Evaluation of direct water reclamation from municipal wastewater by disk tube reverse osmosis membrane (DT-RO) based compact process

Water reclamation from wastewater treatment plants (WWTPs) with small footprint is required for sustainable water management in areas where the land resources available for building WWTPs are limited, for example, developing countries under rapid urbanization. Different from current water reclamation process (conventional activated sludge + reverse osmosis) with long procedures, a concept of compact municipal wastewater treatment process based on disk tube reverse osmosis (DT-RO) for direct water reclamation was proposed and initially evaluated with actual wastewater in this study. Flux of 35.6 LMH under operation pressure of 25-28 bar was achieved with water recovery of 90%. With a simpler pretreatment procedure, it is feasible to achieve high water quality satisfying even the most stringent national municipal wastewater discharge standard in China. The proposed process demonstrated advantages on better energy efficiency for its compact design with limited pretreatment and avoiding destroying organics by energy-intensive aerated biological treatment. Organic matters and nutrients (nitrogen and phosphorus) were concentrated in the retentate, which could perform as pre-concentration for next step recovery. The proposed concept provided an alternative option for water reclamation by compact DT-RO process with high energy efficiency and potentials for resource recovery.