SELO, Single ELODE is a compact second stage dehydrator uses Electro-Osmosis method to further dehydrate the treated sludge cake from conventional dehydrators, to a higher dryness and significant reduction in sludge weight. It can be easily integrated into any of the existing conventional dehydrator such as belt-press, filter press, decanter, gravity dehydration etc. The sludge shall be treated to or below 95wt% by conventional dehydrators before it can be treated by SELO.