{"title":"An efficient and cost-effective advanced reduction process for nitrate removal from various real saline waters using carbon-doped TiO2","authors":"Vahid Aghabalaei , Shima Mardani , Majid Baghdadi , Behnoush Aminzadeh Goharrizi , Zahra Noorimotlagh","doi":"10.1016/j.hazadv.2025.100885","DOIUrl":null,"url":null,"abstract":"<div><div>To meet the Sustainable Development Goals, NO<sub>3</sub><sup>-</sup> must be removed from drinking water. NO<sub>3</sub><sup>-</sup> is removed using IX technology, but waste disposal and the significant amount of NaCl required to make fresh brine have become problems for the economy and the environment. This work utilized an innovative, economical, and eco-friendly photocatalytic denitrification (PD) under visible light exposure for treating and reuse of IX brine waste (IXWB) using glycerol. FESEM-EDX, XRD, BET, FTIR, elemental mapping, and UV-Vis absorption spectra were used for physicochemical characteristics of carbon-doped TiO<sub>2</sub> (CT) nanocomposite. CCD-RSM was utilized for the experimental design and process optimization. With increasing calcination temperature, anatase transformed to rutile, resulting in larger particle sizes/ crystallites and narrower optical band gaps. Additionally, the band gap decreased from 2.98 to 2.58 eV after carbon doping. Under ideal conditions with a mixed A (55 %)/R (45 %) phase of CT sample, the highest PD efficiency was resulted 94 % and 68 % with formic acid and glycerol, respectively. The application of glycerol as an economic hole scavenger for two actual brines provided a NO<sub>3</sub><sup>-</sup> reduction of almost 95 %. The optimized CT sample on the surface of GAC was still stable and active after seven cycles with 18.02 US$/ m<sup>3</sup> operating cost.</div></div>","PeriodicalId":73763,"journal":{"name":"Journal of hazardous materials advances","volume":"20 ","pages":"Article 100885"},"PeriodicalIF":7.7000,"publicationDate":"2025-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of hazardous materials advances","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2772416625002967","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
To meet the Sustainable Development Goals, NO3- must be removed from drinking water. NO3- is removed using IX technology, but waste disposal and the significant amount of NaCl required to make fresh brine have become problems for the economy and the environment. This work utilized an innovative, economical, and eco-friendly photocatalytic denitrification (PD) under visible light exposure for treating and reuse of IX brine waste (IXWB) using glycerol. FESEM-EDX, XRD, BET, FTIR, elemental mapping, and UV-Vis absorption spectra were used for physicochemical characteristics of carbon-doped TiO2 (CT) nanocomposite. CCD-RSM was utilized for the experimental design and process optimization. With increasing calcination temperature, anatase transformed to rutile, resulting in larger particle sizes/ crystallites and narrower optical band gaps. Additionally, the band gap decreased from 2.98 to 2.58 eV after carbon doping. Under ideal conditions with a mixed A (55 %)/R (45 %) phase of CT sample, the highest PD efficiency was resulted 94 % and 68 % with formic acid and glycerol, respectively. The application of glycerol as an economic hole scavenger for two actual brines provided a NO3- reduction of almost 95 %. The optimized CT sample on the surface of GAC was still stable and active after seven cycles with 18.02 US$/ m3 operating cost.