Antibiotics such as streptomycin sulphate are increasingly present in pharmaceutical effluent, posing threat to both the environment and human health. Antibiotics, in general, are refractory and do not break downentirely using traditional wastewater treatment procedures. The purpose of this work is to degrade streptomycin sulphate in simulated pharmaceutical wastewater utilizing rutile mining residue (RMR) as a photocatalyst. This study successfully demonstrated the application of RMR as a sustainable and highly effective advanced photo-oxidation catalyst for degrading streptomycin sulphate in simulated pharmaceutical wastewater. Characterization revealed that RMR possesses an extraordinary natural composition with 65.5% titanium dioxide (TiO₂) and 29.8% iron oxide (Fe₂O₃), creating an ideal Ti-Fe system for Photo-Fenton catalysis with exceptional surface properties (326.653 m²/g surface area and 90.7% micropore dominance). The experimental results showed remarkable performance, achieving up to 96% streptomycin sulphate removal under best conditions (30-35 ml H₂O₂, 20-30 W visible light intensity), with rapid degradation reaching 80% removal within 1.5 hrs. The study revealed exponential enhancement with H₂O₂ concentration, improvement with visible light intensity (from near-zero at 5W to 90-95% at 20-30W), linear scalability with catalyst dosage, and inverse correlation with substrate concentration due to inhibition effects. The RMR catalyst demonstrated excellent reusability across six cycles (maintaining 67.8% efficiency), operating through synergistic Photo-Fenton mechanisms involving iron-catalyzed H₂O₂ decomposition, photochemical iron regeneration, and TiO₂ photocatalytic enhancement. This research represents a breakthrough in sustainable catalyst technology, converting mining waste into a valuable treatment solution that addresses both pharmaceutical wastewater contamination and mining waste disposal, offering significant environmental and cost-effective, visible light operation, and scalable industrial application potential.
Tanko et al. (Thu,) studied this question.