School of Environmental Science and Engineering, Tianjin University, Tianjin, China.
The Key Laboratory of Clean Energy Liaoning Province, Shenyang Aerospace University, Shenyang, China.
Environ Sci Pollut Res Int. 2019 Oct;26(29):29917-29929. doi: 10.1007/s11356-019-06146-2. Epub 2019 Aug 13.
Phosphorus (P), an irreplaceable nutrient for all living organisms, is facing scarcity via phosphate resources. In this research, the effect of suitable additives and temperature on P and heavy metals speciation during sewage sludge (SS) thermochemical treatment was investigated. The results demonstrated that additives (CaO and MgO) could promote the conversion of non-apatite inorganic phosphorus (NAIP) to apatite phosphorus (AP). X-ray diffraction measurements indicated that the phosphorus mineral phase in sewage sludge ash (SSA) mainly was AP, with addition of MgO and CaO. Moreover, orthogonal testing revealed that the optimal molar ratio of Mg:Ca:P for P recovery as AP was 1:3.5:1 at 750 °C. Risk index results implied that the heavy metals in the phosphorus-enriched SSA have low potential ecological risk. Thermodynamic equilibrium calculations revealed that P reacted with the other metal ions was in the following order: Ca > Mg > Al > Fe > Zn > K. Graphical Abstract.
磷（P）是所有生物不可替代的营养物质，但由于磷酸盐资源的短缺，磷的供应正面临危机。在这项研究中，我们研究了合适的添加剂和温度对污水污泥（SS）热化学处理过程中磷和重金属形态的影响。结果表明，添加剂（CaO 和 MgO）可以促进非磷灰石无机磷（NAIP）向磷灰石磷（AP）的转化。X 射线衍射测量表明，在添加 MgO 和 CaO 的情况下，污水污泥灰（SSA）中的磷矿物相主要为 AP。此外，正交试验表明，在 750°C 下，以 AP 形式回收磷的最佳 Mg:Ca:P 摩尔比为 1:3.5:1。风险指数结果表明，富磷 SSA 中的重金属具有低潜在生态风险。热力学平衡计算表明，P 与其他金属离子的反应顺序为：Ca > Mg > Al > Fe > Zn > K。图摘要。
