scholarly journals Statistical approaches to explore the linkages between physicochemical parameters and BQEs, and set river nutrient threshold concentrations in Hungary

Author(s):  
O. Szomolányi ◽  
A. Clement

Abstract The objective of the Water Framework Directive (WFD) is to achieve good ecological status in surface waters by 2027. To make a proper evaluation of the ecological status of watercourses, it is necessary to harmonize class boundaries for chemical and biological quality elements (BQEs). This paper aims to explore the linkages between physicochemical parameters and BQEs and set river nutrient threshold concentrations that support good ecological status. Regression and mismatch methods were applied to find the relationship between phytoplankton (PP) and phytobenthos (PB) environmental quality ratio and mean total phosphorus (TP) and total nitrogen (TN) concentrations. Nutrient thresholds have been suggested for several water types, which are varied in the case of highland rivers 1.8–6.2 mg TN/l, 180–400 μg TP/l; in the case of lowland rivers 1.4–5.0 mg TN/l, and 100–350 μg TP/l. These values are similar to what other studies found, but the relationship between biology and nutrients was weaker. Besides nutrients, additional data of measured dissolved organic carbon, 5-day biochemical oxygen demand, chemical oxygen demand with potassium permanganate method, and information about hydromorphological features were involved in the analysis. The research demonstrates that random forest can be used as a nonlinear, multiparametric model for predicting biological class from five variables with 35–81% error for PP and with 18–47% error for PB.

Author(s):  
Ruben Ladrera ◽  
Miguel Cañedo-Argüelles ◽  
Narcís Prat

Potash mining is significantly increasing the salt concentration of rivers and streams due to lixiviates coming from the mine tailings. In the present study, we have focused on the middle Llobregat basin (northeast Spain), where an important potash mining activity exists from the beginning of the XX century. Up to 50 million tonnes of saline waste have been disposed in the area, mainly composed of sodium chloride. We assessed the ecological status of streams adjacent to the mines by studying different physicochemical and hydromorphological variables, as well as aquatic macroinvertebrates. We found extraordinary high values of salinity in the studied streams, reaching conductivities up to 132.4 mS/cm. Salt-polluted streams were characterized by a deterioration of the riparian vegetation and the fluvial habitat. Both macroinvertebrate richness and abundance decreased with increasing salinity. In the most polluted stream only two families of macroinvertebrates were found: Ephydridae and Ceratopogonidae. According to the biotic indices IBMWP and IMMi-T, none of the sites met the requirements of the Water Framework Directive (WFD; i.e., good ecological status). Overall, we can conclude that potash-mining activities have the potential to cause severe ecological damage to their surrounding streams. This is mainly related to an inadequate management of the mine tailings, leading to highly saline runoff and percolates entering surface waters. Thus, we urge water managers and policy makers to take action to prevent, detect and remediate salt pollution of rivers and streams in potash mining areas.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Leo Posthuma ◽  
Michiel C. Zijp ◽  
Dick De Zwart ◽  
Dik Van de Meent ◽  
Lidija Globevnik ◽  
...  

Abstract Aquatic ecosystems are affected by man-made pressures, often causing combined impacts. The analysis of the impacts of chemical pollution is however commonly separate from that of other pressures and their impacts. This evolved from differences in the data available for applied ecology vis-à-vis applied ecotoxicology, which are field gradients and laboratory toxicity tests, respectively. With this study, we demonstrate that the current approach of chemical impact assessment, consisting of comparing measured concentrations to protective environmental quality standards for individual chemicals, is not optimal. In reply, and preparing for a method that would enable the comprehensive assessment and management of water quality pressures, we evaluate various quantitative chemical pollution pressure metrics for mixtures of chemicals in a case study with 24 priority substances of Europe-wide concern. We demonstrate why current methods are sub-optimal for water quality management prioritization and that chemical pollution currently imposes limitations to the ecological status of European surface waters. We discuss why management efforts may currently fail to restore a good ecological status, given that to date only 0.2% of the compounds in trade are considered in European water quality assessment and management.


Author(s):  
EUKENE OPORTO BENSIG ◽  
MARY JOYCE L. FLORES ◽  
FLEURDELIZ F. MAGLANGIT

The use of surface waters such as rivers for domestic, agricultural andindustrial purposes have made them vulnerable to pollution leading to impairedwater quality. The water quality of Lahug River in Cebu City was evaluated usingcoliforms as indicators, in relation with physicochemical parameters such as biological oxygen demand (BOD), conductivity, dissolved oxygen (DO), nitrate,pH, phosphate, salinity, temperature, total dissolved solids (TDS) and totalsuspended solids (TSS). Sampling was done once a month from November 2011to April 2012 in three stations covering the upstream, midstream and downstream.The multiple tube fermentation technique was used for the analysis of coliforms.The level of these indicator bacteria increased from the upstream towards thelower reaches of the river especially in the months of February to April; however,the difference in values across time was not significant. This implies that therewas a continuous fecal pollution in the river. There were no statistically significantcorrelations between FCs and TCs with the physicochemical parameters. Anegative relationship was observed among FCs and TCs with pH, TSS, DOand nitrate (p>0.05). These results suggest the presence of sewage and organicpollutants in the river.Keywords: Aquatic Ecology, water quality, coliform, physicochemical parameters,experimental design, Philippines


Author(s):  
Bogusław Szulc ◽  
Katarzyna Szulc

AbstractThe main aim of this study was to assess the usefulness of the Biological Diatom Index (BDI) (Lenoir & Coste 1996) for the estimation of water quality in the central section of the Pilica River, located in central Poland in Łódź province. The BDI has never been used before to monitor Polish surface waters. An analysis of the correlations between the values of the BDI and selected physico-chemical parameters was performed, as was an assessment of water quality using the BDI. On the basis of value ranges proposed by Descy and Ector (1996), a good ecological status in the Pilica River was obtained, but this did not correspond with the results achieved from the physico-chemical analysis. This study proposes new value ranges for the BDI. With these new values, the ecological state of the Pilica River changed from good to moderate, which corresponded with the physico-chemical analysis of the water. The new, proposed value ranges for the BDI assess more precisely the quality of water in lowland Polish rivers.


