This research study evaluated the removal of phenol by using different
types of soils and soils plus activated sludge. Treatment time interv
als were one, two, three, five and seven days. Four types of soils-loa
m, sandy loam, silty loam and silty-clay loam-were collected from the
metropolitan Cleveland area and were used in the study. The soil to wa
stewater ratios of 1:1, 1:2 and 1:5 were used in the treatment experim
ent. Activated sludge of various concentrations was added in soils to
improve treatment efficiency. Results showed that the loam, silty loam
and silty-clay loam appeared to be effective in reducing phenol level
s over the given soil/wastewater ratios and designated treatment time
intervals. The phenol removal efficiency ranged from 30 percent to 55
percent. Among the four types of soils which have been added with acti
vated sludge, the silty loam and silty-clay loam proved to be most eff
ective in removing phenol from wastewater with a phenol removal effici
ency up to 70 percent. It was also found that addition of activated sl
udge to the soil enhanced biological oxidation and removal of phenol.