Strategies and practices for sustainable use of water in industrial papermaking processes

The problem of water use in industrial sectors is analyzed in the context of sustainability, and the manufacturing process as one of the most important water consumers is scrutinized. Some practices of water conservation and reduction of water consumption, as well as the implementation of advanced treatment processes for wastewater recycling are considered under the general aspect of process integration and control in order to minimize environmental discharges. Reduction of effluents in papermaking processes are discussed as well as preventative approaches. It is emphasized that four groups of methods can be applied in order to minimize water consumption: process changes, water reuse, regeneration reuse and regeneration recycling. Minimizing the water consumption and thus reducing the hydraulic load may help to improve effluent treatment, reduce operating costs and, when subsequent disposal is to sewers, minimize effluent disposal charges. The data presented show that initially producing less effluents will reduce the demands on the effluent treatment plant and thus save both money and efforts. Separation techniques for minimizing effluents and effluent loads are presented, as well as potential practices to ensure a sustainable use of water, grouped as short term and long term measures. Prevention measures for water consumption in a Romanian paper mill are considered and discussed in relation with best available techniques (BAT), taking into account both economical and environmental benefits.