{"title":"Chemical modification of lettuce leaves using NaOH and EDTA: A brilliant biosorbent for the adsorption of heavy metal ions from aqueous solution","authors":"Van Doan Nguyen, Thi Phuong Nguyen, Anh-Tuan Vu","doi":"10.1016/j.jwpe.2025.107202","DOIUrl":null,"url":null,"abstract":"<div><div>Recently, the use of natural materials to treat pollutants, especially heavy metals in water, has received significant attention in research. In this report, lettuce leaves (LC), an environmentally friendly and cost-effective biosorbent, were chemically modified with NaOH and ethylenediaminetetraacetic acid (EDTA) for the first time in two steps to remove Pb<sup>2+</sup>. The compositional and structural properties of the LC/NaOH/EDTA (LCNE) biosorbent were ascertained by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The effects of diverse operating conditions including working environment pH, sorbate concentration, sorbent mass, modifier content, and working temperature were tested. The experimental results estimated that at pH 6, 91.22 % of Pb<sup>2+</sup> at 80 mg/L concentration was adsorbed by 1.0 g/L sorbent. The second-order kinetic provided better linearity (R<sup>2</sup> = 0.999) to depict the chemisorption, whereas the biosorption isotherm closely followed the Langmuir model, revealing a maximum uptake capacity of 117.51 mg/g. In the multi-metal biosorption system, the biosorption capacity of Pb<sup>2+</sup> was 81.98 mg/g compared to only 26.63 mg/g of Ni<sup>2+</sup>. Our report revealed that Pb<sup>2+</sup> adsorption was moderately stable after many regeneration cycles, i.e., it decreased by almost 20 % after 3 consecutive cycles of immersion in harsh environments. In addition, the efficiency of LCNE in removing Pb<sup>2+</sup> from urban wastewater sample was tested, with 72.48 % of Pb<sup>2+</sup> being adsorbed by the biosorbent. These results underline that LNCE is a biosorbent with excellent application potential for the on-site sequestration of Pb<sup>2+</sup> ions.</div></div>","PeriodicalId":17528,"journal":{"name":"Journal of water process engineering","volume":"71 ","pages":"Article 107202"},"PeriodicalIF":6.3000,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of water process engineering","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2214714425002740","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Recently, the use of natural materials to treat pollutants, especially heavy metals in water, has received significant attention in research. In this report, lettuce leaves (LC), an environmentally friendly and cost-effective biosorbent, were chemically modified with NaOH and ethylenediaminetetraacetic acid (EDTA) for the first time in two steps to remove Pb2+. The compositional and structural properties of the LC/NaOH/EDTA (LCNE) biosorbent were ascertained by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The effects of diverse operating conditions including working environment pH, sorbate concentration, sorbent mass, modifier content, and working temperature were tested. The experimental results estimated that at pH 6, 91.22 % of Pb2+ at 80 mg/L concentration was adsorbed by 1.0 g/L sorbent. The second-order kinetic provided better linearity (R2 = 0.999) to depict the chemisorption, whereas the biosorption isotherm closely followed the Langmuir model, revealing a maximum uptake capacity of 117.51 mg/g. In the multi-metal biosorption system, the biosorption capacity of Pb2+ was 81.98 mg/g compared to only 26.63 mg/g of Ni2+. Our report revealed that Pb2+ adsorption was moderately stable after many regeneration cycles, i.e., it decreased by almost 20 % after 3 consecutive cycles of immersion in harsh environments. In addition, the efficiency of LCNE in removing Pb2+ from urban wastewater sample was tested, with 72.48 % of Pb2+ being adsorbed by the biosorbent. These results underline that LNCE is a biosorbent with excellent application potential for the on-site sequestration of Pb2+ ions.
期刊介绍:
The Journal of Water Process Engineering aims to publish refereed, high-quality research papers with significant novelty and impact in all areas of the engineering of water and wastewater processing . Papers on advanced and novel treatment processes and technologies are particularly welcome. The Journal considers papers in areas such as nanotechnology and biotechnology applications in water, novel oxidation and separation processes, membrane processes (except those for desalination) , catalytic processes for the removal of water contaminants, sustainable processes, water reuse and recycling, water use and wastewater minimization, integrated/hybrid technology, process modeling of water treatment and novel treatment processes. Submissions on the subject of adsorbents, including standard measurements of adsorption kinetics and equilibrium will only be considered if there is a genuine case for novelty and contribution, for example highly novel, sustainable adsorbents and their use: papers on activated carbon-type materials derived from natural matter, or surfactant-modified clays and related minerals, would not fulfil this criterion. The Journal particularly welcomes contributions involving environmentally, economically and socially sustainable technology for water treatment, including those which are energy-efficient, with minimal or no chemical consumption, and capable of water recycling and reuse that minimizes the direct disposal of wastewater to the aquatic environment. Papers that describe novel ideas for solving issues related to water quality and availability are also welcome, as are those that show the transfer of techniques from other disciplines. The Journal will consider papers dealing with processes for various water matrices including drinking water (except desalination), domestic, urban and industrial wastewaters, in addition to their residues. It is expected that the journal will be of particular relevance to chemical and process engineers working in the field. The Journal welcomes Full Text papers, Short Communications, State-of-the-Art Reviews and Letters to Editors and Case Studies