Flocell AB

The advantage with the method is that the basicity of the coagulant is regulated in-situ. The process has obvious environmental benefits. They include less pollutants discharged from WWTP and improved drinking water quality produced in WTP, reduced use of chemicals and lower amount of sludge that has to be deposit. It also entails reduced transport of chemical to and sludge from the plant. The process is controlled and monitored by on-line analysers of water pollutants. On-line monitoring also makes it easier for the operating personnel to quickly correct errors in the plant. Further more the recorded data from the treatment plants are able to facilitate the execution of proper environmental counter-measures by environmental enforcement agencies.

This possibility adds one more parameter that is needed to optimize the coagulation process (besides coagulant dosage and in some cases pH). Furthermore the dosage, basicity and pH are controlled by on-line analysis of the impurities in incoming and treated water. This will improve the quality of treated water, reduce chemical cost and sludge production. The basicity can be regulated in an aluminium sulfate as well as in an aluminium chloride solution. This option makes it possible to use the much cheaper sulfate.