Treatment Plant in Flúðir and Roskilde

In the treatment plant in Hrunamannahreppur, the sludge is processed in three stages. When we talk about stages, we mean the stages that the sludge goes through, that is, the process from when unsorted waste (solids) becomes fertilizer. The process starts with a special sludge treatment truck sucking up all the sediment and sewage from the septic tanks. The compost piles are spread across the six municipalities responsible for the treatment plant in Hrunamannahreppi. Therefore, the car has to drive long distances in order to empty a certain amount of septic tank. The sludge truck empties the septic tank and sludge water, and the floating layer is pumped into the tanker. The solid material is then separated from the sludge water and remains in the car, but the liquid is pumped back into the septic tank. This is done so that the bacterial flora that accelerates decay is active, even though all the sludge is cleaned or removed from septic tanks.

The sludge cleaning truck also has a filter that separates things that are not meant to be in the sludge, such as wet wipes, artificial gums and other unwanted material. The inorganic things that can get into the sludge are then composted. When the sludge cleaning truck is full of sludge, it takes the contents to the reception station located in Hrunamannahreppur and empties the tank of the truck of all sludge. The sludge is placed in a so-called calcifier, where the sludge is mixed with lime. After that, the sludge is placed on a conveyor belt and from there it is transferred to a wagon with a spreader. A tractor then takes over the wagon and spreads the sludge to a certain distribution area inside the Hrunamannahreppur settlement, where the sludge is used for reclamation. 

Purification Plant in Roskilde

In the sludge treatment plant in Roskilde, the process is longer than in the treatment plant in Hrunamannahreppi. The sludge that comes to the treatment plant goes through seven stages, where, among other things, all the resulting liquid is cleaned. The first three steps are the same as in Hrunamannahreppi. In Roskilde, the sludge itself is not only used as fertilizer, but all the water is used again. At the same time, methane gas produced in the cleaning process is used for energy production.