Clay is an inherently occurring material constituted with fined-grained mineral. The minerals are generally less than 2 microns and occur to be plastic in water content which solidify when dried. In the earth surface, clay represents the most available mineral and forms rocks known as shale and is the major component of sedimentary rocks. The small size of the particles and their unique crystal structures give clay materials special properties. These properties include: cation exchange capabilities, plastic behaviour when wet, catalytic abilities, swelling behaviour, and low permeability. They give to clay and clay-based minerals higher application in many industries and processes. To acknowledge all the features of clay and clay-based minerals, the understanding of their properties especially the cation exchange capability which affects the mechanical and physical properties of the clay is important, and also to acquire information about the crystal structure of clay mineral in general and montmorillonite especially. The purpose of this laboratory is to illustrate the importance of chemistry on the physical properties of montmorillonite, the clay mineral most often used to isolate dangerous waste materials from the environment.

The field of arsenic pollution research has grown rapidly in recent years. Arsenic constitutes a broad range of elements from the Earth's crust and is released into the environment from both anthropogenic and natural sources due to its relative mobility under different redox conditions. The toxicity of arsenic is described in its inorganic form, as inorganic arsenic compounds can leach into different environments. Sampling was carried out in the Bestari Jaya catchment while using a land use map to locate the site, and experiments were conducted via sequential extraction and inductively coupled plasma optical emission spectroscopy to quantify proportions of arsenic in the sediment samples. The results show that metals in sediments of nonresidual fractions, which are more likely to be likely released into aquatic environments, are more plentiful than the residual sediment fractions. These findings support the mobility of heavy metals and especially arsenic through sediment layers, which can facilitate remediation in environments heavily polluted with heavy metals.

Fatt (2017) Arsenic speciation using ultra high-performance liquid chromatography and inductively coupled plasma optical emission spectrometry in water and sediments samples,