Integrated treatment of pharmaceutical effluents by chemical coagulation and ozonation

• Chemical coagulation and ozonation process treated pharmaceutical wastewater.
• Coagulant type & dose, settling time and pH effects were investigated.
• Coagulation with alum proved to be effective with a dose of 0.75 g/L at pH 6.

The present study was aimed at treating pharmaceutical industry wastewater employing chemical coagulation and ozonation process. Coagulation was carried out by alum and lime. Parameters like coagulant type & dose, settling time and pH ranging from 0.5 to 1.0 g/L, 10 to 60 min and 4 to 10 respectively were investigated. Coagulation with alum proved to be effective with a dose of 0.75 g/L at pH 6 leading to 59% COD and 76.8% turbidity removal. Ozonation was carried out for 10–60 min. The COD abatement mechanism of ozonation is changed in unbuffered samples and is only 13.5% after 1 h ozonation. However, 93.4% color removal was reported at the same ozonation time. The treatment strategy is handy in treating pharmaceutical wastewaters.