Breaking barriers in solar desalination through photovoltaic-hybrid technology and pretreatment for high-yield WHO-Compliant Water Production

Abstract

Conventional solar stills used in treating water in developing regions, face limitations in productivity and some nutrient removal notably ammonia and nitrate. This study presents an enhanced hybrid solar desalination system (EHSDS) integrating photovoltaic (PV) technology with conventional solar distillation to improve water yield and contaminant removal. The system was evaluated under passive, active (PV-assisted), and hybrid operational modes, with and without pretreatment using sand, charcoal, and combined sand–charcoal filters. Results show that the hybrid mode achieved the highest distillate productivity of 20.3 L/m²·day, significantly exceeding passive and active modes. Thermal efficiency reached 55.52%, demonstrating improved energy utilization. Unlike conventional systems, the study highlights the challenge of removing nitrogenous compounds such as ammonia and nitrate. The incorporation of charcoal-based pretreatment significantly enhanced removal efficiencies, achieving up to 96.67% ammonia reduction and improved nitrate removal, bringing treated water within WHO standards. The findings establish the proposed system as a high-performance solution for decentralized water treatment. The study further clarifies performance metrics by distinguishing productivity per unit area from total daily output, providing a more accurate comparison with existing hybrid desalination systems.