El-Emam Doaa A, Elezaby Amany H, Zeyadah Mohammed A, El-Sonbati Mervat A
Environmental Science Department, Faculty of Science, Damietta University, New Damietta, Egypt.
Sci Rep. 2025 May 20;15(1):17426. doi: 10.1038/s41598-025-02272-9.
This study investigates the utilization of thermally treated drinking water treatment sludge (DWTS) as an eco-friendly adsorbent for the removal of Congo Red (CR) and Crystal Violet (CV) dyes from wastewater, aligning with circular economy principles. The research evaluates the adsorption performance of DWTS by analyzing various factors, including pH, contact time, adsorbent dosage and initial dye concentration. Kinetic and isotherm studies were conducted to elucidate the performance of the adsorbent and investigate the adsorption mass transfer mechanisms. Characterization of the DWTS adsorbent was performed using Energy Dispersive Spectrometry (EDS), Scanning Electron Microscopy (SEM), Zeta potential, point of zero charge, Brunauer-Emmett-Teller (BET), and Fourier Transform Infrared Spectroscopy (FTIR) analysis. The results revealed that the optimal conditions for dye removal were established at 120 min, 2 g adsorbent dosage, 50 mg/L dye concentration, pH5 and pH9, achieving 94.3% and 86.9% for CR and CV, respectively. The dye adsorption equilibrium data fitted well to the Langmuir isotherm model with monolayer maximum adsorption capacity of 21.368 and 10.1419 mg/g for CR and CV dye, respectively. In addition, the kinetic studies showed rapid sorption dynamics following a First-order kinetic model. Moreover, the intra particle diffusion and Elovich models exhibited high correlation coefficient values indicating a contribution of physical and chemical adsorption process. These findings suggest that DWTS is a cost-effective and viable alternative for dye removal in wastewater treatment, with implications for sustainable waste management practices. Additionally, recommendations for the safe disposal of spent adsorbents are discussed, highlighting potential applications in construction materials.
本研究探讨了将热处理后的饮用水处理污泥（DWTS）作为一种环保吸附剂，用于去除废水中的刚果红（CR）和结晶紫（CV）染料，这符合循环经济原则。该研究通过分析各种因素，包括pH值、接触时间、吸附剂用量和初始染料浓度，评估了DWTS的吸附性能。进行了动力学和等温线研究，以阐明吸附剂的性能并研究吸附传质机制。使用能量色散光谱（EDS）、扫描电子显微镜（SEM）、zeta电位、零电荷点、布鲁诺尔-埃米特-泰勒（BET）和傅里叶变换红外光谱（FTIR）分析对DWTS吸附剂进行了表征。结果表明，去除染料的最佳条件为120分钟、吸附剂用量2克、染料浓度50毫克/升、pH值5和pH值9，CR和CV的去除率分别达到94.3%和86.9%。染料吸附平衡数据与朗缪尔等温线模型拟合良好，CR和CV染料的单层最大吸附容量分别为21.368和10.1419毫克/克。此外，动力学研究表明，吸附动力学遵循一级动力学模型，吸附速度很快。此外，颗粒内扩散和埃洛维奇模型显示出较高的相关系数值，表明物理和化学吸附过程都有贡献。这些发现表明，DWTS是废水处理中去除染料的一种经济高效且可行的替代方法，对可持续废物管理实践具有重要意义。此外，还讨论了废吸附剂安全处置的建议，强调了其在建筑材料中的潜在应用。
