Akademik Veri Yönetim Sistemi
POLISH JOURNAL OF ENVIRONMENTAL STUDIES, cilt.31, sa.5, ss.4611-4622, 2022 (SCI-Expanded)
This
study investigated color and COD removal of azo dye Direct
Blue 71 (DB71) by a Fenton-like process in zero-valent iron (Fe0=ZVI). The
UV–vis spectra of DB71 exhibit three main absorption bands – two in the UV
region and one in the visible region. UV–vis spectra showed that the azo
linkages in the molecule structure of the dyes were destroyed during the
decolorization. The influence of various operational parameters such as pH, ZVI
dosages, hydrogen peroxide (H2O2) concentrations and
temperature are studied to determine the optimum conditions for color and COD
removal. pH is highly effective
parameter of decolorization and COD destruction in this work. However, H2O2
concentration and ZVI dosages were not only effective
in the removal of COD for 100 mgL-1
initial DB71 concentration. Therefore, the optimum ZVI:H2O2 ratio is based
on determining the value of COD
removal. Optimum conditions were accepted to be pH of
2.5, ZVI:H2O2 ratio
4:1 and 20oC temperature. The result indicated that 100% of
decolorization efficiency was achieved within 20 min in the range of 150-400
mg/L initial DB71 concentrations by using optimal conditions. Residual COD values were 15.38, 22.35, 22.58, 27.04,
31.86 mg/L for 150, 200, 250, 300, 400 mg/L initial DB71 concentrations at the
end of reaction time, respectively. Additionally, increasing the reaction
temperature from 20 to 40 ◦C
negatively affected
the decolorization and degradation rate DB71. The experimental kinetic data are fitted very well the Behnajady–Modirshahla–Ghanbery
model for color removal of DB71 dye.