Rening av mikrobryggeriers avloppsvatten

The number of microbreweries in Sweden has grown a lot since 2009, from about 30 to 240 breweries. In the production of beer, wastewater is also produced which must be taken care of to avoid inconvenience to people and the environment. How the wastewater should be treated has been a problem for a couple of breweries. This study is based on a case study, Remmarlöv Gårdsbryggeri, that needs a new wastewater treatment. Within the case study characteristics in the wastewater was identified by sampling and analysis in the laboratory. The most noticeable results of the sampling of the wastewater were high levels of COD and BOD, high levels of phosphorus in comparison with the levels of nitrogen, and a low pH in the wastewater. To find out what kind of wastewater treatment methods to use at Remmarlöv Gårdsbryggeri, a survey was made to identify wastewater treatment methods used in Swedish microbreweries. The survey was targeted against major micro breweries in Sweden. The major micro breweries in Sweden was 56 in total, of which 20 of them answered the survey. The survey showed that most of the breweries used municipal wastewater treatment with some pre-treatment in the form of a collection tank, to give more even wastewater, and pH adjustment. Other breweries spread their wastewater on farmland, used an infiltration plant or had an internal wastewater treatment plant. In order to evaluate which wastewater treatment method suited Remmarlöv Gårdsbryggeri, a matrix was made on the treatment methods identified in the survey. Municipal wastewater treatment has the best degree of purification and control after the treatment but would mean a huge cost for Remmarlöv Gårdsbryggeri. Using infiltration by sludgy would mean a good degree of purification together with a pre-treatment to lower the level of phosphorus, is easy to control and would therefore be a suitable treatment for Remmarlöv Gårdsbryggeri. An alternative is spreading the wastewater on farmland or Salix which also have showed good degree of purification and could be controlled due to the farmlands drainage system which ends up in a ditch.