Table 2.

Summary of indirect particle compensation methods for online water quality monitoring.

Methods	Wavelengths (nm)	Parameter	Data Type	Sources	Literature
SW	350 nm	COD	Lab	Ground water	[47]
SW	546 nm	COD	Lab	Simulated water samples	[48]
SW	545 nm	UV254	Lab and field	Surface water	[49]
SW, MSC	550 nm	UV254	Field	Surface water, treated water	[27]
Two wavelengths	254, 340 nm	DOC	Field data	Surface water	[50]
MSC	Full spectra	COD	Lab	Stream water, Simulated water	[51]
PLS	200–400 nm	COD	Lab	Lake water	[19]
PLS	Full spectra	DOC		River water	[52]
PLS	full	Nitrate	Lab	Simulated water	[53]
PLS	380–750 nm	Nitrate, TOC, COD	Lab	Seawater	[54]
PLS	Full spectra	assimilable organic carbon	Pilot	Simulated lake water	[55]
MSC, PLS, PCR	250–740 nm	DOC	Field	Surface water	[18]
PLS, lasso regression and MSR	Full spectra	Nitrate, DOC	Field	Brackish water	[56]
MSR	250, 290, 307.5, 437.5, 447.5, 630, 645 nm	DOC, Fe	Lab and Field	Stream water	[17]
PLS, MSR, local and global	250–740 nm	DOC	Field	Surface water	[57]
Multiple linear regression	260, 265, 280 and 285 nm	TOC	Lab	Drinking water, seawater, river water	[21]
SVM	Full spectra	Nitrate	Lab	River water	[58]