In our analysis of wastewater nutrient recovery, we found a great deal of focus on struvite precipitation with regards to phosphorus removal from wastewater. In addition to phosphorus, struvite contains ammonium, and magnesium, and it can be used either alone or in complex fertilizer formulations with other waste-derived products, microbial inoculants, or conventional inorganic fertilizers. Struvite precipitation from wastewater has the potential to generate 17.3 kg of struvite/million liters per day of sewage thereby reducing carbon dioxide emissions by 53% and reducing imports of chemical fertilizers by 0.38 Mt per year. Publications using struvite have increased substantially, with the hexahydrate [(NH4)Mg(PO4).6H2O] being the dominant form studied (See SI Fig. ). Although it has potential utility as a PK fertilizer, little has been published on potassium struvite (MgK(PO4).6H2O). Since precipitation of struvite from different types of wastewaters is a prominent technology which increasingly applied to recover phosphorus, we compared the publications associated with wastewater treatment for struvite production and overall publications on nutrient recovery from wastewater. The results show that all 3 types of methods are involved in the formation of struvite (Fig. ). Figure shows that chemical processes play a significant role in struvite production. The number of publications on chemical processes (36%) is comparable to that of biological methods (46%). In the case of all publications on nutrient recovery from wastewater, biological treatments account for 66%, physical processes for 22% and chemical processes make up the remaining 12% (Fig. ). While for phosphate recovery as struvite, chemical methods are reported in 36% of publications, three times more often than in overall wastewater treatment publications (Fig. ). For a discussion on specific processes associated with biological, chemical, or physical methods see the following sections.