Rankala Lake quarry water purification via a dual strategy involving hydrodynamic cavitation and ozonation

This research presents a ground-breaking approach to wastewater treatment that leverages hydrodynamic cavitation and ozonation with unprecedented efficiency and environmental benefits by resolving the concern of the ever-present paradox of water scarcity and persistent pollutants in wastewater, and it compels scientists to relentlessly pursue innovative and eco-friendly treatment solutions. This study introduces a pioneering method for treating wastewater employing a sequential approach of hydrodynamic cavitation (HC) coupled with subsequent ozonation (O3). This research examined the process of purifying rainwater collected from the Rankala Lake quarry in Kolhapur, India. The treatment, which lasted for approximately 7 hours each day over a span of three weeks, resulted in notable enhancements in water quality. The initial greenish discoloration and bad odor were notably eradicated within a week, without any chemical additives. The microbial burden decreased significantly from 10⁵ CFU/mL to 10² CFU/mL, indicating a strong level of disinfection. The COD decreased significantly from 110 ppm to less than 10 ppm, while the BOD decreased dramatically to undetectable levels (0 ppm) from 55 ppm. In addition, there was a slight change in the concentration of chloride, water hardness, clarity, and total dissolved solids (TDS). This exemplifies the efficacy of the cavitation process coupled with ozonation for converting polluted, discolored, and malodorous water into purified water appropriate for diverse uses.