranging from 0 to 50, provided that at least one of m and n is not 0, z is an integer ranging from 1 to 50, and R is RA or RA—C(?O)— wherein RA is C4-C22 alkyl or C4-C22 alkenyl.