Details

Autor(en) / Beteiligte

• Zhang, Li
• Sun, Qingxuan
• Dou, Quanhao
• Lan, Shuang
• Peng, Yongzhen
• Yang, Jiachun

Titel

The molecular characteristics of dissolved organic matter in urbanized river sediments and their environmental impact under the action of microorganisms

Ist Teil von

• The Science of the total environment, 2022-06, Vol.827, p.154289-154289, Article 154289

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2022

Quelle

Elsevier ScienceDirect Journals

Beschreibungen/Notizen

• The complex relationships between the molecular composition of dissolved organic matter (DOM) and microbial communities are essential for maintaining the stability of aquatic ecosystems. This study comprehensively analyzed the characteristics and potential effects of DOM molecular composition as well as the relationship between microbial communities and DOM molecular composition in sediments from the Beiyun River, Beijing, China. The results showed that the content of DOM in Beiyun River sediments was 9.93–41.57 g/kg, mainly composed of lignin-like (36.75%) and protein-like (17.79%) substances. Compared with other rivers affected by anthropogenic activities, the higher content of labile substances in the Beiyun River increased the risk of nutrient release. At the same time, 1402 molecules remained stable in each sample, most of which were refractory lignin-like substances and protein-like substances carrying ester groups. The agricultural section contained more common DOM molecules than the urban section, mainly tannin-like and lignin-like substances with unsaturated or cyclic structures. And, the intensity of anthropogenic activities was the main reason affecting the diversity of unique DOM molecular in each sample. Moreover, Dechloromonas as the dominant genus of Proteobacteria was closely related to the biological modification of low unsaturated (DBE < 15) condensed aromatic compounds (P < 0.05). Anaerolineaceae and Anaerolineae belonging to the Chloroflexi phylum have the potential to degrade medium and high molecular weight (M/Z > 400) liable substances (P < 0.05) and release lignin-like substances. In addition, the proportion of protein-like substances can indirectly reflect the risk of nutrient release in sediments affected by urbanization. Thus, the results of this study further reveal the impact of urbanization on rivers, and provide theoretical basis and guidance for pollution control of the Beiyun River and other urbanized rivers worldwide. [Display omitted] •DOM content ranged from 9.93 to 41.57 g/kg but varied spatially.•DOM mainly composed of lignin-like (36.75%) and protein-like (17.79%) substances.•Microbial communities are closely related to the transformation of DOM components.•The proportion of protein-like substances can be used as an indirect indicator.