scholarly journals Characteristics of water quality response to hypolimnetic anoxia in Daheiting Reservoir

2021 ◽  
Author(s):  
Chang Liu ◽  
Shiyan Wang ◽  
Xiaobo Liu ◽  
Huaidong Zhou ◽  
Budong Li ◽  
...  
Keyword(s):  
Water Quality ◽  
Joint Effect ◽  
Ammonia Nitrogen ◽  
Water Diversion ◽  
Tianjin City ◽  
Anoxic Environment ◽  
Reducing Substances ◽  
Quality Response ◽  
Water Quality Deterioration ◽  
Iron And Manganese

Abstract Anoxia is a common phenomenon at the bottom of large reservoirs during thermal stratification. In an anoxic environment, an increasing amount of reducing substances and nutrients are released and settle at the hypolimnion of the reservoir, leading to water quality deterioration and eutrophication. This work presents a case study on Daheiting Reservoir, a part of the Water Diversion Project from the Luanhe River to Tianjin City. With the monitored data of the water temperature and dissolved oxygen content in the reservoir, and based on the mechanism of redox reactions, the water quality response to the hypolimnetic anoxia in Daheiting Reservoir was systematically analyzed. It was found that the release of total phosphorus from the sediments in Daheiting Reservoir was a joint effect of the biological and chemical processes, and the redox reaction in the anoxic zone boosted release of phosphorus. Anoxia in the reservoir caused the ammonia nitrogen released from sediments in the reservoir to accumulate at the hypolimnion, which increased the concentration of ammonia nitrogen in the water. Anoxia in the reservoir led to an increase in the concentration of iron and manganese, which accounts for the major driving factor of release of iron and manganese.

scholarly journals Spatio-Temporal Variation of Total Nitrogen and Ammonia Nitrogen in the Water Source of the Middle Route of the South-To-North Water Diversion Project

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2615
Author(s):  
Guoquan Dong ◽  
Zhenqi Hu ◽  
Xuan Liu ◽  
Yaokun Fu ◽  
Wenjing Zhang
Keyword(s):  
Remote Sensing ◽  
Water Quality ◽  
Total Nitrogen ◽  
Ammonia Nitrogen ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Water Diversion ◽  
Mountainous Area ◽  
Danjiangkou Reservoir ◽  
N Concentration

The quantitative inversion of the concentrations of water quality parameters could clarify the temporal and spatial distribution characteristic, migration, and conversion of water quality parameters. This study took the Danjiangkou Reservoir as the research object, and established an inversion model based on the reflectance of different band combinations of remote sensing analyses on Sentinel-2 images, combined with the water quality monitoring data of total nitrogen (TN) and ammonia nitrogen (NH3-N) of the sampling sites in February 2016. The inversion results of TN and NH3-N in 2020 were obtained, the variation of TN and NH3-N concentrations in the reservoir area were analyzed, and the factors accounting for the variation were discussed. The results indicated that the fitting accuracy using the established model was high for both TN and NH3-N, and R2 was 0.782 for TN and 0.851 for NH3-N, respectively, showing high predication accuracy, which could be suitable for remote sensing inversion of TN and NH3-N concentrations in the Danjiangkou Reservoir. The NH3-N concentration of the Danjiangkou Reservoir was in line with Class I from 2016 to 2020, while the TN concentration was between Class III and IV. The inter-annual changes indicated that the overall water quality had an upward trend. The main tributary in the northern of the Danjiangkou Reservoir had a heavy load of TN, and after entering the reservoir, the flow velocity decreased, which caused nitrogen to accumulate at the river entrance, leading to a high TN concentration. The large slope of the mountainous area cause soil erosion. The lost soil and water carried a large amount of pesticides and fertilizers, and the ground runoff carried a large amount of nitrogen into water body, which could account for the high NH3-N concentration on the east and west sides of the southern part of the Danjiangkou Reservoir.

scholarly journals Modeling Daily and Monthly Water Quality Indicators in a Canal Using a Hybrid Wavelet-Based Support Vector Regression Structure

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1476 ◽  
Author(s):  
Yuxin Wang ◽  
Yuan Yuan ◽  
Ye Pan ◽  
Zhengqiu Fan
Keyword(s):  
Water Quality ◽  
Time Series ◽  
Support Vector Regression ◽  
Quality Indicators ◽  
Extreme Values ◽  
Ammonia Nitrogen ◽  
Stationary Time Series ◽  
Water Diversion ◽  
Support Vector ◽  
Water Quality Indicators

