Percorrer por autor "Jian, Qiying"
A mostrar 1 - 2 de 2
Resultados por página
Opções de ordenação
- Multidimensional characterization of microplastic pollution in subtropical urban soils: Combining geospatial analysis and polymer risk indexingPublication . Du, Aolei; Li, Yanjun; Jian, Qiying; Zhang, Kai; Luo, Yutang; Yan, Jun; Du, Peixin; Power, Deborah Mary; Li, Ying; Ma, YibingMicroplastics (MPs) in urban soils of Macao, a high-density coastal city, were investigated to assess distribution patterns and ecological risks under anthropogenic pressures. MPs were extracted via density separation and H2O2 digestion, characterized using stereomicroscopy and μ-FTIR. Results showed significant accumulation (1.3 × 10³–2.6 × 104 items/kg; mean: 1.1 × 104 items/kg), dominated by fibers (49.4 %) and transparent particles (32.3 %). Polyethylene terephthalate (PET, 37.6 %) and polypropylene (PP, 18.3 %) were predominant, with 20–500 μm fragments as the prevalent size. MP abundance varied significantly across land uses, with traffic and commercial/residential areas exceeding natural green areas (p < 0.05). Population density positively correlated with MP levels (p < 0.01). Traffic activities influenced MP characteristics, while soil conductivity and organic matter correlated with MP abundance. MP shape and size exhibited variable relationships with soil particle content. Risk assessments using pollution load index (PLI), polymer hazard index (PHl), and potential ecological risk index (PERI) revealed substantial ecological threats, with PHl and PERI classifying sites into risk categories IV and V, respectively, driven by high hazard polymers (PAN, PVC). Hierarchical clustering for source analysis of MPs, and geospatial analysis based on the Inverse Distance Weighting (IDW) interpolation method, combined with the abundance of MPs and PERI, to predict the distribution map of soil MP pollution risk in Macao. This study provides critical baseline data on urban MP dynamics in coastal cities. Highlighting the need for targeted mitigation of high-risk polymers in regions with similar anthropogenic stressors.
- Spatiotemporal patterns, loads, and risks of microplastics in the stormwater system of a subtropical coastal cityPublication . Du, Aolei; Xu, Youxiang; Luo, Yutang; Jian, Qiying; Li, Yanjun; Zhan, Ziying; Qiu, Sizhe; Kam, Chon Wa; Chan, Tin-Chak; Huang, Tsz-Yin; Power, Deborah Mary; Zhang, KaiUrban stormwater runoff is a critical pathway for microplastics (MPs) to enter marine ecosystems, posing a significant threat. However, systematic studies on spatiotemporal patterns, loads, and risks of MPs in stormwater systems, particularly in subtropical coastal cities, remain limited. This study characterized MPs in Macao's stormwater drains across seasons, using density separation, H2O2 digestion, stereomicroscopy, and μ-FTIR analysis to investigate their abundance and distribution. MPs were ubiquitous across all sample sites, with abundance ranging from 0.86 to 53.03 n/L. Irregular shaped fragments (56.78 ± 0.13.80%) and the color black (38.44 ± 7.47%) were dominant, and the most common polymers were Polyethylene terephthalate (39.55 ± 16.63%), polypropylene (23.05 ± 18.15%), and polyethylene (9.52 ± 8.87%). While abundance of MPs was higher in the wet season, no significant seasonal variation was found. MP characteristics varied significantly with land use. The concentration range of MPs was estimated to be from 2.86 ± 0.38 to 3145.94 ± 766.74 μg/L, with an overall mean of 454.68 ± 572.20 μg/L through the mass concentration models. The daily MP emission load into the receiving water was estimated to range from 8.29 × 103 to 3.09 × 108 particles per day or 2.66 to 10,365.23 g/day. MP risk was high (Polymer Hazard Index/Potential Ecological Risk Index: III/V) due to hazardous polymers, with spatiotemporal variations further observed from fluctuating water flow erosion. Correlation analysis revealed that MP abundance showed a significant negative correlation with dissolved oxygen and a positive correlation with antecedent rainfall. These findings identify stormwater drains as a key MP conduit, influenced by rainfall and land use, calling for targeted management in urban coastal areas.