Landfill leachate is a major pollutant, especially in arid regions with limited treatment options. This hybrid system combines tannins extracted from Omani date pits with a persulfate-based oxidation process to remove harmful compounds. Optimised through statistical modelling, the treatment achieved 74% reduction in organic pollution, 60% ammonia removal, and 96% colour reduction. By using agricultural waste and requiring minimal infrastructure, the system offers a scalable, low-cost solution for cleaner water in resource-constrained settings