Effects of sewage sludge application methods on the transport of heavy metals with runoff and their mechanisms

Copyright © 2023 Elsevier B.V. All rights reserved..

Woodland utilization is a promising disposal method for sewage sludge (SS). However, the potential risk of heavy metals (HMs) transport with runoff must be considered. Among the various factors influencing HMs loss, SS application methods (Holing application, HA; Broadcasting and mixing application, BM; Broadcasting application, BA) are likely to cause significant effects by altering soil erosion and soil aggregates. This study aimed to determine how SS application methods affect HMs loss, soil aggregates erosion, and how they are related. Accordingly, the losses of HMs in surface runoff, interflow, and sediment were quantified during six simulated rainfalls. The results demonstrated that all methods reduced surface runoff, but BA was the most effective. Additionally, BA significantly reduced the total sediment yield and the total proportion of the <0.05 mm fraction aggregates. Moreover, BA had the smallest cumulative losses of Pb and Cd through surface runoff and Cu, Pb, and Cd through sediment. Sediment was the most important pathway for HMs loss, through which over 76.56 % of HMs were lost. In BA, the <0.05 mm fraction aggregates had the lowest HMs load, whereas in other treatments had the highest (54.33 %-80.33 %). The potential ecological risk coefficient of Cd was beyond "moderate" in all the pathways of BM and "high" in the interflow of each SS treatment. Nonetheless, when the multi-elements were evaluated collectively, the potential ecological risk index for each SS treatment was categorized as "low". Overall, BA not only reduced soil erosion but also posed no risk of HMs pollution. It should be noted that the loss of Cd in the interflow had a great impact, while the <0.05 mm fraction aggregates played a significant role in the HMs load. Thus, the current study not only provides an effective approach for the environmentally safe disposal of SS but also proposes a scientific method for the application of SS in woodlands.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:912

Enthalten in:

The Science of the total environment - 912(2024) vom: 20. Jan., Seite 168909

Sprache:

Englisch

Beteiligte Personen:

Yang, Yuantong [VerfasserIn]
Feng, Weixun [VerfasserIn]
Bao, Li'an [VerfasserIn]
Xian, Lihua [VerfasserIn]
Lu, Jie [VerfasserIn]
Wu, Daoming [VerfasserIn]
Jacobs, Douglass F [VerfasserIn]
Zeng, Shucai [VerfasserIn]

Links:

Volltext

Themen:

Aggregates
Ecological risk
Interflow
Journal Article
Sediment
Simulated rainfall

Anmerkungen:

Date Revised 17.01.2024

published: Print-Electronic

Citation Status PubMed-not-MEDLINE

doi:

10.1016/j.scitotenv.2023.168909

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM365211230