Accurate prediction of water quality indicators plays an important role in the effective management of water resources. The models which studied limited water quality indicators in natural rivers may give inadequate guidance for managing a canal being used for water diversion. In this study, a hybrid structure (WA-PSO-SVR) based on wavelet analysis (WA) coupled with support vector regression (SVR) and particle swarm optimization (PSO) algorithms was developed to model three water quality indicators, chemical oxygen demand determined by KMnO4 (CODMn), ammonia nitrogen (NH3-N), and dissolved oxygen (DO), in water from the Grand Canal from Beijing to Hangzhou. Modeling was independently conducted over daily and monthly time scales. The results demonstrated that the hybrid WA-PSO-SVR model was able to effectively predict non-linear stationary and non-stationary time series and outperformed two other models (PSO-SVR and a standalone SVR), especially for extreme values prediction. Daily predictions were more accurate than monthly predictions, indicating that the hybrid model was more suitable for short-term predictions in this case. It also demonstrated that using the autocorrelation and partial autocorrelation of time series enabled the construction of appropriate models for water quality prediction. The results contribute to water quality monitoring and better management for water diversion.

Potential impacts of slum urbanisation on channel bank storage in the Bang Pakong River, Thailand

2012 ◽  
Vol 7 (4) ◽  
Author(s):  
K. Harriden
Keyword(s):  
Water Quality ◽  
Balance Equations ◽  
Physical Processes ◽  
Social Phenomena ◽  
Urban Settlements ◽  
Recharge Rates ◽  
Water Quality Deterioration ◽  
Informal Urban Settlements ◽  
Storage Processes

Generally regarded as social phenomena, this paper regards slum urbanisation as an environmental actor. Specifically, how slum developments modify hydrogeomorphological processes motivates this research. Using the Bang Pakong River, eastern Thailand, as a case study, a literature review was conducted. The literature reviewed indicated changes in physical processes such as channel bank stability, water quality, flow regimes and the hydrological balance equations can occur with slum development. Given the importance of channel banks as the physical basis of many slum sites, this paper focuses on the possible changes to channel bank storage in the Bang Pakong River following slum urbanisation. The research highlights possible changes to channel bank storage processes, notably decreased storage recharge rates; increased anthropogenic extraction; and probable water quality deterioration. Deeper scientific understanding of how river processes are affected by specific forms of urban development can contribute to better management of both informal urban settlements and rivers.

Living with water: at the cross-roads of change

1995 ◽  
Vol 31 (8) ◽  
pp. 393-400 ◽  
Author(s):  
Joost de Jong ◽  
Peter T. J. C. van Rooy ◽  
S. Harry Hosper
Keyword(s):  
Water Management ◽  
Water Quality ◽  
Water Environment ◽  
Integrated Water Management ◽  
Practical Action ◽  
The People ◽  
Global Perception ◽  
Local Water ◽  
Water Quality Deterioration ◽  
The Way

Until the last two decades, the global perception of how to control our various water bodies was remarkably similar – water management was organised on a sectoral basis, as it always had been. It was only in the 1970s that the people actually responsible for implementing water management began to become aware of the serious implications of such an approach: water quality deterioration, desiccation and an alarming loss of the flora and fauna that characterised their local water environment. It was a growing awareness that led to the formation of the concept of integrated water management, a concept almost universally accepted today as the way forward. However, despite the fact that few dispute the validity of the concept, a number of obstacles remain before this theoretical agreement can be transformed into practical action. Three main bottlenecks stand in the way of implementation: institutional, communicational and socio-political. Whilst solutions to these are available, the key question still to be answered is whether society is really prepared to accept the consequent changes in the way we live that will result from putting the theory of integrated water management into practice. It was this issue that dominated the “Living with water” conference held in Amsterdam in September 1994. The following is a summary of the discussions held there and the various papers that were submitted.

Water-Quality Assessment of Lv-Tang River in Zhanjiang, China

2013 ◽  
Vol 295-298 ◽  
pp. 755-758 ◽  
Author(s):  
Ya Yun Liu ◽  
Zhi Hong Li ◽  
Xiao Jian Liang ◽  
Yan Peng Lin ◽  
Rong Hao Wu ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Quality Index ◽  
Quality Index ◽  
Oxygen Demand ◽  
Pollution Index ◽  
Ammonia Nitrogen ◽  
Single Parameter ◽  
Water Quality Parameter ◽  
National Quality

Based on the water quality investigation data of December in 2010, the water environment quality of Lv-tang River in Zhanjiang national urban wetland park was assessed using single water quality parameter model and integrated water quality index model. The results show that the water quality of Lv-tang River is worse than the national quality standards for Grade V. The water is polluted seriously. The main pollutants are total nitrogen (TN), ammonia nitrogen (NH3-N) and chemical oxygen demand CODCr with their average concentrations of 60.49 mg/L, 30.57 mg/L and 227.38mg/L, respectively. The averages of their single parameter pollution index are 30.25 , 19.79 and 8.74. The average of single parameter pollution index of the river is 8.23 which indicated that the river belongs to heavy pollution zone. The integrated water quality index was 22.5 showing that the river belongs to serious pollution zone.

