Reduction of nutrient load from wastewater and farms – Finnish experience

Ecocentrum Ltd. and Friends of the Baltic NGO continue to study and disseminate the best practices of wastewater treatment in housing sector and in agriculture.

On October 15-16, a trip to Finland in the vicinity of the town of Eura took place. We visited the Jouko Peltonen yhtiöt broiler farm in Köyliö, which has environmentally safe bird manure management, and the Biolan Oy (Biolan) plant, which produces dry toilets, composters, as well as fertilizers and soils based on bird manure and composting products.

Previously, on April 2018 Ecocentrum Ltd together with Friends of the Baltic NGO organized an educational tour to Estonia and Finland for farmers from the Leningrad Region to study the best practices in livestock waste management. During this trip we visited a goat farm, a pig-breeding complex, cattle farms. This time we learned about the work of the poultry farm, which use unique method of bird manure utilization through interaction with the company - manufacturer of fertilizers.

The farm contains 105,000 broiler chickens (in three buildings of 60,000, 30,000 and 15,000 broilers). Growing one broiler chicken is take 37 days. For the life of a broiler is formed about 4 liters of manure. The collection of the manure is automated; 150 modules are installed in the premises to collect the manure into one large container. Next, the litter is transferred to storage. Storage of manure in untight conditions or on open ground is prohibited by law. During the year, manure fills the storage several times. 90% of all manure produced during the year is sent to the Biolan plant, located 14 km from the farm, for the production of granular fertilizers. 10% of the manure is kept in a separate farm storage and in the spring is placed on its own fields for growing feed for chickens. The area of ​​the fields is 50 hectares and they are located in close proximity to the large lake Koyulionjärve, therefore the farm has a big responsibility for preventing the nutrient load into the water body. Different types of grain are grown in the fields, including winter wheat. After harvesting, the grain is dried in a drying unit and only then goes to feed the birds.

Bird manure is valuable in terms of microelements, but highly pathogenic, therefore, at the Biolan plant, when manure is granulating, it is dried and disinfected at a temperature of 90 ° C. Various types of fertilizers are made from manure - for room plants, for potatoes and root crops and other plants. Fertilizers are produced for both individual gardeners and large crop farms. Ecological safety of Biolan fertilizers is confirmed by the Finnish eco-certificate Luomu.

Part of the manure is composted right there on the territory next to the plant of 15 hectares. This is the second largest compost site in Finland, the first is located in Helsinki. The soil for greenhouses and gardens is produced from compost. The materials used for composting and the production of soils are tested in their own laboratory for safety according to the low regulations (pathogenicity, chemical composition). In total, 15 different materials are used - products of composting of chicken manure, materials from forest industry, even carton. Testing is carried out regularly - 1 time per shift (8 hours). Prototypes of materials are stored for 5 years so that in the event of a consumer complaint, the company can prove that the materials were selected and checked for safety. Compost based soils are sold in Finland and exported to different countries.

The Biolan company produces mixtures for dry toilets on the basis of peat (70%) and wood bark (30%). Although in Finland there is currently no shortage of peat, which is traditionally used for dry toilets powders, for the same purpose Biolan plans to use lake moss as a special type of algae. The period of growth of lake moss up to the time of collection is 5 years, while peat is formed much more slowly (1-3 mm per year), that is, it is not a fully renewable resource. Collecting moss helps clean up lakes - minimizes eutrophication. Currently, lake moss is used in filters for cleaning gray water (gray water is all drains with the exception of toilet drains).

Finland is a country of lakes, therefore there is a law in the country according to which all households located up to 100 m from the reservoir are obliged to has wastewater treatment systems. In the country, 1.2 million private sites are located near water, often on a granite base, which excludes the installation of septic tanks and the installation of filtration fields. Therefore, dry toilets actively used in Finland. Together with them, people used filters for cleaning of gray water, which are also installed on the ground. Dry toilets, garden and toilet waste composters, gray water filters are also manufactured by Biolan.

Currently in Finland there is a high demand for composting toilets, since they have a large volume and do not require a separate composter, whereas separating toilets and toilets with filtration needed a separate composter. From the composters, the most efficient are composters with thermal insulation (thermal composters). Thermal insulation allows not to stop the process of composting, even in winter - at minus 20 C degrees on the street is the positive temperature in the composter. And at a temperature of 10 C degrees outside, the temperature inside the composter reaches 70 C degrees, that is, the process of composting is effective. Thermal composters are used for composting both kitchen and toilet waste. At the demonstration sites created by Ecocentrum Ltd. with the support of Biolan Oy in Lomonosov, Gatchina, Volosovsky , Luga districts (links), you can observe the operation of all types of dry toilets, as well as different types of composters for composting toilet waste - thermocomposters of 220 l, 550 l, garden, landscape composters. Demonstration sites were created to inform rural residents and gardeners about environmentally friendly ways to dispose of toilet waste.

In the arsenal of the Biolan Oy not only practical solutions to reduce the nutrient load on water bodies (toilets, composters, gray water filters, a local bioremediation station), but also other products for eco-friendly home improvement - solar electric panels, solar panels for water heating, solar collectors for heating the air in the rooms.