Study on removal effect of methylene blue and Cd2+ with adsorption of recycled activated carbon by microwave irradiation
微波辐射回用活性炭对水中亚甲基蓝和Cd2+去除效果的研究

An integrated granular activated carbon (GAC) adsorption/microwave (MW) irradiation process was investigated for the removal of methylene blue (MB) or/and Cd2+ from aqueous solution. The decoloration efficiency of 100 mL MB solution (1 000 mg/L) by 10 g new GAC was 99.99%. Under the conditions of MW power of 700 W and radiation time of 10 min, the saturated GAC was regenerated by MW irradiation, and being reused for adsorption. The GAC was reused and regenerated by MW irradiation for ten times, the decoloration efficiency of the tenth time regenerated GAC was 99.68%. Without MW irradiation, the decoloration efficiency of GAC was 85.41% at the tenth time. The results showed that microwave irradiation process could efficiently reduce the descent of adsorption capacity of GAC which lead to effective regeneration and reuse. The existence of Cd2+ caused a little decrease of GAC adsorption to MB, while the existence of MB enhanced the adsorption of Cd2+ on GAC. It was also demonstrated that the adsorption of MB on GAC was related to physical properties and that of Cd2+ was related to chemical properties.