Enhanced Biochar for Water Purification

Researchers developed a modified sludge biochar (BZnSBC) using ZnCl2 and ball milling to effectively remove sulfamethoxazole (SMX) from water. BZnSBC showed high adsorption capacity, stability across various conditions, and efficient regeneration, offering a cost-effective solution for water purification.

July 10, 2024

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Mu, et al (2024) Functionally-designed metal salt and ball milling co-modified sludge biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More for adsorptive removal of trace level sulfamethoxazole: Behavior, characterization, mechanism and DFT study. *Journal of Environmental Chemical Engineering.* https://doi.org/10.1016/j.jece.2024.113479

Researchers have developed an innovative method to remove trace amounts of sulfamethoxazole (SMX), a common pollutant, from water using modified sludge biochar (SBC). Sulfamethoxazole, a widely-used antibiotic, poses environmental and health risks even at low concentrations. The study, published in the Journal of Environmental Chemical Engineering, outlines the creation of a biochar material modified with zinc chloride (ZnCl2) and further enhanced by ball milling, resulting in BZnSBC.

The modification process significantly improved the adsorption capacity of the biochar. BZnSBC demonstrated an impressive maximum adsorption capacity of 60,500 µg/g for SMX, which is over eight times higher than untreated SBC. This high efficiency was consistent across a range of real water samples, with elimination rates between 90.7% and 98.1%.

The primary mechanisms facilitating SMX removal included π-π conjugation, pore filling, hydrogen bonding, and Zn-O complexation. These interactions were thoroughly examined through sorption experiments, model fitting, and density functional theory (DFT) calculations. The modified biochar maintained high performance across various pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More levels, salt concentrations, and the presence of humic acids.

Moreover, the study highlighted the regeneration capability of BZnSBC. Using NaOH, the biochar could be efficiently reused, retaining 99.8% of its original adsorption capacity after five cycles. Safety assessments indicated low risks of zinc leachingLeaching is the process where nutrients are dissolved and carried away from the soil by water. This can lead to nutrient depletion and environmental pollution. Biochar can help reduce leaching by improving nutrient retention in the soil. More, ensuring environmental safety.

This research offers a promising, cost-effective approach for water purification, addressing the challenges posed by pollutants like sulfamethoxazole and contributing to safer water ecosystems.