Investigation of the complex microbial community in freshwater sediments in Saidenbach drinking water reservoir, Germany

Field research on the performance of pollutant removal and the structure of the microbial community was carried out on a drinking water reservoir. After one month of operation of a water-lifting aeration system, the water temperature difference between the bottom and the surface decreased from 9.9 to 3.1 °C, and the concentration of the dissolved oxygen (DO) in the bottom layer increased from 0 to 4.2 mg/L. The existing stratification in the reservoir was successfully eliminated. Total nitrogen (TN), total phosphorus (TP), and total organic carbon (TOC) concentrations were reduced by 47.8%, 66.7%, and 22.9%, respectively. High-throughput sequencing showed that Proteobacteria, Bacteroides, and Actinomycetes accounted for 67.52% to 78.74% of the total bacterial population. Differences in the bacterial changes were observed between the enhanced area and the control area. With the operation of the water-lifting aeration system, the populations of bacteria of the main genera varied temporally and spatially. Principal component analysis pointed out a clear evolution in the vertical distribution of the microbial structure controlled by the operation of the aeration system. Permutational analysis of variance showed a significant difference in the microbial community (p < 0.01). Redundancy analysis showed that physical (water temperature, DO) and chemical environmental factors (Chl-a, TOC, TN) were the key factors affecting the changes in the microbial communities in the reservoir water. In addition, a hierarchical partitioning analysis indicated that T, Chl-a, ORP, TOC, pH, and DO accounted for 24.1%, 8.7%, 6.7%, 6.2%, 5.8%, and 5.1% of such changes, respectively. These results are consistent with the ABT (aggregated boosted tree) analysis for the variations in the functional bacterial community, and provide a theoretical basis for the development and application of biotechnology.

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Water Quality Responses during the Continuous Mixing Process and Informed Management of a Stratified Drinking Water Reservoir

Sustainability ◽

10.3390/su11247106 ◽

2019 ◽

Vol 11 (24) ◽

pp. 7106

Author(s):

Zizhen Zhou ◽

Tinglin Huang ◽

Weijin Gong ◽

Yang Li ◽

Yue Liu ◽

...

Keyword(s):

Water Quality ◽

Drinking Water ◽

Quality Improvement ◽

Microbial Community ◽

Organic Carbon ◽

Water Reservoir ◽

Mixing Process ◽

Water Quality Improvement ◽

Continuous Mixing ◽

Drinking Water Reservoir

Aeration and mixing have been proven as effective in situ water quality improvement methods, particularly for deep drinking water reservoirs. While there is some research on the mechanism of water quality improvement during artificial mixing, the changes to water quality and the microbial community during the subsequent continuous mixing process is little understood. In this study, we investigate the mechanism of water quality improvement during the continuous mixing process in a drinking water reservoir. During this period, we found a reduction in total nitrogen (TN), total phosphorus (TP), ammonium-nitrogen (NH4-N), iron (Fe), manganese (Mn), and total organic carbon (TOC) of 12.5%–30.8%. We also measured reductions of 8.6% and 6.2% in TN and organic carbon (OC), respectively, in surface sediment. Microbial metabolic activity, abundance, and carbon source utilization were also improved. Redundancy analysis indicated that temperature and dissolved oxygen (DO) were key factors affecting changes in the microbial community. With intervention, the water temperature during continuous mixing was 15 °C, and the mixing temperature in the reservoir increased by 5 °C compared with natural mixing. Our research shows that integrating and optimizing the artificial and continuous mixing processes influences energy savings. This research provides a theoretical basis for further advancing treatment optimizations for a drinking water supply.

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