Formation of iron plaque on mangrove roots receiving wastewater and its role in immobilization of wastewater-borne pollutants

► Fe plaque formed increased with wastewater discharge, the stronger the wastewater, the more the Fe plaque. ► Fe plaque acted as a reservoir to immobilize eight trace metals and phosphorus. ► Fe plaque had more effect on the immobilization of wastewater-borne Ni, Pb, Cr and P. ► B. gymnorrhiza was the best one for wastewater treatment, followed by E. agallocha, A. ilicifolius was the worst one.