{"title":"Research progress on exhaust gas emissions and control technology during sewage sludge thermal drying: A review","authors":"Wei Ling, Yi Xing, Chengwang Zhao, Chen Hong, Weibo Feng, Yijie Wang, Jiashuo Hu, Jiachen Hou, Lihui Feng","doi":"10.1080/07373937.2023.2260895","DOIUrl":null,"url":null,"abstract":"AbstractThe volume of sewage sludge generated continues to increase, leading to harmful secondary pollution and highlighting the pressing need for sewage sludge reduction. Sewage sludge drying is a well-established method for treating municipal sewage sludge. This study systematically reviews the latest research on the formation and control of gaseous pollutants during sewage sludge thermal drying. First, this paper comprehensively introduces sewage sludge drying, covering its principles, heat sources, and the inevitable generation of waste gas during the drying process of sewage sludge rich in organic matter. Subsequently, it summarizes the methods for detecting sewage sludge drying exhaust gas and outlines the emission characteristics of such exhaust gas. The three main types of dry exhaust gases discussed include volatile nitrogen-containing compounds, represented by ammonia (NH3); volatile sulfur-containing compounds, represented by hydrogen sulfide (H2S); and the benzene series (BTEX). Finally, based on current technical capabilities, this paper proposes two methods for controlling pollution from sewage sludge drying exhaust gas: suppressing pollutant release during the drying process and treating exhaust gas at the end of drying. Inhibition of pollutant release during the drying process primarily involves reducing the types and quantities of pollutants released by adjusting the sewage sludge drying temperature and time, employing sewage sludge conditioning, and implementing others. Drying back-end exhaust gas treatment removes contaminants from the drying exhaust gas through processes like condensation, adsorption, absorption, biodegradation and other methods. This work offers a fresh perspective on understanding how various factors in the sewage sludge drying process influence the characteristics of dried exhaust gas emissions and the overall control of sewage sludge exhaust gas emissions.Keywords: Sewage sludge dryingdry exhaust gasemission characteristicspollution control Disclosure statementNo potential conflict of interest was reported by the authors.Additional informationFundingThis research was funded by the Fundamental Research Funds for the Central Universities (FRF-TP-20-010A2) and the Self-directed Project of State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing (41622202).","PeriodicalId":11374,"journal":{"name":"Drying Technology","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2023-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Drying Technology","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1080/07373937.2023.2260895","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
AbstractThe volume of sewage sludge generated continues to increase, leading to harmful secondary pollution and highlighting the pressing need for sewage sludge reduction. Sewage sludge drying is a well-established method for treating municipal sewage sludge. This study systematically reviews the latest research on the formation and control of gaseous pollutants during sewage sludge thermal drying. First, this paper comprehensively introduces sewage sludge drying, covering its principles, heat sources, and the inevitable generation of waste gas during the drying process of sewage sludge rich in organic matter. Subsequently, it summarizes the methods for detecting sewage sludge drying exhaust gas and outlines the emission characteristics of such exhaust gas. The three main types of dry exhaust gases discussed include volatile nitrogen-containing compounds, represented by ammonia (NH3); volatile sulfur-containing compounds, represented by hydrogen sulfide (H2S); and the benzene series (BTEX). Finally, based on current technical capabilities, this paper proposes two methods for controlling pollution from sewage sludge drying exhaust gas: suppressing pollutant release during the drying process and treating exhaust gas at the end of drying. Inhibition of pollutant release during the drying process primarily involves reducing the types and quantities of pollutants released by adjusting the sewage sludge drying temperature and time, employing sewage sludge conditioning, and implementing others. Drying back-end exhaust gas treatment removes contaminants from the drying exhaust gas through processes like condensation, adsorption, absorption, biodegradation and other methods. This work offers a fresh perspective on understanding how various factors in the sewage sludge drying process influence the characteristics of dried exhaust gas emissions and the overall control of sewage sludge exhaust gas emissions.Keywords: Sewage sludge dryingdry exhaust gasemission characteristicspollution control Disclosure statementNo potential conflict of interest was reported by the authors.Additional informationFundingThis research was funded by the Fundamental Research Funds for the Central Universities (FRF-TP-20-010A2) and the Self-directed Project of State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing (41622202).
期刊介绍:
Drying Technology explores the science and technology, and the engineering aspects of drying, dewatering, and related topics.
Articles in this multi-disciplinary journal cover the following themes:
-Fundamental and applied aspects of dryers in diverse industrial sectors-
Mathematical modeling of drying and dryers-
Computer modeling of transport processes in multi-phase systems-
Material science aspects of drying-
Transport phenomena in porous media-
Design, scale-up, control and off-design analysis of dryers-
Energy, environmental, safety and techno-economic aspects-
Quality parameters in drying operations-
Pre- and post-drying operations-
Novel drying technologies.
This peer-reviewed journal provides an archival reference for scientists, engineers, and technologists in all industrial sectors and academia concerned with any aspect of thermal or nonthermal dehydration and allied operations.