Control of wet scrubber oxidation inhibitor and byproduct recovery

A system, comprising:

• an input to receive a waste gas comprising an acid gas and iodine;
• a wet scrubber to treat the waste gas to remove at least a portion of the acid gas and the iodine from the waste gas and form a scrubbing solution comprising at least one of an acid derived from the acid gas and a derivative thereof and iodine;
• and
• a carbonaceous material to remove, from the scrubbing solution, at least a portion of the iodine, thereby reducing a concentration of iodine in the scrubbing solution.

A system, comprising:

• a thermal unit to combust a mercury-containing feed material and produce a mercury-containing gas stream, wherein the mercury-containing feed material comprises a halogen or halogenated compound and the mercury-containing gas stream comprises the halogen or halogenated compound, an acid gas, and particulates;
• a particulate removal device to remove most of the particulates from the mercury-containing gas stream and form a treated gas stream;
• a wet scrubber to contact the treated gas stream with a scrubber solution and remove the acid gas from the treated gas stream and in a scrubber slurry, the scrubber slurry comprising the halogen or halogenated compound;
• and
• a regeneration facility comprising a carbonaceous material to remove the halogen or halogenated compound from at least part of the scrubber slurry and form a halogen-containing carbonaceous material for recycle to the thermal unit.