| A |
Area |
| A2/O |
Anaerobic/anoxic/oxic |
| AC |
Alternating current |
| A/O |
Anoxic/oxic |
| ADF |
Average daily flow |
| AlCl3 |
Aluminum chloride |
| Al2(SO4)3 |
Aluminum sulfate |
| ASD |
Adjustable speed drives |
| ASM |
Activated sludge models |
| ASM2 |
Activated sludge models, second model |
| ASM3 |
Activated sludge models, third model |
| ATAD |
Autothermal thermophilic aerobic digestion |
| AST |
Activated sludge treatment |
| ATS |
Automatic transfer switch |
| Ax |
Anoxic |
| AxSF |
Anoxic step feed |
| B |
Y-axis intercept |
| BACT |
Best available control technology |
| BEPs |
Best efficiency points |
| BF/AS |
Biofilter/activated sludge |
| BFP |
Belt filter press |
| BioP |
Biological phosphorus |
| BMPs |
Best management practices |
| BNR |
Biological nutrient removal |
| BOD |
Biochemical oxygen demand |
| BOD5 |
Five-day biochemical oxygen demand |
| BOT |
build–own–transfer |
| BOOT |
build–own–operate–transfer |
| BPR |
Biological phosphorus removal |
| BrCl |
Bromine chloride |
| BTU |
British thermal unit |
| CH3COOH |
Acetic acid |
| C2H4O3 |
Peracetic acid |
| C |
Carbon |
| CAD |
Computer-aided design |
| CaO |
Calcium oxide |
| CaCO3 |
Calcium carbonate |
| Ca(OH2) |
Calcium hydroxide |
| Ca(OCl)2 · 4 H2O |
Calcium hypochlorite |
| CAS |
Conventional activated sludge |
| CBOD |
Carbonaceous biochemical oxygen demand |
| CBOD5 |
Five-day carbonaceous biochemical oxygen demand |
| CERCLA |
Comprehensive Environmental Response, Compensation, and Liability Act |
| CFD |
Computational fluid dynamics |
| CFR |
Code of Federal Regulations |
| CFU |
Colony forming units |
| CH4 |
Methane |
| Cl2 |
Chlorine |
| ClO2 |
Chlorine dioxide |
| CM |
Corrective maintenance |
| CMMS |
Computerized maintenance management systems |
| CMOM |
Capacity, management, operation, and maintenance |
| C:N |
carbon-to-nitrogen ratio |
| CPE |
Comprehensive performance evaluation |
| CPU |
Central processing unit |
| CO |
Carbon monoxide |
| CO2 |
Carbon dioxide |
| COD |
Chemical oxygen demand |
| CPR |
Cardiopulmonary resuscitation |
| CPVC |
Chlorinated polyvinyl chloride |
| CSO |
Combined sewer overflow |
| CST |
Capillary suction time |
| CSTR |
Completely stirred tank reactor |
| CT |
Contact time |
| CWA |
Clean Water Act |
| CWSRF |
Clean Water State Revolving Fund |
| D |
Diameter |
| D |
Dose |
| DAF |
Dissolved air flotation |
| dB |
Decibels |
| DBO |
Design–build–operate |
| DBP |
Disinfection byproduct |
| DC |
Direct current |
| DCS |
Distributed control systems |
| DDD |
dichlorodiphenyldichloroethane |
| DDE |
dichlorodiphenyldichloroethylene |
| DDT |
dichlorodiphenyltrichloroethane |
| DMR |
Discharge monitoring report |
| dN |
Denitrification |
| DNA |
Deoxyribonucleic acid |
| DO |
Dissolved oxygen |
| DOB |
Depth of blanket |
| E |
Efficiency |
| EBPR |
Enhanced biological phosphorus removal |
| ED50 |
Effective dose at the 50% level |
| EDMS |
Electronic document management system |
| EHS |
Extremely hazardous substances |
| EH&S |
Environmental Health and Safety |
