Dairy wastewater treatment by peroxi-electrocoagulation method in hybrid electrocoagulation reactor and development of pigment from waste sludge

Water wastage is a major constraint in India, which ranks first in the world regarding milk output and population. Dairy effluent has a significant organic content, making it inappropriate to use the Electro-Fenton method exclusively. This study investigates the influence of hydrogen peroxide dosage on Fe electrode-based dairy wastewater treatment. The preliminary studies have been conducted in batch setup and the incorporation of continuous studies with the effect of hydrogen peroxide dosage in a hybrid electrocoagulation reactor (HECR). Results show that increasing H₂O₂ dosage makes the observed turbidity removal faster. It is validated with zeta potential range as the value approaches zero, allowing better coagulation at the end of 48 h of reaction. The HECR was used for continuous operation, with a discharge pH of 5.11 and a turbidity reduction range of 70–72.02% at a reaction time of 48 h. The research also explores leftover electrocoagulation sludge for pigment production with TiO₂ fillers. The maximum weight loss at 1000 °C in Fe pigments with TiO₂ fillers was only 2.916%, suggesting its coating suitability in high-temperature applications. Generating wealth from waste is the motto of this research.