Alprol Ahmed E, Bakr Ahmed, Al-Saeedi Sameerah I, El-Shafei Ahmed A, Alotaibi Fahd, El-Haron Ehab, Alharthi Maymounah N, Ashour Mohamed
National Institute of Oceanography and Fisheries (NIOF), Cairo, 11516, Egypt.
Environment and Bio-agriculture Department, Faculty of Agriculture, Al-Azhar University, Cairo, Egypt.
Sci Rep. 2025 Sep 12;15(1):32428. doi: 10.1038/s41598-025-15361-6.
The potential of Pterocladia capillacea, a marine red seaweed, as a sustainable and eco-friendly adsorbent was investigated for the removal of toxic hexavalent chromium Cr(VI) (or Cr) and crystal violet dye (CVD) from contaminated water. Characterization of P. capillacea using Fourier-Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), and Brunauer-Emmett-Teller (BET) analysis revealed a porous structure with a high specific surface area (87.17 m²/g) and a negative surface charge (-29.5 mV), ideal for adsorbent applications. Adsorption studies were conducted to assess the impact of operational parameters, such as pH, adsorbent dose, initial pollutant concentration, and temperature. Optimal removal was achieved at pH 1.0 for Cr and CVD. Increasing the adsorbent dose led to higher Cr adsorption, achieving near-complete removal with 0.4 g. An optimal dose of 0.8 g was selected for subsequent experiments. Cr Cr removal was faster during the initial adsorption stage (within 30-60 min), followed by a slower rate due to saturation and reduced pore diffusion. Adsorption was more effective at lower temperatures and followed pseudo-second-order kinetics, suggesting chemisorption as the dominant mechanism. Six isotherm models were used to describe equilibrium adsorption, with the Freundlich model providing the best fit for both Cr and CVD, indicating multilayer adsorption and heterogeneous surface interactions. P. capillacea showed potential for Cr removal in seawater and real wastewater, although efficiency was reduced due to complex matrix effects. Reusability studies indicated a decline in efficiency over multiple cycles; however, Cr uptake remained above 89.2% for CVD. Similar reusability was observed, with an initial removal efficiency of 87.29% for CFD. Although removal efficiency decreased in subsequent cycles, the material remained effective for repeated CVD adsorption. The study demonstrates the potential of P. capillacea as a readily available, cost-effective, and sustainable material for the bioremediation of Cr and synthetic dyes from water, contributing to the development of environmentally friendly water treatment technologies.
研究了一种海洋红藻——纤细软骨藻（Pterocladia capillacea）作为一种可持续且环保的吸附剂，用于从受污染水中去除有毒的六价铬Cr(VI)（或Cr）和结晶紫染料（CVD）的潜力。利用傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）和布鲁诺尔-埃米特-泰勒（BET）分析对纤细软骨藻进行表征，结果显示其具有多孔结构，比表面积高（87.17 m²/g）且表面带负电荷（-29.5 mV），非常适合作为吸附剂应用。进行了吸附研究，以评估操作参数的影响，如pH值、吸附剂剂量、初始污染物浓度和温度。对于Cr和CVD，在pH 1.0时实现了最佳去除效果。增加吸附剂剂量会导致更高的Cr吸附量，使用0.4 g时可实现近乎完全去除。后续实验选择了0.8 g的最佳剂量。在初始吸附阶段（30 - 60分钟内）Cr的去除速度更快，随后由于饱和和孔隙扩散减少，去除速度变慢。在较低温度下吸附更有效，且遵循准二级动力学，表明化学吸附是主要机制。使用六种等温线模型来描述平衡吸附，弗伦德利希模型对Cr和CVD的拟合效果最佳，表明存在多层吸附和非均相表面相互作用。纤细软骨藻在海水和实际废水中显示出去除Cr的潜力，尽管由于复杂的基质效应效率有所降低。可重复使用性研究表明多次循环后效率会下降；然而，对于CVD，Cr的吸附量仍保持在89.2%以上。观察到类似的可重复使用性，CFD的初始去除效率为87.29%。尽管在后续循环中去除效率下降，但该材料对重复的CVD吸附仍然有效。该研究证明了纤细软骨藻作为一种易于获得、经济高效且可持续的材料，用于从水中生物修复Cr和合成染料的潜力，有助于开发环境友好型水处理技术。