scholarly journals Research on Water Environment Regulation of Artificial Playground Lake Interconnected Yangtze River

2018 ◽  
Vol 15 (10) ◽  
pp. 2110 ◽  
Author(s):  
Weiwei Song ◽  
Xingqian Fu ◽  
Yong Pang ◽  
Dahao Song ◽  
Qing Xu ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Level ◽  
Yangtze River ◽  
Flood Control ◽  
Numerical Models ◽  
Rapid Development ◽  
Control Level ◽  
Water Environment ◽  
Water Diversion ◽  
Coupled Models

With the rapid development of China, water pollution is still a serious problem despite implementation of control measures. Reasonable water environment management measures are very important for improving water quality and controlling eutrophication. In this study, the coupled models of hydrodynamics, water quality, and eutrophication were used to predict artificial Playground Lake water quality in the Zhenjiang, China. Recommended “unilateral” and “bilateral” river numerical models were constructed to simulate the water quality in the Playground Lake without or with water diversion by pump, sluice and push pump. Under “unilateral” and “bilateral” river layouts, total nitrogen and total phosphorus meet the landscape water requirement through water diversion. Tourist season in spring and summer and its suitable temperature result in heavier eutrophication, while winter is lighter. Under pumping condition, water quality and eutrophication of “unilateral” river is better than “bilateral” rivers. Under sluice diversion, the central landscape lake of “unilateral river” is not smooth, and water quality and eutrophication is inferior to the “bilateral”. When the water level exceeds the flood control level (4.1 m), priority 1 is launched to discharge water from the Playground Lake. During operation of playground, when water level is less than the minimum level (3.3 m), priority 2 is turned on for pumping diversion or sluice diversion to Playground Lake. After opening the Yangtze river diversion channel sluice, priority 3 is launched for sluice diversion to the Playground Lake. When the temperature is less than 15 °C, from 15 °C to 25 °C and higher than 25 °C, the water quality can be maintained for 15 days, 10 days and 7 days, respectively. Corresponding to the conditions of different priority levels, reasonable choices of scheduling measures under different conditions to improve the water quality and control eutrophication of the Playground Lake. This article is relevant for the environmental management of the artificial Playground Lake, and similar lakes elsewhere.

Features of Water Function Zoning of the Surface Water in Sichuan Province

2015 ◽  
Vol 730 ◽  
pp. 221-229
Author(s):  
Rui Kun Cai ◽  
Fu Quan Ni ◽  
Yu Deng
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Water Resources ◽  
Agricultural Production ◽  
Production Management ◽  
Sichuan Province ◽  
Wastewater Discharge ◽  
Agricultural Wastewater ◽  
Key Points ◽  
Water Quality Deterioration

In this study, based on the water function zoning and the related analyses on the current situations and tendency of the pollutions on water environments in Sichuan province, concluded that the primary cause responsible for the deterioration of water resources is the discharge of agriculture wastewater, and the strengthening of agricultural production management as well as the reduction of the agricultural wastewater discharge are the key points to alleviate the water-quality deterioration.

scholarly journals The in situ remediation of aquaculture water and sediment by commercial probiotics immobilized on different carriers

2021 ◽  
Author(s):  
Mengmeng Yi ◽  
Chun Wang ◽  
He Wang ◽  
Xi Zhu ◽  
Zhigang Liu ◽  
...  
Keyword(s):  
Water Quality ◽  
High Throughput Sequencing ◽  
Relative Concentration ◽  
Ammonia Nitrogen ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Treatment Groups ◽  
Walnut Shells ◽  
Water And Sediment ◽  
Aquaculture Water

Abstract In the present study, we investigated the effect of probiotics immobilized by oyster shells (Os), vesuvianite (Ve) and walnut shells (Ws) on the remediation of aquaculture water and sediment by analyzing the variation of ammonia-nitrogen (NH4–N), nitrate-nitrogen (NO3–N), nitrite-nitrogen (NO2–N), total nitrogen (TN), total phosphorus (TP) and chemical oxygen demand (CODCr), as well as the microbiota of the water and sediment. The positive or negative effects of the treatment groups on the water quality parameters were both observed. Compared with their effects on water quality parameters, the treatment groups had better effects on sediment parameters. Group Ve had the best remediation effect of NH4–N and NO3–N in the sediment (decreased by 5.22 and 1.66 times, respectively). Group Os showed a lower relative concentration of TN and CODCr (decreased by 3.77 and 0.95 times, respectively). The high-throughput sequencing results revealed that the immobilized probiotics increased the relative abundances of functional bacteria in the treatment groups at the phylum and genus level. The above results showed that probiotics immobilized by oyster shells, vesuvianite and walnut shells positively affected the aquaculture environment's remediation, especially the sediment.

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