Direct nanofiltration or ultrafiltration of WWTP effluent?

From August to December 1999, DHV Water BV (DHV) conducted a study at the D riebergen sewage treatment plant of the technical feasibility of effluent p ost-treatment to achieve Maximum Acceptable Risk (MAR) quality. The study w as commissioned by the Stichtse Rijnlanden District Water Authority and the part of the study concerned with membrane filtration was conducted in co-o peration with Stork Friesland. This article provides a brief description of the study results achieved using the two membrane filtration units. Conduc ting the studies simultaneously enabled proper comparison of product qualit y, technical operational management and the costs of ultrafiltration and na nofiltration. The article attempts to answer the question of how far new de velopments in membrane technology provide prospects for producing water wit h a genuine added value.