A Pilot Trial of Sani Process for Saline Sewage Treatment

A novel Sulfate reduction Autotrophic denitrification and Nitrification Integrated (SANI) process has been recently developed by the Hong Kong University of Science and Technology in partnership of Delft University of Technology. This novel process can remove COD through sulfate reduction and nitrate through autotrophic denitrification using produced sulfide. After a 500-day lab-scale trial, we have recently conducted a pilot trial of 10 m3/day using de-gritted saline sewage in Tung Chung, Hong Kong. The SANI pilot plant confirmed the excellent performance of the SANI process, achieving 85% removal of both TSS and COD. No elemental sulfur accumulated in the plant and no sludge was wasted during the entire trial period of around 210 days. The ORP and UVT254 of the plant effluent were +200 mV and 75%, enabling effective ultraviolet disinfection and a good control of sewage septicity.