Toxicity identification and evaluation of nitrification inhibitors in wastewaters

In order to reduce the content of nitrogen in treated wastewater, microbial processes conducting nitrification of nitrogenous compounds and denitrific ation to gaseous nitrogen are included in the sewage wastewater treatment p rocess. A set of compounds has been found inhibitory to these microorganism s. A procedure is presented for identification of nitrification inhibitors in wastewaters. This includes fractionation of the wastewater sample and lo cation of the inhibitory effect using a nitrification inhibition assay wher e pure cultures of Nitrobacter are used. A series of unsaturated fatty acid s and two monoterpenes were found to constitute the inhibitory effect in a wastewater sample from a plant for drying wood-derived fuel. (C) 2000 by Jo hn Wiley & Sons, Inc.