The effects of the experimental parameters such as the initial
CR concentration (40–100mg L−1), pH (2–14), adsorbent
dosage (1–10 g L−1), agitation speed (100–1200 rpm) and temperature
(298–338 K) on the adsorptive removal of CR ions
were studied in batch mode for a variable specific period of
contact time (0–60min). The CR solution was prepared by dissolving
the accurate amount of CR (99%) in distilled water, it
is used as a stock solution and diluted to the required initial
concentrations; pH was adjusted with HCl (0.1mol L−1) or
NaOH (0.1mol L−1). For the kinetic studies, desired quantities
of ASAC were contacted with 10mL of CR solutions in Erlenmeyer
flasks. Then, the flasks were placed on a rotary shaker
at 300 rpm and the samples were taken at regular time intervals
and centrifuged at 3000 rpm for 10min. The CR content in
the supernatant was analyzed with a Perkin Elmer UV–visible
spectrophotometer (Model 550S, max = 494nm). The amount
of CR molecules adsorbed by activated carbon qt (mg g−1) was
calculated from the following equation: