BIOM-360 Lecture Notes - Lecture 21: Chemical Oxygen Demand, Biochemical Oxygen Demand, Fecal Coliform
2 May 2018
School
Department
Course
Professor
Wastewater Treatment Maintains Human and Environmental Health
G.I. tract is always at a nice, warm temperature. Coliforms and fecal coliforms.
Wastewater Treatment Processes: Primary and Secondary
Primary
Removes solid material and forms sludge (physical materials that precip. out)
Now moving into secondary step of treatment
Secondary
Dissolved organic matter transformed into microbial biomass and CO2
Forms stable floc - settles well.
Want to go after stable floc
Something that precipitates well and goes straight to the bottom.
Bulking sludge - does not settle properly.
Activated sludge system
Horizontal flow of materials with recycling of sludge.
Horizontal movement to obtain particulate precipitate.
Anaerobic Digestion
Often sludges from aerobic sewage treatment,
together w/ materials settled out in 1o
treatment, are further treated by anaerobic
digestion.
Reduces the amount of sludge for disposal
Produces methane
Wastewater Treatment Processes: Last Steps
Tertiary
Removal of nitrogen and phosphorus that may promote eutrophication
Removes heavy metals, biodegradable organics, and remaining microbes
Constructed wetlands
Employed in treatment of liquid wastes and for bioremediation
Measuring Water Quality
Testing often a measurement of carbon removal
TOC levels
Total Organic Carbon
COD test
Chemical Oxygen Demand
BOD test
Biochemical Oxygen Demand
Document Summary
G. i. tract is always at a nice, warm temperature. Removes solid material and forms sludge (physical materials that precip. out) Dissolved organic matter transformed into microbial biomass and co 2. Something that precipitates well and goes straight to the bottom. Horizontal flow of materials with recycling of sludge. Often sludges from aerobic sewage treatment, together w/ materials settled out in 1 o treatment, are further treated by anaerobic digestion. Removal of nitrogen and phosphorus that may promote eutrophication. Removes heavy metals, biodegradable organics, and remaining microbes. Employed in treatment of liquid wastes and for bioremediation. Do not measure nitrate, phosphate, or sulfate levels (algal growth contributors). Groundwater (water in gravel beds below surface soil) Microbiological processes in groundwater are not well understood. Bioreactors: microbes change stored chemical energy in organic matter to electricity. Continuously feed a rich diet of organic substrates. Protons diffuse across the membrane and are deposited on anode.
