The aim of this study is to optimize the removal conditions of C.I. Acid black 1 (AB1) by a brown alga
biomass, Cystoseira indica, and a red alga biomass, Gracilaria persica, using Box-Behnken design. The
variables examined were the biomass dosage (0.5e1.5 g L1), initial AB1 concentration (10e50 mg L1),
initial pH (2e6) and time (20e80 min). The determination coefficients (R2) of predicted models were
0.9903 and 0.9955 for C. indica and G. persica biomass, respectively. These findings indicated models high
validity in predicting the AB1 removal by both of biomasses. At the optimum conditions, the maximum
removal efficiencies of AB1 achieved for C. indica and G. persica were 90.76 and 98.18%, respectively.
These results also imply that the used brown and red algal biomasses are favorable biosorbents for the
removal of AB1 from aqueous solutions.
