EFFICIENT APPROACHES TOWARDS REMOVAL OF POLLUTANTS FROM WATER

Abstract

Synthetic polymers are one of the most significant pollutants in the aquatic environment, because of abilities such as buoyancy and extreme persistency. Serious effects are expected from so-called micro/nanoplastics (particle size <1µm) that are reported in rivers, lakes as well as the ocean and accumulate in sediments worldwide. Often, MPs/NPs are too small to be seen and are unevenly distributed in the environment due to differences in shape, size, and density, rendering them difficult to find and quantify in environmental samples. In addition, along with the plastic pollution, dissolved pollutants (i.e., dyes and heavy metals) are also contaminating the water resources causing a significant impact on the environment. The purpose of this research was to develop analytical methods to test the efficient removal of dissolved pollutants (e.g. organic dyes, heavy metal ions) and emerging pollutants such as polymer micro- and nanoparticles from spiked water samples. Fluorescent PMMA, PVAc and PVC nanoparticles were selected as the polymers of choice for the current study owing to their highest abundance (building and construction sector) in the environment. For deeper insights into the sorption process of organic contaminants and synthetic polymer particles, batch experiments were conducted to determine sorption kinetics and sorption isotherms of synthetic polymer particles and different model compounds (Acid Fuchsin, Cu(II), Zn(II), PTC) adsorbed on the surface of single adsorbent (chemically modified) via layer-by-layer technique. Furthermore, influences of the different parameters (i.e., initial concentration, time, and amount of adsorbent) and detailed characterizations (i.e., UV-Vis, Fluorescence spectroscopy, TGA, EA, FTIR, SEM, Zeta Potential and DLS etc) before and after adsorption process were performed for all experiments and sorption efficiency was ~ 98% for all contaminants. Moreover, coprecipitation method was also evaluated (~ 99 % efficient) in detail for removal of polymer particles from water. As plastic based nanomaterials are a growing source of environmental concern, the methods developed and tested in this thesis could have significant impact on water purification in the future.