Trinary Component Adsorption of Methylene Blue, Methyl Orange, and Methyl Red from Aqueous Solution Using TiO2/Activated Carbon oleh Nguyen Thi Thanh Tu, Tran Si Thanh, Phan Tu Quy, Tran Thi Minh Ha, Phan Thi Kim Thu, Nguyen Hong Bich, Le Van Thanh Sơn, Vo Thang Nguyen, Dao Ngoc Nhiem, Pham Khac Lieu, Dinh Quang Khieu