VIDEREGÅENDE RENSNING AF DRIKKEVAND – DENITRIFIKATION / Advanced Purification of Drinking Water - Denitrification
Water treatment in Denmark is generally based on unpolluted groundwater, where aeration and rapid sand filtration normally suffice. The growing threat of pollution has prompted the industry to investigate into advanced treatment processes. Some unpolluted groundwater resources are difficult to treat. Processes presently in use include stripping, chemical precipitation, biological nitrification, whereas chemical oxydation with ozone and treatment with GAC is used on a large surface work. Pilot test for biological denitrification was conducted on cold groundwater in a fluidized bed reactor using sand as carrying material. Nitrate reduction of 98 % at a removal rate of 284 mg NO3-N/ l*h was achieved. The treated water had increased permanganate-value corresponding to 20 mg/1 COD. Posttreatment by precipitation and chlorination is foreseen.