An integrated approach for the characterization of groundwater quality using multivariate statistical techniques and spatial analysis

ABSTRACT. Ground water accessed via wells in areas of Tiruvallur district of the southern Indian state of Tamil Nadu has been a subject to increase sea-water intrusion. The present study highlights the potable water crisis in the northern district evaluated using GIS-assisted determination of water quality parameters across fifty sampling sites. The most informative parameters evaluated within this study were TDS, EC, TH, Na+, Mg2+, Ca2+, Cl- and SO42- while parameters such as pH, CO32-, etc. had limited correlated significance to water quality. The total dissolved solids (TDS) and electrical conductivity (EC) determined in the study area indicated significantly elevated levels across the sampling sites. Weighted arithmetical indexing (WAI) of the water quality parameters indicated 30 out of 50 water sources meet the tolerance limits for both drinking and irrigation. Based on BIS standards, only 13 sites met acceptable limits for safe drinking water. Principal component analysis and piper plot analysis revealed a significant involvement of Mg2+, Na+, Cl- and SO42- in the impairment of water quality, particularly in the coastal zones. Spatial hydro-chemical profiles developed in this study reveal ‘hot-spots’ of sea-water tainted water sources, and the hydro-chemical dominance of alkali earth components. Altogether, the study findings indicate a widening water crisis on top of over-exploited water resources and discuss possible factors and remedial steps in addressing the situation.   KEY WORDS: Ground water, Principal component analysis, Piper Plot, Water quality index, Irrigation suitability   Bull. Chem. Soc. Ethiop. 2022, 36(2), 241-260.                                                           DOI: https://dx.doi.org/10.4314/bcse.v36i2.1                                                       &nbsp

Synthesis and characterization of SiO₂-Chitosan supported AgNPs and its catalytic application for reduction of malachite green

546-552Designing novel nanocatalysts for the reduction of water borne dyes is a topic of recent research interest. A new composite, SiO2-chitosan supported AgNPs (3-11%), has been synthesized and characterized through FT-IR, XRD, BET and SEM. The catalytic activity of the composites has been investigated through reduction of malachite green as a model reaction in the presence of NaBH4. The reduction is rapid and followed pseudo first order kinetics. Increase of pH increased the rate of reduction compared to low pH, as at a low pH, NaBH4 decomposed directly and rapidly. An increase in NaBH4 content also increased the rate. The results indicate that the reduction can also be extended to other water borne reducible contaminants

transesterification; Gas Chromatography;

Biodiesel characterization and optimization study of used frying palm oi