Bench-Scale Evaluation of Ultrafiltration and Nanofiltration Membranes For The Treatment Of A Kraft-Caustic Extraction Stage Effluent From A Softwood Lin, 1992 Environmental Conference Proceedings

The kraft pulp and paper industry is currently faced with the challenge of substantially reducing its discharge of conventional and toxic pollutants to the receiving environment without compromising its competitiveness. Researchers interested in developing alternative schemes for meeting this challenge are focusing on two areas: (i) pollution prevention through the implementation of internal measures to minimize water usage and reduce the generation of toxic contaminants, and (ii) end-of-pipe treatment through the use of innovative effluent treatment schemes for the removal of undesirable components from process waste streams. In this context, the use of innovative separation and destruction processes is expected to reduce the water usage of the kraft mills while minimizing the discharge of toxic contaminants to the environment.

Among the separation processes that are being investigated for developing closed-loop process water circuits, ultrafiltration (UF) and nanofiltration (NF) are attracting considerable attention from researchers in many industrialized countries. In Canada, a major study is under way at the Wastewater Technology Centre (WTC) to evaluate the effectiveness and costs of UF/NF for the removal of toxics from bleach plant effluents at kraft mills. The objective of this program is to assess the technical and economic feasibility of integrating UF/NF in the mill circuits and as part of innovative effluent management schemes which will minimize the release of toxic compounds to the receiving environment.