In this research, several food grade (edible) surfactants are systemat
ically evaluated for various loss mechanisms: precipitation, adsorptio
n, and coacervation (for nonionic surfactants). Cloud points for the p
olyethoxylate sorbitan (T-MAZ) surfactants are much higher than aquife
r temperatures, and the effects on surfactant losses should be minimum
. Precipitation boundaries of bis(2-ethylhexyl) sodium sulfosuccinate
(AOT) and sodium mono- and dimethylnaphthalene sulfonate (SMDNS) were
established. Existing precipitation models successfully predicted prec
ipitation boundaries for SMDNS but showed minor deviations for AOT res
ults. AOT was more susceptible to precipitation than the cosurfactant
evaluated, SMDNS. Nonionic polyethoxylate (POE = 20) sorbitan monostea
rate (T-MAZ-60) and POE(80) sorbitan monolaurate (T-MAZ-28) formed liq
uid crystal phases at high surfactant concentrations (> 0.5 wt %) whit
e POE(20) sorbitan monolaurate (T-MAZ-20) and POE(20) sorbitan monoole
ate (T-MAZ-80) remained in aqueous solution at concentrations up to 5
wt %. T-MAZ-60 and T-MAZ-28 also showed a continuous increase of ''ads
orption'' at high surfactant concentrations (likely due to liquid crys
tal formation). Other surfactants showed Langmuirian-shaped isotherms
at high concentration, while the cosurfactant SMDNS experienced neglig
ible adsorption. On a mass basis, the maximum adsorption (q(max) in mu
mol/g) was higher for T-MAZ surfactants than for alkylphenol ethoxyla
tes, AOT, and disulfonated surfactants.