Chapters authored
Low Dimensional Nanostructures: Measurement and Remediation Technologies Applied to Trace Heavy Metals in Water
A nanostructure is a system in which at least one external dimension is in the nanoscale, it means a length range smaller than 100 nm. Nanostructures can be natural or synthetic and determine the physicochemical properties of bulk materials. Due to their high surface area and surface reactivity, they can be an efficient alternative to remove contaminants from the environment, including heavy metals from water. Heavy metals like mercury (Hg), cadmium (Cd), arsenic (As), lead (Pb), and chromium (Cr) are highly poisonous and hazardous to human health due to their non-biodegradability and highly toxic properties, even at trace levels. Thus, efficient, low-cost, and environmentally friendly methodologies of removal are needed. These needs for removal require fast detection, quantification, and remediation to have heavy metal-free water. Nanostructures emerged as a powerful tool capable to detect, quantify, and remove these contaminants. This book chapter summarizes some examples of nanostructures that have been used on the detection, quantification, and remediation of heavy metals in water.
Part of the book: Trace Metals in the Environment
Mobility of Heavy Metals in Aquatic Environments Impacted by Ancient Mining-Waste
The mobility of heavy metals in aquatic environments, impacted by discharges from mining waste, is one of the major processes causing metal pollution mainly by arsenic (As), cadmium (Cd), lead (Pb), zinc (Zn) and iron (Fe), which could be risky for biota and human health. The heavy metals contained in mining waste constituted by large amounts of sulfides can reach the aquatic compartments by acid mine drainage and runoff and eventually become deposited in sediments and associated with colloidal material, being this one of the main reservoirs and ways of transport. However, the mobility of heavy metal is influenced by their specific chemical properties and undergo several physicochemical phenomena as sorption, oxidation–reduction, hydrolysis and this can be influenced by water flow, the size and composition of geological material. Hence, this work aims to review the processes and mechanism involved in the fate and transport of heavy metals from mining-waste to aquatic compartments and the methods used for identification of the specific chemical species associated with their mobility and ecological risk.
Part of the book: Water Quality