Residual effect of biochar from bamboo (Gigantochloa) on the growth of Tithonia diversifolia as a phytoaccumulator of mercury on ex-gold mining soilIrwan Darfis, Amsar Maulana, Aprisal, Dewi Rezki, Susilawati Kasim and HerviyantiE3S Web Conf., 677 (2025) 08005DOI: https://doi.org/10.1051/e3sconf/202567708005