Next Article in Journal
Use of Hyperspectral Reflectance and Water Quality Indices to Assess Groundwater Quality for Drinking in Arid Regions, Saudi Arabia
Previous Article in Journal
Review of Advanced Oxidation Processes Based on Peracetic Acid for Organic Pollutants
Previous Article in Special Issue
Effects of Light-Emitting Diode Illumination on Sediment Surface Biological Activities and Releases of Nutrients and Metals to Overlying Water in Eutrophic Lake Microcosms
 
 
Article

Improvement of Water Quality by Light-Emitting Diode Illumination at the Bottom of a Field Experimental Pond

1
College of Life and Environmental Sciences, Wenzhou University, Wenzhou 325035, China
2
National and Local Joint Engineering Research Center of Ecological Treatment Technology for Urban Water Pollution, Wenzhou University, Wenzhou 325035, China
3
Environmental Department, West Japan Engineering Consultants, Inc., Fukuoka 8100004, Japan
4
Faculty of Agriculture, Saga University, Saga 8408502, Japan
5
Civil Engineering Research Institute for Cold Region, Public Works Research Institute, Sapporo 0628602, Japan
6
Aqua Restoration Research Center, Public Works Research Institute, Kakamigahara 5016021, Japan
7
Graduate School of Engineering, Kyushu University, Fukuoka 8190395, Japan
8
Graduate School of Science and Technology for Innovation, Yamaguchi University, Ube 7558611, Japan
*
Authors to whom correspondence should be addressed.
Academic Editor: George Arhonditsis
Water 2022, 14(15), 2310; https://doi.org/10.3390/w14152310
Received: 13 June 2022 / Revised: 12 July 2022 / Accepted: 20 July 2022 / Published: 25 July 2022
Remediation of water quality by stimulating algal photosynthesis using light-emitting diodes (LEDs) has attracted attention, but few studies have examined this in outdoor freshwater environments. To understand the effects of LED illumination on water quality, the dissolved oxygen (DO), temperature, pH, and electric conductivity were monitored over 5 months in three depressions with or without a red/blue LED light at the bottom of an experimental pond. The effects of the blue LED on water quality were evident in the period with less rainfall after the change of water quality to an equilibrium state; DO and pH were higher, and EC was lower for the blue LED than for the control. The diel changes of these variables were also lower for the blue LED. The effects of the red LED on DO and pH were also evident, but to a lesser extent compared to those of the blue LED. A vertical mixing of water associated with a nighttime cooling of the surface water was suggested by a rapid DO increase after a temperature decrease in the control. Such internal water circulation and an inflow of water after rainfall might have obscured the LED effects in the rainy period. The bottom water of the blue LED had a higher density and species richness of phytoplankton than that of the control at the end of the experiment. A lower density of phytoplankton and higher nutrient concentrations in the red LED might have been due to a higher density and feeding activity by zooplankton. Our results confirmed the applicability of LED illumination in stimulating algal photosynthesis, and in improving the oxygen condition of the bottom water in freshwater ponds. View Full-Text
Keywords: eutrophic ponds; bottom layer; anoxic condition; light-emitting diode; algal community; photosynthesis eutrophic ponds; bottom layer; anoxic condition; light-emitting diode; algal community; photosynthesis
Show Figures

Graphical abstract

MDPI and ACS Style

Iseri, Y.; Hao, A.; Haraguchi, T.; Oishi, T.; Kuba, T.; Asai, K.; Kobayashi, S. Improvement of Water Quality by Light-Emitting Diode Illumination at the Bottom of a Field Experimental Pond. Water 2022, 14, 2310. https://doi.org/10.3390/w14152310

AMA Style

Iseri Y, Hao A, Haraguchi T, Oishi T, Kuba T, Asai K, Kobayashi S. Improvement of Water Quality by Light-Emitting Diode Illumination at the Bottom of a Field Experimental Pond. Water. 2022; 14(15):2310. https://doi.org/10.3390/w14152310

Chicago/Turabian Style

Iseri, Yasushi, Aimin Hao, Tomokazu Haraguchi, Tetsuya Oishi, Takahiro Kuba, Koji Asai, and Sohei Kobayashi. 2022. "Improvement of Water Quality by Light-Emitting Diode Illumination at the Bottom of a Field Experimental Pond" Water 14, no. 15: 2310. https://doi.org/10.3390/w14152310

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