致癌物质的排放，致畸,粉煤灰（FA）的城市生活垃圾焚烧（MSWI）和诱变多环芳烃（PAHs）引起了人们的广泛关注。通过利用磁铁矿（Fe3O4）作为催化剂和过氧化氢（H2O2）作为氧化剂，水热处理（HT）已成为在FA的MSWI期间降解PAHs的实用方法。在这项研究中,作为传统羟基磷灰石（HAP）的替代品，首次合成了蛋壳衍生的磁性羟基磷灰石（MHAP），并将其应用于H2O2体系中MSWIFA中PAHs的水热催化降解。PAHs的降解效率不仅受H2O2的影响，而且受羟基磷灰石的选择影响。在使用H2O2的水热处理期间添加HAP或MHAP显著降低了总PAH浓度和毒性当量(TEQ),优于没有H2O2。在水热系统中存在H2O2时，MHAP与HAP相比表现出优越的催化活性。随着MHAP用量的增加，PAHs的水热解毒作用增加。通过使用0.5mol/LH2O2作为氧化剂和15wt％的MHAP作为催化剂，PAH总降解率为88.9%，显著的TEQ降解率为98.3%。值得注意的是,4-6环PAHs的水平，特别是苯并（a）芘（BaP）和二苯并（a，h)蒽(DahA),TEQ为1.0时，显着降低(分别降低了69.4%和46.0%，分别)。MHAP在水热催化过程中保持稳定，而H2O2被MHAP有效激活并在水热条件下分解产生强氧化性羟基（·OH）。•MHAP表面上H2O2和金属分解产生的OH充当催化活性中心，有效地将高环PAHs转化为低环PAHs。这些发现为通过水热催化氧化在MSWIFA中进行PAH解毒提供了有价值的见解和技术基础。
The emission of carcinogenic, teratogenic, and mutagenic polycyclic aromatic hydrocarbons (PAHs) during municipal solid waste incineration (MSWI) of fly ash (FA) has attracted significant attention. Hydrothermal treatment (HT) has emerged as a practical approach for degrading PAHs during MSWI of FA by utilizing magnetite (Fe3O4) as a catalyst and hydrogen peroxide (H2O2) as an oxidizing agent. In this study, as an alternative to traditional hydroxyapatite (HAP), eggshell-derived magnetic hydroxyapatite (MHAP) was synthesized and applied in the hydrothermal catalytic degradation of PAHs in MSWI FA in an H2O2 system for the first time. The degradation efficiency of the PAHs is influenced not only by H2O2 but also by the choice of hydroxyapatite. Adding HAP or MHAP during hydrothermal treatment with H2O2 substantially reduced the overall PAH concentration and toxicity equivalent quantity (TEQ), superior to that without H2O2. MHAP demonstrated superior catalytic activity compared to HAP in the presence of H2O2 in the hydrothermal system. The hydrothermal detoxification of the PAHs increased with increasing MHAP dosage. By employing 0.5 mol/L H2O2 as the oxidant and 15 wt% MHAP as the catalyst, a total PAH degradation rate of 88.9 % was achieved, with a remarkable TEQ degradation rate of 98.3 %. Notably, the level of 4-6-ring PAHs, particularly benzo(a) pyrene (BaP) and dibenz(a,h)anthracene (DahA), with a TEQ of 1.0, was significantly reduced (by 69.4 % and 46.0 %, respectively). MHAP remained stable during the hydrothermal catalytic process, whereas H2O2 was effectively activated by MHAP and decomposed to produce strongly oxidizing hydroxyl (•OH) under hydrothermal conditions. •OH produced from the decomposition of H2O2 and metals on the surface of MHAP act as catalytically active centers, efficiently converting high-ring PAHs to low-ring PAHs. These findings provide valuable insights and a technological foundation for PAH detoxification in MSWI FA via hydrothermal catalytic oxidation.
