A comparative analysis of Boron Removal using constructed wetlands and alternative technologies, highlighting key factors affecting constructed wetland efficiency

Excessive levels of boron (B) in wastewater are problematic due to their toxicity to both plants and aquatic fauna. The removal of B is both economically burdensome and technically challenging, often requiring sophisticated methods such as adsorption and reverse osmosis. Constructed wetlands (CWs) offer a promising and costeffective alternative for B removal. This review paper compiles the recent research on B removal, detailing key findings and identifying areas for potential enhancement. It provides a comparative analysis of CWs with other B removal technologies, evaluates the environmental impact of CWs in terms of COQ-equivalent reduction, and examines the various pathways for B removal. Factors influencing the efficiency of B removal, such as CW type, plant selection, choice of media, hydraulic retention time (HRT), hydraulic loading rate (HLR), mass loading rate (MLR), pH, and inlet B concentrations, are thoroughly reviewed. Based on the compiled data, the recommended operating conditions to optimize B removal in CWs include an HRT of 10 to 14 days, a pH range between 6 and 10, inlet B concentrations below 20 mg/L, and a mass loading rate under 3000 mg/m2 per day.