Yang Xinyi, Liu Jingjing, Huang Xuejin, Cui Hemin, Wei Ligang, Shao Guolin, Fu Xu, Liu Na, An Qingda, Zhai Shangru
School of Light Industry and Chemical Engineering, Dalian Polytechnic University Dalian 116034 China
Dalian Zhonghuida Scientific Instrument Co. Ltd Dalian 116023 China.
RSC Adv. 2024 Jul 29;14(33):23606-23620. doi: 10.1039/d4ra04416a. eCollection 2024 Jul 26.
The cost-effective and green separation of dye pollutants from wastewater is of great importance in environmental remediation. Industrial seaweed residue (SR), as a low-cost cellulose source, was used to produce carboxylated nanorized-SR (NSR) oxalic acid (OA)-water pretreatments followed by ultrasonic disintegration. Fourier transform infrared spectroscopy, X-ray polycrystalline diffraction, nitrogen isotherms, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, X-ray photoelectron spectrometry, particle charge detection, zeta potential and retro titration experiments were utilized to explore the physiochemical properties of samples. The NSRs with carboxyl content of 4.58-6.73 mmol g were prepared using 10-60% OA-water pretreatment. In the case of 20% OA-water pretreatment, the highest NSR yield (73.9%) and nanocellulose content (80.2%) were obtained. Through self-assembly induced by the electrostatic interaction, magnetic NSR composite adsorbents (MNSRs) were prepared with the combination of NSR and FeO nanoparticles (NPs). The carboxylated NSR with negative charge demonstrated good affinity for FeO NPs. The FeO NPs were perfectly microencapsulated with the NSR when the NSR/FeO mass ratio was higher than 1/1. The adsorption properties of the MNSR for methylene blue (MB) removal from aqueous solution were investigated. The adsorbent with NSR/FeO mass ratio of 1/1 (MNSR1/1) exhibited optimum performance in terms of the magnetic properties and adsorption capacity. The MNSR1/1 showed high adsorption ability in a pH ≥7 environment. According to the Langmuir fitting, the maximum adsorption capacity of MNSR1/1 for MB reached 184.25 mg g. The adsorption of MB complies with the pseudo-second-order kinetic model. MNSR1/1 still maintained good adsorption properties after the fifth cycle of adsorption-desorption. MNSR1/1 could selectively adsorb cationic dye (, MB and methyl violet) from wastewater, with hydrogen bonding and electrostatic interaction as the main force.
从废水中经济高效且环保地分离染料污染物在环境修复中具有重要意义。工业海藻残渣（SR）作为一种低成本的纤维素来源，通过草酸（OA）-水预处理并随后进行超声破碎来制备羧基化纳米级SR（NSR）。利用傅里叶变换红外光谱、X射线多晶衍射、氮气等温线、扫描电子显微镜、透射电子显微镜、振动样品磁强计、X射线光电子能谱、颗粒电荷检测、zeta电位和返滴定实验来探究样品的物理化学性质。使用10%-60%的OA-水预处理制备了羧基含量为4.58-6.73 mmol/g的NSR。在20% OA-水预处理的情况下，获得了最高的NSR产率（73.9%）和纳米纤维素含量（80.2%）。通过静电相互作用诱导的自组装，将NSR与FeO纳米颗粒（NPs）结合制备了磁性NSR复合吸附剂（MNSRs）。带负电荷的羧基化NSR对FeO NPs表现出良好的亲和力。当NSR/FeO质量比高于1/1时，FeO NPs被NSR完美微囊化。研究了MNSR从水溶液中去除亚甲基蓝（MB）的吸附性能。NSR/FeO质量比为1/1的吸附剂（MNSR1/1）在磁性和吸附容量方面表现出最佳性能。MNSR1/1在pH≥7的环境中表现出高吸附能力。根据朗缪尔拟合，MNSR1/1对MB的最大吸附容量达到184.25 mg/g。MB的吸附符合准二级动力学模型。MNSR1/1在第五次吸附-解吸循环后仍保持良好的吸附性能。MNSR1/1可以选择性地从废水中吸附阳离子染料（如MB和甲基紫），以氢键和静电相互作用为主要作用力。
