scholarly journals Assessment of Automatically Monitored Water Levels and Water Quality Indicators in Rivers with Different Hydromorphological Conditions and Pollution Levels in Greece

Hydrology ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 86
Author(s):  
Angeliki Mentzafou ◽  
George Varlas ◽  
Anastasios Papadopoulos ◽  
Georgios Poulis ◽  
Elias Dimitriou
Keyword(s):  
Water Quality ◽  
Time Series ◽  
Quality Indicators ◽  
High Frequency ◽  
Automatic Monitoring ◽  
Water Levels ◽  
High Temporal Resolution ◽  
Water Quality Indicators ◽  
Pollution Levels ◽  
Riverine Ecosystems

Water resources, especially riverine ecosystems, are globally under qualitative and quantitative degradation due to human-imposed pressures. High-temporal-resolution data obtained from automatic stations can provide insights into the processes that link catchment hydrology and streamwater chemistry. The scope of this paper was to investigate the statistical behavior of high-frequency measurements at sites with known hydromorphological and pollution pressures. For this purpose, hourly time series of water levels and key water quality indicators (temperature, electric conductivity, and dissolved oxygen concentrations) collected from four automatic monitoring stations under different hydromorphological conditions and pollution pressures were statistically elaborated. Based on the results, the hydromorphological conditions and pollution pressures of each station were confirmed to be reflected in the results of the statistical analysis performed. It was proven that the comparative use of the statistics and patterns of the water level and quality high-frequency time series could be used in the interpretation of the current site status as well as allowing the detection of possible changes. This approach can be used as a tool for the definition of thresholds, and will contribute to the design of management and restoration measures for the most impacted areas.

scholarly journals Soil and Water Quality Indicators of Diversified Farming Systems in a Saline Region of the Mekong Delta, Vietnam

Agriculture ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 38 ◽  
Author(s):  
Lam Van Tan ◽  
Thanh Tran ◽  
Ho Huu Loc
Keyword(s):  
Water Quality ◽  
Quality Indicators ◽  
Saltwater Intrusion ◽  
Coastal Region ◽  
Mekong Delta ◽  
Farming Systems ◽  
Water Levels ◽  
Cropping Patterns ◽  
Water Quality Indicators ◽  
Soil And Water

Saltwater intrusion, a consequence of climate change and decreased water levels, has been increasingly severe in the Mekong Delta region. Thanh Phu District, Ben Tre Province, Vietnam, is a coastal region where agricultural production and local livelihood have been impaired by saltwater intrusion, resulting in the adoption of multiple coping strategies, including rotations and intercropping. This study aims to measure and evaluate soil and water quality indicators of multiple farming systems in Thanh Phu district and contributes to developing suitable cropping patterns. Soil indicators were pH, electrical conductivity, and exchangeable Na+. Water quality characteristics include pH, salinity, dissolved N and P, alkalinity, H2S, and chemical oxygen demand (COD). The results indicated that water pH and salinity were at suitable levels to support the growth of prawn but were below the critical level required to grow black tiger shrimp and white-legged shrimp. Water alkalinity, dissolved N, P, and COD were not constraining for the growth of shrimps. However, a significant concentration of H2S may cause disadvantages for shrimp growth.

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.

Application of a Pilot-Scale Pulsed Electrocoagulation system to OCC-Based Paper Mill Effluent

TAPPI Journal ◽  
2009 ◽  
Vol 8 (3) ◽  
pp. 14-20 ◽  
Author(s):  
YUAN-SHING PERNG ◽  
EUGENE I-CHEN WANG ◽  
SHIH-TSUNG YU ◽  
AN-YI CHANG
Keyword(s):  
Water Quality ◽  
Quality Indicators ◽  
Paper Mill ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Optimal Dosage ◽  
Water Quality Indicators ◽  
Paper Mill Effluent ◽  
Treated Effluent ◽  
True Color

Trends toward closure of white water recirculation loops in papermaking often lead to a need for system modifications. We conducted a pilot-scale study using pulsed electrocoagulation technology to treat the effluent of an old corrugated containerboard (OCC)-based paper mill in order to evaluate its treatment performance. The operating variables were a current density of 0–240 A/m2, a hydraulic retention time (HRT) of 8–16 min, and a coagulant (anionic polyacrylamide) dosage of 0–22 mg/L. Water quality indicators investigated were electrical con-ductivity, suspended solids (SS), chemical oxygen demand (COD), and true color. The results were encouraging. Under the operating conditions without coagulant addition, the highest removals for conductivity, SS, COD, and true color were 39.8%, 85.7%, 70.5%, and 97.1%, respectively (with an HRT of 16 min). The use of a coagulant enhanced the removal of both conductivity and COD. With an optimal dosage of 20 mg/L and a shortened HRT of 10 min, the highest removal achieved for the four water quality indicators were 37.7%, 88.7%, 74.2%, and 91.7%, respectively. The water qualities thus attained should be adequate to allow reuse of a substantial portion of the treated effluent as process water makeup in papermaking.

