Water contamination with antimony (Sb) and arsenic (As) poses a serious threat to both ecosystems and human health. While numerous studies explore pollutant removal from water using modified 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, tackling Sb and As simultaneously has received less attention. This study bridges that gap by presenting a new biochar composite that effectively removes both contaminants from water, while also reusing valuable waste materials.

The proposed solution, electrolytic manganese residue (EMR)-biochar composite (EB), is derived from a one-step pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More process combining EMR, a hazardous waste product, with distillers grains, a leftover from bioethanol production. Researchers investigated the optimal conditions for creating EB with the highest adsorption capacity for both As and Sb. Their findings:

• Optimal temperature and ratio: A pyrolysis temperature of 750°C and a 3:1 ratio of EMR to distillers grains resulted in the most effective EB for removing As and Sb.
• Environmental factors: Certain ions like bicarbonate, phosphate, and humic acid can partially hinder EB’s adsorption capacity.
• High adsorption potential: EB boasts an impressive maximum adsorption capacity for As(III), As(V), Sb(III), and Sb(V) of 40.92, 40.54, 34.36, and 9.42 mg/g, respectively.
• Multiple adsorption mechanisms:Complexation, hydrogen bonding, and pore filling are identified as the key mechanisms behind EB’s effectiveness.

This innovation carries significant advantages:

• Dual target: EB tackles both As and Sb pollution, addressing a previously less-explored concern.
• Waste utilization: By using EMR and distillers grains, EB promotes safe waste management and resource recovery.
• Promising alternative: Compared to other engineered biochar composites,EB demonstrates strong potential as a cost-effective and environmentally friendly solution for cleaning up As and Sb-contaminated water.

While further research is needed to assess EB’s performance in real-world soil and water remediation scenarios, this study offers a promising avenue for sustainable and efficient removal of these harmful pollutants.

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Wei, et al (2024) Electrolytic manganese residue-biochar composite for simultaneous removal of antimony and arsenic from water: Adsorption performance and mechanisms. Journal of Cleaner Production, In Press. https://doi.org/10.1016/j.jclepro.2024.140623