| EM |
Electromotive force |
| EMP |
Energy management plan |
| EMS |
Environmental management system |
| EPAM |
Emulsion polyacrylamide |
| EPCRA |
Emergency Planning and Community Right-to-Know Act |
| EQ |
Exceptional quality |
| U.S. EPA |
U.S. Environmental Protection Agency |
| F:M |
Food-to-microorganism ratio |
| FAC |
Free available chlorine |
| Fe |
Iron |
| FeCl2 |
Ferrous chloride |
| FeCl3 |
Ferric chloride |
| FEMA |
Federal Emergency Management Agency |
| FF/SG |
Fixed-film and suspended growth processes |
| FOG |
Fats, oil, and grease |
| FR |
Federal Regulations |
| FRP |
Fiberglass-reinforced plastic |
| FSS |
Fixed suspended solids |
| FWA |
Flow-weighted average |
| GAC |
Granular activated carbon |
| GBT |
Gravity belt thickener |
| GC |
Gas chromatography |
| GFI |
Ground fault interrupter |
| GIS |
Geographic information system |
| GPS-X |
General purpose simulator |
| GS |
General service |
| H |
Head |
| H2 |
Hydrogen |
| HAZCOM |
Hazardous Communication Standard |
| H/O/A |
Hand-off-auto |
HCO3-2
|
Biocarbonate |
| H2CO3 |
Carbonic acid |
| H2O |
Water |
| H2O2 |
Hydrogen peroxide |
| H2SO4 |
Sulfuric acid |
| H2S |
Hydrogen sulfide |
| H3PO4 |
Phosphoric Acid |
| HCl |
Hydrochloric acid |
| HDPE |
High-density polyethylene |
| HGL |
Hydraulic grade line |
| HIV |
Human immunodeficiency virus |
| hL |
Headloss |
| HLR |
Hydraulic loading rate |
| HOBr |
Hypobromous acid |
| HOCl |
Hypochlorous acid |
| HP |
Horsepower |
| HPO |
High-purity oxygen |
| HRMS |
Human resources management system |
| HRT |
Hydraulic residence (retention) time |
| HVAC |
Heating, ventilation, and air conditioning |
| I |
Intensity of UV radiation |
| I&C |
Instrumentation and control |
| IFAS |
Integrated fixed-film activated sludge |
| IMLR |
Internal mixed-liquor recirculation |
| ISO |
International Organization for Standardization |
| ISV |
Initial settling velocity |
| IT |
Information technology |
| IUs |
Industrial users |
| k |
Rate constant |
| KMnO4 |
Potassium permanganate |
| KVAR |
Kilovar |
| LAN |
Local area network |
| LiCl |
Lithium chloride |
| LIF |
Laser-induced fluorescence |
| LC50 |
Lethal concentration at the 50% level |
| LDA |
Laser Doppler anemometry |
| LE |
Ludzack–Ettinger |
| LEL |
Lower explosivity limit |
| LIMS |
Laboratory information management systems |
| µ |
Biomass growth rate |
| m |
Slope of straight line |
| M |
Mass |
| MBRs |
Membrane bioreactors |
| MCCs |
Motor control center |
| MCRT |
Mean cell residence time |
| MgNH4PO4 |
Magnesium ammonium phosphate |
| MIS |
Management information system |
| ML |
Mixed liquor |
| mLE |
Modified Ludzack–Ettinger |
| MLR |
Mixed-liquor recycle |
| MLSS |
Mixed-liquor suspended solids |
| MLVSS |
Mixed-liquor volatile suspended solids |
| MMR |
Mumps, Measles, and Rubella |
| MPN |
Most probable number |
| MS |
Mass spectrometry |
| MSDS |
Material safety data sheet |
| N |
Speed |
| N/dN |
Nitrify/denitrify |
| N2 |
Nitrogen |
| NaCl |
Sodium chloride |
| Na2Al2O4 |
Sodium aluminate |
| Na2CO3 |
