Changes In River Water Quality Research Articles

Water quality monitoring by nanostructured films in a sensing unit system

Abstract Presented here is a study about the capability of a sensing unit to detect changes in river water quality. In order to determine its accuracy, water quality was monitored at 11 points along the Veado River in Presidente Prudente, Brazil. To have a basis for comparison, a water quality index (WQI) was developed following methods previously applied in different watersheds. Results showed an accurate relationship between WQI and electric impedance readings detected by the sensing unit. Principal components analysis (PCA) was used to derive results in a form that can be correlated with WQI calculated for each sample point, which showed the potential application of this device.

Water quality monitoring by nanostructured films in a sensing unit system

Abstract Presented here is a study about the capability of a sensing unit to detect changes in river water quality. In order to determine its accuracy, water quality was monitored at 11 points along the Veado River in Presidente Prudente, Brazil. To have a basis for comparison, a water quality index (WQI) was developed following methods previously applied in different watersheds. Results showed an accurate relationship between WQI and electric impedance readings detected by the sensing unit. Principal components analysis (PCA) was used to derive results in a form that can be correlated with WQI calculated for each sample point, which showed the potential application of this device.

Urban groundwater baseflow influence upon inorganic river-water quality: The River Tame headwaters catchment in the City of Birmingham, UK

Summary Understanding the linkage between urban land, groundwater, baseflow and river contamination at the city scale is lacking. This study evaluates the influence of inorganic (major/minor ions and metals) groundwater contamination in the Triassic sandstone–Quaternary deposits aquifer system underlying the City of Birmingham, UK upon the baseflow and water quality of the river Tame. Baseflow water-quality data have been collected from a riverbed piezometer network installed in the 7.4 km reach crossing the effluent unconfined sandstone aquifer and compared to river and aquifer water-quality data. Overall, the inorganic chemical quality of the baseflow was not as poor as potentially surmised from the urbanisation present. Baseflow impact upon river-water quality was also low. These conclusions were underpinned by evidences of: limited river-water quality changes along the reach; some river concentrations being diluted by better quality baseflow; only occasional breaching of water-quality criteria; limited impact upon river-reach quality local to elevated baseflow dicharges; natural attenuation occurrence within the riverbed; and, modest, albeit somewhat uncertain, baseflow mass fluxes. Baseflow fluxes to the reach were in the ranges 100–3500 t/yr for major ions, 1–50 t/yr for minor ions and 1–500 kg/yr for toxic metals with zinc and nickel most prominent. The sporadic occurrence of elevated baseflow concentrations was ascribed to discrete groundwater plume discharges. More detailed sub-reach studies would be required to fully resolve discrete plume baseflow contributions and improve mass flux estimates. Not uncommonly, the urban river studied was already contaminated and hence persistent baseflow fluxes may assume more importance if the river became cleaner through other control measures. Future research should hence consider the emergent significance of urban baseflows. There are needs to: conduct similar studies to investigate if city-scale baseflow impacts are comparable elsewhere; research the importance of spatially and temporally dynamic attenuation in the riverbed; and, develop improved baseflow mass flux estimation methods.

Changes in the impact of anthropogenic effects on river water quality during the last 50 years in Japan

Japan’s rapid urbanisation over the last 50 years has resulted in land use and lifestyle changes, all of which are likely to have changed the quality of river water, and consequently the wetland and coastal environment. We examined changes in river water quality over this period by means of a review of previous studies. Around the 1950s, the weighted average of chloride using discharge of Japan’s 30 major rivers was 6.1 mg/l while in the 2000s it was 11.3 mg/l. Because there were no significant changes in the natural conditions, we have attributed the increase to the urbanisation of the last 50 years. Nitrate levels in the mountain streams of southern Japan have increased, particularly in the western part of the Kanto region. As this area is located on the leeward side of the Tokyo Metropolitan Area, depositions from aerosols are thought to be the main cause of the increased nitrate concentration. These two findings suggest that certain uses of land may affect river water quality differently over time, and that changes in land use may also affect river water quality in remote areas.

