Work out nutrient removal efficiency instantly with clear inputs, formula shown and shareable results.
Nutrient removal efficiency is the percentage reduction in total nitrogen and total phosphorus. Biological nutrient removal typically achieves 70-85% nitrogen and 80-95% phosphorus with chemical polishing. The Redfield ratio of 16:1 by moles indicates which nutrient limits algal growth in the receiving water.
Removal efficiency
Removal % = (influent - effluent) x 100 / influent, for each nutrient
Nutrient consent limits protect against eutrophication and are legally enforceable. Confirm limits and averaging periods in the specific permit.
Removing the non-limiting nutrient does not reduce algal growth. Freshwater is usually phosphorus limited and marine water nitrogen limited, which is why consent priorities differ between inland and coastal works.
Available carbon for denitrification. Where the influent COD to nitrogen ratio is below about 8, an external carbon source such as methanol or acetate is needed to reach low total nitrogen.