EFCT: Environmental Footprint Comparison Tool.  A tool for understanding environmental decisions related to the forest products industry.  Water. headerlink
Effects of decreased water use on emissions to air

When a pulp and paper facility reduces the amount of water used, chemical concentrations and temperatures in the mill water system often increase. This can result in increased emissions of a number of volatile compounds found in mill water systems.

For instance, a typical water reduction strategy in chemical pulp mills is to recycle evaporator condensate to the brownstock area. This can double or triple methanol air emissions in process vents.

Mills using elemental chlorine free (ECF) bleaching, that seek to recycle a portion or all of their bleach plant effluent to the recovery area, may find substantial increases in gaseous hydrochloric acid (HCl(g)) emissions from the kraft recovery boiler.

Reducing water use can reduce energy requirements, resulting in reductions of combustion-related emissions to air. The inverse question, regarding the effects of reducing combustion-related air emissions on water use, is examined in the section of this Tool on SOx and NOx.

More information on the relationship of water reuse and emissions to air can be found by following the links to the right.

More information:

Organic air emissions

Inorganic air emissions