P-recovery with struvite

Phosphate is a crucial component of artificial fertilisers, but the main mining areas are slowly becoming depleted, which makes phosphate recovery all the more important. That’s why we developed ANPHOS^® technology.

Today, chemical addition in the wastewater treatment is a convenient way to remove phosphate, and though it does remove phosphate, it also produces additional sludge, increasing operating costs. Capturing phosphate in a sub-stream by promoting struvite formation lowers those costs and creates a valuable product.

Application

ANPHOS^® technology can be used in both the industrial and the municipal sector, as the phosphorus recovery process can take place in the main flow (industry) or in a sub-flow, such as the filtrate of a digestate dewatering system (municipal STP) by means of controlled struvite formation.

Process

ANPHOS^® technology is a batch process and consists of two process steps; a stripping tank and a reaction tank. In the stripping tank, CO₂ is stripped from the wastewater, increasing its pH. The water is then pumped to the reaction tank, where magnesium is added to the water to set the controlled struvite formation process in motion. The struvite settles in the reactor and is transported to a dewatering or struvite recovery system. The overflow of the reaction tank is the effluent of the struvite system, which can either be treated further or be discharged.

Advantages of the ANPHOS^® technology

• Controlled struvite formation;
• Prevents struvite formation further down the line;
• Produces valuable struvite;
• Only requires a source of magnesium;
• Reduces sludge production in subsequent systems;