Inner Mongolia Engineering Research Center of Comprehensive Utilization of Bio-Coal Chemical Industry, Baotou 014010, China.
School of Chemistry and Chemical Engineering, Inner Mongolia University of Science and Technology, Baotou 014010, China.
Molecules. 2023 Jun 27;28(13):5031. doi: 10.3390/molecules28135031.
Heavy metal pollution caused by industrial wastewater such as mining and metallurgical wastewater is a major global concern. Therefore, this study used modified lignite as a low-cost adsorbent for heavy metal ions. Pingzhuang lignite was dissolved and modified using B3 to prepare a biotransformed-lignite adsorbent (BLA). The O, H, and N contents of the BLA increased after transformation, and the specific surface area increased from 1.81 to 5.66 m·g. Various adsorption properties were investigated using an aqueous solution of Cu(Ⅱ). The kinetic and isothermal data were well-fitted by pseudo-second-order and Langmuir models, respectively. The Langmuir model showed that the theoretical Cu(II) adsorption capacity was 71.47 mg·g. Moreover, large particles and a neutral pH were favorable for the adsorption of heavy metal ions. The adsorption capacities of raw lignite and BLA were compared for various ions. Microbial transformation greatly improved the adsorption capacity, and the BLA had good adsorption and passivation effects with Cu(II), Mn(II), Cd(II), and Hg(II). Investigation of the structural properties showed that the porosity and specific surface area increased after biotransformation, and there were more active groups such as -COOH, Ar-OH, and R-OH, which were involved in the adsorption performance.
重金属污染是一个全球性的问题，主要是由采矿和冶金废水等工业废水引起的。因此，本研究使用改性褐煤作为一种低成本的重金属离子吸附剂。采用 B3 对平庄褐煤进行溶解和改性，制备了生物转化褐煤吸附剂（BLA）。转化后，BLA 的 O、H 和 N 含量增加，比表面积从 1.81 增加到 5.66 m·g。采用 Cu（Ⅱ）水溶液对各种吸附性能进行了研究。动力学和等温线数据分别很好地符合拟二级和朗缪尔模型。朗缪尔模型表明，Cu（Ⅱ）的理论吸附容量为 71.47 mg·g。此外，大颗粒和中性 pH 有利于重金属离子的吸附。比较了原褐煤和 BLA 对各种离子的吸附容量。微生物转化大大提高了吸附容量，BLA 对 Cu（Ⅱ）、Mn（Ⅱ）、Cd（Ⅱ）和 Hg（Ⅱ）具有良好的吸附和钝化作用。结构性质的研究表明，生物转化后孔隙率和比表面积增加，并且存在更多的活性基团，如-COOH、Ar-OH 和 R-OH，这些基团参与了吸附性能。
