Microorganisms in sand filters for wastewater treatment (2017-2018)

In this project the performance of sand filters for on-site wastewater treatment is investigated focusing on identifying active microbes and reasons for excess sludge formation. The project is funded by the Swedish Agency for Marine and Water Management.

Sand filters and drain fields are common on-site wastewater treatment techniques in Sweden. In future, their use might increase because they could be used without post-treatment according to the recently suggested regulations for on-site wastewater treatment. Many newly built sand filters have been found to have functional problems due to sludge formation in the distribution chamber, aeration pipes and the filter bed itself. This might be problematic because the sludge formation possibly decreases the removal of BOD, pathogens and phosphorus in the filter and can lead to clogging. Soil-based treatment techniques are suitable for on-site wastewater treatment because they are passive and relatively cheap. Therefore, it is important to increase knowledge about these methods so that a good performance of sand filters and drain fields can be achieved.

The project is funded by the Swedish Agency for Marine and Water Management and is carried out in collaboration between Luleå University of Technology, Kungsbacka municipality and Chalmers University of Technology in Gothenburg.

Inga Herrmann, Annelie Hedström and Maria Viklander