Dead-end forward osmosis as an alternative for deep sludge dewatering: Evaluation method and characteristics analysis

•Dead-end forward osmosis (DEFO) technology was verified for deep sludge dewatering.•An evaluation model including DEFO sludge dewatering characteristics was proposed.•Dewatering process proceeded regardless of whether the filter cake broke.•DEFO filter cake showed an unusually dense upper and loose lower structure.