scholarly journals Responses of water environmental indicators to climate conditions in the middle and lower reaches of Lijiang River

2021 ◽  
Author(s):  
Dantong Zhu ◽  
Xiangju Cheng ◽  
Wuhua Li ◽  
Fujun Niu ◽  
Jianhui Wen
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Wind Speed ◽  
Water Body ◽  
Sunshine Duration ◽  
Water Environment ◽  
Climate Conditions ◽  
Lijiang River ◽  
External Sources ◽  
The Difference

Abstract With global climate change and increasingly extreme weather conditions, the water environment of the Lijiang River Basin is facing huge threats. Past studies have mostly focused on large-scale areas or have regional characteristics. Therefore, this study is based on the meteorological, hydrological, and water quality data of the Lijiang River from 2012 to 2018, using the analysis method Spearman's rank correlation coefficient, sensitivity , and contribution rate to quantitative analysis of the relationship between climate conditions and water environment indicators. The results show that the oxidation and alkalinity of the water in the Lijiang River Basin gradually increase, and the intensity becomes stronger as it goes downstream. DO increase and the concentrations of COD Mn , BOD 5 , and NH 4 -N all decreased, and water quality improved year by year. The input of external pollution has led to an upward trend in TP in Yangshuo. DO is positively correlated with wind speed and negatively correlated with other climate indicators. NH 4 -N and TP are mainly affected by precipitation, streamflow, humidity, and sunshine duration, only sunshine duration is negatively correlated. Pollutants from Guilin to Yangshuo on both sides of the Lijiang River were carried by the surface runoff into the water body contain a certain amount of organic matter and acidic matter. Water environment indicators are not very sensitive to precipitation and streamflow, humidity and wind speed have higher sensitivity. Water temperature and sunshine duration have a positive effect on reducing NH 4 -N and TP. Various climate conditions can help reduce organic matter in the water body where there are few external sources and the opposite contribution with external sources. No climate condition can dominate one water environment indicator of two stations at the same time. The difference between Yangshuo and Guilin is mostly due to the input of external sources on both sides of the Lijiang River, which leads to the difference in sensitive climate conditions. Construction of non-point source pollution reduction facilities and sewage treatment measures are very necessary.

scholarly journals Variation in palladium and water quality parameters and their relationship in the urban water environment

2020 ◽  
Author(s):  
Yuyan Liu ◽  
Fangfang Ding ◽  
Caiye Ji ◽  
Dan Wu ◽  
Lin Wang ◽  
...  
Keyword(s):  
Water Quality ◽  
Correlation Coefficient ◽  
Water Body ◽  
Wet Deposition ◽  
Water Environment ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Urban Water ◽  
Rainfall Runoff ◽  
Receiving Water

Abstract Palladium (Pd) is widely used in vehicle exhaust catalysts (VECs) to reduce toxic emissions from motor vehicles. The study aimed to quantitatively determine Pd content and water quality parameters, to analyze the variation differences and to explore the effect of water quality parameters on Pd content in the urban water environment system (wet deposition–rainfall runoff–receiving water body–estuary) of the city of Haikou, Hainan Island, China. The method used in this study included microwave digestion under high pressure and temperature, analysis by inductively coupled plasma mass spectrometry, quality control of the experimental procedure and guaranteed recovery (85% −125%). The results showed that the dissolved Pd average content in the urban water environment system was the highest in rainfall runoff (4.93 ng/L), followed by that in the receiving water body (4.56 ng/L), and it was the lowest in wet deposition (0.1 ng/L). The suspended Pd average content was the highest in the estuary (2.83 ng/L), followed by that in rainfall runoff (1.26 ng/L), and it was the lowest in wet deposition (6 × 10−4 ng/L). The particle–water partition ratio of the estuary Pd was the highest (1.26), followed by that of Pd in rainfall runoff (0.26). The particle–water partition ratio of the wet deposition Pd was the lowest (6 × 10−3). The dissolved Pd was correlated with the pH, Cl−, and total suspended solids (TSS) (correlation coefficient = 0.52, −0.68, 0.39, p < 0.05; regression coefficient = 1.27, −1.39, 0.01). The suspended Pd was only correlated with Cl− and TSS (correlation coefficient = −0.36, 0.76, p < 0.05; regression coefficient = −1.45, 0.01). Cl− and TSS were the most closely related to Pd in the water environment system. Although individual factors such as pH, Cl−, and TSS had certain migration and transformation effects on Pd in the wet deposition–rainfall runoff–receiving water body–estuary system, the probability of strong correlations was not high. In particular, Eh was not related to the dissolved nor suspended Pd content (correlation coefficient = 0.14, 0.13), which may be due to the synergistic effect of the multiple physical factors on Pd. This study was helpful to better understand the environmental behavior of Pd and provided important theoretical support for the prevention and protection against urban water environmental pollution.

