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Package Treatment Plant Use in Scandinavia

This is a series of notes translated from this document.

Scandinavian countries are well ahead of the UK, in terms of nutrient removal from waster water. Whilst countries such as Sweden, Norway and Finland use similar techniques of waste water treatment, septic tanks, package treatment plants etc.) thier understanding of their performance is perhaps more advanced than here in the UK. Although in some areas there reliance on hard to maintain systems does not work well.

Suitable Techniques for Nutrient Removal

Solutions for finishing A variety of post-processing, or finishing, solutions exist described in appendix 2 to the handbook ("Small drains - Handbook for general council", Swedish Environmental Protection Agency, 2008).

All techniques described are stated to be suitable as post-treatment after mini-treatment plants.

The techniques that described are:

 Biofilter ditch (overgrown open trench)

 Resorption ditch (closed ditch)

 Over-sieving

 Constructed wetland

 Irrigation with waste water

 Root zone facility

 Infiltration

 Soil bed

 Membrane filtration

Problems in Finland

Even in Finland, problems are experienced with the function of mini sewage treatment plant due to lack of maintenance. A survey came out to the fact that over two-thirds of the investigated mini-treatment plants do not met the Finnish purification requirements. With the right care, however, they were considered capable achieve the desired function and thus meet the requirements. The most common problems overflowing sludge tanks and a lack of precipitation chemicals were seen everywhere

Phosphate Removal in Norway

A mini water treatment plant in Norway can be biological, chemical or biological/chemical. In a Norwegian mini-treatment plant includes biological treatment in the form of activated sludge or as biofilm. Chemical purification takes place by adding precipitation chemical, either simultaneously with it the biological treatment or as post-precipitation. So you don't combine chemical precipitation with soil bed. You don't use that kind of either enclosed phosphor filters that are marketed in Sweden (but have solutions there phosphorus-absorbing materials are mixed into soil-based solutions).

Treatment Plant with 91% P Removal (Phosphorous / Phosphate)

Minireningsverk BC UV (Mini treatment plant BC UV)

Waste Water Treatment in Greenland

Notes from this paper.