respectively; (d) a wastewater discharge subject to regulation by the Clean Water
Act (CWA) and the hazardous waste mixed with the small loss of discarded
commercial chemical products or intermediaries used as raw materials in
manufacturing or produced as by-products; (e) a wastewater discharge subject
to regulation by the Clean Water Act (CWA) and the hazardous waste mixed with
a laboratory wastewater containing small amounts of listed toxic wastes; (f) a
wastewater discharge subject to regulation by the Clean Water Act (CWA) and
the hazardous waste mixed with the heat exchanger bundle cleaning sludge
(petroleum refining industry).
Multiple hearth furnace incinerator Sludge passes downward through a series of
hearths. Dewatered sludge cake or small solid wastes are fed to the top hearths. In
the upper hearths, the water content is vaporized and the sludge or solid wastes
are dried. In the middle hearths, the sludge or solid wastes are ignited and burned.
In the lower hearths, the slow-burning materials is continuously burned, and the
ash undergoes cooling.
Municipal solid waste (MSW) Residential solid waste and some non-hazardous
commercial, institutional, and industrial wastes. This material is generally sent to
municipal landfills for disposal.
Natural gas Underground deposits of gases consisting of 50 to 90 percent methane
(CH 4 ) and small amounts of heavier gaseous hydrocarbon compounds such as
propane (C 3 H 8 ) and butane (C 4 H 10 ).
Natural resources These resources naturally exist, such as surface water, groundwater, ice, snow, air, plants, animals, minerals, metals, soils, rocks, oils, underground gases, light, winds, radiation, etc. that are useful or potentially useful.
Uses of natural resources include agricultural, industrial, household, recreational
and environmental activities.
Natural variability Variations in the mean state and other statistics (such as
standard deviations or statistics of extremes) of the climate on all time and
space scales beyond that of individual weather events. Natural variations in
climate over time are caused by internal processes of the climate system as well
as changes in external influences, such as volcanic activity and variations in the
output of the sun.
Nectar flow (a) It is a time of harvest when nectar is plentiful and bees produce and
store surplus honey; also called honey flow. (b) It is called honey flow which is a
time when nectar is plentiful and bees produce and store surplus honey.
NGO It is a Nongovernmental Organization. Any nonprofit, voluntary citizens’
organization which can be organized at a local, national or international level.
Nitrate (NO 3 ) An oxygenated form of nitrogen.
Nitrification It is a biological process by which ammonia in wastewater is
converted by Nitrosomonas and Nitrobacter to nitrite, then to nitrate in the
presence of oxygen. The biological reactions involved in these conversions
may take place during activated sludge treatment, or a separate stage following
removal of carbonaceous materials. Separate stage nitrification may be accomplished via suspended growth or attached growth unit processes. In either case,
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M.-H. S. Wang and L. K. Wang
Act (CWA) and the hazardous waste mixed with the small loss of discarded
commercial chemical products or intermediaries used as raw materials in
manufacturing or produced as by-products; (e) a wastewater discharge subject
to regulation by the Clean Water Act (CWA) and the hazardous waste mixed with
a laboratory wastewater containing small amounts of listed toxic wastes; (f) a
wastewater discharge subject to regulation by the Clean Water Act (CWA) and
the hazardous waste mixed with the heat exchanger bundle cleaning sludge
(petroleum refining industry).
Multiple hearth furnace incinerator Sludge passes downward through a series of
hearths. Dewatered sludge cake or small solid wastes are fed to the top hearths. In
the upper hearths, the water content is vaporized and the sludge or solid wastes
are dried. In the middle hearths, the sludge or solid wastes are ignited and burned.
In the lower hearths, the slow-burning materials is continuously burned, and the
ash undergoes cooling.
Municipal solid waste (MSW) Residential solid waste and some non-hazardous
commercial, institutional, and industrial wastes. This material is generally sent to
municipal landfills for disposal.
Natural gas Underground deposits of gases consisting of 50 to 90 percent methane
(CH 4 ) and small amounts of heavier gaseous hydrocarbon compounds such as
propane (C 3 H 8 ) and butane (C 4 H 10 ).
Natural resources These resources naturally exist, such as surface water, groundwater, ice, snow, air, plants, animals, minerals, metals, soils, rocks, oils, underground gases, light, winds, radiation, etc. that are useful or potentially useful.
Uses of natural resources include agricultural, industrial, household, recreational
and environmental activities.
Natural variability Variations in the mean state and other statistics (such as
standard deviations or statistics of extremes) of the climate on all time and
space scales beyond that of individual weather events. Natural variations in
climate over time are caused by internal processes of the climate system as well
as changes in external influences, such as volcanic activity and variations in the
output of the sun.
Nectar flow (a) It is a time of harvest when nectar is plentiful and bees produce and
store surplus honey; also called honey flow. (b) It is called honey flow which is a
time when nectar is plentiful and bees produce and store surplus honey.
NGO It is a Nongovernmental Organization. Any nonprofit, voluntary citizens’
organization which can be organized at a local, national or international level.
Nitrate (NO 3 ) An oxygenated form of nitrogen.
Nitrification It is a biological process by which ammonia in wastewater is
converted by Nitrosomonas and Nitrobacter to nitrite, then to nitrate in the
presence of oxygen. The biological reactions involved in these conversions
may take place during activated sludge treatment, or a separate stage following
removal of carbonaceous materials. Separate stage nitrification may be accomplished via suspended growth or attached growth unit processes. In either case,
466
M.-H. S. Wang and L. K. Wang