As a product of phosphorous recovery from anaerobic digestion (AD) of waste activated sludge (WAS), vivianite has received increasing attention. However, key factors controlling vivianite formation have not yet been fully addressed. Thus, this study was initiated to ascertain key factors controlling vivianite formation. A simulation of chemical equilibriums indicates that interfering ions such as metallic ions and inorganic compounds may affect vivianite formation, especially at a PO₄^3-concentration lower than 3 mM. The experiments demonstrated that the rate of ferric bio-reduction conducted by dissimilatory metal-reducing bacteria (DMRB) and the competition of methane-producing bacteria (MPB) with DMRB for VFAs (acetate) were not the key factors controlling vivianite formation, and that ferric bio-reduction of DMRB can proceed when a sufficient amount of Fe³⁺ exists in WAS. The determined affinity constants (K_s) of both DMRB and MPB on acetate revealed that the K_HAc constant (4.2 mmol/g VSS) of DMRB was almost 4 times lower than that of MPB (15.67 mmol/g VSS) and thus MPB could not seriously compete for VFAs (acetate) with DMRB. As a result, vivianite formation was controlled mainly by the amount of Fe³⁺ in WAS. In practice, a Fe/P molar ratio of 2:1 should be enough for vivianite formation in AD of WAS. Otherwise, exogenously dosing Fe³⁺ or Fe²⁺ into AD must be applied in AD.

作为废活性污泥 (WAS) 厌氧消化 (AD) 回收磷的产物，蓝铜矿越来越受到关注。然而，控制蓝铜矿形成的关键因素尚未完全解决。因此，本研究旨在确定控制蓝铜矿形成的关键因素。化学平衡的模拟表明，金属离子和无机化合物等干扰离子可能会影响蓝铜矿的形成，尤其是在 PO ₄ ^3-浓度低于 3 mM。实验表明，异化金属还原菌 (DMRB) 进行的铁生物还原速率以及产甲烷菌 (MPB) 与 DMRB 竞争 VFA（醋酸盐）并不是控制蓝铜矿形成的关键因素。当WAS中存在足够量的Fe ³⁺时，DMRB的三价铁生物还原可以进行。DMRB 和 MPB 对醋酸盐的亲和常数 (K _{s ) 表明，DMRB 的 K HAc}常数 (4.2 mmol/g VSS) 几乎是 MPB (15.67 mmol/g VSS) 的 4 倍，因此 MPB 可以不认真与 DMRB 竞争 VFA（醋酸盐）。结果，蓝铜矿的形成主要受Fe ^{3+量的控制。}在WAS。在实践中，2:1 的 Fe/P 摩尔比应该足以在 WAS 的 AD 中形成蓝铜矿。否则，必须在 AD 中应用外源性剂量 Fe ³⁺或 Fe ²⁺进入 AD。