No abstract

Hg(II) ions in wastewater is highly toxic to the environment and human health, yet many materials exhibit lower adsorption efficiency, and few studies report the reutilization of Hg(II)-loaded waste materials. Here, a cheap and efficient adsorbent was prepared for removal of Hg(II) based on corn bract (CB) loading copper sulfide (CuS), and the Hg(II)-adsorbed material was reused as a photocatalyst. By changing the adsorption variables such as pH, adsorbent dosage, Hg(II) concentration, contact time and coexisted ions, the reasonable adsorption conditions were obtained. The study indicated the adsorption capacity and removal rate of CB/CuS reached 249.58 mg/g and 99.83% at pH 6 with 20 mg CB/CuS, 50 mL Hg(II) concentration (100 mg/L) and 60 min, and coexisting ions did not affect the uptake of Hg(II). The adsorption behavior of CB/CuS toward Hg(II) followed pseudo-second-order and Langmuir model with the theoretical maximum adsorption capacity of 316.46 mg/g. Finally, we have explored an alternative strategy to dispose spent adsorbents by converting the CB/CuS/HgS into a photocatalyst for degradation of rhodamine B with removal rate of 98%. Overall, this work not only develops a promising material for treatment of Hg(II)-containing wastewater, but opens a new approach for the value-added utilization of waste adsorbent.