Original data of 'Carbon availability determines the stability of nitrate–vanadium co-remediation in layered biofilters'
Description
This dataset compiles original experimental data from a study investigating the stability and functional dynamics of nitrate–vanadium co-remediation in a vertically stratified biofilter system under varying carbon availability conditions. The research is grounded in the hypothesis that carbon supply regulates electron allocation among competing redox processes, thereby influencing the long-term stability of coupled nitrate reduction and vanadium [V(V)] reduction in subsurface environments. The dataset includes the following components: Water quality and operational parameters: Measurements of influent and effluent concentrations of NO₃⁻–N, NO₂⁻–N, NH₄⁺–N, V(V), dissolved organic carbon (DOC), and pH over a 330-day operational period. These data reflect system performance during both carbon-sufficient and carbon-limited phases. Reactor performance and kinetic responses: Time-series data capturing removal efficiencies and loading capacities for nitrate and vanadium across different operational stages. The dataset documents a clear biphasic transition from synergistic co-remediation to selective denitrification associated with declining DOC levels. Substrate characteristics and spatial stratification effects: Information on the physicochemical properties and carbon-release profiles of stratified lignocellulosic substrates (wheat straw, corn straw, and corncob), illustrating the formation of a vertical labile-to-recalcitrant carbon gradient within the biofilter.
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Steps to reproduce
Data Collection Steps to Reproduce 1) Reactor Construction and Operation: A laboratory-scale up-flow anaerobic column reactor was constructed using a stratified packing of agricultural residues: wheat straw (bottom), corn straw (middle), and corncob (top), each mixed with quartz sand to maintain permeability. The reactor was operated under anoxic conditions and continuously fed with groundwater amended to 50 mg L⁻¹ NO₃⁻–N (as NaNO₃) and 10 mg L⁻¹ V(V) (as NaVO₃) for 330 days using a peristaltic pump to control hydraulic retention time. 2) Water Quality and Chemical Analyses: Influent and effluent samples were filtered (0.22 μm) and analyzed for NO₃⁻–N, NO₂⁻–N, NH₄⁺–N, and V(V) using UV–Vis spectrophotometry (Hach DR6000). Dissolved organic carbon (DOC) was measured using a TOC analyzer (Analytik Jena Multi N/C 2100), and pH was monitored with a Mettler Toledo pH meter, following APHA standard methods. 3) Organic Matter and Solid-Phase Characterization: Dissolved organic matter evolution was characterized using fluorescence excitation–emission matrix (EEM) spectroscopy. Structural and functional group changes in lignocellulosic substrates were analyzed using Fourier transform infrared spectroscopy (FTIR). The valence state and immobilization of vanadium in solid samples were determined by X-ray photoelectron spectroscopy (XPS) after freeze-drying and grinding. 4) Metagenomic Sequencing and Functional Analysis: Biomass samples from different reactor layers were collected at multiple time points. DNA was extracted, sequenced using the Illumina NovaSeq platform, and analyzed through standard bioinformatics workflows, including quality control, assembly, and functional annotation against KEGG, NR, and COG databases. Sequencing data are publicly available in the NCBI SRA database (accession: PRJNA1059762). 5) Thermodynamic and Performance Analysis: Thermodynamic feasibility and electron allocation for nitrate and V(V) reduction were evaluated using the McCarty–Rittmann electron-equivalent framework. Time-series performance data were analyzed to identify phase transitions associated with carbon availability thresholds.
Institutions
- China University of Geosciences (Beijing)Beijing, Beijing
Categories
Funders
- National Key Research & Development Program of ChinaGrant ID: 2024YFC3712600