Abstract

The biosorption potential of cost-effective and agricultural residue, Ipomoea carnea wood (ICW) was examined by the removal of cationic dye, methylene blue (MB) from aqueous solution. The surface morphology, structural and thermal properties of untreated ICW were analyzed using Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Thermo-gravimetric Analysis (TGA), respectively. The effects of different parameters namely concentration of biosorbent, initial pH, initial MB composition and temperature on biosorption capacity and biosorption (%) were studied. The kinetic and equilibrium models were developed to fit the experimental data on MB biosorption. The maximum biosorption capacity of 39.38 mg g⁻¹ was obtained at 40 °C using Langmuir model. The removal of MB was found to be significantly varying with temperature. Box–Behnken design was applied to optimize the biosorption parameters. The optimized condition for MB biosorption was evaluated as dosage of 3.1 g L⁻¹, pH of 7.04, Temperature of 49.1 °C, MB concentration of 30.48 mg L⁻¹ and maximum biosorption (%) of 83.87. The regeneration of ICW was investigated by five cycles using a suitable eluting agent. Hence, ICW without any pretreatment and chemical modification is a potential candidate for the removal of MB in terms of availability and economy of the process.

• Novelty statement

• Ipomoea carnea wood (ICW) without any pretreatment explored a potential biosorbent for the removal of methylene blue (MB) in terms of availability and economy of the process.

• The physico-chemical properties of ICW characterized using Scanning Electron Microscopy, Fourier transform infrared spectroscopy and Thermo-gravimetric Analysis showed ICW as a promising biosorbent for MB removal.

• Presence of heterogeneous with rugged morphological structure, cavities, irregular shape and size of large pores provide the better biosorption capability for MB molecules using ICW without any pretreatment or chemical modification.

• Analysis of kinetic and isotherm models was performed to examine the better fitness of experimental data with model. Thermodynamic parameters indicating feasible and endothermic MB biosorption.

• Statistical design of experiments is used to optimize the condition and corresponding maximum MB removal using Derringer’s desired function methodology.

• Untreated ICW is a potential reusable biosorbents, effectively employed in successive biosorption and desorption process for the removal of MB from aqueous solutions.

摘要

通过从水溶液中去除阳离子染料亚甲基蓝（MB）来研究具有成本效益的农业残留物番薯木（ICW）的生物吸附潜力。分别使用扫描电子显微镜（SEM），傅里叶变换红外光谱（FTIR）和热重分析（TGA）分析未经处理的ICW的表面形态，结构和热性能。研究了生物吸附剂浓度，初始pH，初始MB组成和温度等不同参数对生物吸附量和生物吸附率的影响。建立了动力学和平衡模型以适合MB生物吸附的实验数据。最大生物吸附量39.38 mg g ^-1使用Langmuir模型在40℃获得。发现MB的去除随温度显着变化。Box–Behnken设计用于优化生物吸附参数。MB生物吸附的最佳条件评估为剂量为3.1 g L ^-1，pH为7.04，温度为49.1°C，MB浓度为30.48 mg L ^-1和最大生物吸附（％）为83.87。使用合适的洗脱剂，通过五个循环研究了ICW的再生。因此，就工艺的可用性和经济性而言，未经任何预处理和化学改性的ICW是去除MB的潜在候选者。

• 新颖性声明

• 不加任何预处理的番薯木（ICW）就该方法的可用性和经济性而言，探索了一种潜在的生物吸附剂来去除亚甲基蓝（MB）。

• 用扫描电子显微镜，傅立叶变换红外光谱和热重分析表征的ICW的理化性质表明，ICW是一种有前途的MB去除生物吸附剂。

• 异质性具有凹凸不平的形态结构，空腔，不规则形状和大孔尺寸，使用ICW无需任何预处理或化学修饰即可为MB分子提供更好的生物吸附能力。

• 进行了动力学和等温线模型的分析，以检验实验数据与模型的更好适应性。热力学参数表明可行的和吸热的MB生物吸附。

• 实验的统计设计用于使用Derringer的所需函数方法优化条件和相应的最大MB去除量。

• 未经处理的ICW是潜在的可重复使用的生物吸附剂，有效地用于连续的生物吸附和解吸过程中，以从水溶液中去除MB。