The effect of pH on adsorption of MB and EY was investigated by varying the initial pH from 3 to 11. Different adsorbent amount (1 g L−1, 2 g L−1 and 3 g L−1) were mixed in a 250 mL conical flask of dye solution over the concentration range of 100–400 mg L−1 and were stirred at 100 rpm in an orbital incubator shaker (laboratory Tech, LSI-1005R).