Saloy Ltd.
An effective phosphorus, humus, and suspended
solids precipitation method
Emission catcher for the precipitation of phosphorus
and organic matter (humus)
Vertical separation pipeline
for the removal of suspended solids
September 2014
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Introduction – A non-electrical precipitation method for the reduction of
environmental strains on water systems
The water treatment equipment and method developed by Saloy Ltd. have been proven effective in treating drainage
water in both agricultural and peat production year after year.
Using iron sulfate, the emission catcher binds organic matter (humus) and phosphorus from drainage water. Connected
to a sediment pond, the compact vertical separation pipeline reduces the amount of suspended solids in the water.
Simultaneously, it operates as the sediment pond for the sludge precipitated by the emission catcher.
The emission catcher is always connected to a sediment pond, in which the water is allowed to settle and the sludge to
descend. The sediment pond, designed to reduce the amount of suspended solids, is about 2.5 meters deep, groundbased, and the bottom insulated with a plastic sheet. Adjoined to the sediment pond is the patented vertical separation
pipeline, in which water flows up and down rapidly. An aggregate pump is used to collect the sediment sludge off the
bottom of the insulated pond.
The first emission catcher designed for peat production was installed in the summer of 2010. The first combination of an
emission catcher and a vertical sediment pond was installed in April 2012 in Kyyjärvi, Central Finland. The Kyyjärvi peat
production site is a part of the TASO-project, an environmental water preservation program developed in collaboration
with three Finnish ministries. The second combination was installed at a peat production site in Kihniö, in December
2012. The removal rate of suspended solids at the peat production sites have an average of 70%. Emission catchers
have also been installed at bog areas in Marttila, Southwest Finland, and Luumäki, Southeast Finland.
The first agricultural emission catcher was installed in Iittala, Hämeenlinna, Southern Finland, in May 2012. At this site,
the emission catcher was installed in connection to a traditional sediment pond, followed by wetland. The rate of removal
of phosphorus in the first control sample was 91%. A combination of an emission catcher and a vertical sediment pond
has worked to treat water in an agricultural ditch in Sauvo, Southwest Finland since March 2013. The Sauvo –project is
a part of the RAKI –project lead by the Ministry of the Environment.
The latest Saloy water treatment systems were installed in the spring and summer of 2013:
- Pien-Saimaa, Taipalsaari – Levänen: Emission catcher + traditional sediment pond
- Lahti – Vesijärvi: Combo (emission catcher + vertical separation pipeline + insulated sediment pond)
As the Vesijärvi –site features the newest equipment, it is an excellent location for a tour of the entire system.
Emission catcher
The emission catcher consists of a single vertical pipe, connected to a chemical container at the top, and a precipitation
tank at the bottom. Below is a picture of the installation of an emission catcher at the peat production site in Kihniö, in
December 2012. In addition to the one in Kihniö, emission catchers can be found at the peat production site in Marttila, as
well as the agricultural sites in Pien-Saimaa, and Lahti.
Measurements of the emission catcher:
Height: 2.5 meters
Diameter: 1.5 meters
The emission catcher is buried underground. The
aboveground parts are covered with an insulating
board for wintertime. A chemical pipeline connects
the topmost chemical container and the
precipitation tank. The chemical, ferric sulfate, is
mixed in inside the tank.
By exploiting the natural gravitational pull, the
emission catcher releases doses of granulated
iron sulfate into the water. The purpose of the iron
sulfate is to precipitate phosphorus and humus
from the water. The dosage depends on the
desired rate of removal (reduction). Typically, a
3
dosage ratio of 1 : 20 m (1 liter of chemical per 20
– 30 000 liters of water) is used.
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On the left is a picture of the emission
catcher in Marttila, Southwest Finland.
For precipitation purposes, the emission catcher uses a granulated Ferix-3 – ferric sulfate by Kemira, available in 1000 kg
bags. In essence, all the municipal wastewater treatment plants in Finland use iron sulfate to treat water. The chemical
container of the emission catcher holds up to two 1000 kg bags of the chemical, which is only consumed when water
flows inside the system. One liter of the chemical costs approximately 0.48€, and is enough to treat about 30 000 liters of
flowing water.
