Wang Yujing, Zhang Hua, Lv Fan, Xu Bin, He Pinjing
Institute of Waste Treatment & Reclamation, College of Environmental Science and Engineering, Tongji University, Shanghai, People's Republic of China.
Shanghai Institute of Pollution Control and Ecological Security, Shanghai, People's Republic of China.
J Air Waste Manag Assoc. 2025 Aug;75(8):624-635. doi: 10.1080/10962247.2025.2503405. Epub 2025 Jun 4.
Odor is a serious issue for municipal solid waste treatment process, and chemical absorption is a common technology for odor control. Interactions among odorants will influence the performance of chemical absorption, and they are still not fully understood. This work took the common and important odorants, including hydrogen sulfide (HS), methanethiol, propanethiol and acetaldehyde, as examples, to investigate the removal performance of mixed odorants by sodium hypochlorite (NaClO) solution at different concentrations, and interactions among the odorants. The absorption experiments were conducted in gas-washing bottles with single or mixture of HS, methanethiol, propanethiol and acetaldehyde as the inlet gases, and NaClO solutions at different concentrations as the absorption solutions. The thermodynamic equilibrium was simulated. Acetaldehyde was eliminated mainly by physical absorption, and the removal efficiency was not affected by the other three odorants. The removal efficiencies of HS, methanethiol, and propanethiol increased with the chlorine concentration ([Cl]), and reached nearly 100% by the NaClO solution of pH = 12.19, [Cl] = 158.00 mg/L. HS, methanethiol, and propanethiol competed for reacting with NaClO. HS was more effectively removed than methanethiol and propanethiol due to its lower pKa value. The removal efficiency of methanethiol decreased linearly with the increase in methanethiol and HS concentrations mainly due to the consumption of NaClO. Propanethiol removal was decreased by both methanethiol and HS, and methanethiol had more influence than HS due to the higher consumption of NaClO. The odor control performance could be overestimated when there are several important odorants, and only the removal efficiency of a single odorant was considered. Correspondingly, suggestions for chemical scrubber operation were provided, including the consideration of odorant interactions, the selection of monitoring odorants, and the optimization of operating parameters (pH and [Cl]) using machine learning methods. Chemical absorption is widely applied for odor control, and the interaction between odorants is an important influencing factor of the performance. Hydrogen sulfide, methanethiol, propanethiol and acetaldehyde are common and important odorants emitted during municipal solid waste treatment. This work investigated the removal performance of chemical absorption for the single and mixture of these odorants, and revealed the interaction between them, as well as the risk of overestimating odor performance with the removal efficiency of a single odorant, which can provide insights into optimizing odor control technologies.
气味是城市固体废物处理过程中的一个严重问题，化学吸收是一种常见的气味控制技术。气味物质之间的相互作用会影响化学吸收的性能，而目前人们对此仍未完全了解。本研究以常见且重要的气味物质，包括硫化氢（H₂S）、甲硫醇、丙硫醇和乙醛为例，研究了不同浓度的次氯酸钠（NaClO）溶液对混合气味物质的去除性能以及气味物质之间的相互作用。吸收实验在洗气瓶中进行，以H₂S、甲硫醇、丙硫醇和乙醛的单一或混合物作为进气，以不同浓度的NaClO溶液作为吸收液。对热力学平衡进行了模拟。乙醛主要通过物理吸收被去除，其去除效率不受其他三种气味物质的影响。H₂S、甲硫醇和丙硫醇的去除效率随氯浓度（[Cl]）的增加而提高，pH = 12.19、[Cl] = 158.00 mg/L的NaClO溶液对它们的去除率接近100%。H₂S、甲硫醇和丙硫醇竞争与NaClO反应。由于H₂S的pKa值较低，其比甲硫醇和丙硫醇更有效地被去除。甲硫醇的去除效率随甲硫醇和H₂S浓度的增加呈线性下降，主要是由于NaClO的消耗。丙硫醇的去除受到甲硫醇和H₂S的抑制，且由于NaClO消耗较高，甲硫醇的影响比H₂S更大。当存在几种重要的气味物质而仅考虑单一气味物质的去除效率时，气味控制性能可能会被高估。相应地，本文提供了化学洗涤器操作的建议，包括考虑气味物质的相互作用、选择监测气味物质以及使用机器学习方法优化操作参数（pH和[Cl]）。化学吸收广泛应用于气味控制，气味物质之间的相互作用是影响其性能的重要因素。硫化氢、甲硫醇、丙硫醇和乙醛是城市固体废物处理过程中常见且重要的气味物质。本研究考察了化学吸收对这些气味物质单一和混合时的去除性能，揭示了它们之间的相互作用，以及仅用单一气味物质去除效率高估气味控制性能的风险，可为优化气味控制技术提供参考。
