Is water age a reliable indicator for evaluating water quality effectiveness of water diversion projects in eutrophic lakes?

2016 ◽  
Vol 542 ◽  
pp. 281-291 ◽  
Author(s):  
Xiaoling Zhang ◽  
Rui Zou ◽  
Yilin Wang ◽  
Yong Liu ◽  
Lei Zhao ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Diversion ◽  
Reliable Indicator ◽  
Water Age ◽  
Eutrophic Lakes

Effects of Fe addition on sediment P dynamics in a eutrophic lake

2021 ◽  
Author(s):  
Melanie Münch ◽  
Rianne van Kaam ◽  
Karel As ◽  
Stefan Peiffer ◽  
Gerard ter Heerdt ◽  
...  
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Surface Water ◽  
Water Column ◽  
Sediment Cores ◽  
Surface Water Quality ◽  
Water Interface ◽  
Eutrophic Lakes ◽  
Fe Addition

<p>The decline of surface water quality due to excess phosphorus (P) input is a global problem of increasing urgency. Finding sustainable measures to restore the surface water quality of eutrophic lakes with respect to P, other than by decreasing P inputs, remains a challenge. The addition of iron (Fe) salts has been shown to be effective in removing dissolved phosphate from the water column of eutrophic lakes. However, the resulting changes in biogeochemical processes in sediments as well as the long-term effects of Fe additions on P dynamics in both sediments and the water column are not well understood.</p><p>In this study, we assess the impact of past Fe additions on the sediment P biogeochemistry of Lake Terra Nova, a well-mixed shallow peat lake in the Netherlands. The Fe-treatment in 2010 efficiently reduced P release from the sediments to the surface waters for 6 years. Since then, the internal sediment P source in the lake has been increasing again with a growing trend over the years.</p><p>In 2020, we sampled sediments at three locations in Terra Nova, of which one received two times more Fe during treatment than the other two. Sediment cores from all sites were sectioned under oxygen-free conditions. Both the porewaters and sediments were analysed for their chemical composition, with sequential extractions providing insight into the sediment forms of P and Fe. Additional sediment cores were incubated under oxic and anoxic conditions and the respective fluxes of P and Fe across the sediment water interface were measured.</p><p>The results suggest that Fe and P dynamics in the lake sediments are strongly coupled. We also find that the P dynamics are sensitive to the amount of Fe supplied, even though enhanced burial of P in the sediment was not detected. The results of the sequential extraction procedure for P, which distinguishes P associated with humic acids and Fe oxides, as well as reduced flux of Fe(II) across the sediment water interface in the anoxic incubations, suggest a major role of organic matter in the interaction of Fe and P in these sediments.</p><p>Further research will include investigations of the role of organic matter and sulphur in determining the success of Fe-treatment in sequestering P in lake sediments. Based on these data in combination with reactive transport modelling we aim to constrain conditions for successful lake restoration through Fe addition.</p>

Improving water age estimation in a drinking water distribution network by field study and digital modeling

2021 ◽  
Author(s):  
Jon Kristian Rakstang ◽  
Michael B. Waak ◽  
Marius M. Rokstad ◽  
Cynthia Hallé
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Network Model ◽  
Age Estimation ◽  
Water Distribution ◽  
Distribution Network ◽  
Distribution Networks ◽  
Plate Count ◽  
Water Age ◽  
Drinking Water Distribution

<p>Municipal drinking water distribution networks are complex and dynamic systems often spanning many hundreds of kilometers and serving thousands of consumers. Degradation of water quality within a distribution network can be associated to water age (i.e., time elapsed after treatment). Norwegian distribution networks often consist of an intricate combination of pressure zones, in which the transport path(s) between source and consumer is not easily ascertained. Water age is therefore poorly understood in many Norwegian distribution networks. In this study, simulations obtained from a water network model were used to estimate water age in a Norwegian municipal distribution network. A full-scale tracer study using sodium chloride salt was conducted to assess simulation accuracy. Water conductivity provided empirical estimates of salt arrival time at five monitoring stations. These estimates were consistently higher than simulated peak arrival times. Nevertheless, empirical and simulated water age correlated well, indicating that additional network model calibration will improve accuracy. Subsequently, simulated mean water age also correlated strongly with heterotrophic plate count (HPC) monitoring data from the distribution network (Pearson’s R= 0.78, P= 0.00046), indicating biomass accumulation during distribution—perhaps due to bacterial growth or biofilm interactions—and illustrating the importance of water age for water quality. This study demonstrates that Norwegian network models can be calibrated with simple and cost-effective salt tracer studies to improve water age estimates. Improved water age estimation will increase our understanding of water quality dynamics in distribution networks. This can, through digital tools, be used to monitor and control water age, and its impact on biogrowth in the network.</p>

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.

