A novel composite absorbent was developed based on dissolved cellulose fibers (as matrix) reinforced with microfibrillated cellulose (MFC). Both cellulose fibers and microfibrillated cellulose were functionally modified using an organic solvent-free approach to introduce carboxyl groups onto cellulose and the surface of MFC. To further enhance the adsorption capacity, nanosized CaCO₃ was added as a pore forming agent during the formation of dissolved cellulose/MFC (CMFC) composites and removed in acidic conditions afterward. The structure and morphology of as-synthesized adsorbents were identified using a scanning electron microscope, Fourier transform infrared spectroscope, thermogravimetric analyzer, and Brunauer–Emmet–Teller instrument. An orthogonal experimental design and software SPSS were utilized to reveal the impact of influencing factors (pH, temperature, and the concentration of pore forming agent) on dye removal. The results were imitated by kinetic models and adsorption isotherms, which revealed that the carbonylated CMFCs had a maximum adsorption capacity of Methylene Blue of 303 mg g^–1. The results of pseudo-second-order kinetic and the Langmuir isotherm modeling indicated that the adsorption was monolayer and governed by chemisorption.

中文翻译：

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溶解纤维素纤维/微纤化纤维素组成的新型复合吸附剂，用于从水溶液中去除染料

基于微纤化纤维素（MFC）增强的溶解纤维素纤维（作为基质），开发了一种新型复合吸收剂。使用无有机溶剂的方法对纤维素纤维和微纤化纤维素进行功能改性，以将羧基引入纤维素和MFC的表面。为了进一步提高吸附能力，纳米级CaCO ₃在形成溶解的纤维素/ MFC（CMFC）复合材料的过程中，将其作为孔形成剂加入，然后在酸性条件下将其除去。使用扫描电子显微镜，傅立叶变换红外光谱仪，热重分析仪和Brunauer-Emmet-Teller仪器鉴定合成的吸附剂的结构和形态。利用正交实验设计和软件SPSS揭示了影响因素（pH，温度和成孔剂浓度）对染料去除的影响。通过动力学模型和吸附等温线模拟了结果，结果表明羰基化的CMFCs对亚甲基蓝的最大吸附容量为303 mg g ^–1。拟二级动力学和Langmuir等温线模型的结果表明，吸附是单层的，并受化学吸附的支配。