Department of Chemical Engineering, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
Department of Chemical Engineering, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
Chemosphere. 2022 Sep;303(Pt 2):135008. doi: 10.1016/j.chemosphere.2022.135008. Epub 2022 May 25.
The presence of emerging contaminants in water and wastewater resources is of ongoing concern for public health and safety. Pharmaceutical compounds are designed to be biologically active and therefore may have effects on nontarget organisms in terrestrial and aquatic environments, even at trace concentrations. The presence of pharmaceutical and personal care products (PPCPs) in wastewater treatment plants is reported in various countries worldwide, mostly in the levels of nanograms to micrograms per litre. The present study investigates the thermal degradation of municipal sewage sludge containing PPCPs at various heating rates. The examined characteristics of the samples include thermal decomposition behavior, volatile release characteristics, and pyrolytic product composition. Thermal characterization of the PPCPs was conducted using differential scanning calorimetry. The gaseous products and typical functional groups of the released volatiles detected by Fourier-transform infrared spectroscopy mainly contained CO, CO, small-chain hydrocarbons, and oxygen- and nitrogen-containing functional groups together with other species. In addition, the potential of bioenergy production was investigated as a spin-off opportunity during thermal degradation of biosolids. Study results showed that PPCP concentrations can be lowered significantly by thermal treatment of municipal biosolids. Antifungal/antibacterial agents together with opioids, in particular triclosan and tramadol, showed less resistance to thermal degradation while antibiotics could be more recalcitrant to heat treatment. The thermodynamic results provide an important reference for future reactor design and the thermochemical treatment of biosolids as well as their conversion to value-added products.
水中和废水中新兴污染物的存在持续引起公众对健康和安全的关注。药物化合物旨在具有生物活性，因此即使在痕量浓度下，也可能对陆地和水生环境中的非目标生物产生影响。在世界范围内的许多国家都报告了废水处理厂中存在药物和个人护理产品（PPCP），其浓度大多在纳克/升至微克/升的范围内。本研究在不同的加热速率下研究了含有 PPCP 的城市污水污泥的热降解。研究的样品特性包括热分解行为、挥发性释放特性和热解产物组成。使用差示扫描量热法对 PPCP 进行了热特性分析。通过傅里叶变换红外光谱检测到的气态产物和释放出的挥发性物质的典型官能团主要包含 CO、CO、小链烃以及含氧和含氮官能团以及其他物质。此外，还研究了在热解生物固体过程中作为附带机会的生物能源生产潜力。研究结果表明，通过对城市生物固体进行热处理，可以显著降低 PPCP 的浓度。抗真菌/抗菌剂以及阿片类药物，特别是三氯生和曲马多，对热降解的抵抗力较弱，而抗生素对热处理的抵抗力可能更强。热力学结果为未来的反应器设计以及生物固体的热化学处理及其转化为增值产品提供了重要参考。
