Rafeek, M. R., Rabat, N. E., Nisa Yahya, W. Z., & Abdul Ghani, M. (2019). Adsorption and Desorption of Nickel (II) Ion by Oil Palm Empty Fruit Bunch grafted Polyvinyl Alcohol Hydrogel. Chemical Engineering Transactions, 72, 175-180. https://doi.org/10.3303/CET1972030