MBR and Sludge glossary (H)

Herreshoff furnace
Another name for a multiple hearth furnace

HF
Hollow fibre (membrane)

HFRB
Hair and Fibre Reinforced Biomass

Horizontal disc dryers
A type of conductive dryer based on externally heated discs or rings rotating in the sludge solids

HPSEC
High performance size exclusion chromatography

HRT
Hydraulic retention time

HVAC
Heat, ventilation and air conditioning

Hydraulic loading rate HLR
Amount of water fed into a process per process unit cross-sectional area per unit time

Hydraulic resistance
Resistance to flow resulting from water flowing through a porous medium

Hydraulic retention time HRT
Retention time of the liquid in a vessel

Hydro-pyrolysis
Thermochemical treatment in the absence of water at elevated hydrogen pressures intended to favour the formation of biogas as the primary product

Hydrochar
Solid charcoal-like product generated from non-oxidative thermochemical processes in the presence of water

Hydrogenotrophic bacteria
Bacteria which feed off hydrogen

Hydrolysis
Reaction with water to break down large organic molecules into smaller, generally more biodegradable ones

Hydrothermal carbonisation HTC
Low-temperature thermochemical treatment in the presence of water and absence of air favouring the formation of biochar as the primary product

Hydrothermal gasification HTG
High-temperature thermochemical treatment in the presence of water and absence of air favouring the formation of bio-oil as the primary product

Hydrothermal liquefaction HTL
Intemediate-temperature thermochemical treatment in the presence of water and absence of air favouring the formation of gas (syngas) as the primary product

Hydrothermal processes HTP
Thermochemical treatment in the presence of water and absence of air