Process terms
AnSU- Anaerobic Tank Sludge Units (lb TSS in Anaerobic selector)
ASU- Activated Sludge Unit or Aerated Sludge Units (lb TSS in aeration tank)
A-Tank- Aeration tank
ATC- Aeration Tank concentration (MLSS % by spin)
AxSU- Anoxic Sludge Units (lb TSS in Anoxic selector)
BLT- Clarifier blanket thickness
BNR- Biological Nutrient Removal
BOD5- 5-day Biological Oxygen Demand (mg/L)
BPR- Biological Phosphorus Removal
CBOD- Carbonaceous BOD5 (mg/L)
COD- Chemical Oxygen Demand
CSC- Clarifier Solids concentration (core sample- average solids in entire clarifier)
CSU- Clarifier Sludge Units (lb TSS in Clarifier)
D/M- Divalent/ Monovalent ratio
DN- Denitrification
D.O- Dissolved Oxygen (mg/L)
ESU- Effluent Sludge Units (lb solids wasted in the effluent)
F/M- Food to Microorganism ratio (lb BOD removed/ lb MLVSS in system)
Ft- Foot or Feet
FTU- Formazine Turbidity Units
g- Gram
Gal- Gallon
h- Hour
L- Liter
lb- Pound
MCRT- Mean Cell Residence Time
Meq- Millequivalent
mg- Milligram
mg/L- Milligrams per liter
MG- Million gallons
MGD- Million Gallons per day
MLSS- Mixed Liquor Suspended Solids (mg/L)
Min- Minute
mL- Milliliter
MLVSS- Mixed Liquor Volatile Suspend Solids
mV- Millivolt
MW- Molecular Weight
Um- Micrometer or Micron (1/1,000,000 meters or .00004 inches) Human blood cell 5 micron
N/DN- Nitrification/ Denitrification
ORP- Oxidation Reduction Potential (mV)
OUR- Oxygen Uptake Rate (mg/O2/L/min)
PAO- Phosphorus Accumulating Organism
Q- Influent flowrate (MGD)
RAS- Return Activated Sludge
RASS- Return Activated Sludge Solids (mg/L)
RSF- Return Sludge Flow (MGD)
RSC- Return Sludge Concentration (mg/L)
RSU- Return Sludge Units (lb TSS returned to the process from the clarifier)
SAC- Clarifier Surface Area (ft2)
SBOD5- Soluble BOD5 (mg/L)
SDR- Solids Distribution Ratio (ratio of ASU to CSU include AX and AN solids)
SDTA- Solids Detention Time in Aerator (hours)
SDTAN- Solids Detention Time in Anerobic Selector (hours)
SDTAX- Solids Detention Time in the Anoxic Selector (hours)
SDTC- Solids Detention Time in the Clarifier (hours)
SL- Space Loading (lb BOD/103ft3 of biological reactor Volume)
SLR- Solids Loading Rate in the Clarifier (lb/ft2/day)
SOR-Surface Overflow rate in the clarifier (gal/ft2/day)
SOUR- Specific Oxygen Uptake Rate (mg O2/hr/g MLVSS in the system)
SS- Suspended Solids
SSCt- Settled Sludge Concentration calculated from the settleometer test at settling time (mg/L)
SSVt – Settled Sludge Volume in settleometer at Time (ml)
Substrate- Food
SVI- Sludge Volume Index (mL/g)
TKN- Total Kjeldahl Nitrogen (mg/L, NH3 + organic nitrogen)
TSS- Total Suspended Solids (mg/L)
TSU- Total Sludge Units (lb TSS in system, ASU +AnSU + AxSU + CSU)
TWU- Total Waste Units (lb/day, WSU + ESU)
VolA- Volume of Aeration Tank (MG)
VolAn- Volume of Anaerobic Selector (MG)
VolAx- Volume of Anoxic Selector (MG)
VolC- Volume of Clarifier (MG)
WAS- Waste Activated Sludge
WCR- Weight to Concentration Ratio (MLSS/ATC. mg/L% by spin)
WSC- Waste Sludge Concentration (mg/L)
WSF- Waste Sludge Flow Rate (MGD)
WSU- Waste Sludge Units (lb/day)

Microscope Terms

Eyepiece- Usually a 10x magnification that you look thru
Objectives- Magnifying part usually 4x, 20x, 10x, 40x, 100x (multiply by eyepiece for total)
Stage- Where the slide is placed for viewing
Phase Condenser- This focuses the light and necessary for Phase contrast viewing
Course Focus Knob- Moves the stage up and down further per turn
Fine Focus Knob- Moves the stage in minor increments
Light Source- Multiple scopes will have halogen bulbs or LED lights
Binocular- Two eyepieces similar to Binoculars
Trinocular- Binocular with the addition of a port for a camera

Protozoa and Metazoa Terms
▪ Anterior- front part of the cell
▪ Bacterivore- eats bacteria
▪ Buccal- relates to the mouth structure
▪ Cyst- body enclosed in extracellular lorica
▪ Cytoplasm- the matter that makes up cells
▪ Cytostome- the “mouth”
▪ Daughter cells- product of cell division
▪ Diffusion feeding-predator relies on the prey to make contact-(ex. Suctoria)
▪ Detritus- dead plant and animal material
▪ Encyst- to change from active to cyst form
▪ Eukaryotic- cells with nuclei and other membranous organelles
▪ Extracellular- outside the cell
▪ Extrusomes-organelle to catch, kill or protect
▪ Flagellum- filamentous structure used for motion
▪ Heliozoan- a protist with stiff radiating arms
▪ Heterotrophic- a mode of nutrition with which the organism uses molecules
created by another organism
▪ Intracellular- inside the cell
▪ Lorica-organic or inorganic casing or shell
▪ Mastax- grinding structure behind the mouth of rotifers
▪ Meiosis-two cells combine (sexual reproduction)
▪ Mitosis-nucleus of a cell divides to create two new nuclei
▪ Nucleus-an organelle where most of the DNA is located
▪ Omnivore-eats bacteria, plant, other ciliates
▪ Organelle-a structure found inside eukaryotic cells
▪ Peristome-the area around the mouth
▪ Phagocytosis-ingest food particles and enclose them with membrane to form
food vacuoles
▪ Polysaccharide-a molecule composed of many sugar molecules. Includes
cellulose and starch
▪ Prokaryotic-cells without nucleus-bacteria
▪ Pinocytosis-ingesting material by enclosing it within a membrane

▪ Raptorial-organism moves around for food
▪ Sessile-organisms that are fixed to a substrate. Stalk or lorica
▪ Spasmoneme-contractile element in stalk
▪ Suspension feeding-feeding on suspended particles-stalk ciliates
▪ Test-a rigid shell around an organism
▪ Trophic-organisms that are active and feeding
▪ Vacuole-a cavity in the cell enclosed by a membrane (ex. food and expulsion)