Ran Li, Binyu Lu, Wen-Wen Liu, Zebing Li, Yi-Ming Kuo
{"title":"Effectiveness of bioretention system with saturated zone and different dry-wet alterations on nitrogen removal: performance and microbial community.","authors":"Ran Li, Binyu Lu, Wen-Wen Liu, Zebing Li, Yi-Ming Kuo","doi":"10.1007/s10653-025-02637-z","DOIUrl":null,"url":null,"abstract":"<p><p>This study redefines bioretention systems (BRSs) by elucidating how saturated zone (SZ) depths (0‒480 mm) and antecedent dry days (ADDs: 0.5‒4 days) orchestrate microbial-driven nitrogen removal without organic carbon supplementation. Through lab-scale experiments with Pennisetum alopecuroides, we demonstrate that optimized hydrologic-microbial synergy shifts nitrogen elimination from passive filtration to a self-sustaining redox interface. Critically, coupling deeper SZs (> 320 mm) with moderate dry-wet cycles (> 3-day ADDs) activated autotrophic denitrification via Saccharibacteria and Bradyrhizobium, reducing NO<sub>3</sub><sup>-</sup>-N accumulation to 7.59 ± 0.29 mg/L (31.7% removal) while achieving stable NH<sub>4</sub><sup>+</sup>-N removal (> 61.4‒68.8%) across conditions. In contrast, shallow SZs (< 160 mm) disrupted microbial cooperation, favoring incomplete nitrification and nitrate leakage. Proteobacteria dominated functional guilds in optimal SZ scenarios (e.g., 480 mm SZ with 4 ADDs), where total inorganic nitrogen removal surpassed non-saturated systems by 25‒30%, proving carbon-independent pathways. The highest NH<sub>4</sub><sup>+</sup>-N removal (68.8 ± 1.5%) occurred at 160 mm SZ with 2 ADDs, yet sustained efficiency required hydrologic thresholds that stabilized redox gradients. Microbial networks revealed deterministic assembly of nitrifier-denitrifier consortia under controlled hydrology, contrasting the stochasticity in suboptimal designs. These insights establish SZ-ADD-microbe codependencies as a design cornerstone, replacing ad hoc filtration metrics. By prioritizing microbial niche differentiation over soil adsorption, this work resolves the paradox of nitrate pollution in carbon-limited stormwater, offering a mechanistic blueprint for adaptive, carbon-neutral BRSs-a critical advance for eutrophication mitigation.</p>","PeriodicalId":11759,"journal":{"name":"Environmental Geochemistry and Health","volume":"47 8","pages":"325"},"PeriodicalIF":3.8000,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Environmental Geochemistry and Health","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.1007/s10653-025-02637-z","RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
This study redefines bioretention systems (BRSs) by elucidating how saturated zone (SZ) depths (0‒480 mm) and antecedent dry days (ADDs: 0.5‒4 days) orchestrate microbial-driven nitrogen removal without organic carbon supplementation. Through lab-scale experiments with Pennisetum alopecuroides, we demonstrate that optimized hydrologic-microbial synergy shifts nitrogen elimination from passive filtration to a self-sustaining redox interface. Critically, coupling deeper SZs (> 320 mm) with moderate dry-wet cycles (> 3-day ADDs) activated autotrophic denitrification via Saccharibacteria and Bradyrhizobium, reducing NO3--N accumulation to 7.59 ± 0.29 mg/L (31.7% removal) while achieving stable NH4+-N removal (> 61.4‒68.8%) across conditions. In contrast, shallow SZs (< 160 mm) disrupted microbial cooperation, favoring incomplete nitrification and nitrate leakage. Proteobacteria dominated functional guilds in optimal SZ scenarios (e.g., 480 mm SZ with 4 ADDs), where total inorganic nitrogen removal surpassed non-saturated systems by 25‒30%, proving carbon-independent pathways. The highest NH4+-N removal (68.8 ± 1.5%) occurred at 160 mm SZ with 2 ADDs, yet sustained efficiency required hydrologic thresholds that stabilized redox gradients. Microbial networks revealed deterministic assembly of nitrifier-denitrifier consortia under controlled hydrology, contrasting the stochasticity in suboptimal designs. These insights establish SZ-ADD-microbe codependencies as a design cornerstone, replacing ad hoc filtration metrics. By prioritizing microbial niche differentiation over soil adsorption, this work resolves the paradox of nitrate pollution in carbon-limited stormwater, offering a mechanistic blueprint for adaptive, carbon-neutral BRSs-a critical advance for eutrophication mitigation.
期刊介绍：
Environmental Geochemistry and Health publishes original research papers and review papers across the broad field of environmental geochemistry. Environmental geochemistry and health establishes and explains links between the natural or disturbed chemical composition of the earth’s surface and the health of plants, animals and people.
Beneficial elements regulate or promote enzymatic and hormonal activity whereas other elements may be toxic. Bedrock geochemistry controls the composition of soil and hence that of water and vegetation. Environmental issues, such as pollution, arising from the extraction and use of mineral resources, are discussed. The effects of contaminants introduced into the earth’s geochemical systems are examined. Geochemical surveys of soil, water and plants show how major and trace elements are distributed geographically. Associated epidemiological studies reveal the possibility of causal links between the natural or disturbed geochemical environment and disease. Experimental research illuminates the nature or consequences of natural or disturbed geochemical processes.
The journal particularly welcomes novel research linking environmental geochemistry and health issues on such topics as: heavy metals (including mercury), persistent organic pollutants (POPs), and mixed chemicals emitted through human activities, such as uncontrolled recycling of electronic-waste; waste recycling; surface-atmospheric interaction processes (natural and anthropogenic emissions, vertical transport, deposition, and physical-chemical interaction) of gases and aerosols; phytoremediation/restoration of contaminated sites; food contamination and safety; environmental effects of medicines; effects and toxicity of mixed pollutants; speciation of heavy metals/metalloids; effects of mining; disturbed geochemistry from human behavior, natural or man-made hazards; particle and nanoparticle toxicology; risk and the vulnerability of populations, etc.
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
