Phosphorous recovery from laundry effluents as Struvite and Struvite-K: A batch crystallization study based on a three-factor central composite design

The recovery of phosphate resources from laundry wastewater and the production process in the forms of Struvite and Struvite- K were investigated through a batch crystallization experiment using a magnetic stirrer at stirring rates ranging from 100 to 250 rpm and temperatures ranging from 25 to 35° C in addition to setting the initial pH level at 9, closely monitored, and maintained to optimize phosphate recovery as Struvite using surface response methodology based on a three-factor central composite design. Moreover, the mineralogical phase compositions and morphology of the precipitated solid powder of phosphate recovery were analysed using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques, equipped with energy-dispersive X-ray (EDX) analysis. The precipitated solid powder exhibited the highest yields of Struvite and Struvite- K achieved at 35° C with a feather-shaped morphology. The recovery of phosphate in the form of Struvite and Struvite- K has the potential to prevent it from entering water bodies while also reducing the need to mine raw phosphate rock to generate high-value fertilizer. • The experimental approach provides insight into the recovery of phosphate from laundry effluent. • The high phosphorus concentration could be restored when temperatures rise. • A high quantity of Struvite and Struvite-K linked to the recovery of phosphate resources. • Struvite and Struvite-K crystallization can be used to successfully treat laundry waste.