Powdered form of bones of silver carp fish, an available species in Bangladesh, was investigated as a prominent bioadsorbent for the removal of Congo red from synthetic solution. Experiments were conducted in batch process, and a number of influencing parameters, such as solution pH, adsorbent dosage, contact time, and initial Congo red concentration, were thoroughly investigated for optimization. Kinetic and equilibrium data were well described by pseudo-second-order model and Langmuir isotherm, respectively. Suitability of pseudo-second-order model to best fit with the adsorption process was corroborated by squared sum of errors analysis. Mass transfer mechanism was confirmed by intraparticle pore diffusion and Bangham’s diffusion models. Maximum sorption capacity of fish bone powder was found to be 666.67 mg·g⁻¹. The optimum condition (adsorbent dose: 5 g·L⁻¹; pH: 2.0; operating time: 4 h) for maximum sorption was determined as well. The increasing negative value of Gibbs free energy (ΔG) with temperature rise indicated spontaneous nature and feasibility of adsorption. The positive values of ΔH and ΔS suggested that the adsorption reaction is endothermic and random (at the solid/liquid interface) in nature. The activation energy (29.84 kJ·mol⁻¹) indicated that the sorption process was of physisorption type. A considerably high adsorption capacity pointed towards utilization of this apparently useless biomaterial as an effective adsorbent.

中文翻译：

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鲢鱼 (Hypophthalmichthys molitrix) 鱼骨粉去除刚果红：动力学、平衡和热力学研究

鲢鱼的粉末状骨头是孟加拉国的一种可用物种，被研究作为一种重要的生物吸附剂，用于从合成溶液中去除刚果红。实验以批处理方式进行，并彻底研究了许多影响参数，如溶液 pH 值、吸附剂剂量、接触时间和初始刚果红浓度，以进行优化。动力学和平衡数据分别由伪二阶模型和朗缪尔等温线很好地描述。伪二阶模型最适合吸附过程的适用性通过误差平方和分析得到证实。通过颗粒内孔扩散和 Bangham 扩散模型证实了传质机制。发现鱼骨粉的最大吸附量为666.67 mg·g ^-1. 还确定了最大吸附的最佳条件（吸附剂剂量：5 g·L ^-1；pH：2.0；操作时间：4 小时）。随着温度升高，吉布斯自由能 (Δ G ) 的负值增加表明吸附的自发性和可行性。Δ H和 Δ S的正值表明吸附反应本质上是吸热和随机的（在固/液界面）。活化能(29.84 kJ·mol ^-1 )表明吸附过程为物理吸附类型。相当高的吸附能力表明可以利用这种明显无用的生物材料作为有效的吸附剂。