Simultaneous removal of carbonate and denitrification of water - using calcium hydroxide as precipitant and biomass, supported on pptd. calcium carbonate, as denitrifying agent

摘要

In the removal of carbonate and the denitrification of water, the water is simultaneously freed from carbonate by action of Ca(OH)2 as precipitant, and denitrified by a biomass, with addn. of nutrients: the CaCO3 pptd. during removal of carbonate is used as support for the biomass. The nutrient for the biomass is ethanol or acetic acid. A suspended, and pref. stirred, bed forms in the concn. of the pptd. CaCO3, or CaCO3 sludge token from the upper end of the reactor may be recycled to the bottom of the reactor. A flocculation and/or sedimentation stage, pref. several flocculation stages, with a concentrator, may follow the reactor, with addn. of flocculating agents and aids. CaCO3 sludge is taken from the concentrator and recycled to the reactor.