investigated using activated carbon prepared from milk vetch. Scanning electron
microscopy, Brunauer–Emmett–Teller, and Fourier transform infrared were carried out to
characterize as-prepared activated carbon. The adsorption process was optimized by
response surface methodology based on central composite design. Accordingly, a 4-CP
removal of 89.52% was obtained with a reaction time of 49 min, initial 4-CP concentration of …