迫切需要稳定污泥中的重金属(HM),以促进其回收和再利用。热解是一种不仅稳定这些金属而且生产生物炭的有前途的方法。我们的研究探讨了特定HMs(Cr,Mn,Ni,Cu,Zn,As,和Pb)在各种条件下的共热解过程中,包括是否存在微塑料(PVC和PET)。我们检查了这些塑料的不同浓度(1%,5%,10%,和15%)和温度(300°C,500°C,和700°C)。研究结果表明,微塑料,特别是PVC,促进锌和锰的迁移,导致Zn和Pb在较高温度下的显著挥发,峰值在700°C。温度的升高也显着影响HM迁移,随着显示,在使用PET和PVC的系统中,显著的损失率攀升了18.0%和16.3%,分别,温度从300°C飙升至700°C。此外,我们的形态分析表明,微塑料有助于将某些HM从不稳定的形式转化为更稳定的形式,表明它们在热解过程中对HM稳定的有益作用。这项研究极大地丰富了我们对微塑料对污水污泥热解中HM行为的影响的理解,为污染控制和环境管理策略提供新的途径。
Stabilizing heavy metals (HMs) in sewage sludge is urgently needed to facilitate its recycling and reuse. Pyrolysis stands out as a promising method for not only stabilizing these metals but also producing biochar. Our research delves into the migration and transformation of specific HMs (Cr, Mn, Ni, Cu, Zn, As, and Pb) during co-pyrolysis under various conditions, including the presence and absence of microplastics (PVC and PET). We examined different concentrations of these plastics (1 %, 5 %, 10 %, and 15 %) and temperatures (300 °C, 500 °C, and 700 °C). Findings reveal that microplastics, particularly PVC, enhance the migration of Zn and Mn, leading to significant volatilization of Zn and Pb at higher temperatures, peaking at 700 °C. The increase in temperature also markedly influences HM migration, with As showcasing notable loss rates that climbed by 18.0 % and 16.3 % in systems with PET and PVC, respectively, as temperatures soared from 300 °C to 700 °C. Moreover, our
speciation analysis indicates that microplastics aid in transforming certain HMs from unstable to more stable forms, suggesting their beneficial role in HM stabilization during pyrolysis. This study significantly enriches our understanding of microplastics\' impact on HM behavior in sewage sludge pyrolysis, offering new avenues for pollution control and environmental management strategies.