Efficient Cr(VI) removal from wastewater by activated carbon superparamagnetic composites - Nogueira, Helton Pereira; Toma, Sérgio Hiroshi; Silveira Junior, Alceu Totti; Carvalho, Alexandrina Aparecida Costa; Fioroto, Alexandre Minami; Araki, Koiti (Microchemical Journal, 2019)