Departamento de Ingeniería Bioquímica, Unidad Profesional Adolfo López Mateos, Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Mexico City, Mexico.
PLoS One. 2020 Feb 6;15(2):e0228595. doi: 10.1371/journal.pone.0228595. eCollection 2020.
Acid orange 74 (AO74) is a chromium-complex monoazo acid dye widely used in the textile industry. Due to being highly toxic and non-biodegradable, it must be removed from polluted water to protect the health of people and the environment. The aim of this study was two-fold: to evaluate the biosorption of AO74 from an aqueous solution by utilizing HCl-pretreated Lemna sp. (HPL), and to examine dye desorption from the plant material. The maximum capacity of AO74 biosorption (64.24 mg g-1) was reached after 4 h at the most adequate pH, which was 2. The biosorption capacity decreased 25% (to 48.18 mg g-1) during the second biosorption/desorption cycle and remained essentially unchanged during the third cycle. The pseudo-second-order kinetics model concurred well with the experimental results of assays involving various levels of pH in the eluent solution and distinct initial concentrations of AO74. NaOH (0.01 M) was the best eluent solution. The Toth isotherm model best described AO74 biosorption equilibrium data. FTIR analysis confirmed the crucial role of HPL proteins in AO74 biosorption. SEM-EDX and CLSM techniques verified the effective biosorption/desorption of the dye during the three cycles. Therefore, HPL has potential for the removal of AO74 dye from wastewaters.
酸性橙 74（AO74）是一种广泛应用于纺织工业的铬络合单偶氮酸性染料。由于其具有高毒性和不可生物降解性，必须从受污染的水中去除，以保护人类和环境的健康。本研究旨在评估利用 HCl 预处理浮萍（HPL）从水溶液中吸附 AO74，并研究从植物材料中解吸染料的情况。在最适宜的 pH 值 2 下，4 小时后达到 AO74 最大吸附容量（64.24 mg g-1）。在第二个吸附/解吸循环中，吸附容量下降了 25%（至 48.18 mg g-1），在第三个循环中基本保持不变。准二级动力学模型与涉及洗脱液中不同 pH 值和不同初始 AO74 浓度的实验结果非常吻合。NaOH（0.01 M）是最佳的洗脱液。托特（Toth）等温线模型很好地描述了 AO74 吸附平衡数据。FTIR 分析证实了 HPL 蛋白在 AO74 吸附中的重要作用。SEM-EDX 和 CLSM 技术验证了在三个循环中染料的有效吸附/解吸。因此，HPL 具有从废水中去除 AO74 染料的潜力。