Nutrient fluxes through boundaries in the hypolimnion of Sau reservoir: expected patterns and unanticipated processes

By contrast to many natural lakes, the summer hypolimnion in advection-dominated systems like canyon-shaped reservoirs is not isolated from direct inputs from the river. This has important implications in the evolution of limnological features of the hypolimnion through the stratified period, especially if the river water directly plunges as a density current into the hypolimnion as a consequence of temperature differences. Taking the Sau Reservoir (Spain) as a prototype for this kind of systems, we present data from 11 years of monitoring to show how the river water entering the reservoir during summer is the main factor determining hypolimnetic nutrient concentrations. The empirical regression approach used all through the paper also stressed the effect of the improvement in water quality experienced by the river during the studied period on the improvement of the water quality stored in the summer hypolimnion of the reservoir. Since the change in river water quality was the consequence of the implementation of remediation measures at the basin scale, we advocate these solutions to manage reservoir eutrophication problems in this type of systems, which, in addition, had other unexpected benefits for the hypolimnetic water quality in Sau Reservoir.

Over 130 years of experience with Riverbank Filtration in Düsseldorf, Germany

Research Article| June 01 2006 Over 130 years of experience with Riverbank Filtration in Düsseldorf, Germany P. Eckert; P. Eckert 1Stadtwerke Düsseldorf AG, Höherweg 100, 40233, Düsseldorf, Germany Tel: ++492118359, Fax: ++49211778359; E-mail: peckert@swd-ag.de Search for other works by this author on: This Site PubMed Google Scholar R. Irmscher R. Irmscher 1Stadtwerke Düsseldorf AG, Höherweg 100, 40233, Düsseldorf, Germany Search for other works by this author on: This Site PubMed Google Scholar Journal of Water Supply: Research and Technology-Aqua (2006) 55 (4): 283–291. https://doi.org/10.2166/aqua.2006.0012 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Share Icon Share Twitter LinkedIn Tools Icon Tools Cite Icon Cite Permissions Search Site Search nav search search input Search input auto suggest search filter All ContentAll JournalsThis Journal Search Advanced Search Citation P. Eckert, R. Irmscher; Over 130 years of experience with Riverbank Filtration in Düsseldorf, Germany. Journal of Water Supply: Research and Technology-Aqua 1 June 2006; 55 (4): 283–291. doi: https://doi.org/10.2166/aqua.2006.0012 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Since 1870 Riverbank filtration (RBF) on the river Rhine, Germany has been used successfully by the Düsseldorf waterworks as the first step for treating drinking water. The aim of this article is to present the experience in applying RBF with a focus on the purification efficiency of this natural treatment process. At the Düsseldorf waterworks, the influence of long-term as well as periodic changes of the river water quality on the RBF processes were investigated.While for the first 80 years drinking water treatment was based only on RBF, additional technical treatment became necessary together with the decreasing Rhine water quality in the 1960's. The decontamination of the river was attended successfully by the waterworks along the Rhine. As a result of the increased river water quality the purification processes during RBF became again more efficient. However, periodic changes of river water quality and hydraulics influence the natural purification processes during RBF and have to be considered. Flood events are accompanied by shorter travel times and less effective natural purification. The changing river water temperature trigger a string of subsequent hydrogeochemical reactions within the aquifer. The performed investigations show that even during flood events and during extreme low water, the multi protective barrier concept including both natural and technical purification has proven to be a reliable method for drinking water production. drinking water treatment, hydrochemistry, riverbank filtration This content is only available as a PDF. © IWA Publishing 2006 You do not currently have access to this content.

Primary Cause of Water Pollution in the Headwaters of River Cibin, Central Romania, With Special Reference to Sheep Overgrazing

Hydrological investigations were conducted through August into September 2003 and August 2004 on the River Cibin in the Danube drainage system on the northern slope of the Southern Carpathians, central Romania. The main purpose of the present paper is to clarify the actual circumstances of water pollution in the headwater basin due to human activity. The concentration of dissolved substances in the river water shows the maximum value at the uppermost observation point and decreases downstream due to dilution. Such a characteristic spatial change in river water quality is significantly affected by untreated household effluent and raw sewage from a settlement, which is located on the mountain ridge. During the summer season, a marked contamination of river water is found at some particular points where sheared wool is washed directly in the river channel. From the viewpoint of the primary factor affecting water quality, the river water in the watershed is clearly classified into four categories according to the difference in concentration and composition of the major dissolved substances. It is pointed out that the distinguishing features of water quality are consistent with the nature of both land use and water use.

