Enhancing Adsorption Efficiency: Hydrophilic Sludge Biochar for Cr(VI) and Methylene Blue Removal

Hydrophilic sludge biochar (HKBC), synthesized via pyrolysis and modification, exhibits enhanced adsorption capacities for removing Cr(VI) and methylene blue from wastewater. Surface modifications increase functional groups and surface area, enabling efficient pollutant removal, offering a sustainable solution for environmental remediation.

March 17, 2024

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Zhao, Liu, et al (2024) Effects and mechanisms on Cr(VI) and methylene blue adsorption by acid (NH₄)₂S₂O₈ 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. *Separation and Purification Technology.* https://doi.org/10.1016/j.seppur.2024.127100

In the quest for efficient removal of toxic pollutants like Cr(VI) and methylene blue (MB) from wastewater, a novel approach has emerged. Hydrophilic sludge biochar (HKBC), synthesized via a meticulous two-step process involving 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 and modification, has shown remarkable promise. The modification process, utilizing KHCO3 activation and acidic (NH4)2S2O8 modification, significantly augmented the specific surface area and functional groups of the biochar.

Characterization studies revealed heightened hydrophilicity, polarity, and increased presence of oxygenic and amino functional groups in HKBC. These alterations resulted in a notable enhancement of the biochar’s adsorption capacity. HKBC demonstrated exceptional removal efficiency, with rates of 97.42% for Cr(VI) and 99.98% for MB in water.

The study delved into the adsorption mechanisms, uncovering a combination of surface complexation, reduction, ion exchange, and electrostatic forces for Cr(VI) removal, while MB removal involved surface complexation, π-π interactions, electrostatic, and hydrogen bond forces. The kinetics and thermodynamics of the uptake processes further validated the efficacy of HKBC, showing spontaneous and endothermic behaviors.

The significance of this work lies in offering a viable solution for the treatment of wastewater contaminated with dyes and chromium, addressing both environmental and health concerns. By repurposing sludge into HKBC, a resourceful and eco-friendly approach is introduced, aligning with efforts to transform waste into valuable assets.

In conclusion, the synthesis of hydrophilic sludge biochar represents a promising advancement in wastewater treatment technology, showcasing enhanced adsorption capabilities for the removal of hazardous pollutants, thereby contributing to the pursuit of a cleaner and safer environment.