58 / 2023-05-28 14:47:47

污泥蛋白热解过程中磷的迁移转化路径及定向调控机制研究

污泥,磷,热解,生物炭

污泥热解炭可作为一种磷肥替代品，回收利用磷资源。但热解过程中磷的形态会显著影响热解炭中磷的可利用性。本文选用污泥蛋白为模型化合物，在200−500 ℃下进行热解，旨在提出磷在热解过程中可能的迁移转化路径。结果表明，热解过程中有机磷分解生成焦磷酸根和正磷酸根。这些含磷离子与不同的金属离子结合生成AlPO₄、Na₃PO₄、Ca₃(PO₄)₂、Na₄P₂O₇等。另向污泥蛋白中添加10%的CaO进行热解，探究磷的定向转化机制。加入CaO后，AP含量可达到原料中的16倍，变为热解炭中的主要形态。这可以归因于钙离子的引入促进许多新的含磷相（Ca₁₀(PO₄)₆(OH)₂和Ca₂P₂O₇）的形成，Ca−P含量占总磷的68.32%。由此可见，磷的生物有效性与温度和CaO的定向调控密切相关，证明了污泥热解炭作为磷肥代替品的潜力。



The sludge pyrolysis carbon can be used as a substitute for phosphate fertilizer to recycle phosphorus resources. However, the form of phosphorus in the pyrolysis process will significantly affect the availability of phosphorus in the pyrolysis carbon. In this paper, sludge protein was selected as a model compound for pyrolysis at 200 − 500°C, aiming to propose a possible migration and transformation path of phosphorus during pyrolysis. The results showed that organic phosphorus decomposed into pyrophosphate and orthophosphate during pyrolysis. These phosphorus-containing ions combine with different metal ions to form AlPO₄, Na₃PO₄, Ca₃(PO₄) ₂, Na₄P₂O₇, etc. In addition, 10 % CaO was added to the sludge protein for pyrolysis to explore the directional conversion mechanism of phosphorus. After adding CaO, the content of AP can reach 16 times of that in the raw material and become the main form in the pyrolytic carbon. This can be attributed to the introduction of calcium ions to promote the formation of many new phosphorus-containing phases (Ca₁₀ (PO₄) ₆ (OH) ₂ and Ca₂P₂O₇), and the content of Ca−P accounts for 68.32 % of total phosphorus. It can be seen that the bioavailability of phosphorus is closely related to the directional regulation of temperature and CaO, which proves the potential of sludge pyrolysis carbon as a substitute for phosphate fertilizer.