A two-dimensional water-quality model for a winding and topographically complicated river

In this paper, a two-dimensional numerical calculation algorithm for water-quality modeling is presented. The algorithm is designed specifically for river systems with complicated geometric conditions. When velocity field data of the river are not available, the numerical calculation algorithm for the water-quality modeling can be used to project river-water quality by using a topographic map of the river course and a finite element method. The calculation results of the water-quality model can show the concentration fields of various pollutants. The water-quality model was applied to a case-study in the Hengyang City section of Xiangjiang River in Hunan Province, China. The river under consideration is winding and has an isle between two branches. In 1995, Chinese government secured a World Bank loan to conduct a Waterways Project in the study region. It was expected that construction works in the river section might affect water quality. Given that the project would change the hydrological regime of the river system and discharges, and so would affect water quality, there would be a need for model results that would predict the water-quality impacts of the Waterways Project. In particular, the study intended to apply the model to identify changes in river-water quality associated with the construction of Dayuandu navigation key project. It is hoped that the numerical calculation algorithm for the water-quality modeling presented in this paper can also be applied to other shallow rivers with similar topographical conditions.

ダム構造物の影響 河川連続体で不連続の原因となるダム貯水による水質変化

ダム構造物の影響 河川連続体で不連続の原因となるダム貯水による水質変化

Analysis of long-term and seasonal river water quality changes in Latvia

An analysis of long-term historical records of the concentrations of major ions, TDS and nutrients for 20 river sites in Latvia is reported. Periods of water quality observations ranged from 15 to 43 years. A study of the quarterly adjusted time series showed that characteristic features of the data are non-normal distributions, seasonality, serial correlation and presence of significant trends that are mostly positive. The application of state-of-the-art software, based on non-parametric statistics such as the Seasonal Kendall slope estimator and the Seasonal Hodges-Lehmann estimator, made it possible to investigate these water quality records more accurately than other methods allow. Typical seasonal variations and concentration-discharge relationships were analyzed for different constituents. It was shown that fertilizer application and marsh land reclamation can cause widespread and intensive river water quality changes. Concentration increases of as much as 5–10 times that of background values were detected for NO 3 −, Cl −, Na + + K + and SO 4 2−. The main water quality changes took place in the 1960s and the early 1970s when fertilizer applications and reclamation works increased. After that, concentration increases for constituents other than NO 3 − and SO 4 2− were statistically insignficiant. The significant increases for NO 3 − and SO 4 2− were probably due to the additional impact of increased atmospheric deposition. The results of long-term changes of river loads entering the Baltic Sea and the Gulf of Riga from Latvian territory are examined.

A Study on the Impact of Urban and Industrial Development in the Linggi River Basin, Malaysia. 2. Chemical Environment

An investigation of the chemical environment of the Linggi River Basin was carried out at 15 main and 27 supplementary stations between January 1983 and January 1984. Spatial and temporal changes in pH, specific conductivity, alkalinity, chloride, ammonia-nitrogen, nitrite-nitrogen, nitrate-nitrogen, orthophosphate, dissolved oxygen, BOD, and diurnal variations were studied in relation to influence of various kinds of pollutants. The chemical composition of natural water analysed at a few undisturbed forest stream stations in the basin can be considered very good. A drastic change in river water quality was noticed in downstream polluted stations. The pH in the basin varied from 4.05 to 10.5 units, conductivity from 23.0–1,500 umhos/cm, alkalinity from 6.0–1,388 mg/l, chloride from 0.9–160.9 mg/l, orthophosphate from 0.5–5.21 mg/l, ammonia-N from 0.001–53.75 mg/l, nitrite-N from 0.0–8.2 mg/l, nitrate-N from 0.03–6.77 mg/l and BOD3, from 0.32–384.0 mg/l and COD from 0.02 to 79.2 unit. Among all the rivers, very high values were recorded at Kundor, Simin and Linggi (sensu stricto).

Water quality indices as indicators of ecosystem change

The operational management of water quality requires a methodology that can provide precise information on cycles and trends in water quality in an objective and reproducible manner. Such information can be provided by the adoption of a water quality indexing system. The continuous scale afforded by a water quality index allows changes in river water quality to be highlighted. At the same time the sub-division of this scale into a series of water quality and water use categories provides an easy means of relating information to government and public.The development of four independent water quality indices (WQIs) is outlined. These have been applied to data for a number of UK river reaches. The results of these applications indicate the utility of these indices in the classification of water quality and the monitoring of ecosystem change.

Flow-driven water quality simulation models

A method is presented for simulating the gross changes in river water quality which may result from natural variations in flow, systematic changes to the flow regime as a whole or major changes in discharge quality. The mathematical model described, once calibrated, requires historic flow data which cover the range of conditions of interest; for example, a typical drought year. Applications are described in which the model was used on a desk-top mini-computer to produce medium and long term predictions of river quality under a variety of flow regimes and to investigate the effects on water quality of a new reservoir.