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Emelie Hedlund, Master Programme in Natural Resources Engineering
Emelie Hedlund, Master Programme in Natural Resources Engineering View original picture , opens in new tab/window

Master's thesis publication on drinking water treatment

Published: 19 May 2019

Emelie Hedlund Nilsson completed her studies in Natural Resource Technology at Luleå University of Technology before the summer with a master's project in drinking water treatment; "Biological separation of iron and manganese in groundwater works: A study in Klöverträsk with regard to treatment periods and seasonal variations". The work was carried out in collaboration with Luleå municipality.

The levels of iron and manganese in incoming raw water in groundwater plants often exceed the National Food Agency's limit values. A common way to separate the metals is with potassium permanganate, a costly chemical that often requires careful dosing and adjusting the pH to function optimally. Emelie conducted a one-year pilot experiment in which a raw water with too high iron and manganese levels was passed through a filter prepared with a bacterial culture. The bacterial culture was of a kind with the ability to oxidize the metals and thus precipitate them out of the raw water.

The study showed that bacteria separation showed a higher degree of purification for both iron and manganese than the existing chemical separation. The biological separation retained a high degree of purification despite seasonal variations in raw water quality, a treatment period in the plant of about 5 h / day and without the need for pH adjustment of the raw water.