Oilfield
wastewater treatment by combined microfiltration and biological processes
J.C. Campos, R.M.H. Borges, A.M. Oliveira, R.
Nobrega, G.L. Sant’-Anna-2002
Water Research, 36(1): 95-104
(from Current Contents)
Abstract :
This work deals with the treatment of offshore
oilfield wastewater from the Campos Basin (Rio de Janeiro State, Brazil).
After coarse filtration, this high saline wastewater was microfiltrated
through mixed cellulose ester (MCE) membranes, resulting in average removals
of COD, TOC, O&G and phenols of 35%, 25%, 92% and 35%, respectively. The
permeate effluent was fed into a 1-L air-lift reactor containing polystyrene
particles of 2 mm diameter, used as support material. This reactor was
operated for 210 days, at three hydraulic retention times (HRT): 48, 24 and
12 h. Even when operated at the lowest HRT (12 h), removal efficiencies of
65% COD, 80% TOC, 65% phenols and 40% ammonium were attained. The final
effluent presented COD and TOC values of 230 and 55 mg/L, respectively.
Results obtained by gas chromatography analyses and toxicity tests with
Artemia salina showed that a significant improvement in the effluent's
quality was achieved after treatment by the combined
(microfiltration/biological) process.
(Univ Fed Rio de Janeiro, COPPE, POB 68502,
BR-21945970 Rio De Janeiro, Brazil, e-mail of G.L. Sant’-Anna: lippel@peq.coppe.ufrj.br)