Method and Sample-Related Problems in the Determination of AOX in Effluents, 1994 Environmental Conference Proceedings

J. Sullivan, M. Douek

The effects of various analytical parameters, including shaking time, number of adsorptions, quantities of granular activated carbon (GAC) and nitrate, and the total volume of water used during adsorption of C-stage effluents, on shaker AOX results were investigated. AOX analyses of C- and E-stage effluents were also conducted on low (AOX < 1000)="" and="" high="" (aox=""> 1000) molecular weight fractions and on several model compounds. The results show that low molecular weight AOX is poorly recovered by the shaker method, while high molecular weight AOX is essentially quantitatively recovered. Considerably better recoveries of low molecular weight AOX are obtained by the column method. The effects of storage conditions and preservation techniques on AOX stability were also determined. Several recommendations, based on these results, were made for improving AOX recovery from kraft and sulphite effluents by both methods, and for maintaining the integrity of samples during storage.