Which combination is used to coat sedimentation basin walls to rid the basin of slime growth?

Which combination is used to coat sedimentation basin walls to rid the basin of slime growth?

• A. copper sulfate and lime
• B. sodium carbonate peroxyhydrate
• C. dimethylalkylamine and lime
• D. zinc pentahydrate

Answer: (A)

Controlling slime on sedimentation basin walls relies on forming a protective biocidal coating that makes the surface inhospitable to algae and slime-forming organisms. Copper sulfate provides copper ions that are toxic to algae and many bacteria, reducing growth on contact with the coated surface. Lime helps establish and maintain a durable film on the walls by adjusting pH and promoting deposition of calcium carbonate, which helps the coating adhere and stay effective. Together, they create a lasting coating that keeps slime from re-establishing on the basin walls between cleanouts. Other options don’t provide this combination of a lasting coating plus active biocide. Sodium carbonate peroxyhydrate is an oxidant and wouldn’t form the stable wall film needed for long-term slime control. Dimethylalkylamine with lime isn’t a standard, proven wall-coating regimen for basins. Zinc pentahydrate acts as a biocide but isn’t used with lime to create the same durable coating on basin walls.

Controlling slime on sedimentation basin walls relies on forming a protective biocidal coating that makes the surface inhospitable to algae and slime-forming organisms. Copper sulfate provides copper ions that are toxic to algae and many bacteria, reducing growth on contact with the coated surface. Lime helps establish and maintain a durable film on the walls by adjusting pH and promoting deposition of calcium carbonate, which helps the coating adhere and stay effective. Together, they create a lasting coating that keeps slime from re-establishing on the basin walls between cleanouts.

Other options don’t provide this combination of a lasting coating plus active biocide. Sodium carbonate peroxyhydrate is an oxidant and wouldn’t form the stable wall film needed for long-term slime control. Dimethylalkylamine with lime isn’t a standard, proven wall-coating regimen for basins. Zinc pentahydrate acts as a biocide but isn’t used with lime to create the same durable coating on basin walls.