scholarly journals Distribution of TN and TP in Dongchang Lake from Sediment and Non-sediment Water Recharge Based on MIKE21

2021 ◽  
Vol 261 ◽  
pp. 02084
Author(s):  
Zhiran Xin ◽  
Liqing Ren
Keyword(s):  
Water Quality ◽  
Urban Population ◽  
Water Environment ◽  
Ecological Environment ◽  
Continuous Increase ◽  
Improvement Strategies ◽  
Before And After ◽  
Water Recharge ◽  
Change Trend ◽  
The Difference

With the continuous increase of urban population, the eutrophication of urban lakes is becoming more and more serious. It is necessary to improve the ecological environment of lakes by water supplement. In this study, TN (total nitrogen) and TP (total phosphorus) of Dongchang Lake before and after water replenishment were sampled and measured, and the hydrodynamic, water quality and sediment MIKE21 models of Dongchang Lake were established. Finally, the variation trend of TN and TP of Dongchang Lake before and after water replenishment of sediment and non-sediment water were simulated, and the following conclusions are drawn: During water replenishment, the TP concentration of each point will rise, and the TP concentration of non-sediment water is higher. After the completion of the water replenishment process, the TP concentration at each point decreases in turn. Under the two water replenishment modes, the difference of TP concentration gradually become narrower, but the TP concentration in non-sediment water is higher. The change trend of TN is similar to that of TP, but after the increase of TN concentration caused by water supply, the concentration of TN remains high in the next few days. This study provides an empirical basis for the development of lake water environment improvement strategies.

scholarly journals Identification of significant pressures and assessment of wastewater discharge on Krivaja River water quality

2017 ◽  
Vol 71 (5) ◽  
pp. 407-418
Author(s):  
Vesna Pesic ◽  
Milena Becelic-Tomin ◽  
Djurdja Kerkez ◽  
Bozo Dalmacija ◽  
Dejan Krcmar ◽  
...  
Keyword(s):  
Water Quality ◽  
Risk Assessment ◽  
Organic Matter ◽  
Surface Water ◽  
Impact Assessment ◽  
Water Body ◽  
Suspended Solids ◽  
Municipal Wastewater ◽  
Point Sources ◽  
Wastewater Discharge

One of the key stages of the process of preparing management plans for the river basin is the analysis of pressures and impacts, as well as the risk assessment of failing to achieve the environmental objectives. DPSIR framework (Driving Forces-Pressure-State-Impact-Response) was developed by the European Agency for the environmental protection, and makes the conceptual basis for the pressures and impacts analysis, taking into account the complexity of the interactions in the environment and represents the tool for their analysis. Impact assessment of the water body requires some quantitative information to describe the condition of the water body and/or the pressures that act on it. The aim of the study was to determine the effect of wastewater discharge on Krivaja watercourse. Impact assessment is carried out based on data of polluters? wastewater and monitoring information for water in Krivaja. For each site at which sampling was performed, the specific risk quotients for surface water were calculated, as the ratio of the each pollutant concentration in surface water at the sampling point and environmental quality standards for pollutants, as well as their sum that represents the risk index. In order to have the integrated perceive of processes in the Krivaja River, taking into account cumulative effects from point sources, the concept of total maximum daily load was applied, using which the pollution amount, that can be discharged daily in a water body without degrading his prescribed/required quality, was calculated. Comparison of emitted loads from pollution point sources with maximum allowable ones was performed. Wastewaters of different polluters located on Krivaja are, due to insufficient treatment, very loaded with organic matter and nutrients. Krivaja receives daily 1332 m3 of wastewater, 999 kg COD, 722 kg BOD, 144 kg of nitrogen, 4.3 kg of phosphorus and 627 kg of suspended solids. Of the total wastewater volume, the majority (69%) originates from municipal wastewater, 81% of the total amount of organic matter comes from the industry, while nutrients mostly originate from municipal wastewater. Loading of Krivaja with wastewater is major, uneven and unbalanced. Water quality of Krivaja is unsatisfactory. According to national legislation there is the exceedance of maximum permissible values for Class II for watercourse (good status) for most parameters, in all sampling locations and in both sampling periods. Parameters that exceeded the value for the Class II are dissolved oxygen, organic matter content, suspended solids, nutrients. Water flow in the river is not sufficient to receive the total amount of the pollutant load from point sources. Risk assessment, based on the monitoring results, indicates that the river Krivaja is possibly at risk of failing to meet the required water quality because the most of the values exceeded the limit values.

