{"title":"Development of an ion exchange process for ammonium removal and recovery from municipal wastewater using a metakaolin K-based geopolymer","authors":"","doi":"10.1016/j.chemosphere.2024.143559","DOIUrl":null,"url":null,"abstract":"<div><div>Ion exchange represents a promising process for ammonium removal from municipal wastewater (MWW), in order to recover it for fertilizer production. Previous studies on ammonium ion exchange neglected the assessment of process robustness and the optimization the desorption/recovery step. This study aimed at developing a continuous-flow process of ammonium removal/recovery based on a metakaolin K-based geopolymer, named G13. Process robustness was assessed by operating 7 adsorption/desorption cycles with two types of MWW. These tests resulted in satisfactory and constant performances: operating capacity at 40 mg<sub>N</sub> L<sup>−1</sup> in the inlet = 12 mg<sub>N</sub> g<sub>dry sorbent</sub><sup>−1</sup>, bed volumes of treated MWW at the selected breakpoint = 199–226, ammonium adsorption yield = 88–91%. Empty bed contact time (EBCT) was decreased from 10 to 5 min without any reduction in performances. The NH<sub>4</sub><sup>+</sup> adsorption process was effectively simulated by the Thomas model, allowing a model-based assessment of the effect of EBCT reductions on process performances. An innovative desorption procedure led to high ammonium recovery yields (86–100%) and to a desorbed product composed primarily of KNO<sub>3</sub> (54%<sub>w</sub>) and NH<sub>4</sub>NO<sub>3</sub> (39%<sub>w</sub>), two salts largely used in commercial fertilizers. The energy consumption of ammonium removal/recovery with G13 resulted 0.027 kWh m<sup>−3</sup><sub>treated WW</sub>, with a relevant reduction in comparison to traditional nitrification/denitrification, whereas the operational cost resulted equal to 60–110% of the cost of the benchmark process. These results show that G13 is a promising material to recover ammonium in a circular economy approach.</div></div>","PeriodicalId":276,"journal":{"name":"Chemosphere","volume":null,"pages":null},"PeriodicalIF":8.1000,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemosphere","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0045653524024597","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Ion exchange represents a promising process for ammonium removal from municipal wastewater (MWW), in order to recover it for fertilizer production. Previous studies on ammonium ion exchange neglected the assessment of process robustness and the optimization the desorption/recovery step. This study aimed at developing a continuous-flow process of ammonium removal/recovery based on a metakaolin K-based geopolymer, named G13. Process robustness was assessed by operating 7 adsorption/desorption cycles with two types of MWW. These tests resulted in satisfactory and constant performances: operating capacity at 40 mgN L−1 in the inlet = 12 mgN gdry sorbent−1, bed volumes of treated MWW at the selected breakpoint = 199–226, ammonium adsorption yield = 88–91%. Empty bed contact time (EBCT) was decreased from 10 to 5 min without any reduction in performances. The NH4+ adsorption process was effectively simulated by the Thomas model, allowing a model-based assessment of the effect of EBCT reductions on process performances. An innovative desorption procedure led to high ammonium recovery yields (86–100%) and to a desorbed product composed primarily of KNO3 (54%w) and NH4NO3 (39%w), two salts largely used in commercial fertilizers. The energy consumption of ammonium removal/recovery with G13 resulted 0.027 kWh m−3treated WW, with a relevant reduction in comparison to traditional nitrification/denitrification, whereas the operational cost resulted equal to 60–110% of the cost of the benchmark process. These results show that G13 is a promising material to recover ammonium in a circular economy approach.
期刊介绍:
Chemosphere, being an international multidisciplinary journal, is dedicated to publishing original communications and review articles on chemicals in the environment. The scope covers a wide range of topics, including the identification, quantification, behavior, fate, toxicology, treatment, and remediation of chemicals in the bio-, hydro-, litho-, and atmosphere, ensuring the broad dissemination of research in this field.