Analysis on decolorization of molasses distillery wastewater treatment using microalgae

2022 Fiscal Year Final Research Report

• Project/Area Number: 17K12832
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Environmental engineering and reduction of environmental burden
• Research Institution: Ibaraki University
• Principal Investigator: Noguchi Mana 茨城大学, 農学部, 研究員 (30724207)
• Project Period (FY): 2017-04-01 – 2023-03-31
• Keywords: 好酸性微細藻類 / 高有機物負荷耐性 / 微細藻類バイオマス / 廃糖蜜蒸留廃液 / 排水処理

Outline of Final Research Achievements

From samples collected from environmental water (e.g. discharge water from food processing plant, acidic hot spring), microalgae growth were observed in 82 samples. Within those samples, microalgae in 16 samples showed the tolerance to the digestive supernatant from a domestic wastewater treatment plant in Ishikawa prefecture.
Three isolated microalgae (Chlorella vulgaris, Chlorella emersonii, Parachlorella kessleri) were incubated in 10-times diluted simulated distillery wastewater (pH adjusted). Within three strains, Parachlorella kessleri showed the highest TOC and COD removal rate. In the second test, Chlorella vulgaris, Parachlorella kessleri, and Chlamydomonas eustigma were incubated in 10-times diluted simulated distillery wastewater (pH 3.0). Colorant (evaluated by Abs260) were 0.2-11.2%. The findings of this study showed the possibility of the microalgae application to the molasses distillery wastewater treatment.

Free Research Field

環境微生物工学

Academic Significance and Societal Importance of the Research Achievements

バイオエタノールの排水処理において排水基準を満たすためには嫌気的処理と何らかの二次処理を組み合わせる必要があるが，とくに後段の処理を導入することでエネルギー・コストが高まる．本研究で獲得した複数の新たな高有機物負荷・低pHに耐性のある微細藻類を利用することで，将来的には生物処理で最もエネルギー・コストのかかる曝気を省略または削減できる可能性を示している．今後獲得した微細藻類に対しより詳しい解析を進めていくことでバイオエタノール廃水のより効率的な排水処理プロセスの実現が期待される．