Ac. Kilroy et Nf. Gray, PILOT-PLANT INVESTIGATIONS OF THE TREATABILITY OF ETHYLENE-GLYCOL BY ACTIVATED-SLUDGE, Environmental technology, 13(3), 1992, pp. 293-300
Activated sludge pilot plant studies were carried out in order to inve
stigate the treatability of ethylene glycol, an organic chemical commo
nly used as a coolant in the pharmaceutical industry. Four completely
mixed, single-stage, activated sludge units, with a capacity of 80-lit
res were operated in parallel. The effect of various concentrations of
the test chemical on the sludge settleability, the sludge growth, and
the plant performance in terms of BOD and COD removal were examined d
uring the study. It was concluded that a concentration of 0.1% ethylen
e glycol in the raw wastewater of the full-scale plant was treatable,
as higher concentrations appeared to cause a deterioration in the floc
structure and to enhance Nocardia scum formation on the surface of th
e aeration basin.