Department of Chemical Engineering, MNGPC, Pudhucherry, 605008, India.
Department of Civil Engineering, Pondicherry Engineering, College, Pudhucherry, 605014, India.
Environ Res. 2021 Aug;199:111364. doi: 10.1016/j.envres.2021.111364. Epub 2021 May 24.
This research study reported the feasibility of cadmium removal using green algae, Caulerpa scalpelliformis, under controlled environmental conditions. The algal biosorbent could effectively remove cadmium under broad range of test conditions, namely, initial pH (3-6), adsorbent mass (0.5-2.5 gL) and shaking speed (60-100 rpm). The best operating conditions were identified using Central Composite Design under Response Surface methodology and found to be pH - 4.9, adsorbent mass - 2.1 gL and shaking speed - 90 rpm. Equilibrium studies were conducted and monolayer sorption was identified as the mechanism, confirmed by Langmuir isotherm (R = 0.9920). The maximum Cd uptake achieved at optimal conditions was 111.11 mg g. The kinetic constants of the best fit model (pseudo second order) were determined. The thermodynamic feasibility was verified (ΔG < 0) and the biosorption process was found to be endothermic (ΔH > 0). The mass transfer studies shows that the mass transfer coefficient was inversely related to the temperature. Presence of favorable surface functional groups and enhanced surface area confirmed the suitability of the synthesized biosorbent for effective removal of cadmium.
本研究报告了在受控环境条件下使用绿藻石莼（Caulerpa scalpelliformis）去除镉的可行性。藻类生物吸附剂可以在广泛的测试条件下有效去除镉，即初始 pH 值（3-6）、吸附剂质量（0.5-2.5 g/L）和搅拌速度（60-100 rpm）。最佳操作条件是使用响应面法中的中心复合设计确定的，结果为 pH 值-4.9、吸附剂质量-2.1 g/L 和搅拌速度-90 rpm。进行了平衡研究，确定单层吸附是吸附机制，这一机制通过朗缪尔等温线（R=0.9920）得到了证实。在最佳条件下，Cd 的最大摄取量达到了 111.11 mg/g。确定了最佳拟合模型（伪二级）的动力学常数。验证了热力学可行性（ΔG < 0），并且发现吸附过程是吸热的（ΔH > 0）。传质研究表明，传质系数与温度成反比。存在有利的表面官能团和增强的表面积证实了合成生物吸附剂对有效去除镉的适用性。
