Article: Achieving Reuse Quality Water Using Multiple-Barrier Treatment

By Manuel de los Santos and Terry Reid

As clean water supplies become more limited, the demand for reuse water will continue to grow. Regardless of the treatment system used, the success of any reuse program relies on the biological treatment and the solid/liquid separation. The incorporation of nitrogen and phosphorus removal to the treatment scheme broadens the opportunities where reclaimed water can be acceptable.

While Membrane Bioreactors (MBR) are growing in acceptance, this technology puts the membranes in the direct application of mixed liquor suspended solids (MLSS), where solids concentrations of 8-10 g/l are a common practice. While the MBR process can offer advantages with respect to space requirements, the elevated solids concentrations demands a higher energy input.