Hai, et al (2024) Removal of ammonium from water by a bentonite 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 composite. Colloid and Polymer Science. https://doi.org/10.21203/rs.3.rs-4723030/v1

A study conducted by researchers at Vietnam National University has introduced a new method for removing ammonium (NH4+) from water using a bentonite biochar composite (BRK). This composite was synthesized from natural bentonite and rice husk biochar through a 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 at 400°C, followed by chemical activation with potassium hydroxide (KOH).

The BRK was evaluated for its ability to remove ammonium from water under different conditions, including variations in 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, temperature, and the presence of competing ions such as sodium, potassium, calcium, and magnesium. The study found that BRK exhibited a strong ion-exchange capacity, which was identified as the primary mechanism for ammonium removal.

Optimal ammonium adsorption occurred in solutions with pH values between 6 and 9. The composite performed best at lower temperatures, with a maximum Langmuir adsorption capacity of 22.51 mg/g at 10°C. However, the presence of coexisting cations diminished BRK’s efficiency, with divalent ions like calcium and magnesium having a more significant inhibitory effect compared to monovalent ions like sodium and potassium.

The study highlights BRK as a cost-effective and sustainable solution for water treatment, particularly in areas where ammonium contamination is prevalent. Its potential application in real-world water treatment systems suggests a promising step toward addressing ammonium pollution while also promoting circular economy practices through the utilization of agricultural waste. Future research should focus on field trials to validate BRK’s practical applicability.