scholarly journals Some aspects of restoration of degradated sewage receivers

2019 ◽  
pp. 539-541
Author(s):  
Hubert Komorowski ◽  
Agnieszka Karczmarczyk ◽  
Jozef Mosiej
Keyword(s):  
Water Quality ◽  
Water Body ◽  
Phosphorus Content ◽  
Water Environment ◽  
Phosphorus Release ◽  
Phosphorus Cycle ◽  
Oxic Condition ◽  
River Bed ◽  
Water Ecosystem ◽  
Sediment Component

Bottom sediments are naturally connected with water body of the river and it is essential inpollutant balance, Natural phosphorus cycle in water environment is sedimentation cycle,Once introduced to water ecosystem can be removed by different chemical, biological andphysical processes and loses its environmental mobility as a sediment component,In studied case the contaminants load was radically reduced by construction of wastewatertreatment plant in city of Lodz, But the water quality improvement was not commensurate tothis reduction, Such situation could be the result of increased phosphorus release fromsediments deposed in the course of decades in river bed, On the distance the phosphateconcentration increases up to 25 km downstream the WWfP outlet and it can not beexplained by other pollution sources. The phosphorus content in the sediment is as high as 27 1 mg kg- dw, The equilibrium phosphate concentration (EPCo) experiment showed that itcould be released to water body, The preliminary results showed that EPCo value exceed in 3 some points limit polish water quality norm and amount to 1.2 mg PO4 dm- in oxic condition,

scholarly journals Coordinated Development of Water Environment Protection and Water Ecological Carbon Sink in Baiyangdian Lake

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 2066
Author(s):  
Yanli Li ◽  
Jinxu Lv ◽  
Lijun Li
Keyword(s):  
Carbon Dioxide ◽  
Water Quality ◽  
Water Body ◽  
Carbon Sink ◽  
Diffusion Flux ◽  
Water Environment ◽  
Phosphorus Concentration ◽  
Nitrogen And Phosphorus ◽  
Coordinated Development

“The Hebei Xiongan New Area Planning Outline” states that the carbon sink of the water body should be improved and the quality of Baiyangdian water should be improved by cleaning the sludge, but the treatment of endogenous pollution in the water body will release a large amount of carbon dioxide, which will reduce the carbon sink of Baiyangdian, which makes the improvement of water body quality and increasing carbon sink conflicting. In order to realize the coordinated development of Baiyangdian water quality improvement and carbon sink increase, this paper establishes the calculation model of the amount of sludge to be cleared to improve the unit water quality and the amount of carbon dioxide released by clearing the silt using the release flux and diffusion flux of nitrogen and phosphorus elements in the water body, and the relationship between the content of nitrogen and phosphorus elements, the depth of Baiyangdian sludge excavation and the amount of carbon dioxide released: as the content of nitrogen and phosphorus elements in the water decreases, the depth of sludge excavated to improve the unit water body increases, and the amount of carbon dioxide released gradually increases. As the nitrogen and phosphorus content in the water decreases, the depth of dredged sludge to improve the quality of the water body increases, the carbon dioxide released gradually increases, and when the nitrogen and phosphorus concentration reaches 0.18 g/m3 and 0.6 g/m3 respectively, the carbon dioxide released will increase exponentially. Thus, we propose countermeasures to improve the water quality of Baiyangdian and increase the carbon sink capacity: we can improve the water quality by reasonable dredging before the water quality reaches poor category 3; we can achieve the dual goals of improving the water quality and increasing the carbon sink by increasing the reed planting area.

