Achieving biologically stable drinking water

This article combines microbiological theory and European practice to demonstrate how biological processes within a water treatment plant can remove the organic and inorganic substrates that cause or contribute to biological instability. Theory and practive indicate that ammonium and manganese ions and biodegradable organic compounds can be removed by attached-growth processes such as fixed bed, fluidized bed, and rapid sand filters. Low temperatures do not preclude good treatment. A quantitative kinetic model, which accurately describes field results, provides a sound basis for successful design and operation of biological water treatment processes. Following a biological process with conventional processes is recommended to provide multiple barriers against the escape of microorganisms into the finish water.