scholarly journals Sediment Remediation for Ecosystem in Eutrophic Lakes

2002 ◽  
Vol 2 ◽  
pp. 885-891 ◽  
Author(s):  
Y. Amano ◽  
K. Taki ◽  
K. Murakami ◽  
T. Ishii ◽  
H. Matsushima
Keyword(s):  
Water Quality ◽  
Green Algae ◽  
Hybrid System ◽  
Size Reduction ◽  
Control Effect ◽  
Sediment Remediation ◽  
Eutrophic Lakes

The remediation method — namely, a hybrid system combined with DAF and CRM — is studied in this paper for the size reduction of aqua-ecological circulation and for the elution control in lakes. Results show that two effects on water quality purification, the sediment washout effect and the elution control effect, can be induced by this system, and the biota inhabiting the lake is therefore shifted into an oligotrophic aspect, from blue algae to green algae and/or diatoms.

scholarly journals ANALISIS KUALITAS AIR UNTUK KONSENTRASI FLUORIDE PADA SISTEM JARINGAN DISTRIBUSI AIR MINUM DENGAN FLUORIDASI

2019 ◽  
Vol 2 (1) ◽  
pp. 11 ◽  
Author(s):  
Arif Susanto ◽  
Purwanto Purwanto ◽  
Agus Hadiyarto
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Water Distribution ◽  
Dental Health ◽  
Distribution Network ◽  
Fluoride Concentration ◽  
Water Distribution Network ◽  
Water Supply Systems ◽  
Water Age ◽  
Drinking Water Distribution

Abstract:. The requirement of consumed drinking water so that it does not create disturbance to public health is that it needs a quality monitoring. Water fluoridation in Tembagapura City aims to reach its concentration level toward certain safe level, and it can provide maximum benefits for dental health. Analysis and simulation methods using EPAnet software. The results of hydrolic simulation and water quality for fluoride concentration of each node and link in the drinking water distribution network system have changed in every time change following the drinking water distribution segment. From hydraulic simulations, especially for head and flow at separate points, it consists of simultaneous solution in flow equivalence for every junction and headloss relationship in every link of network as a result of hydraulic balancing. New segment will be made at the end of each link that receives inflow from a node if the quality of the new node is different from the link in the last segment. Every pipe in network contains singular segment where the water quality is in line with the preliminary quality stated in the preliminary node. With the availability of hydraulic model and water quality for fluoride concentration, a further research can be conducted for chlorine decay, growth of by product i.e. Trihalomethans (THMs) as well as water age simultaneously in drinking water supply systems in Tembagapura City.  Keyword: EPAnet, distribution network, fluoride concentration. Abstrak: Persyaratan kualitas air minum yang dikonsumsi masyarakat agar tidak menimbulkan gangguan kesehatan, maka penyelenggara air minum perlu melakukan pemantauan kualitasnya. Fluoridasi air di Kota Tembagapura ditujukan untuk mencapai tingkat konsentrasi fluoride pada level tertentu yang aman dan dapat memberikan manfaat maksimal bagi kesehatan gigi. Metode analisis dan simulasi menggunakan perangkat lunak EPAnet. Hasil simulasi hidrolis dan kualitas air untuk konsentrasi fluoride pada setiap node dan link pada sistem jaringan distribusi air minum berubah pada setiap perubahan waktu mengikuti segmen distribusi air minum tersebut. Dari simulasi hidrolis, khusus untuk head dan aliran pada titik yang terpisah meliputi penyelesaian secara simultan dalam persamaan aliran untuk tiap sambungan (junction), dan hubungan headloss pada setiap link pada jaringan sebagai akibat dari hydrolic balancing. Segmen baru terbentuk pada akhir dari setiap link yang menerima inflow dari sebuah node, jika kualitas node baru berbeda dari link pada segmen terakhir. Setiap pipa dalam jaringan mengandung segmen tunggal, di mana kualitas air sebanding dengan kualitas awal yang ditetapkan di node awal. Dengan tersedianya model hidrolis dan kualitas air untuk konsentrasi fluoride, maka dapat dilakukan penelitian lanjutan untuk peluruhan klorin, pertumbuhan by product yaitu trihalomethans (THMs) serta usia air secara simultan pada sistem penyediaan air minum di Kota Tembagapura.Kata Kunci: EPAnet, jaringan distribusi, konsentrasi fluoride.

Optimal Model of Hydrodynamic Controlling on Pumps and Slice Gates for Water Quality Improvement

2013 ◽  
Vol 316-317 ◽  
pp. 732-740 ◽  
Author(s):  
Hui Ping Zhou ◽  
Wei Yun Shao ◽  
Li Jie Jiang
Keyword(s):  
Water Quality ◽  
Quality Improvement ◽  
Objective Function ◽  
River Network ◽  
Water Diversion ◽  
Engineering Practice ◽  
Optimal Model ◽  
Water Quality Improvement ◽  
Quality Objective ◽  
The Cost

In order to evaluate the effective of the hydrodynamic control of pumps and slice gates in plain river network on the water quality improvement, an optimal mathematic model of hydrodynamic controlling on the pumps and slice gates in plain river network was established by combining the water quality objective function and the cost objective function together. The cost function has been set as the main objective function, while the water quality objective function was simplified as the restrained condition for every required water quality index, through which the multi-objective optimization was transferred into a single-objective optimization. Then, this optimal model was solved by coupling the water environmental model with the hybrid genetic algorithm. The case study of Jiaxing river network shows that the proposed hydrodynamic controlling optimal model in this paper can develop the optimal water diversion scheme for water quality improvement and cut its cost. It works better compared to the traditional water quality objective function and can be used in the engineering practice.

