Stability of Iron Oxyhydroxide Mineral Colloid: Impact of Ionic Strength, Dissolved Organic Matter and Nanoplastics

Arya, Lavish (2023) Stability of Iron Oxyhydroxide Mineral Colloid: Impact of Ionic Strength, Dissolved Organic Matter and Nanoplastics. Masters thesis, Indian Institute of Science Education and Research Kolkata.

Text (MS dissertation of Lavish Arya (18MS148)) Thesis_18MS148.pdf - Submitted Version Restricted to Repository staff only Download (2MB)

Abstract

Iron Oxyhydroxides (IO) such as magnetite and goethite are an important constituents of natural water matrices and play significant role in the biogeochemical cycle on the earth. Meanwhile, recent scientific evidence found huge accumulation of nanoplastics (NPs) in aqueous systems, which can interact with IO and may hamper the stability of IO. This study aims to understand the impact of NPs on the aggregation and sedimentation kinetics of IO with varying environmental parameters (HA, IS) and natural water matrices (river and groundwater). Magnetite and goethite showed higher aggregation rate in presence of divalent CaCl2 in all cases. Presence of HA with NaCl produced a stabilizing effect, while CaCl₂ with HA lead to higher aggregation rate. Furthermore, higher sedimentation was observed in groundwater (GW) than river water (RW). Based on a few assumptions, a theoretical study was also conducted to quantify the settling time of the magnetite, goethite and NPs using the stokes law. This study demonstrates that type of ions, natural organic matter plays an important role in the stability of IO. The presence of anthropogenic contaminants like nanoplastics can influence the fate of IO in the aqueous systems.

Actions (login required)

View Item