Next Article in Journal
Optimal Alternative for Quantifying Reference Evapotranspiration in Northern Xinjiang
Previous Article in Journal
Hydrochemistry of the Lhasa River, Tibetan Plateau: Spatiotemporal Variations of Major Ions Compositions and Controlling Factors Using Multivariate Statistical Approaches
 
 
Article

Effective Purification of Eutrophic Wastewater from the Beverage Industry by Microbubbles

1
Faculty of Agriculture and Marine Science, Kochi University, Nankoku 783-8502, Kochi, Japan
2
Sakamoto-Giken Inc., Nankoku 783-0007, Kochi, Japan
3
Department of Social Design Engineering, National Institute of Technology (KOSEN), Kochi College, Nankoku 783-8508, Kochi, Japan
*
Author to whom correspondence should be addressed.
Present address: Kochi Study Center, The Open University of Japan, Akebono-cho 780-8072, Kochi, Japan.
Academic Editor: Hassimi Abu Hasan
Water 2021, 13(24), 3661; https://doi.org/10.3390/w13243661
Received: 15 November 2021 / Revised: 9 December 2021 / Accepted: 17 December 2021 / Published: 20 December 2021
Beverage industries often discharge large amounts of organic matter with their wastewater. Purification of the effluent is their obligation, but it is nontrivial. Among wastewater components, removal of dissolved organic matter often requires much effort. Therefore, a special effective technique must be considered. Microbubbles (1–100 μm) have several special properties of relevance to wastewater treatment. In this study, the effectiveness of microbubbles for treating and purifying beverage wastewater was evaluated. Orange juice, lactic acid drink, and milk were used as model substrates of dissolved organic matter, and degradation experiments were carried out. Rates of air supply by microbubbles were 0.05% (air/wastewater) min−1. Results indicated that the total organic carbon (TOC) in an experimental vessel containing milk (high nitrogen content) decreased by 93.1% from 11.0 to 0.76 g during a 10-day incubation. The TOC of lactic acid drink (least nitrogen content) decreased by 66.3%, from 15.6 to 5.26 g, and the TOC of orange juice (medium nitrogen content) decreased by 82.7%, from 14.8 to 2.55 g. Large amounts of particulate organic matter floated on the water surface in the milk with microbubbles and were removed easily, while almost no floating materials were observed in the orange juice and lactic acid drink. In contrast, in the macrobubble treatment (diameter 0.1 to 2 mm), only 37.0% of TOC in the milk was removed. Whereas the macrobubble treatments were anaerobic throughout the incubations, the microbubble treatments returned to aerobic conditions quickly, and brought 10 times greater bacterial abundances (>108 cells mL−1). These results suggest that microbubbles are much superior to macrobubbles in supplying oxygen and accelerating the growth of aerobic bacteria, and that wastewater containing more nitrogenous compounds was purified more effectively than that with less nitrogen by microbial degradation and floating separation. View Full-Text
Keywords: microbubbles; beverage wastewater; purification; floatation separation; oxygen supply; degradation of organic matter microbubbles; beverage wastewater; purification; floatation separation; oxygen supply; degradation of organic matter
Show Figures

Graphical abstract

MDPI and ACS Style

Fukami, K.; Oogi, T.; Motomura, K.; Morita, T.; Sakamoto, M.; Hata, T. Effective Purification of Eutrophic Wastewater from the Beverage Industry by Microbubbles. Water 2021, 13, 3661. https://doi.org/10.3390/w13243661

AMA Style

Fukami K, Oogi T, Motomura K, Morita T, Sakamoto M, Hata T. Effective Purification of Eutrophic Wastewater from the Beverage Industry by Microbubbles. Water. 2021; 13(24):3661. https://doi.org/10.3390/w13243661

Chicago/Turabian Style

Fukami, Kimio, Tatsuro Oogi, Kohtaro Motomura, Tomoka Morita, Masaoki Sakamoto, and Takashi Hata. 2021. "Effective Purification of Eutrophic Wastewater from the Beverage Industry by Microbubbles" Water 13, no. 24: 3661. https://doi.org/10.3390/w13243661

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop