Performance evaluation of Fe-loaded regenerated activated carbon prepared from waste mercuric chloride catalysts

In this paper, the waste mercuric chloride catalysts (WMCC) were successfully recycled and then modified by ferrum (Fe) loading. Various analysis techniques were used to study the reaction mechanism of Fe loading modified regenerated activated carbon (RAC). Results show that the absorbed organic matter is the main reason causing the WMCC inactivation and it will thoroughly decompose beyond 334 °C. With assistance of microwave energy, the WMCC can be activated by roasting at 500 °C for 30 min. At this moment, the base material of the RAC still maintained the graphite structure. The experimental results of the adsorption performance of Fe-loaded RAC that prepared from different Fe loading additions on arsenic (As) in arsenic-containing wastewater show that: the Fe-loaded RAC with Fe loading addition of 12.51 wt% has a maximum As (V) removal efficiency of 86.76%. The main phase composition of the Fe-loaded RAC is Fe2O3 and Fe3O4, and its defect density is the largest, which is considered to be the main reason for the effective adsorption of As (V).