Green synthesis of a highly efficient biosorbent for organic, pharmaceutical, and heavy metal pollutants removal: Engineering surface chemistry of polymeric biomass of spent coffee waste

•Using coffee waste as a green, renewable, and cheap biosorbent with tunable surface chemistry.•One-pot facile and versatile chemical modification of polymeric materials of the biosorbent.•Excellent affinity of the engineered sulfonated biosorbent toward ionic and polar pollutants.•Superior adsorption capacity of 812, 302, and 462 mg/g with respect to MB, Cr(VI), and TC.•Endothermic and spontaneity of adsorption process, as shown by kinetic and thermodynamic study.