Gypsum-integrated, goethite-modified biochar enhances Cd and As immobilization in contaminated paddy soil under contrasting redox conditions - Iftikhar Ali Ahmad; Muhammad Mehran; Sharjeel Haider; Zaryab Murad; Md. Shoffikul Islam; Qingling Fu; Jun Zhu; Hongqing Hu (Environmental Geochemistry and Health, 2026)