Molecular transformation of dissolved organic matter in manganese ore-mediated constructed wetlands for fresh leachate treatment

Md. Hasibur Rahaman; Tong Yang; Zhongyi Zhang; Wenbo Liu; Zhongbing Chen; Jacek Mąkinia; Jun Zhai

doi:10.1016/j.jenvman.2024.120834

Molecular transformation of dissolved organic matter in manganese ore-mediated constructed wetlands for fresh leachate treatment

Abstract

The organic matter (OM) and nitrogen in Fresh leachate (FL) from waste compression sites pose environmental and health risks. Even though the constructed wetland (CW) can efficiently remove these pollutants, the molecular-level transformations of dissolved OM (DOM) in FL remain uncertain. This study reports the molecular dynamics of DOM and nitrogen removal during FL treatment in CWs. Two lab-scale vertical-flow CW systems were employed: one using only sand as substrates (act as a control, CW-C) and the other employing an equal mixture of manganese ore powder and sand (experimental, CW-M). Over 488 days of operation, CW-M exhibited significantly higher removal rates for chemical oxygen demand (COD), ammonia nitrogen (NH4 +-N), and dissolved organic matter (represented by dissolved organic carbon, DOC) at 98.2 ± 2.5%, 99.2 ± 1.4%, and 97.9 ± 1.9%, respectively, in contrast to CW-C (92.8 ± 6.8%, 77.1 ± 28.1%, and 74.7 ± 9.5%). The three-dimensional fluorescence excitation-emission matrix (3D-EEM) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analyses unveiled that the influent DOM was predominantly composed of readily biodegradable protein-like substances with high carbon content and low unsaturation. Throughout treatment, it led to the degradation of low O/C and high H/C compounds, resulting in the formation of DOM with higher unsaturation and aromaticity, resembling humic-like substances. CW-M showcased a distinct DOM composition, characterized by lower carbon content yet higher unsaturation and aromaticity than CW-C. The study also identified the presence of Gammaproteobacteria, reported as Mn-oxidizing bacteria with significantly higher abundance in the upper and middle layers of CW-M, facilitating manganese cycling and improving DOM removal. Key pathways contributing to DOM removal encompassed adsorption, catalytic oxidation by manganese oxides, and microbial degradation. This study offers novel insights into DOM transformation and removal from FL during CW treatment, which will facilitate better design and enhanced performance.

Citations

0

CrossRef
0

Web of Science
0

Scopus

Authors (7)

Md. Hasibur Rahaman
Tong Yang
Zhongyi Zhang
Wenbo Liu
Zhongbing Chen
Jacek Mąkinia prof. dr hab. inż.
Jun Zhai

Cite as

Full text

full text is not available in portal

full content of the article see on external site open in new tab

Keywords

Details

Category:

Articles

Type:

artykuły w czasopismach

Published in:

JOURNAL OF ENVIRONMENTAL MANAGEMENT no. 358,
ISSN: 0301-4797

Language:

English

Publication year:

2024

Bibliographic description:

Rahaman M. H., Yang T., Zhang Z., Liu W., Chen Z., Mąkinia J., Zhai J.: Molecular transformation of dissolved organic matter in manganese ore-mediated constructed wetlands for fresh leachate treatment// JOURNAL OF ENVIRONMENTAL MANAGEMENT -Vol. 358, (2024), s.120834-

DOI: