Haoufazane Chaimaa, Zaaboul Fatima, El Monfalouti Hanae, Sebbar Nada Kheira, Hefnawy Mohamed, El Hourch Abderrahim, Kartah Badr Eddine
Laboratory of Plant Chemistry, Organic and Bioorganic Synthesis, Faculty of Sciences, Mohammed V University in Rabat, 4 Avenue Ibn Battouta, BP, P.O. Box 1014, Rabat 10090, Morocco.
Laboratory of Materials, Nanotechnologies and Environment, Chemistry Department, Faculty of Sciences, Mohammed V University of Rabat, Rabat 10090, Morocco.
Molecules. 2024 Oct 11;29(20):4806. doi: 10.3390/molecules29204806.
The presence of pollutants in water sources, particularly dyes coming by way of the textile industry, represents a major challenge with far-reaching environmental consequences, including increased scarcity. This phenomenon endangers the health of living organisms and the natural system. Numerous biosorbents have been utilized for the removal of dyes from the textile industry. The aim of this study was to optimize discarded stems as constituting an untreated natural biosorbent for the efficient removal of C.I. Direct Black 80, an azo textile dye, from an aqueous solution, thus offering an ecological and low-cost alternative while recovering the waste for reuse. The biosorbent was subjected to a series of characterization analyses: scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET) method, X-ray diffraction (XRD), and infrared spectroscopy (IR) were employed to characterize the biosorbent. Additionally, the moisture and ash content of the plant stem were also examined. The absorption phenomenon was studied for several different parameters including the effect of the absorption time (0 to 360 min), the sorbent mass (3 to 40 g/L), the pH of the solution (3 to 11), the dye concentration (5 to 300 mg/L), and the pH of the zero-charge point (2-12). Thermodynamic studies and desorption studies were also carried out. The results showed that an increase in plant mass from 3 to 40 g/L resulted in a notable enhancement in dye adsorption rates, with an observed rise from 63.96% to 97.08%. The pH at the zero-charge point (pHpzc) was determined to be 7.12. The percentage of dye removal was found to be highest for pH values ≤ 7, with a subsequent decline in removal efficiency as the pH increased. Following an initial increase in the amount of adsorbed dye, equilibrium was reached within 2 h of contact. The kinetic parameters of adsorption were investigated using the pseudo-first-order, pseudo-second-order and Elovich models. The results indicated that the pseudo-first-order kinetic model was the most appropriate for the plant adsorbent. The isotherm parameters were determined using the Langmuir, Frendlich, Temkin, and Dubinin-Radushkevich models. The experimental data were more satisfactory and better fitted using the Langmuir model for the adsorption of dye on the plant. This study demonstrated that stems could be employed as an effective adsorbent for the removal of our organic dye from an aqueous solution.
水源中污染物的存在，尤其是来自纺织工业的染料，是一个重大挑战，会带来深远的环境后果，包括水资源日益稀缺。这种现象危及生物和自然系统的健康。许多生物吸附剂已被用于去除纺织工业废水中的染料。本研究的目的是优化废弃茎杆，使其成为一种未经处理的天然生物吸附剂，用于从水溶液中高效去除偶氮纺织染料C.I.直接黑80，从而提供一种生态且低成本的替代方案，同时回收废物以供再利用。对该生物吸附剂进行了一系列表征分析：采用扫描电子显微镜（SEM）、热重分析（TGA）、布鲁诺尔-埃米特-泰勒（BET）法、X射线衍射（XRD）和红外光谱（IR）对生物吸附剂进行表征。此外，还检测了植物茎杆的水分和灰分含量。研究了吸附现象的几个不同参数，包括吸附时间（0至360分钟）、吸附剂质量（3至40克/升）、溶液pH值（3至11）、染料浓度（5至300毫克/升）以及零电荷点pH值（2 - 12）。还进行了热力学研究和解吸研究。结果表明，植物质量从3克/升增加到40克/升会显著提高染料吸附率，观察到的吸附率从63.96%上升到97.08%。零电荷点pH值（pHpzc）测定为7.12。发现pH值≤7时染料去除率最高，随着pH值升高，去除效率随后下降。在吸附染料量最初增加后，接触2小时内达到平衡。使用准一级、准二级和Elovich模型研究了吸附动力学参数。结果表明，准一级动力学模型最适合该植物吸附剂。使用朗缪尔、弗伦德利希、坦金和杜宾宁-拉杜舍维奇模型确定了等温线参数。实验数据用朗缪尔模型描述染料在植物上的吸附更令人满意且拟合效果更好。本研究表明，茎杆可作为从水溶液中去除这种有机染料的有效吸附剂。
