Engineering Applications on Reclaimed Water Treatment and Reuse of Hotel's High Grade Gray Water

The design and operation of membrane bio-reactor (MBR) process treating hotel's high grade gray water were introduced. The main processes were hydrolysis and acidification, MBR and disinfection, through which the removal rates of BOD5, SS and NH3-N were above 90%. The effluent reached the requirements of Reclamation and Reuse of Urban Sewage: Quality of Urban Service Water (GB/T18920-2002), for road irrigating, greening and toilet flushing. The hydraulic retention time of reclaimed water tank was increased to 12h, which enhanced the utilization rate of the reclaimed water to 90%. The designed wastewater amount was 360m(3)/d. Every year, the saving water amount is 13.14 million tons, the net income is 693800 yuan and the static payback period is 1.3 years. The project reduces some pollutants and creates numerous economic benefits.