Sodium carbonate |
| Na2SO3 |
Sodium sulfite |
| NaClO2 |
Sodium chlorite |
| NaHCO3 |
Sodium bicarbonate |
| NaOCl |
Sodium hypochlorite |
| NaOH |
Sodium hydroxide |
| NaS2O5 |
Sodium metabisulfite |
| NBOD |
Nitrogenous biochemical oxygen demand |
| NEC |
National Electric Code |
| NEMA |
National Electrical Manufacturers Association |
| NFPA |
National Fire Protection Association |
| NH3 |
Ammonia |
| NH3-N |
Ammonia as nitrogen |
NH4+
|
Ammonia ion |
| NH4HCO3 |
Ammonium bicarbonate |
| NH4OH |
Ammonium hydroxide |
| NIOSH |
National Institute for Occupational Safety and Health |
NO2-2
|
Nitrite |
NO3-2
|
Nitrate |
| NO, NO2, and NOx |
Nitrogen oxides |
| NOD |
Nitrogenous oxygen demand |
| NPDES |
National Pollutant Discharge Elimination System |
| NPSH |
Net positive suction head |
| NTU |
Nephelometric turbidity unit |
| O&M |
Operations and maintenance |
| O2 |
Molecular or free oxygen |
| O3 |
Ozone |
| OCI-2 |
Hypochlorite ion |
| OCP |
Operator control panel |
| OD |
Oxygen demand |
| ORP |
Oxidation–reduction potential |
| OSHA |
Occupational Safety and Health Act |
| OTE |
Oxygen transfer efficiency |
| OTR |
Oxygen transfer rate |
| OUR |
Oxygen uptake rate |
| Ox |
Aerobic or oxic |
| ρ |
Density |
| P |
Phosphorus |
| P3 |
Public–private partnerships |
| Patm |
Absolute atmospheric pressure |
| P&IDs |
Process and instrumentation drawings |
| PAM |
Polyacrylamide |
| PB |
Brake power |
| PM |
Wire or motor power |
| Pvp |
Fluid vapor pressure |
| PW |
Water power |
| PAOs |
Phosphorus-accumulating organisms |
| PAC |
Powdered activated carbon |
| PCs |
Personal computers |
| PCBs |
Polychlorinated biphenyls |
| PCS |
Process control system |
| PD |
Positive displacement |
| PDA |
Personal digital assistant |
| PDM |
Predictive maintenance |
| PELs |
Permissible exposure limits |
| PFC |
Power factor correction |
| PFRP |
Processes to further reduce pathogens |
| PLCs |
Programmable logic controllers |
| PM |
Preventive maintenance |
| PMP |
Planned maintenance program |
| PMS |
Personnel management system |
PO4-2
|
Phosphate |
| POs |
Purchase orders |
| POTWs |
Publicly owned treatment works |
| PP |
Polypropylene |
| PPE |
Personal protective equipment |
| P/PM |
Predictive/preventive maintenance |
| PSA |
Pressure swing adsorption |
| PSRPs |
Processes to significantly reduce pathogens |
| PRV |
Pressure-reducing valve |
| PTFE |
Polytetrafluoroethylene |
| PUCs |
Public utilities commissions |
| PVC |
Polyvinyl chloride |
| PVDF |
Fluorinated polyvinylidene |
| Q |
Volumetric flowrate |
| Q |
Sludge heating requirement |
| QS |
Solids loading rate |
| QWW |
Wastewater flow |
| QA |
Quality assurance |
| QAP |
Quality assurance plan |
| QAPP |
Quality assurance project plan |
| QAU |
Quality assurance unit |
| QC |
Quality control |
| QRAS |
Return activated sludge flow |
| QWAS |
Waste activated sludge flow |
| RAS |
Return activated sludge |
| RBCs |
Rotating biological contactors |
| RCM |
Reliability centered maintenance |
| RCFA |
Root-cause failure analysis |
| RCRA |
