Before revision: High retention times cause an increased need for additional reactors to maintain throughput increasing equipment costs Nutrient removal Nitrogen removal in the A-stage can reach 30-40 %, as nitrogen of organic compounds is incorporated in upflow anaerobic sludge blanket (UASB) reactor sludge.
After revision: High retention times cause an increased need for additional reactors to maintain throughput increasing equipment costs Nutrient removal Nitrogen removal in the A-stage can reach 30–40 %, as nitrogen of organic compounds is incorporated in upflow anaerobic sludge blanket (UASB) reactor sludge.