treat oil refinery effluent allowed reduction of up to 52% of sludge
disposal, without harm to the COD removal efficiency or sludge
settleability. Different lots of rhamnolipid produced by P.
aeruginosa added at the same concentration yielded the same
result, showing a further potential application of biosurfactants in
the area of effluenttreatment and waste minimization. The process
modification by the addition of biossurfactant can contribute to
processes intensification, reducing from 38.5 to 51.7% the area
occupied by the secondary sedimentation tank and other sludge
treatment units and sludge disposal costs. However, the cost of
biosurfactant production must be reduced to enable the modification
of the proposed process.