Key technologies for the operation and maintenance of wastewater from photovoltaic modules: progress and application analysis of process adaptability and economic optimization

Considering the complex pollution characteristics of high ammonia nitrogen (NH3-N), high chemical oxygen demand(COD) and high salinity in photovoltaic (PV) module production wastewater, this paper focuses on process compatibility and cost-effectiveness optimization. It systematically reviews the technological evolution of PV-related wastewater treatment and summarizes the innovative pathway of a graded treatment approach coupled with dynamic interlocking processes. Demondtration through a case study at a 300MW PV park in Ningxia confirmed the pollutant removal efficiency and economic advantages of the proposed process. The results demonstrated an average NH3-Nremoval rate of 98.5%, COD degradation exceeding 95%, salinity recovery purity of 93%, and a 26.7% reduction in per-ton treatment costs compared to conventional methods. To address technical bottlenecks such as salinity separation precision, directions including AIoT-enabled intelligent operation were proposed. This study provides dual technical and economic solutions to achieve zero-liquid discharge for PV industry wastewater.