2.5. Effect of solution pH
In this study, 0.20 L of dye solution of 50 mg/L initial concentration
at different pH values (2.0–11.0) was agitated with 0.60 g of JFP
in a water-bath shaker at 30 ◦C. Agitation was made for 180 min
at a constant agitation speed of 130 rpm. After equilibrium was
established, the sorbent was separated from the dye solution using
filtration and the dye concentrations were similarly measured by
a double beam UV–vis spectrophotometer. The pH was adjusted
with 0.1N NaOH and 0.1N HCl solutions and measured by using a
pH meter (Ecoscan, EUTECH Instruments, Singapore).