Abstract: An electrodialysis cell (40) suitable for removal of paint solubilizer from electrocoat paint ultrafilter permeate includes a tubular, non-conductive housing (42), a substantially cylindrical, hollow object electrode (48) in the housing, a substantially cylindrical counter electrode (52) situated within the hollow object electrode, and a tubular ion exchange membrane (50) around the counter electrode but spaced from the counter electrode as well as the object electrode. The counter electrode and the tubular membrane together define an annular electrolyte passageway while the object electrode and the tubular membrane together define an annular ultrafilter permeate passageway. The object electrode-to-counter electrode area ratio is at least about 6.

Abstract: An electrodialysis cell (40) suitable for removal of paint solubilizer from electrocoat paint ultrafilter permeate includes a tubular, non-conductive housing (42), a substantially cylindrical, hollow object electrode (48) in the housing, a substantially cylindrical counter electrode (52) situated within the hollow object electrode, and a tubular ion exchange membrane (50) around the counter electrode but spaced from the counter electrode as well as the object electrode. The counter electrode and the tubular membrane together define an annular electrolyte passageway while the object electrode and the tubular membrane together define an annular ultrafilter permeate passageway. The object electrode-to-counter electrode area ratio is at least about 6.

Abstract: A flue gas desulfurization method for efficiently removing sulfur oxides from a gas stream with an aqueous sodium sulfite- and sodium bisulfite-containing absorption solution, in which absorber effluent solution at a pH of from 5.8 to 6.6 and having an active sodium concentration of from 0.5 M to 0.9 M is regenerated with sufficient ground limestone to yield a treated solution with a higher pH of from 6.3 to 7.0 and whose bisulfite concentration is reduced by from 35 to 70%.