2021 ◽  
Vol 188 ◽  
pp. 107108
Author(s):  
Sanna Lötjönen ◽  
Markku Ollikainen ◽  
Niina Kotamäki ◽  
Markus Huttunen ◽  
Inese Huttunen

2021 ◽  
Author(s):  
Benjámin Kaizer ◽  
Zoltán Gribovszki ◽  
Péter Kalicz

<p>The current climatic conditions of the Hungarian Great Plain is not adequate for the forest cover. Surplus water is essential to maintain good ecological status and growth rate of forests. Moreover, in the drying climate of the Great Plain without excess water the survival of forest vegetation is  questionable.</p><p>In this study, we try to indicate the positive effect of the excess water on the growth of the trees next to the Danube in Gemenc wetland (close the southern border of Hungary). The logging data were collected from 2000 to 2009. Sampled forest compartments were clustered into two groups based on the stand position to the levee (exposed to inundation of Danube or not). The effects of the Danube are evaluated using local hydrological measurements (e.g. gauge at Mohács).</p><p>The forest growth itself is not the best indicator because it is also influenced by several other ecological variables. To control better these variables two forest stands were selected aged about 110 years. One of them is located behind a summer levee (low crown height levee), which is inundated only by the high floods. Another forest compartment is outside the main levee and never inundated. These stands are sampled to prepare dendrochronological analysis, which gives us higher time-resolution data. We hope these analyses will help us to interpret the relationship between forest growth and water<br>conditions.</p><p>This research has been supported by the Ministry of Agriculture in Hungary.</p>


Author(s):  
Elena GAVRILESCU ◽  
Gilda Diana BUZATU

In Dolj County there are a number of lakes that are particularly important, because they have a large quantity of water, some of them originating from hydrotechnical accumulations, and other from natural waters. In the present study, it was performed the monitoring of the water quality of the lakes in Dolj County, in the year of 2012, namely: Victoria - Geormane, Bistreţ and Caraula. The ecological conditions of the natural and artificial lakes was established based on the state of acidification, of the oxygen regime (dissolved oxygen, biochemical oxygen demand and chemical oxygen demand), the degree of eutrophication (biogenic substances, phytoplankton biomass and chlorophyll “a”) and also based on transparency. The water samples were taken from three points: tail, middle and upstream of the lake and were analyzed using high performance equipment, namely: pH-meter, spectrophotometer DR 2010, Sechi disc, BOD5 system. In terms of the degree of eutrophication, the water from the studied lakes belongs to the third category of water quality. Geormane is a natural lake which has a very good ecological status, except regarding the eutrophication, which is considerably visible. Bistret lake has a good environmental status and is visible eutrophic. Caraula lake’s water belongs to the third category of water quality, being heavily eutrophic.


2020 ◽  
Vol 6 (2) ◽  
pp. 23-28
Author(s):  
O. A. F Wokoma ◽  
◽  
O. S Edori ◽  

Wastewater samples were collected from an oil industry at the point of discharge for a period of two years, from January 2018 – December 2019. The wastewater samples were analyzed for different physicochemical parameters such as temperature, turbidity, total dissolved solids (TDS), total suspended solids (TSS), conductivity, pH, alkalinity, salinity, total hydrocarbon content (THC), biochemical oxygen demand (BOD) and chemical oxygen demand (COD) to examine their conformity to fulfill requirements as recommended by World Health Organization (WHO), Federal Ministry of Environment (FME) and Drinking Water Association (DWA). The results indicated that all the parameters in the discharged wastewater were within acceptable limits of the regulatory bodies. The field data showed that the investigated firm conformed to the law by carrying out proper procedures before discharging the effluents into the public drain and river. Therefore, the release of wastewater from the industry doesn't constitute a danger to the environment as well as aquatic organisms. Keywords: Physicochemical parameter, wastewater discharge, oil industry, environment, contaminants


Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 339
Author(s):  
Shuangshuang Liu ◽  
Min Yao ◽  
Shiyue Chen ◽  
Xingzhong Yuan

The relationship between the diatom taxa preserved in surface lake sediments and environmental variables in Dongping Lake was explored using multivariate statistical methods. The statistical analysis showed that the lake was eutrophicated in all seasons. Transparency, chlorophyll a (Chla) and total phosphorus (TP) were the dominant environmental factors in spring and summer, and NH4+-N and chemical oxygen demand (COD) were the dominant environmental factors in autumn and winter. Sixteen genera and 43 species of diatom were found in the surface sediments, and the dominant diatom genera were Aulacoseira, Ulnaria, Cyclotella, Navicula and Fragilaria. A redundancy analysis (RDA) and Monte Carlo permutation 20 test revealed that COD, pH, TP, conductivity and transparency were significant factors influencing diatom assemblage change, meaning that the distribution of the diatom assemblages were mostly influenced by nutrient composition, light intensity and ion concentrations.


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