Department of Chemical & Materials Engineering, University of Auckland, Auckland, 1010, New Zealand.
Department of Chemical & Materials Engineering, University of Auckland, Auckland, 1010, New Zealand; Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, PR China.
Chemosphere. 2021 Dec;285:131486. doi: 10.1016/j.chemosphere.2021.131486. Epub 2021 Jul 8.
Phosphorus recovery has attracted increasing interest due to the potential depletion of phosphorus resources. One promising solution is to recover phosphorus via struvite precipitation from wastewater or other waste that is in rich of phosphate. However, product quality control during such process is always challenging due to the variation and complexity of wastewater compositions. For example, subcritical wet oxidation (SCWO) effluent is rich in phosphorus and nitrogen but contains a large amount of acetic acid, while its effect on struvite recovery is hardly known. Therefore, central composite design (CCD), considering pH, acetic acid level, Mg level and Ca level, was used to evaluate the effect of acetic acid on struvite purity, phosphorus removal, morphology and reaction kinetics. The experimental data were statistically analysed by analysis of variance (ANOVA) and principal components analysis (PCA). The results indicate that pH and Mg level have a significant impact on phosphorus removal (pH: p-value < 0.0001, Mg: p-value < 0.0001) and struvite purity (pH: p-value = 0.0410, Mg: p-value < 0.0001), Ca level only affects the struvite purity (p-value = 0.0333). The presence of acetic acid, within the studied range (8.77-34.53 mM), has a negligible effect on struvite morphology, phosphorus removal and reaction kinetics, but a slightly positive effect on struvite purity. Findings of this research would be beneficial to determine the feasibility of acetic acid-rich wastewater as a phosphorus source for struvite recovery.
由于磷资源的潜在枯竭，磷回收引起了越来越多的关注。一种有前途的解决方案是通过从富含磷酸盐的废水或其他废物中进行鸟粪石沉淀来回收磷。然而，由于废水成分的变化和复杂性，该过程中的产品质量控制一直具有挑战性。例如，亚临界湿式氧化（SCWO）流出物富含磷和氮，但含有大量乙酸，而其对鸟粪石回收的影响却鲜为人知。因此，使用中心复合设计（CCD）考虑 pH、乙酸水平、Mg 水平和 Ca 水平，以评估乙酸对鸟粪石纯度、磷去除、形态和反应动力学的影响。通过方差分析（ANOVA）和主成分分析（PCA）对实验数据进行了统计分析。结果表明，pH 和 Mg 水平对磷去除（pH：p 值<0.0001，Mg：p 值<0.0001）和鸟粪石纯度（pH：p 值=0.0410，Mg：p 值<0.0001）有显著影响，Ca 水平仅影响鸟粪石纯度（p 值=0.0333）。在所研究的范围内（8.77-34.53 mM），乙酸的存在对鸟粪石形态、磷去除和反应动力学几乎没有影响，但对鸟粪石纯度有略微的积极影响。这项研究的结果将有助于确定富含乙酸的废水作为鸟粪石回收磷源的可行性。
