FÖRFÄLLNING AV HUMUSRIKA YTVATTEN – APPLICERAD SLUTNING TILLVATTENVERKETS RÅVATTENINTAG / Pre-Treatment of Humus Contaminated River Waters – Applied at the Intake of Water Works
This paper presents a new technology for the treatment of humus contaminated river warers, using ferri/flocculation and floating sedimentarions tanks, insralled in a lakewater body, connected to ihe main water resevoire of the Vaasa potable water works, in Finland. The capacity ofthis plant is 1 000 m3/h. It started in the summar 1995. Vaasa water works serve 55000 inh. with drinking water. The main water works treatment process consist of chemical coagulation, flotarion and slow sandfiltration. The raw water is pumped from the river Kyro and is characterized by high and varying concentrations of humus, ranging through the seasons from 20 up to more than 150 ppm as KMnO4-consumption. Preliminary pre-treatment tests were made during 1992-93, including ferriflocculation with dosing of ferrisalts at rawwater pumping station and sedimentation of the tlocs in a nearby lake, Bergträsket. “Complete abstract not presented.”