Kento Nishi, Ryota Endo, Tatsushi Matsuyama, Junichi Ida
{"title":"遮光对固定化在遮光水凝胶上的硝化细菌光抑制的影响。","authors":"Kento Nishi, Ryota Endo, Tatsushi Matsuyama, Junichi Ida","doi":"10.2166/wst.2025.048","DOIUrl":null,"url":null,"abstract":"<p><p>Microalgae-nitrifying bacterial consortia have attracted attention as energy-efficient nitrogen removal methods that do not require aeration. However, the photoinhibition of nitrifying bacteria is a hurdle to their practical application. We have developed a 'light-shielding hydrogel' that mitigates the photoinhibition of nitrifying bacteria, and it demonstrated the performance of high ammonia removal even under strong light irradiation. However, the effect of carbon black (CB) concentration in hydrogel and its optimization have not yet been examined. In this study, the light-shielding effect was evaluated by measuring the light transmitted through a light-shielding hydrogel layer and comparing the experimental and theoretical values. Increasing the CB concentration from 0.1 to 0.5% effectively reduced the light transmission from 13 to 2.5% at a thickness of 1 mm. The actual nitrification activity and the theoretical activity determined from the light transmission were close in the range of 900-1,600 μmol photons m<sup>-2</sup> s<sup>-1</sup> of irradiated light intensity. Based on these results, the theoretical predictions obtained in this study may contribute to the prediction of photoinhibition mitigation. Therefore, it is expected to provide suitable conditions for optimizing the preparation of light-shielding hydrogels and pave the way for their application in outdoor wastewater treatment processes.</p>","PeriodicalId":23653,"journal":{"name":"Water Science and Technology","volume":"91 7","pages":"850-860"},"PeriodicalIF":2.6000,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effect of light shielding on the photoinhibition of nitrifying bacteria immobilized on a light-shielding hydrogel.\",\"authors\":\"Kento Nishi, Ryota Endo, Tatsushi Matsuyama, Junichi Ida\",\"doi\":\"10.2166/wst.2025.048\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Microalgae-nitrifying bacterial consortia have attracted attention as energy-efficient nitrogen removal methods that do not require aeration. However, the photoinhibition of nitrifying bacteria is a hurdle to their practical application. We have developed a 'light-shielding hydrogel' that mitigates the photoinhibition of nitrifying bacteria, and it demonstrated the performance of high ammonia removal even under strong light irradiation. However, the effect of carbon black (CB) concentration in hydrogel and its optimization have not yet been examined. In this study, the light-shielding effect was evaluated by measuring the light transmitted through a light-shielding hydrogel layer and comparing the experimental and theoretical values. Increasing the CB concentration from 0.1 to 0.5% effectively reduced the light transmission from 13 to 2.5% at a thickness of 1 mm. The actual nitrification activity and the theoretical activity determined from the light transmission were close in the range of 900-1,600 μmol photons m<sup>-2</sup> s<sup>-1</sup> of irradiated light intensity. Based on these results, the theoretical predictions obtained in this study may contribute to the prediction of photoinhibition mitigation. Therefore, it is expected to provide suitable conditions for optimizing the preparation of light-shielding hydrogels and pave the way for their application in outdoor wastewater treatment processes.</p>\",\"PeriodicalId\":23653,\"journal\":{\"name\":\"Water Science and Technology\",\"volume\":\"91 7\",\"pages\":\"850-860\"},\"PeriodicalIF\":2.6000,\"publicationDate\":\"2025-04-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Water Science and Technology\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://doi.org/10.2166/wst.2025.048\",\"RegionNum\":4,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2025/4/2 0:00:00\",\"PubModel\":\"Epub\",\"JCR\":\"Q3\",\"JCRName\":\"ENGINEERING, ENVIRONMENTAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Water Science and Technology","FirstCategoryId":"93","ListUrlMain":"https://doi.org/10.2166/wst.2025.048","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/4/2 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
Effect of light shielding on the photoinhibition of nitrifying bacteria immobilized on a light-shielding hydrogel.
Microalgae-nitrifying bacterial consortia have attracted attention as energy-efficient nitrogen removal methods that do not require aeration. However, the photoinhibition of nitrifying bacteria is a hurdle to their practical application. We have developed a 'light-shielding hydrogel' that mitigates the photoinhibition of nitrifying bacteria, and it demonstrated the performance of high ammonia removal even under strong light irradiation. However, the effect of carbon black (CB) concentration in hydrogel and its optimization have not yet been examined. In this study, the light-shielding effect was evaluated by measuring the light transmitted through a light-shielding hydrogel layer and comparing the experimental and theoretical values. Increasing the CB concentration from 0.1 to 0.5% effectively reduced the light transmission from 13 to 2.5% at a thickness of 1 mm. The actual nitrification activity and the theoretical activity determined from the light transmission were close in the range of 900-1,600 μmol photons m-2 s-1 of irradiated light intensity. Based on these results, the theoretical predictions obtained in this study may contribute to the prediction of photoinhibition mitigation. Therefore, it is expected to provide suitable conditions for optimizing the preparation of light-shielding hydrogels and pave the way for their application in outdoor wastewater treatment processes.
期刊介绍:
Water Science and Technology publishes peer-reviewed papers on all aspects of the science and technology of water and wastewater. Papers are selected by a rigorous peer review procedure with the aim of rapid and wide dissemination of research results, development and application of new techniques, and related managerial and policy issues. Scientists, engineers, consultants, managers and policy-makers will find this journal essential as a permanent record of progress of research activities and their practical applications.