ZERO LIQUID DISCHARGE (ZLD) AND SLUDGE VALORIZATION: DUAL PATHWAYS FOR SUSTAINABLE WASTEWATER MANAGEMENT IN INDIA

Indias rapid industrial growth has intensified wastewater challenges, with Zero Liquid Discharge (ZLD) systems emerging as a regulatory solution. While ZLD enables partial water recovery, operator insights reveal persistent inefficiencies: 30 50% of wastewater remains unrecycled, often disposed of through unsustainable tanker discharge. High energy costs, heavy chemical use, and frequent breakdowns further undermine its viability, positioning ZLD more as a compliance tool than a sustainable practice. To address these gaps, this study explores sludge valorization as a complementary pathway. Textile effluent treatment plant sludge, after composting, demonstrated significant agronomic potential; enhancing germination, biomass, and yield across diverse crops by 13 40% compared to commercial NPK fertilizers. Laboratory analysis confirmed that heavy metals remained below FAO/WHO safety thresholds, ensuring crop and soil safety. This makes sludge-derived fertilizers safe and viable for farmer use, reducing reliance on costly chemicals. Together, the findings underscore the promise of hybrid models that integrate sludge valorization, innovation, and policy reform for sustainable wastewater management in India