Hydrochemical modelling of water quality in terms of emerging micropollutants in Mpumalanga, Gauteng and North West Provinces

This study was therefore conducted to determine major hydrochemical processes controlling water quality and the occurrence of EMPs mainly, carbamazepine (CBZ), tonalide (AHTN), galaxolide (HHCB), caffeine (CAF), technical 4-nonylphenol (NP) and bisphenol A (BPA) in water from Mpumalanga, Gauteng and North West Provinces in South Africa. Grab water samples were collected bi-monthly between June 2014 and April 2016 from 44 water sources using standard sampling procedures. BPA, NP, CAF, HHCB, AHTN, CBZ were extracted, cleaned and enriched using autotrace-SPE at neutral pH and analyzed using GC × GC-TOFMS. Kruskal Wallis-test was used to test for temporal variations in occurrence of the analytes. The Geochemist's Workbench® Release 11 software, Surfer Golden Graphics for surface mapping, PHREEQC software and bivariate ion plots were used determine the major hydrogeochemical processes. The mean concentrations of EMPs varied from 3.48 μg/L for CAF to 421.53 μg/L for HHCB. Although the Kruskal Wallis test revealed no any statistically significant temporal variations in concentrations of the analytes in water samples at 95% confidence level, their occurrence and distribution vary spatially with BPA being the most widely distributed EMP and was present in 62% of the sampled sites. Municipal waste water inputs, agricultural pollution, ion-exchange reactions, carbonate and silicate weathering were the major processes controlling water quality in the study area. This study may as...
Source: Physics and Chemistry of the Earth, Parts ABC - Category: Science Source Type: research