Fig. 5. The influence of shaking time on P mineral solubility from P-loaded water treatment residual (WTR). Adapted from Lindsay (1979). DCP, dicalcium phosphate (CaHPO4); DCPD, dicalcium phosphate dibasic (CaHPO4·2H2O); OCP, octacalcium phosphate [Ca4H(PO4)3·2.5H2O]; TCP, tricalcium phosphate [Ca3(PO4)2].