Dynamic column adsorption of As on iron-oxide-coated natural rock (IOCNR) and sludge management

AbstractAn extended column adsorption study on arsenic (As(III)/As(V)) was conducted using the developed adsorbent iron-oxide-coated natural rock. We considered a column with a diameter of 2 cm and varying bed depths, including 10 , 15 , and 20 . The breakthrough (C/C0 = 0.016) times were 31.0, 49.0, and 63.0 h and the exhaust (C/C0 = 0.90) times were 60.0, 90.0, and 110.0 h, respectively for As(III). For As(V), those were found to be (breakthrough times corresponding to C/C0 = 0.0033) 5.0, 11.0, and 18.0 h and 20.0, 27.0, and 36.0 h, respectively. The up-flow rate was maintained at 8 mL min−1. The As(III) and As(V) concentrations were 0.6 and 3 mg L−1. Bohart and Adams sorption model was employed to determine the important column design parameters. The column was designed by the bed-depth-service-time model. The adsorption capacity (N0) and the adsorption rate constant (K) calculated were 295.30 mg L−1 and 20.41 L mg−1 h−1, respectively, for As(III) and 599.82 mg L−1 and 0.233 L mg−1 h−1, respectively, f...