Ball-milling enhanced iron-loaded biochar from biomass gasification ash in fluidized bed for wastewater Cr(VI) adsorption - Mingjie Xiong; Guanshuai Zhang; Chen Yang; Zhenming Li; Jieyu Lei; Zhenjie Sun; Chen Wang; Nawal Al-Muntaser; Zhongren Ba; Feiqiang Guo; Zhijie Fu (Journal of Water Process Engineering, 2026)