Treatment effect of a slow sand filter with a cover equipped with blue LED

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K04326
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22060:Environmental systems for civil engineering-related
• Research Institution: Fukushima National College of Technology
• Principal Investigator: Takaara Tomoko 福島工業高等専門学校, 都市システム工学科, 准教授 (80455112)
• Co-Investigator(Kenkyū-buntansha): 渡部 徹 山形大学, 農学部, 教授 (10302192) ; 西山 正晃 山形大学, 農学部, 准教授 (10802928)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 緩速ろ過 / 藻類 / LED / 生物ろ過膜 / 覆蓋 / 浄水場

Outline of Final Research Achievements

The slow sand filtration method is adopted in small water purification plants because it has low maintenance costs and can be operated stably. However, because it is affected by natural conditions, the method of maintaining the sand filter is sometimes determined based on the engineer's experience. This study investigated "LED-equipped cover-cover slow sand filtration" to strengthen the sand filter's safety and reduce the maintenance burden. This technology can form a biofilter with filamentous algae as the dominant species by irradiating the slow sand filtration basin with blue LED light. We confirmed that clogging of the sand filter can be reduced by utilizing the algae's turbidity-trapping function. The cell density of the algae in the biofilter can be adjusted by controlling the irradiation conditions of the blue LED.

Free Research Field

水処理工学

Academic Significance and Societal Importance of the Research Achievements

本研究で検討したLED装備覆蓋緩速ろ過池は，小規模浄水場の安全性の強化と，維持管理しやすい施設を目指すものである．生物ろ過膜中の藻類の増殖を青色LEDでコントロールすることで，ろ過閉塞の発生を抑制できることを確認した．技術者不足が進む水処理業界において，地方の安定した浄水場運転の一助となるものである．