Abstract:
Herbal pharmaceutical industry generates wastewater containing very high-level of chemical
oxygen demand (COD), high levels of biological oxygen demand (BOD), color intensity and
suspended solids. Therefore, the main objective of this study was to reduce the high level of
COD by enhancing the activity of tertiary treatment stage by modifying advance oxidation
process. The specific objectives were to find the suitable chemical concentrations for the process
and to find the optimum conditions for better performance of Activated Carbon as an absorbent
in wastewater treatment. Herbal pharmaceutical wastewater samples which contain 1493 mgL-1
of COD level after the secondary treatment were used for the study. Samples were treated with
different concentrations of FeSO4 and H2O2 (Fenton reagent) at constant pH level, temperature
and reaction time (1hr). After the treatment, the samples were filtered via different concentration
of activated charcoal (AC) by changing the stirring time. According to the results the highest
COD removal efficiency (45%) was observed with [FeSO4] of 3,333.33 mgL-1, [H2O2] of 83.33
mlL-1 and maintaining the reaction medium in pH 3. Moreover, the results show that 75.6% of
COD removal efficiency by AC (2 gL-1). However, AC showed the lowest time (15 minutes) for
achieving the final result. Hence it could be inferred that use of Fenton reaction with [FeSO4] of
3,333.33 mgL-1, and [H2O2] of 83.33 mlL-1 at pH 3 and filter the treated water through the AC is
a promising solution to remove high level of COD in herbal pharmaceutical industry wastewater.
