Mn/Ti-doped carbon xerogel for efficient catalysis of microcystin-LR degradation in the water surface discharge plasma reactor.

The novel catalysts of Mn/Ti-doped carbon xerogel (CX) were synthesized for efficient degradation of microcystin-LR (MC-LR) in the water surface discharge plasma reactor. The degradation efficiency of 79.7% was obtained in 6 min with 0.5 wt% Ti impregnation of CX, and it would be increased with higher amount of Ti. In particular, Mn-doped CX resulted in larger mesoporous particle diameter and higher porosity in the matrix, and thereby, the highest efficiency of 88.6% was achieved for CX-Ti-Mn. The possible degradation pathway of MC-LR was elucidated on the basis of the LC-MS analysis. It demonstrated that Adda chain was cleaved from the MC-LR cyclic peptide by OH radical attack after plasma discharge in the presence of catalysts, and the generated nontoxic products can be further easily degraded in the biological treatment. Therefore, Mn/Ti-doped carbon xerogel is promising as the catalyst for the improvement of MC-LR degradation in the water surface discharge plasma reactor.