Removal of Hg⁰ from flue gas using two homogeneous photo‐fenton‐like reactions

Abstract

Removal of Hg 0 using two homogeneous Photo‐Fenton‐Like reactions was first investigated in a photochemical reactor. Effects of process parameters on Hg 0 removal were studied. Free radical and reaction products were analyzed. Removal pathways of Hg 0 were discussed. Simultaneous removal of Hg 0 , NO, and SO 2 is also studied briefly. The results show that UV power, wavelength, H 2 O 2 concentration, and solution pH have great effects on Hg 0 removal. Hg 0 , and SO 2 concentrations, solution temperature, Fe 3+ , Cu 2+ , , and concentrations also have significant effects on Hg 0 removal. However, concentrations of CO 2 , NO, O 2 , Cl − , , , SiO 2 , Al 2 O 3 , and Fe 2 O 3 only have slight effects on Hg 0 removal. Hg 0 /NO/SO 2 can be simultaneously removed by Photo‐Fenton‐Like reactions. ·OH was captured, and / /Hg 2+ were also detected. Removals of Hg 0 by photochemical oxidation and ·OH oxidation play a major role, and removal of Hg 0 by H 2 O 2 oxidation only plays a secondary role in removal of Hg 0 . © 2015 American Institute of Chemical Engineers AIChE J , 61: 1322–1333, 2015