Grit: It includes sand, gravel, cinders, coffee grounds, small stones, cigarette filter
tips, and other large-sized unwanted materials in wastewater.
Head loss: It is an indirect measure of loss of energy or pressure of flowing water. It
is measured as the difference in elevation between the upstream water surface and
the downstream water surface.
Heterotrophic: Microorganisms that use organic matter (carbon) for energy and
growth and can grow in both aerobic and anoxic environments using both
dissolved and chemically bound oxygen (nitrates).
Hydraulic retention time (HRT): The given time it takes wastewater, including
any return flows, to pass through a certain area.
Hypochlorination: Application of sodium hypochlorite (liquid) for disinfection is
also called hypochlorination. It achieves the same result as that of chlorination
using chlorine gas. Its use is generally limited to smaller water or wastewater
treatment facilities or where there are significant health and safety concerns
regarding the handling and use of chlorine gas.
Incineration: It is dry combustion of sludge or solid wastes to produce an inert ash.
This ash can then be beneficially used or disposed of in a sanitary landfill. The
process must dry the sludge cake or small solid wastes, destroy the volatile
content by burning, and finally produce a sterile ash. A variety of incinerator
configurations exist. The most common include (a) multiple hearth furnace
incinerator and (b) fluidized bed incinerator.
Innovative biological wastewater treatment system: It normally includes
(a) preliminary treatment units (i.e., screen, comminutor, grit chamber, etc. for
the removal of sand, gravel, cinders, coffee grounds, small stones, cigarette filter
tips, logs, cans, and other large-sized unwanted materials from raw wastewater),
(b) primary flotation clarification for removing mainly total suspended solids
from preliminary effluent, (c) secondary biological treatment units (such as
activated sludge aeration or equivalent plus secondary flotation clarification) for
removing dissolved organic/inorganic pollutants from primary effluent, and
(d) tertiary treatment plant units (i.e., filtration, granular activated carbon adsorption, ion exchange, oxidation, nitrification, denitrification, and/or disinfection) for
final polishing the secondary effluent in order to meet the effluent discharge
standards.
Innovative physicochemical flotation wastewater treatment system: It includes
(a) preliminary treatment units (i.e., screen, comminutor, grit chamber, etc. for the
removal of sand, gravel, cinders, coffee grounds, small stones, cigarette filter tips,
logs, cans, and other large-sized unwanted materials from raw wastewater),
(b) primary flotation clarification for removing mainly total suspended solids
from preliminary effluent, (c) secondary physicochemical treatment units (such as
chemical precipitation/coagulation or equivalent plus secondary flotation clarification) for removing dissolved organic/inorganic pollutants from primary effluent, and (d) tertiary treatment plant units (i.e., filtration, granular activated carbon
adsorption, ion exchange, oxidation, nitrification, denitrification, and/or disinfection) for final polishing the secondary effluent in order to meet the effluent
3 Biological Processes
147
tips, and other large-sized unwanted materials in wastewater.
Head loss: It is an indirect measure of loss of energy or pressure of flowing water. It
is measured as the difference in elevation between the upstream water surface and
the downstream water surface.
Heterotrophic: Microorganisms that use organic matter (carbon) for energy and
growth and can grow in both aerobic and anoxic environments using both
dissolved and chemically bound oxygen (nitrates).
Hydraulic retention time (HRT): The given time it takes wastewater, including
any return flows, to pass through a certain area.
Hypochlorination: Application of sodium hypochlorite (liquid) for disinfection is
also called hypochlorination. It achieves the same result as that of chlorination
using chlorine gas. Its use is generally limited to smaller water or wastewater
treatment facilities or where there are significant health and safety concerns
regarding the handling and use of chlorine gas.
Incineration: It is dry combustion of sludge or solid wastes to produce an inert ash.
This ash can then be beneficially used or disposed of in a sanitary landfill. The
process must dry the sludge cake or small solid wastes, destroy the volatile
content by burning, and finally produce a sterile ash. A variety of incinerator
configurations exist. The most common include (a) multiple hearth furnace
incinerator and (b) fluidized bed incinerator.
Innovative biological wastewater treatment system: It normally includes
(a) preliminary treatment units (i.e., screen, comminutor, grit chamber, etc. for
the removal of sand, gravel, cinders, coffee grounds, small stones, cigarette filter
tips, logs, cans, and other large-sized unwanted materials from raw wastewater),
(b) primary flotation clarification for removing mainly total suspended solids
from preliminary effluent, (c) secondary biological treatment units (such as
activated sludge aeration or equivalent plus secondary flotation clarification) for
removing dissolved organic/inorganic pollutants from primary effluent, and
(d) tertiary treatment plant units (i.e., filtration, granular activated carbon adsorption, ion exchange, oxidation, nitrification, denitrification, and/or disinfection) for
final polishing the secondary effluent in order to meet the effluent discharge
standards.
Innovative physicochemical flotation wastewater treatment system: It includes
(a) preliminary treatment units (i.e., screen, comminutor, grit chamber, etc. for the
removal of sand, gravel, cinders, coffee grounds, small stones, cigarette filter tips,
logs, cans, and other large-sized unwanted materials from raw wastewater),
(b) primary flotation clarification for removing mainly total suspended solids
from preliminary effluent, (c) secondary physicochemical treatment units (such as
chemical precipitation/coagulation or equivalent plus secondary flotation clarification) for removing dissolved organic/inorganic pollutants from primary effluent, and (d) tertiary treatment plant units (i.e., filtration, granular activated carbon
adsorption, ion exchange, oxidation, nitrification, denitrification, and/or disinfection) for final polishing the secondary effluent in order to meet the effluent
3 Biological Processes
147