Wind effects change in Taihu Lake with climate change background

2021 ◽  
Author(s):  
Sien Liu ◽  
Qinghua Ye ◽  
Jie Zhou
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
Shallow Lakes ◽  
Taihu Lake ◽  
Three Dimensional ◽  
Reference Scenario ◽  
Wind Condition ◽  
Water Age ◽  
Climate Change Effects ◽  
Wind Events

<p>Large shallow lakes globally are threatened by eutrophication, and climate change is believed to aggregate the situation. Wind, as the most important momentum source and the major contributor to consistently change the hydrodynamic patterns inside the large shallow lakes, is highly susceptible to climate change. Taihu Lake, which is the 3<sup>rd</sup> largest shallow lake in China and pertains crucial social and economic values, is chosen in this study as an example. Due to climate change, the wind condition of Taihu Lake shows a significantly decreasing trend of wind speed and the frequency of extreme wind events. Previous studies have paid little attention to the climate change effects on wind hydrodynamics and its implications on water quality has not yet been thoroughly described. Here in this study, we use a well-calibrated and validated three-dimensional Delft3D model to investigate the spatial and temporal heterogeneity of wind induced hydrodynamics and its water quality implications with climate change. The model results give a prediction of less current speed, lower wave height and bottom shear stress compared to the reference scenario, while the three dimensionality of flow field remains. Further, water age is used to demonstrate the influence of external nutrient sources, i.e. the input from adjacent river networks in the basin. Large water ages are observed and potentially it would enhance the accumulation of nutrients and deterioration of water quality.</p>

scholarly journals Assessment and Management of Pressure on Water Quality Protection along the Middle Route of the South-to-North Water Diversion Project

2019 ◽  
Vol 11 (11) ◽  
pp. 3087 ◽  
Author(s):  
Baolong Han ◽  
Nan Meng ◽  
Jiatian Zhang ◽  
Wenbo Cai ◽  
Tong Wu ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use Changes ◽  
Water Diversion ◽  
Water Protection ◽  
The South ◽  
Water Quality Protection ◽  
Functional Zoning ◽  
Water Diversion Project ◽  
North Water ◽  
Global Concern

Water scarcity in densely populated areas is a global concern. In China, ensuring water supply and quality in the middle of the South-to-North Water Diversion Project has become a major challenge due to the complexity and diversity of landscape features and the trunk canal construction in the crossing area of this route. Precise assessments of the pressures on water protection along the route are urgently needed. This article provides a rigorous methodological framework to assess water quality protection, identifying the intensity of human disturbance along the route within 2-km radius buffer areas on both sides of the trunk canal, based on land-use changes from 2005 to 2015. The results show that more than 10,000 ha of pervious surfaces were transformed into impervious surfaces, leading to undesirable outcomes. The results of this study can be used for decisive support in China’s environmental management, such as with main functional zoning policy and ecological red lines policy.

scholarly journals Legionella Diversity and Spatiotemporal Variation in the Occurrence of Opportunistic Pathogens within a Large Building Water System

Pathogens ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 567 ◽  
Author(s):  
Helen Y. Buse ◽  
Brian J. Morris ◽  
Vicente Gomez-Alvarez ◽  
Jeffrey G. Szabo ◽  
John S. Hall
Keyword(s):  
Water Quality ◽  
Water System ◽  
Bulk Water ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Opportunistic Pathogens ◽  
Water Age ◽  
Large Building ◽  
Survival Mechanisms ◽  
Culture Positive

Understanding Legionella survival mechanisms within building water systems (BWSs) is challenging due to varying engineering, operational, and water quality characteristics unique to each system. This study aimed to evaluate Legionella, mycobacteria, and free-living amoebae occurrence within a BWS over 18–28 months at six locations differing in plumbing material and potable water age, quality, and usage. A total of 114 bulk water and 57 biofilm samples were analyzed. Legionella culturability fluctuated seasonally with most culture-positive samples being collected during the winter compared to the spring, summer, and fall months. Positive and negative correlations between Legionella and L. pneumophila occurrence and other physiochemical and microbial water quality parameters varied between location and sample types. Whole genome sequencing of 19 presumptive Legionella isolates, from four locations across three time points, identified nine isolates as L. pneumophila serogroup (sg) 1 sequence-type (ST) 1; three as L. pneumophila sg5 ST1950 and ST2037; six as L. feeleii; and one as Ochrobactrum. Results showed the presence of a diverse Legionella population with consistent and sporadic occurrence at four and two locations, respectively. Viewed collectively with similar studies, this information will enable a better understanding of the engineering, operational, and water quality parameters supporting Legionella growth within BWSs.

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