WELTEC BLUE WATER Slurry and Digestate Processing
Regions with intensive livestock breeding have a serious oversupply of liquid manure. The available area in such regions is often not large enough to make use of the accumulating amount of nutrients. Therefore, there is a need for sustainable solutions for improved transportability and reduction of the nutrient surplus.
With its BLUE WATER processing technology, WELTEC has created a solution to this problem. Since 2007, the technology has already been successfully used in around 17 locations.
How It Works
In a multi-stage process, the WELTEC BLUE WATER processing system separates solid matter from water. The result: About 50 percent clear water, approximately 25 percent solid matter and about 25 percent liquid nutrient concentrate. This technology has already been in continuous use for several years and is successfully applied at about 15 locations with intensive livestock breeding or large biogas plants. One of the key benefits of the solution – which is already well established worldwide – is the high technical plant availability. The scalable modular system can be used from an amount of 50,000t/year. If processing needs are higher, a combination of several WELTEC BLUE WATER lines can easily be implemented.
1. Addition of Flocculants & Polymers
First, additives are mixed with the source material with a custom-developed mixer. This enables a short reaction time and economical use of individually composed flocculants. The additives ensure flocculation of even the finest components. At the same time, the addition of polymers facilitates the separation of certain substances from the water and the minimisation of odours.
2. Belt Filter Press
In the next step, the substances are drained in a special belt filter process. In this process, they are transported on a belt filter over various rolls and cylinders and pressedagainst a second water-permeable belt with increasing pressure. The drained solid matter has a dry matter content of about 30 percent and can subsequently be used as fertiliser, compost, litter or biogas substrate.
3. Flotation Tank & Fine Filter
The remaining liquid phase is first treated in a stainless flotation tank. Using fine air bubbles, small organic particles and suspended matter are separated and settle in a floating layer and to the bottom of the tank. The foam and sludge are then re-transferred to the treatment process. The other solid components of the liquid phase are separated by a filter.
4. Reverse Osmosis & Ion Exchanger
The final process step comprises the application of a three-stage reverse osmosis procedure. The remaining liquid phase has already reached a very clean state. The semipermeable membranes in the three-stage reverse osmosis procedure can separate 95 to 99 percent of the dissolved salts and nutrients. The separated nutrient concentrate can be used as liquid fertiliser that is easy to transport. The clean water that is left over from the treatment in the ion exchanger can be used at the local facilities or be returned to the water cycle.
Your advantages
The WELTEC BLUE WATER processing plant impresses with its high quality in technology and conception. This results in numerous advantages for the user:
- Tried and tested technology with high plant availability
- Concentration of nutrients, resulting in the following:
- Enhanced transportability
- Reduction of the fertiliser application cost
- Reduction of the ground and surface water contamination with nitrogen and phosphor
- Reduction of the storage needs for slurry and digestate
- Approximately 50 percent of the source material turns into clean water
- Solid phase can be sold as mineral fertiliser, agricultural fertiliser, litter, biogas substrate, compost, etc.
- Designed for slurry from livestock breeding, digestate from biogas plants and industrial wastewater