S-type Dissolved Oxygen Distribution along Water Depth in a Canyon-shaped and Algae Blooming Water Source Reservoir: Reasons and Control

Abstract

Dissolved oxygen (DO) is a crucial indicator of water quality. DO usually shows a monotonic decrease along water depth during thermal stratification in reservoir, whereas metalimnetic oxygen minimum (MOM) is observed in some cases. Although MOM phenomena have been reported in different areas, the characteristics of different reservoirs are greatly different, and few comprehensive studies have been published regarding MOM in Chinese drinking water source reservoirs. The DO distribution along water depth was determined and the detailed reasons were clarified by two-years of field monitoring. In addition the effect of water lifting aerators (WLAs) on DO improvement was investigated in the Lijiahe Reservoir in Northwest China. A typical S-type DO distribution with two anaerobic water layers, below the epilimnion (10–25 m water depth) and above the sediment (bottom water), was observed derived from the decomposition of dead algae or organic matter and the restriction of DO vertical exchange. Moreover, after WLAs’ operation since 10 June 2018, the water body was completely mixed and DO was rich and uniform along water depth by eliminating the water stratification and inhibiting algae growth. The deep understanding of the DO distribution in a deep canyon-shaped reservoir and the technical support for reservoir restoration are meaningful for optimizing reservoir management.

Prevalence, Distribution, and Diversity of Salmonella Strains Isolated From a Subtropical Lake

“…The highest DO concentrations are usually present at or near the surface of water bodies (Huang et al, 2019). Salmonella spp.…”

Iron-Activated Carbon Systems to Enhance Aboriginal Aerobic Denitrifying Bacterial Consortium for Improved Treatment of Micro-Polluted Reservoir Water: Performances, Mechanisms, and Implications

“…Due to the low concentration of N and P in raw water, synthetic micro-polluted source water was prepared in this study by adding KNO 3 and KH 2 PO 4 . Based on the previous reports of drinking water reservoir in China during summer, the concentrations of 2.5 mg/L of NO 3 – -N and 0.16 mg/L of TP were used in this study. ,, The chemical characteristics of raw water are described in Table S1.…”

“…Micro-polluted reservoirs, in which the concentration of pollutants (i.e., nitrate, organic matter, etc.) is below 10 mg/L, often play a vital role in supplying water for industries, agriculture activities, and domestic drinking water. , The existence of nitrate in drinking water poses potential risks to human health and contributes to eutrophication, resulting in further deterioration of water quality. − Therefore, a novel treatment technology to deal with nitrogen pollution in lakes and reservoirs is an international research hotspot.…”

“…The general aim of this work is to explore the mechanisms of iron-AC systems to enhance aboriginal aerobic denitrifying bacterial consortium for improved treatment of micro-polluted reservoir water based on microbial ecology characteristics. To this end, the specific objectives of this study were to (1) evaluate the removal performances of nitrate and other pollutants from micro-polluted water, (2) analyze the pathways of iron compounds, (3) analyze the shifts in microbial community structure and metabolic functional patterns using 16S rRNA gene sequencing, and (4) evaluate the interspecific interactions of mixed-culture microbial communities by network analysis. Overall, this study aims to provide an innovative strategy to enhance aboriginal aerobic denitrification for the in situ treatment of micro-polluted water and a theoretical basis for engineering applications.…”

Study on Dynamic Behaviors of Water Quality and Mechanisms of Eutrophication in Kandawgyi Lake, Yangon City, Myanmar

“…Besides, excessive nutrients may also result in eutrophication; and harmful algal blooms, which are one of the consequences of dissolved oxygen depletion, and the establishment of an anoxic environment at the bottom of lakes and reservoirs (Huang et al, 2019). The first paper found out that the average value of total nitrogen (TN) was 2.21 mg/L and the average value of total phosphorus (TP) was 0.56 mg/L.…”