Resource Conservation and Recovery Act |
| RDT |
Rotary drum thickeners |
| RF/AS |
Roughing filter / Activated sludge |
| RFP |
Request for proposal |
| RFQ |
Request for qualifications |
| RMP |
Risk management program |
| RNA |
Ribonucleic acid |
| RTDs |
Resistance temperature detectors |
| S |
Solids or sludge mass flowrate |
| SA |
Surface area |
| SAE |
Standard aeration (electrical) efficiency |
| SAR |
Sodium adsorption ratio |
| SARA |
Superfund Amendments and Reauthorization Act |
| SARS |
Severe acute respiratory syndrome |
| SBOD |
Soluble biochemical oxygen demand |
| SBR |
Sequencing batch reactors |
| SCADA |
Supervisory control and data acquisition |
| SCBA |
Self-contained breathing apparatus |
| SF |
Safety factor |
| SIK |
Timer, indicator, and control |
| SIU |
Significant industrial user |
| SK |
Spulkraft |
| SLA |
Service level agreement |
| SLR |
Solids loading rate |
| SMR |
Self-monitoring report |
| SNDN |
Simultaneous nitrification/denitrification |
| SO2 |
Sulfur dioxide |
| SOL |
Soluble organic loading |
| SOPs |
Standard operating procedures |
| SOTR |
Standard oxygen transfer rate |
| SOUR |
Specific oxygen uptake rate |
| SP |
Soluble phosphorus |
| SPCC |
Spill prevention and countermeasures control |
| SPDES |
State Pollution Discharge Elimination System |
| SRF |
State Revolving Fund |
| SRT |
Solids residence (retention) time |
| SS |
Suspended solids |
| SSO |
Sanitary sewer overflow |
| SSV |
Settled sludge volume |
| SVI |
Sludge volume index |
| SWD |
Side-water depth |
| T |
Temperature |
| T |
Turbidity |
| TD |
Tetanus and diphtheria |
| TDH |
Total dynamic head |
| TDS |
Total dissolved solids |
| TF |
Trickling filter |
| TF/AS |
Trickling filter/activated sludge |
| TF/RBC |
Trickling filter/rotating biological contactor |
| TF/SC |
Trickling filter/solids contact |
| THM |
Trihalomethane |
| TIMS |
Training information management system |
| TKN |
Total Kjeldahl nitrogen |
| TOC |
Total organic carbon |
| TOD |
Total oxygen demand |
| TOL |
Total organic loading |
| TP |
Total phosphorus |
| TPAD |
Temperature-phased anaerobic digestion |
| TR |
Turnover rate |
| TRE |
Toxicity reduction evaluation |
| TSCA |
Toxic Substances Control Act |
| TS |
Total solids |
| TSS |
Total suspended solids |
| U |
Fluid velocity |
| U |
Heat transfer coefficient |
| UASB |
Upflow anaerobic sludge blanket reactor |
| UEL |
Upper explosive limit |
| UPS |
Uninterruptible power system |
| UV |
Ultraviolet |
| V |
Voltage |
| V |
Volume |
| v2/2g |
Velocity head |
| VA:ALK |
Volatile acid-to-alkalinity ratio |
| VAR |
Vector attraction reduction |
| VFA |
Volatile fatty acid |
| VOC |
Volatile organic compound |
| VFDs |
Variable frequency drives |
| VS |
Volatile solids |
| VSA |
Vacuum swing adsorption |
| VSS |
Volatile suspended solids |
| W |
Watts |
| W |
Weight |
| W/WW ITA |
Water and Wastewater Instrumentation Testing Association |
| ω |
Rotational speed |
| WAN |
Wide area network |
| WAS |
Waste activated sludge |
| WWTPs |
Wastewater treatment plants |