Reconstruction and modernization of the WWTP Zermatt
- Cavern ARA Zermatt
A project under special conditions:
Reconstruction and modernization of the WWTP Zermatt
At the end of the year 2012 an innovative membrane biology plant will start to clean the wastewater of the treatment plant in Zermatt, Switzerland.
Initial start-up of the plant was in 1982 and it had been designed for 22.000 inhabitants. Due to the increasing numbers of tourists who visit Zermatt, especially in winter, the WWTP has to be upgraded and modernized.
A tight schedule and a limited area were challenging for the design and construction of the dosing systems. This waste water treatment plant was built in a cavern, deep in the rock and is situated at 1600 meters above sea level. Easy to imagine, that there is a lack of space inside the cavern. And the access to Zermatt is a narrow road.
Steps of the preparation
In principle there are four steps of treatment in the Zermatt plant. At first, the mechanical cleaning, with a raking system to eliminate textiles or paper (or other undissolved contents). Additional grid and fat separators follow.
In the second step, the chemical treatment with flocculant agents and ferric salts is inducing the biological treatment.
In the biological cleaning, microorganisms decompose the remaining organic waste.
The sludge treatment is the last step in the process.
- Chemical tanks
Modernization and extension of the biological cleaning
The modernization will allow the treatment of waste water equivalent to 60.000 inhabitants. To achieve this, the activated sludge process has to be substituted by the more efficient membrane biology treatment, accompanied by additional nitrification and denitrification.
Our services
Alltech has supplied various storage tanks and dosing stations, which are used in the membrane cleaning process, precipitation and flocculation.
·Chemical tank with safety bund and dosing stations for sodium hypochlorite
·Chemical tank with safety bund and dosing stations for citric acid
·Chemical tank with safety bund and dosing stations for caustic
·CONTINUFLOC preparation and dosing systems for polymers for sludge treatment
For the WWTP Zermatt we have supplied cylindrical tanks that meet the requested high quality and safety standards.
For the tanks made of polyethylene the design and production is according to the relevant German design certifications of the DIBT. Alltech is a specialized manufacturer according to WHG (the German Federal Water Act). For Switzerland the tanks have the approvals according to KVU of the SVTI (Swiss Association for Technical Inspections). The tanks are fully equipped with the relevant safety components.
Therefore, we can guarantee for the high operating safety standard.
In the design process of the storage and dosing stations, the different properties of the chemicals must be taken into account and characteristics as chemical resistance, pressure, dosing output, type of control and adjustment range must be considered. For degasing chemicals – like Hypo – it is necessary to use special accessories to ensure the high dosing accuracy.
The dosing skids are equipped with the reliable and robust piston-diaphragm-dosing pumps of the FKM type.
The dosing output can be adjusted linearly and continuously. With three available sizes we cover the complete range of performance. The wet end can be selected in PVC, PPH, PVDF or stainless steel and the diaphragm is made of PTFE. All metering pumps of the FKM series are equipped with an integrated pressure relief valve certified by the Technical Control Board. The output of the pump can be adjusted linearly and continuously in the range of 0-100% while the pump is on duty or out of operation. The adjustment of the dosing output can be carried out by the guidance system via signal 4-20 mA.
No compromises when it comes to quality
With regard to the special geographic conditions of the waste water treatment plant Zermatt it is important to have robust, long-lasting design and dosing systems with reliable function. It was of importance that Alltech supplies a complete solution – not only components.
High quality materials have been the first choice and our customer made no compromises when it came to quality. In the long term this is for sure the best strategy!