Ye Jinyu, Gao Yuan, Gao Huan, Zhao Qingqing, Xu Dan, Zhou Minjie, Shi Meng, Xue Xiangdong
School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China; Zhejiang-Singapore Joint Laboratory for Urban Renewal and Future City, Hangzhou 310023, China.
School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou, Zhejiang 310023, China; Zhejiang-Singapore Joint Laboratory for Urban Renewal and Future City, Hangzhou 310023, China.
J Hazard Mater. 2025 Apr 5;487:137136. doi: 10.1016/j.jhazmat.2025.137136. Epub 2025 Jan 6.
Despite growing attention to the environmental pollution caused by tire wear particles (TWPs), the effects of pristine and photoaged TWPs (P-TWPs and A-TWPs) and their TWP leachates (TWPLs; P-TWPL and A-TWPL) on key nitrogen removal processes in estuarine sediments remain unclear. This study explores the responses of the denitrification rate, anammox rate, and nitrous oxide (NO) accumulation to P-TWP, A-TWP, P-TWPL, and A-TWPL exposure in estuarine sediments, and assesses the potential biotoxic substances present in TWPLs. P-TWPs reduced the denitrification rate by 17.1 ± 10.0 % and increased NO accumulation by 28.1 ± 18.7 %. The A-TWPs not only reduced the denitrification rate by 31.3 ± 8.3 % and increased NO accumulation by 43.1 ± 22.0 %, but also decreased the anammox rate by 22.1 ± 13.3 %. A-TWPs further inhibited the denitrification rate by reducing nitrate reductase activity and the abundance of its gene (narG), while simultaneously decreasing hydrazine synthase activity and the abundance of its gene (hzo), thereby slowing the anammox rate. NO accumulation after exposure to TWPs and TWPLs was positively correlated with the activity ratio of NO-producing and NO-consuming enzymes. Zinc (Zn) release in A-TWPL was 48.5 ± 6.9 % higher than that in P-TWPL, which is a crucial reason for the higher biotoxicity produced by A-TWPs. In addition, the abundance of denitrifying and anammox bacteria closely linked to the Zn, manganese, and arsenic concentrations in the TWPLs. This study provides insights into assessing the environmental risks posed by TWPs to estuarine ecosystems.
尽管人们越来越关注轮胎磨损颗粒（TWPs）造成的环境污染，但原始和光老化的TWPs（P-TWPs和A-TWPs）及其TWP浸出液（TWPLs；P-TWPL和A-TWPL）对河口沉积物中关键氮去除过程的影响仍不清楚。本研究探讨了河口沉积物中反硝化速率、厌氧氨氧化速率和一氧化二氮（N₂O）积累对P-TWP、A-TWP、P-TWPL和A-TWPL暴露的响应，并评估了TWPLs中存在的潜在生物毒性物质。P-TWPs使反硝化速率降低了17.1±10.0%，并使N₂O积累增加了28.1±18.7%。A-TWPs不仅使反硝化速率降低了31.3±8.3%，使N₂O积累增加了43.1±22.0%，还使厌氧氨氧化速率降低了22.1±13.3%。A-TWPs通过降低硝酸还原酶活性及其基因（narG）的丰度进一步抑制反硝化速率，同时降低肼合酶活性及其基因（hzo）的丰度，从而减缓厌氧氨氧化速率。暴露于TWPs和TWPLs后的N₂O积累与产N₂O和消耗N₂O酶的活性比率呈正相关。A-TWPL中的锌（Zn）释放量比P-TWPL高48.5±6.9%，这是A-TWPs产生更高生物毒性的关键原因。此外，与TWPLs中的锌、锰和砷浓度密切相关的反硝化和厌氧氨氧化细菌的丰度。本研究为评估TWPs对河口生态系统造成的环境风险提供了见解。
