Zero Liquid Discharge (ZLD) is a progressive wastewater treatment system that ensures total elimination of liquid effluent. It employs techniques like electrodialysis, thermal systems, and crystallizers to reclaim water and isolate solid waste. ZLD aids in reducing contamination, improving water reuse, and meeting stringent environmental policies. Common in petrochemical, dye, and fertilizer industries, ZLD encourages responsible water use and supports long-term ecological preservation.