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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #422856
Research Project: Sustaining Productivity and Ecosystem Services of Agricultural and Horticultural Systems in the Southeastern United States

Location: Soil Dynamics Research

Title: Co-transport and retention of arsenic and pine wood biochar in saturated porous media: Fate and interaction mechanisms under solution chemistry and practical feasibility

Author
item KUMAR, RAKESH - Auburn University
item LAMBA, JASMEET - Auburn University
item ADHIKARI, SUSHIL - Auburn University
item Torbert Iii, Henry

Submitted to: ACS ES&T Engineering
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/8/2025
Publication Date: 5/8/2025
Citation: Kumar, R., Lamba, J., Adhikari, S., Torbert III, H.A. 2025. Co-transport and retention of arsenic and pine wood biochar in saturated porous media: Fate and interaction mechanisms under solution chemistry and practical feasibility. ACS ES&T Water. https://doi.org/10.1021/acsestwater.5c00232.
DOI: https://doi.org/10.1021/acsestwater.5c00232

Interpretive Summary: Arsenic (As) contamination in groundwater causes serious health and environmental concerns. The use of pine wood raw biochar (PWBC) has been considered or the practical feasibility and sustainable water management. A study was conducted to determine the adsorptive properties of and engineered iron-modified biochar (Fe-PWBC) in As(V) removal. Co-transport and deposition of As(V) with PWBC and Fe-PWBC were analyzed in saturated columns and experimental data were modeled using HYDRUS-1D and simulated for effective As removal in managed aquifer recharge technique. Understanding the fate and remediation of arsenic in saturated porous media is crucial for effective transport and deposition. Overall, raw and iron-modified biochars act as carriers for arsenic in saturated porous media and facilitate adsorption onto their active sites during their co-transport and deposition governed by solution chemistry.

Technical Abstract: Geogenic arsenic (As) contamination in groundwater causes serious health and environmental concerns. Anthropogenic actions also contaminate groundwater aquifer systems, severely impacting human health and ecosystems due to inadequate water management. Considering practical feasibility and sustainable water management, this research work aims to determine the adsorptive properties of pine wood raw biochar (PWBC) and engineered iron-modified biochar (Fe-PWBC) in As(V) removal. Co-transport and deposition of As(V) with PWBC and Fe-PWBC were analyzed in saturated columns and experimental data were modeled using HYDRUS-1D and simulated for effective As removal in managed aquifer recharge technique. Sand-packed saturated columns lead to high As(V) deposition at 0 mM, whereas, IS of 10 mM mobilizes As(V) at pH 6.7 ± 0.1. Considering co-transport, the adsorptive behavior of PWBC and Fe-PWBC were analyzed for 5-10 mg/L As(V) under the effects of pH (5.5 ± 0.1 – 10.5 ± 0.1), ionic strength (0-10 mM), arsenic concentrations (5-10 mg/L), and biochar dosage (50-100 mg/L). Increased biochar deposition was observed significantly with increased ionic strength due to aggregation and ionic effects, in which Fe-PWBC showed potential As(V) adsorption compared to PWBC. Understanding the fate and remediation of arsenic in saturated porous media is crucial for effective transport and deposition. Overall, raw and iron-modified biochars act as carriers for arsenic in saturated porous media and facilitate adsorption onto their active sites during their co-transport and deposition governed by solution chemistry.