Saha Dipendu, Schlosser Ryan, Lapointe Lindsay, Comroe Marisa L, Samohod John, Whiting Elijah, Young David S
Chemical and Materials Engineering Department, Widener University, 1 University Place, Chester, PA 19013, USA.
Molecules. 2025 Jul 3;30(13):2848. doi: 10.3390/molecules30132848.
This study presents a sustainable approach for synthesizing high-performance activated carbon from Alga through hydrothermal carbonization followed by chemical activation using potassium hydroxide. The resulting activated carbon exhibited a high Brunauer-Emmett-Teller (BET) surface area of 1747 m/g and a total pore volume of 1.147 cm/g, with micropore volume accounting for 0.4 cm/g. Characterization using Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS), X-ray Photoelectron Spectroscopy (XPS), and gas adsorption analyses confirmed the presence of hierarchical micro- and mesoporosity as well as favorable surface functional groups. The synthesized carbon was used to fabricate electrodes for membrane capacitive deionization (MCDI) along with cation and anion-selective membranes, which were then tested with saline water (500-5000 ppm) and synthetic hard water (898 ppm of total salts). The salt adsorption capacity (SAC) reached 25 (batch) to 40 (continuous) mg/g, while rapid adsorption rates with average salt adsorption rates (ASARs) values exceeding 10 (batch) to 30 (continuous) mg·g·min during early stages were obtained. Batch MCDI experiments demonstrated a higher SAC compared to continuous operation, with non-monotonic trends in SAC observed as a function of feed concentration. Ion adsorption kinetics were influenced by ion valency, membrane selectivity, and pore structure. The specific energy consumption (SEC) was calculated as 8-21 kJ/mol for batch and 0.1-0.5 kJ/mol for continuous process. These performance metrics are on par with or surpass those reported in the recent literature for similar single-electrode CDI configurations. The results demonstrate the viability of using Alga-derived carbon as an efficient and eco-friendly electrode material for water desalination technologies.
本研究提出了一种可持续的方法，通过水热碳化从藻类合成高性能活性炭，随后使用氢氧化钾进行化学活化。所得活性炭具有1747 m²/g的高布鲁诺尔-埃米特-泰勒（BET）表面积和1.147 cm³/g的总孔体积，其中微孔体积为0.4 cm³/g。使用扫描电子显微镜-能量色散X射线光谱（SEM-EDS）、X射线光电子能谱（XPS）和气体吸附分析进行表征，证实了存在分级微孔和介孔以及良好的表面官能团。合成的碳与阳离子和阴离子选择性膜一起用于制造膜电容去离子（MCDI）电极，然后用盐水（500-5000 ppm）和合成硬水（总盐含量898 ppm）进行测试。盐吸附容量（SAC）达到25（间歇）至40（连续）mg/g，同时在早期阶段获得了快速吸附速率，平均盐吸附速率（ASARs）值超过10（间歇）至30（连续）mg·g⁻¹·min⁻¹。间歇MCDI实验表明其SAC高于连续操作，并且观察到SAC随进料浓度呈非单调趋势。离子吸附动力学受离子价态、膜选择性和孔结构的影响。间歇过程的比能耗（SEC）计算为8-21 kJ/mol，连续过程为0.1-0.5 kJ/mol。这些性能指标与近期文献报道的类似单电极CDI配置相当或更优。结果表明，使用藻类衍生的碳作为水淡化技术的高效且环保电极材料是可行的。
