Operation of an ASB Wastewater Treatment System Treating Kraft and Newsprint Wastewater without the Addition of Nutrients, 1999 Environmental Conference Proceedings

R. Hunter

Tasman Pulp and Paper Co, Ltd

A. Slade

New Zealand Forest Research Institute, Ltd

Fletcher Challenge Paper Tasman Mills (Tasman) in Kawerau, New Zealand operates an integrated kraft pulp and mechanical printing paper mill using managed plantation forest residue pinus radiata as a fibre source. As an integral part of the operation of the site, the company operates a 6-day hydraulic retention time, 4 pond aerated stabilisation basin (ASB) wastewater treatment plant. This plant was installed during the 1970’s and has provided efficient treatment of all of the wastewater from the site before it is discharged to the Tarawera River.

The ASB treatment plant operates with a BOD reduction efficiency of greater than 90% and is able to do so under a wide variety of adverse conditions that would potentially normally take such a plant out of operation for some considerable time. These conditions are as a result of the occasional unstable operation of the pulp and paper mills. Of extreme interest, and the focus of this paper is the ability of the company to operate a plant such as this with the level of success that is achieved and without the addition of nutrients at all.