The emission catcher is best suited for ditches with a flow rate of up to about 200 – 300 liters / second. Because of its
higher rate of removal (70%), the emission catcher is more effective in removing phosphorus and humus than wetlands.
To illustrate, the one million euro Tuusulanjärvi wetland only reached a removal rate of 29% during the control period
st
st
between January 1 and December 31 2010.
Vertical separation pipeline and insulated ground pond
The vertical separation pipeline, in which water moves in rapid up-and-down motion, reduces the amount of suspended
solids in the water. It is also used as the sediment pond for the emission catcher. The pipeline also connects to a 2.5meter deep ground sediment pond. The system operates year-round.
The image on the left is the part of the pipeline
above water in a field ditch in the Lahti
precipitation site.
Inside the pipeline, water runs in rapid up-anddown motion. The vertical separation pipeline is
directly connected to a 2.5-meter deep, ground
sediment pond insulated with plastic.
Both the emission catcher and vertical separation pipeline are low maintenance. The only work required is to fill up the
chemical container of the emission catcher, and remove sludge off the bottom of the sediment pond. An optional alarm
system can be installed in the chemical container that notifies the user’s cell phone when a refill is needed. An aggregate
powered water pump is used to remove sludge off the base of the hard-bottomed sediment pond.
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Principle chart of the complete, year-round Saloy system
Pictures of Saloy Ltd. equipment at the most recent agricultural sites
Below are pictures from the most recent Saloy water treatment locations. On the left is a picture from Vesijärvi – Lahti,
and on the right a picture from Levänen – Taipalsaari, Pien-Saimaa. Both systems are of the newest design, with a
combination of the chemical container and the precipitation tank in a single vertical pipe.
As illustrated by the pictures, the Saloy Ltd. water treatment equipment can be conveniently placed and landscaped.
Water sample results from Pien-Saimaa (RAKI-project, in collaboration with the Ministry of the
Environment)
The water sample results on the next page are dated between April and August 2014. This project is a collaborated effort
with the Ministry of the Environment. The average reduction rate of dissolved phosphorus that suits as such as
nourishment for algae has from April to August been up to 94 %, and the average reduction rate for total phosphorus has
as well been excellent, 75 %. Nitrogen levels are reduced as a byproduct of phosphorus precipitation, and can thus be
thought of as a nice bonus.
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Source: Saimaan Vesi- ja ympäristötutkimus Ltd
Investment costs
The treatment system developed by Saloy only requires a fraction of the surface area required by traditional ponds, and is
simple and easy to set up. As its installation and investment costs are low, the system in its entirety is extremely cost
effective.
Prices (approximate), VAT 0%:
- Emission catcher (chemical container and precipitant tank) ~ 20 000 €
- Vertical separation pipeline ~ 5 000 €
- Excavation work (case by case) ~ 5 000 €
Please note that these prices are approximations - a final quote can only be given following a visit to the site in question.
The emission catcher and the vertical separation pipeline are durable, perennial, and can be transported from one
location to another.
Saloy Engineering Ltd
Road and water construction engineer Tapio Salminen founded Saloy Ltd in 1978. Between the years 1974 and 1978
Salminen worked in the Finnish Maritime Administration with a specialization in underwater construction.
Since 2005 Saloy has focused on staving off blue-green algae, as well as treating agricultural and peat production runoffs
of phosphorus, humus and suspended solids.
The mechanical and chemical water treatment method developed by Saloy Ltd is:
- Energy self-sufficient
- Easy care
- Efficient
- Year-round
- Has low investment costs and
- Only takes up a fraction of the surface area required by other methods
Contact information
Tapio Salminen
CEO, Water engineer
tel. +358 10 6666 310
e-mail. [email protected]
www.saloy.net
Antti Kivimaa
Senior advisor
tel. +358 400 501 780
[email protected]