SNABBA METODER FÖR BESTÄMNING AV ERFORDERLIG ALUMINIUMSULFATDOS VID YTVATTENVERK / Rapid Methods for the Determination of Required Alum Dosage in Surface Water Treatment Plants
A sufficient coagulant dose is essential in order to obtain chemically treated humic surface water of satisfactory quality. But it is bad economy to apply too high a dosage just to be on the safe side. Studies at water treatment plants with large variations in the raw water humic content have shown that efficient supervision of the process may reduce the amount of chemicals added by about 30 %. Rapid methods how to determine the adequate coagulant dosage are described. These methods can replace the more complicated jar-test method when a conventional testing procedure is desired, i.e. when no studies of the reduction of specified matter are to be carried out. The tests described can be carried out manually when there is no need of frequent testing. The design and function of on-line instruments is described. In these the manual procedures are automatized. These instruments may serve as coagulant dose sensors in water treatment plants. “Complete abstract not presented.”