Total Suspended Solids. (TSS) What is it?
Total suspended solids, or TSS, are the solid particles mixed in water or effluent. Suspended solids in pulp and paper mill effluents come from wood fibre losses , additives such as
clay and
ash, and microorganisms from effluent treatment systems.
Why does it matter?
When TSS is discharged to receiving water it may have several negative effects:
- It can block the penetration of light through the water, affecting the growth of certain plants;
- It can settle on the bottom of the lake or river, burying bottom-dwelling organisms;
- It can carry other pollutants with it into the sediments, harming the bottom-dwelling organisms and the fish, which eat these organisms.
How is it measured?
TSS is measured by pouring a known amount of sample through a filter and weighing the amount of material that is left on the filter.
How do we control it?
Control of TSS discharges is done at Resolute Forest Products within the mill process and later through effluent treatment. It is a good idea to control losses inside the mill as recovered material may be recycled and reused in process thereby reducing raw material requirements. Afterward, the unavoidable losses can be controlled through effluent treatment using gravity
clarifiers or settling basins. These collected solids are either burned as supplemental fuel or are sent to a landfill.