MEASURES FOR ENVIRONMENT CONSERVATION IN ENCLOSED COASTAL SEAS

2017 ◽  
Author(s):  
Keizo Negi ◽  
Keizo Negi ◽  
Takuya Ishikawa ◽  
Takuya Ishikawa ◽  
Kenichiro Iba ◽  
...  
Keyword(s):  
Water Pollution ◽  
Water Quality ◽  
Water Mass ◽  
Sea Water ◽  
Red Tide ◽  
Water Environment ◽  
Quality Standard ◽  
Tokyo Bay ◽  
View Point ◽  
High Concentration

Japan experienced serious water pollution during the period of high economic growth in 1960s. It was also the period that we had such damages to human health, fishery and living conditions due to red tide as much of chemicals, organic materials and the like flowing into the seas along the growing population and industries in the coastal areas. Notable in those days was the issues of environment conservation in the enclosed coastal seas where pollutants were prone to accumulate inside due to low level of water circulation, resulting in the issues including red tide and oxygen-deficient water mass. In responding to these issues, we implemented countermeasures like effluent control with the Water Pollution Control Law and improvement/expansion of sewage facilities. In the extensive enclosed coastal seas of Tokyo Bay, Ise Bay and the Seto Inland Sea, the three areas of high concentration of population, we implemented water quality total reduction in seven terms from 1979, reducing the total quantities of pollutant load of COD, TN and TP. Sea water quality hence has been on an improvement trend as a whole along the steady reduction of pollutants from the land. We however recognize that there are differences in improvement by sea area such as red tide and oxygen-deficient water mass continue to occur in some areas. Meanwhile, it has been pointed out that bio-diversity and bio-productivity should be secured through conservation/creation of tidal flats and seaweed beds in the view point of “Bountiful Sea” To work at these challenges, through the studies depending on the circumstances of the water environment in the enclosed coastal seas, we composed “The Policy of Desirable State of 8th TPLCS” in 2015. We have also added the sediment DO into the water quality standard related to the life-environmental items in view of the preservation of aquatic creatures in the enclosed water areas. Important from now on, along the Policy, is to proceed with necessary measures to improve water quality with good considerations of differences by area in the view point of “Beautiful and bountiful Sea”.

Development of Dialog System Model for Eutrophication Control between Discharging River Basin and Receiving Water Body – Case Study of Lake Sagami (Japan)

1989 ◽  
Vol 21 (12) ◽  
pp. 1821-1824
Author(s):  
M. Suzuki ◽  
K. Chihara ◽  
M. Okada ◽  
H. Kawashima ◽  
S. Hoshino
Keyword(s):  
Water Management ◽  
Water Quality ◽  
Expert System ◽  
River Basin ◽  
Water Body ◽  
Water Bodies ◽  
Quality Data ◽  
Pollution Load ◽  
Water Quality Data ◽  
Receiving Water

A computer program based on expert system software was developed and proposed as a prototype model for water management to control eutrophication problems in receiving water bodies (Suzuki etal., 1988). The system has several expert functions: 1. data input and estimation of pollution load generated and discharged in the river watershed; 2. estimation of pollution load run-off entering rivers; 3. estimation of water quality of receiving water bodies, such as lakes; and 4. assisting man-machine dialog operation. The program can be used with MS-DOS BASIC and assembler in a 16 bit personal computer. Five spread sheets are utilized in calculation and summation of the pollutant load, using multi-windows. Partial differential equations for an ecological model for simulation of self-purification in shallow rivers and simulation of seasonal variations of water quality in a lake were converted to computer programs and included in the expert system. The simulated results of water quality are shown on the monitor graphically. In this study, the expert system thus developed was used to estimate the present state of one typical polluted river basin. The river was the Katsura, which flows into Lake Sagami, a lake dammed for water supply. Data which had been actually measured were compared with the simulated water quality data, and good agreement was found. This type of expert system is expected to be useful for water management of a closed water body.

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.

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