Enhancing Volatile Solids Reduction by Application of Sludge Ozonation using the Lyso? Process to Aerobic Digesters

摘要

Ozonation of a recirculated stream from an aerobic digester has been employed to reduce volatilernsolids. The Praxair Lyso? process, which utilizes plug flow principles for the ozone – sludgernlysis reaction was used as the Ozone contactor. Sludge drawn from the aerobic digester isrncirculated through the Lyso? where the sludge and ozone are contacted. Plug flow operationsrnminimizes excessive ozone consumption by enhancing the selectivity of ozone for cell lysisrnrather than random COD oxidation. Sludge ozonation enabled up to 80% sludge reduction withrnless than 10 days of HRT in the digester, indicating significant enhancement of Volatile SolidsrnReduction (VSR). The specific ozone utilization values obtained during the tests ranged fromrn0.01-0.03 kg O3/kg SS removed. This specific ozone consumption value is about an order ofrnmagnitude lower than alternative sludge ozonation concepts.rnWe develop a conceptual model of sludge ozonation process using the GPS-X? processrnmodeling software platform. A simplified metric for reporting ozone effectiveness rates in sludgernozonation processes is proposed.