Spatio-temporal Variations in Water Quality Parameter Trends in River Waters

2018 ◽  
Vol 69 (10) ◽  
pp. 2940-2952 ◽  
Author(s):  
Martina Zelenakova ◽  
Pavol Purcz ◽  
Radu Daniel Pintilii ◽  
Peter Blistan ◽  
Petr Hlustik ◽  
...  
Keyword(s):  
Water Quality ◽  
Chemical Oxygen Demand ◽  
Quality Indicators ◽  
Water Resource Management ◽  
Oxygen Demand ◽  
Temporal Variations ◽  
Water Quality Parameter ◽  
Agricultural Activity ◽  
Water Quality Indicators ◽  
Nitrite Nitrogen

Evaluating trends in water quality indicators is a crucial issue in integrated water resource management in any country. In this study eight chemical and physical water quality indicators were analysed in seven river profiles in the River Laborec in eastern Slovakia. The analysed water quality parameters were biochemical oxygen demand (BOD5), chemical oxygen demand (CODCr), pH, temperature (t), ammonium nitrogen (NH4+-N), nitrite nitrogen (NO2--N), nitrate nitrogen (NO3--N), and total phosphorus (TP). Data from the monitored indicators were provided by the Ko�ice branch of the Slovakian Water Management Company, over a period of 15 years from 1999 to 2013. Mann�Kendall non-parametric statistical test was used for the trend analysis. Biochemical and chemical oxygen demand, ammonium and nitrite nitrogen content exhibit decreasing trends in the River Laborec. Decreasing agricultural activity in the area has had a significant impact on the trends in these parameters. However, NO2--N was the significant parameter of water quality because it mostly exceeds the limit value set in Slovak legislation, Regulation No. 269/2010 Coll. In addition, water temperature revealed an increasing trend which could be caused by global increase in air temperature. These results indicate that human activity significantly impacts the water quality.

scholarly journals Utilization of factor analysis in waterworks engineering

2004 ◽  
Vol 52 (2) ◽  
pp. 121-128
Author(s):  
Petra Nováková
Keyword(s):  
Water Quality ◽  
Factor Analysis ◽  
Quality Indicators ◽  
Water Reservoir ◽  
Statistical Processing ◽  
Point Of View ◽  
Water Quality Indicators ◽  
Quality Of Water ◽  
The Individual

The aim of the work was to elaborate and evaluate the water quality of water reservoir Vranov nad Dyjí. Fresh water was sampled in five different locations of the reservoir (three important tributaries, dam and water captation locality). Ten, the most essential water quality indicators were selected. From the point of view of water quality indicators complexity the most integrated samples were taken in the water captation locality (period 1984 – 2002). At other locations, there were missing dates from the eightieth, but their volume was sufficient for statistical processing.Correlation analyses for the individual locations and dimensions were done as so as determination coefficients for all localities during the time period of 1994 – 2002. The results demonstrate very good allocation of the water captation from the point of view of the water flow.Multiples and factor analysis was done for the period of 1984 – 2002 in the locality Jelení zátoka where the object of water captation is situated. The results of the analysis are nine factors, which influence the water quality of the reservoir. From the point of view of the importance three factors were interpreted.The analyses and results are part of my Ph.D. thesis. The results will be used for other evaluations of the water quality in the reservoir and tributaries, for activities in the catchment’s area and for proposal processing other zones of second level of protected areas.

scholarly journals Monitoring of the hydrochemical regime of growing ponds

2020 ◽  
Vol 22 (93) ◽  
pp. 45-49
Author(s):  
S. I. Kravets ◽  
O. V. Krushelnytska ◽  
N. V. Poliukhovych
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Quality Indicators ◽  
Fish Farming ◽  
Growing Season ◽  
Pond Water ◽  
Total Hardness ◽  
Normative Values ◽  
Hydrochemical Regime ◽  
Water Quality Indicators

The growth and development of fish depend on the physicochemical properties of water, such as temperature, turbidity, concentration of hydrogen ions (pH), dissolved oxygen, total alkalinity, total hardness, nitrates, nitrites, etc. The article presents data on the hydrochemical regime of growing ponds of the farm “Rudnyky” of Lviv region. Studies have shown that the water quality indicators of growing ponds during the growing season are within the normative values and the water is suitable for fish farming. In the breeding ponds of the Rudnyky fishery, the water quality indicators fluctuated within the following limits, namely: the hydrogen index (pH) was within the maximum permissible concentrations (6.7–8.0). The content of dissolved oxygen in the water during the growing season was within normal limits (6.5 to 7.8 mg/l) and fully met the requirements for carp fish ponds, the alkalinity of the water was average and varied between 2.40 and 3.20 mg-eq/l, permanganate and dichromate oxidation varied slightly – 8.6–15.45 mgO/l and 25.6–40.50 mgO/l, which corresponds to the normative indicators for fish farming. The concentration of ammonium nitrogen (NH4+) in the growing ponds of the farm averaged 0.008–0,520 mg N/l, the content of nitrites and nitrates was 0.002–0.100 mg N/l and 0.060–0,520 mg N/l, respectively. The average concentration ranged from 0.10 mg P/l to 0.40 mg P/l of mineral phosphorus (PO4-3), which did not exceed the normative values. The amount of total iron in the water of the pond did not have high values, averaged 0.10–0.38 mg Fe/l, which was within the maximum allowable concentrations. The values of total hardness of water were determined as moderately hard and were in the range of 2.9–5.0 mg-eq/l. The salt composition of pond water was characterized by total mineralization, the ratio of ions and the content of chlorides, sulfates, bicarbonates. During the study period, the content of chlorides (Cl-) sulfates (SO4 2-); hydrocarbons (HCO3-), did not exceed the maximum allowable concentration. Among the cations in the pond water, calcium ions (Ca2+ ) predominated, their content averaged 28.2–80 mg Ca/l. In the studied pond, the concentration of magnesium (Mg2+) reached average values – 6.8–20.0 mg/l. The total mineralization of water was 300.4–440.4 mg/l. By the nature of the ionic composition, the water of the growing ponds belongs to the hydrocarbonate composition of the calcium group.

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