MBR and Sludge glossary (D)

Da
Dalton

DE
Dead-end (or full flow)

Decanter/Decanting centrifuge
Alternative term for solid bowl centrifuge

Denitrification
Biochemical conversion of nitrate to nitrogen gas

Denitritation
Biochemical conversion of nitrite to nitrogen gas

Dewatering
Removal of water from sludge to generate a non-flowing solids product (or 'cake')

Diaphragm/membrane press
Modification of filter press providing enhanced pressure by using an inflatable diaphragm in the filter cells

Differential velocity
Difference in the rotational velocities of the screw conveyor and bowl of a centrifuge

Digestate
Residual solids, normally as a 20% solids slurry, from anaerobic digestion (AD)

Disc nozzle centrifuge
Centrifuge based on a series of stacked inverted cones

Dissolved air flotation DAF
Thickening process using precipitated air to encourage flotable suspended solids to rise to the tank surface, where they are removed by skimming

Dissolved carbon
Concentration of dissolved carbon in mg/L

Dissolved oxygen concentration DOC
Concentration of dissolved oxygen in mg/L

DMBR
Diffusion membrane bioreactor

DO
Dissolved oxygen

DOC
Dissolved organic carbon

Drainability
Extent/rate of draining of water from settled sludge solids

Drum filter/screen
Cylindrical screen of a screw press through which filtrate passes

Dry carbonisation
Carbonisation (sludge thermochemical treatment favouring the formation of the solid phase as the primary production) in the absence of water

Dry solids DS
Solids content of sludge either as a percentage or in units of mass per unit volume

Dry thermochemical methods
Thermochemical treatment in the absence of water, normally comprising incineration, pyrolysis and gasification

Drying bed
Shallow beds with a porous base used to dewater sludge by draining

DS
Dry solids