experimentA series of standards or sample solutions containing As(V) weretransferred into 250 mL beakers and the pH value was adjusted tothe desired value with 0.1 mol L-1HCl or 0.1 mol L-1NaOH solutions.The volume was made up to 100 mL with ultrapure water and 5 mgof ALIQUAT 336-MWCNTs was added. This mixture was then placedin a shaker for 10 min to facilitate adsorption of the metal ions on to the sorbent.