In ACS Sustainable Chem. Eng. 2018, 6 (10), 12542–12561, I saw the term "coexistent metals", but I could not find a definition for that on the Internet. So what does it mean?
Karapinar et al. utilized ammonium-loaded zeolite as a seeding material for precipitating calcium phosphate and suggested the possibility of using the precipitate-ammonium loaded zeolites as fertilizer. The efficiency of chemical precipitation is affected by alkalinity, organic matter content and the coexistent metals.