ABAC	Ammonia-Based Aeration Control
ABR	Ada Boost Regression
ACO	Ant Colony Optimization
ACR	Anaerobic Contact Reactor
AD	Anaerobic Digestion
ADM	Anaerobic Digestion Model
AE	Aeration Energy
AECI	Aeration Energy Cost Index
AFBR	Anaerobic Fluidized-Bed Reactor
AFNN	Adaptive Fuzzy Neural Network
AFR	Anaerobic Filter Reactor
AI	Artificial Intelligence
ALD	Approximate Linear Dependence
ALK	Alkalinity
AnMBR	Anaerobic Membrane Bioreactor
ANN	Artificial Neural Network
AOP	Advanced Oxidation Process
ARMA	Autoregressive Moving Average Stochastic Model
ARMAX	AutoRegressive Moving Average with eXogenous input
ARX	AutoRegressive with eXogenous input model
AS	Activated Sludge
ASI	Absorbance Slope Index
ASM	Activated Sludge Model
ASP	Activated Sludge Process
BAF	Biological Aerated Filter
BN	Bayesian Network
BOD5	5-Days Biochemical Oxygen Demand
BODst	Short-Term Biochemical Oxygen Demand
Boosting-IPW-PLS	Boosting–iterative predictor weighting–partial least square
BPFANN	Backpropagation Function Artificial Neural Network
BSM	Benchmark Simulation Model
CAS	Conventional Activated Sludge
CC	Correlation Coefficient
CDI	Chronic Daily Intake
CNN	Convolutional Neural Network
COD	Chemical Oxygen Demand
Cu-NP	Copper Nanoparticle
CV	Controlled Variable
DAS	Differential Absorbance Spectra
DDM	Data-Driven Model
DenseNet	Densely Connected Convolutional Network
DL	Deep Learning
DO	Dissolved Oxygen
DOM	Dissolved Organic Matter
EB	Electron Beam
EC	Electrical Conductivity
EEM	Excitation–Emission Matrix
EGSB	Expanded Granular Sludge Bed
EPS	Extracellular Polymeric Substance
EQI	Effluent Quality Index
FB	Feedback
FF	Feedforward
FFNN	Feedforward Neural Network
FI	Fluorescence Index
FLC	Fuzzy Logic Control
FOPTD	First-Order Plus Time Delay
FPE	Final Prediction Error
FPI	Fractional order Proportional Integral
FPLS	Fuzzy Partial Least Square
FPLS-DBN	Fuzzy Partial Least Square-Based Dynamic Bayesian Network
GA	Genetic Algorithm
GBR	Gradient Boost Regression
GD	Gradient Descent
GHG	Greenhouse Gas
HGO	High Gain Observer
HQ	Hazard Quotient
HRT	Hydraulic Retention Time
HW	Hammerstein–Wiener Model
IAC	Iterative Adaptive Critic
IAE	Integral of Absolute Error
IFAS	Integrated Fixed Film Activated Sludge
IMC	Internal Model Control
ISE	Integral Square Error
ISE	Ion-Selective Electrode
IWA	International Water Association
IWW	Industrial Wastewater
IWWTP	Industrial Wastewater Treatment Plant
KLD	Kilo Liter per Day
LM	Levenberg–Marquardt algorithm
LNMIIT	LNM Institute of Information Technology
LQ	Linear Quadratic
MATLAB	Matrix Laboratory
MBBR	Moving Bed Biofilm Reactor
MBR	Membrane Bioreactor
MGPR	Multivariate Gaussian Processes Regression
MIMO	Multi-Input Multi-Output
MLFCN	Machine Learning Fully Connected Network
MLPANN	Multi-Layer Perceptron Artificial Neural Network
MLR	Multivariate Linear Regression
MLSS	Mixed Liquor Suspended Solids
MLVSS	Mixed Liquor Volatile Suspended Solids
MOPC	Multi-Objective Predictive Control
MPC	Model Predictive Control
MRVM	Multivariate Relevant Vector Machine
MSE	Mean Squared Error
MV	Manipulated Variable
MWW	Municipal Wastewater
MWWTP	Municipal Wastewater Treatment Plant
NARX	Nonlinear AutoRegressive with eXogenous input model
NARXNN	Nonlinear AutoRegressive eXogenous Neural Network
NMC	Nonlinear Internal Model Control
NMPC	Nonlinear Model Predictive Control
NP	Nanoparticle
NTP	Non-Thermal Plasma
NOM	Natural Organic Matter
O&G	Oil and Grease
OCI	Operational Cost Index
OFPC	Output Feedback Predictive Control
OR	Oxygen Requirement
ORP	Oxidation-Reduction Potential
OUR	Oxygen Uptake Rate
PARAFAC	Parallel Factor Analysis
PDS	Peroxydisulfate
PI	Proportional Integral
PID	Proportional Integral Derivative
PMBC	Process Model-Based Control
PRBS	Pseudo-Random Binary Sequence
PRWWTP	Petroleum Refinery Wastewater Treatment Plant
PSO	Particle Swarm Optimization
PVA	Polyvinyl Alcohol
RAS	Return Activated Sludge
RB49	Reactive Blue 49
RBB	Reactive Black B
RBC	Rotating Biological Contactor
QFT	Quantitative Feedback Theory
RBFNN	Radial Basis Function Neural Network
RFR	Random Forest Regression
RLS	Recursive Least Square
RMSE	Root Mean Square Error
RNN	Recurrent Neural Network
ROS	Reactive Oxygen Species
SAFF	Submerged Aerobic Fixed Film
SBR	Sequencing Batch Reactor
SCADA	Supervisory Control and Data Acquisition
SIMO	Single-Input Multi-Output
SISO	Single-Input Single-Output
SME	Small And Medium Enterprise
SMP	Soluble Microbial Product
SOFNN	Self-Organizing Fuzzy Neural Network
SOPTD	Second-Order Plus Time Delay
SOUR	Specific Oxygen Uptake Rate
SQP	Sequential Quadratic Programming
SRF	Sludge Recirculating Flow
SRT	Sludge Retention Time
SS	Suspended Solids
SSC	Supervisory Sequential Controller
SVI	Sludge Volume Index
SVM	Support Vector Machine
T	Temperature
TDS	Total Dissolved Solids
TF	Transfer Function
TMOOA	Transfer Multi-Objective Optimization Algorithm
TMP	Transmembrane Pressure
TN	Total Nitrogen
TOC	Total Organic Carbon
TP	Total Phosphorous
TPANN	Two-Part ANN
TrOC	Trace Organic Contaminant
TSS	Total Suspended Solids
UASB	Up-flow Anaerobic Sludge Blanket
UI	Unknown Input
UIS	Unknown Input State
UV	Ultraviolet
UVA	Ultraviolet Absorbance
UV-VIS	Ultraviolet–Visible
VFA	Volatile Fatty Acid
VFD	Variable Frequency Drive
WRBFNN	Wavelet Radial Basis Function-Based Neural Network
WWTP	Wastewater Treatment Plant
XWTP	Xiangcheng Drinking Water Treatment Plant