Exam 3

BOD

CHON+O2→H20+CO2+more bugs+NH3, direct measure of O2 utilized, indirect measure of biodegradable organic matter

SMOG

VOCs+NOx+O3+light→aerosol particulate materials

Acid rain

SO2+O3+H2O→H2SO4

Dewatering of biosolids

Mechanical/physical removal of H2O

Nitrification

NH3+O2→NO3+H2O+H+, converts ammonia to less toxic forms, electron acceptor: O2, electron donor: NH3

Denitrification

CHON+NO3→N2(gas)+CO2, reduces nitrate in soils and aquatic systems which can lead to eutrophication

Eutrophication

Excessive growth of algae and aquatic plants which leads to an increase in BOD resulting in death of aquatic life

Aerobic biofilm process

Uses a thin layer of microorganisms to remove pollutants from wastewater, O2 diffuses into film

Anaerobic digestion

Destroys solids and pathogens, helps thicken sludge

Facultative lagoon

Aerobic+anaerobic biological treatment, destroys BOD and solids

Septic system

Anaerobic, biologic and settling

Sequencing batch reactor (SBR)

Aerobic, TSS, BOD, NH3 treated in activated sludge processes

Anaerobic sludge digestion

Biosolids→CH4+CO2

Biological phosphorous removal

Anoxic/anaerobic, uses microorganisms to remove P from wastewater

NPDES

BOD, TSS, pH

Methanogenesis

Hydrolysis: organic matter broken down to carbs, sugars

Acidogensis: further broken down to acids

Methanogenesis: molecules converted to methane (CH4) and CO2

PM 2.5

Particulate matter with diameter < 2.5 micrometer, can penetrate into lungs

SOx

Sulfur oxides, harmful air pollutant, SMOG, acid rain

How can anaerobic treatment lower pH?

During the process, the microorganisms produce organic acids which can lower the pH of wastewater

Ozone

Good in stratosphere because it blocks UV, bad in troposphere because it is a harmful air pollutant

Adiabatic lapse rate

Air temperature decreases with altitude

Inversion

The temperature at some elevation starts to increase with elevation, therefore as the pollutant rises then cools it becomes denser than the surrounding air

Thickening

Removing water to create a more concentrated solid material

Dewatering

Further removal of water using mechanical equipment

Digestion

Breaking down organic matter via anaerobic digestion