We clean domestic wastewater before we return it to surface water. RWZI Beverwijk cleans wasterwater, and one of the products that remains from this process is sludge. There are a lot of valuable materials and substances in this sludge, such as phosphate. We are looking for partners who upcycle this sludge and make new valuable materials from this 'waste'.
Domestic wastewater contains many different materials and substances that do not belong in surface water. RWZI Beverwijk purifies this domestic water to comply with governmental guidelines and we then bring it back to the North Sea Kanaal. Sludge is formed during this purification process, and this sludge includes the material phosphate. Phosphate does not belong in surface water, but is definitely no waste as well. In fact, phosphate is indispensable for our food production and has a few other benefits.
From sludge to phosphate
RWZI Beverwijk makes the sludge ready for the drying plant in Beverwijk. Sludge is poured into a sink where magnesium chloride is added. This results in the phosphate compound struvite. This struvite drops down during the process and can easily be separated from the sludge. The struvite that is now stored in Beverwijk is good to use as fertilizer.
Only by incomplete washing of this struvite, it will contains many organic particles. This makes it difficult to sell this fertilizer directly to factories. One of the legal conditions is that bacteria and viruses present are killed. This can be done by heating or, for example, by treatment with a disinfectant like hydrogen peroxide.
Besides fertilizer, struvite can be used for the production of phosphoric acid. It can also be regenerated. When that is done, ammonia and magnesium phosphate is released. Ammonia can be used in many ways, like fuel, fertilizer or gas cleaning, for example. The magnesium phosphate can, again, be used as fertilizer.
Struvite as a valuable material?
With a separation plant and a cyclone, RWI has now separated and stored one hundred tons of struvite. There is a great opportunity to re-use the struvite as a raw material. We are looking for partners that have ideas about the opportunity of reusing this struvite. Comments under this article are welcome.
RWZI Beverwijk seeks to ways to use the obtained struvite. For this, we are looking for a partner who can further use the struvite into a directly usable product. The purpose of this cooperation is to take a next step in our sustainability mission, close the circuit and to ensure that this valuable raw material is not lost. In the case that this struvite becomes profitable, that is obviously another advantage.
Are you the partner we are looking for? Or do you have an idea, example or tip? Let us know with a response under this article.