Adsorption kinetics experiments
The adsorption kinetics experiment was carried out at initial arsenate concentration of 20 mg/L with adsorbent dosage of 0.1 g/L, and the solution pH value was controlled at 2.0 during adsorption process by adding a certain amount of NaOH or HNO3. After adsorption experiments, the solution was filtered using 0.22 μm syringe filter and arsenate concentration was measured by an inductively coupled plasma optical emission spectrometer (ICP-OES, Optima 2000 DV, PerkinElmer). 20
Breakthrough study experiments
The feed solution used in breakthrough experiments had arsenic concentration of 1 mg/L and a pH of 2.0. It was introduced to both composite-1 and equivalent packed columns from a syringe pump (Nexus 6000 Syringe Pump, Chemyx). In the case of composite-1, one end was sealed and the other end served as the outlet, as shown in Supplementary Figure S7. In the case of packed columns, active MOF adsorbents were packed and held by the filter papers, as shown in Supplementary Figure S8. After collecting recovery samples, an aliquot of each sample was analysed using ICP-OES for residual arsenic concentration measurement.
