The use of the kaldnes suspended carrier process in treatment of wastewaters from the forest industry

One pilot plant study and two full scale studies have been carried out seeking for the optimal use of the Kaldnes suspended carrier process in treatment of wastewaters from the forest industry. The wastewater used in all three cases came from secondary fiber mills. The studies show that the Kaldnes process as a highly loaded stage (typically 15-25 kg COD/m³·d) in series with an activated sludge stage forms an efficient, stable and competitive combination process both regarding investment and operating costs. This is especially true when treating wastewaters with a composition that makes them unsuited for treatment in an activated sludge process. The flexibility and compactness of the Kaldnes suspended carrier process also makes it an ideal choice for upgrading of existing treatment plants.