Multivariate statistical techniques for the evaluation of spatial and temporal variations in water quality of Gomti River (India)—a case study

https://digital.csic.es/bitstream/10261/217846/1/1-s2.0-S0160412013001220-main.pdf

Accumulation of perfluoroalkyl substances in human tissues

Comparison of self-organizing maps classification approach with cluster and principal components analysis for large environmental data sets.

This study investigates the spatial water quality pattern of seven stations located along the main Langat River. Environmetric methods, namely, the hierarchical agglomerative cluster analysis (HACA), the discriminant analysis (DA), the principal component analysis (PCA), and the factor analysis (FA), were used to study the spatial variations of the most significant water quality variables and to determine the origin of pollution sources. Twenty-three water quality parameters were initially selected and analyzed. Three spatial clusters were formed based on HACA. These clusters are designated as downstream of Langat river, middle stream of Langat river, and upstream of Langat River regions. Forward and backward stepwise DA managed to discriminate six and seven water quality variables, respectively, from the original 23 variables. PCA and FA (varimax functionality) were used to investigate the origin of each water quality variable due to land use activities based on the three clustered regions. Seven principal components (PCs) were obtained with 81% total variation for the high-pollution source (HPS) region, while six PCs with 71% and 79% total variances were obtained for the moderate-pollution source (MPS) and low-pollution source (LPS) regions, respectively. The pollution sources for the HPS and MPS are of anthropogenic sources (industrial, municipal waste, and agricultural runoff). For the LPS region, the domestic and agricultural runoffs are the main sources of pollution. From this study, we can conclude that the application of environmetric methods can reveal meaningful information on the spatial variability of a large and complex river water quality data.

/pdf/spatial-water-quality-assessment-of-langat-river-basin-1st8apys04.pdf

Spatial water quality assessment of Langat River Basin (Malaysia) using environmetric techniques.

Impact of pesticides used in agriculture and vineyards to surface and groundwater quality (North Spain)

Chemometrics characterisation of the quality of river water

This paper describes the use of Ag/Ag2S and Ag/AgI ion-selective electrodes by means of chemical pretreatment of a silver wire or tube for the determination of cysteine (RSH) in batch and flow injection analysis (FIA).

Chemically Treated Silver Electrodes for the Determination of Cysteine

Determination of concentrations at hydrolytic potentiometric titrations with models made by artificial neural networks

The preparation of an ion-selective electrode by chemical treatment of copper wire and its application for the measurements of copper (II) and iodide ions is described. The proposed reaction mechanism at the sensing surface, which explains the response of the electrode to Cu2+ and iodide ions, is discussed. The prepared electrode was suitable for direct potentiometric measurements of iodide and copper (II) in batch experiments down to concentrations of 1 × 10–5 mol L–1. A tubular electrode, prepared in the same way, may be used as a potentiometric sensor in a flow-injection analysis for Cu (II) and/or iodide determinations.

Preparation of an ion-selective electrode by chemical treatment of copper wire for the measurement of copper(II) and iodide by batch and flow-injection potentiometry

The preparation and usability of a sulphide ion-selective microelectrode, prepared by chemical pretreatment of silver wire with Hg2+ and sulphidization in alkaline sulphide solution is described. The electrode is suitable for direct potentiometric measuring of sulphide in alkali solutions of concentrations down to 4×10−7 mol/l. It can be used for the potentiometric measurement of various thiocompounds in alkali and neutral media. The 15 min required for each chemical treatment are enough for the preparation of the described electrode.

Danilo Dobčnik

Papers

Chemometrics characterisation of the quality of river water

Chemically Treated Silver Electrodes for the Determination of Cysteine

Determination of concentrations at hydrolytic potentiometric titrations with models made by artificial neural networks

Preparation of an ion-selective electrode by chemical treatment of copper wire for the measurement of copper(II) and iodide by batch and flow-injection potentiometry

Preparation of a sulphide ion-selective microelectrode with chemical pretreatment of silver wire in Hg(II) solution