Environmental Engineering Reference
In-Depth Information
19
Engineered Nanoscale Materials for
Deluorida
tion of Groundwater
Shihabudheen M. Maliyekkal
Environmental Engineering Division, School of Mechanical and Building Sciences,
VIT University, Chennai Campus, Chennai, India
CONTENTS
19.1 Introduction to Groundwater Pollution .......................................................................... 377
19.2 Search for Affordable Treatment Options ...................................................................... 378
19.3 Fluoride: A Global Groundwater Threat ........................................................................ 379
19.3.1 Fluoride-Free Water: Solution and Challenges .................................................. 381
19.3.2 Overview of Deluoridation Technologies ......................................................... 381
19.4 Deluoridation of Water Using Nanoscale Materials .................................................... 382
19.4.1 Metals and Metal Oxides/Hydroxides/Oxyhydroxide .................................... 383
19.4.1.1 Alkaline Earth Metal-Based Oxides .................................................... 383
19.4.1.2 Alumina and Other Aluminum-Based Materials .............................. 383
19.4.1.3 Transition Metal-Based Oxides ............................................................ 385
19.4.2 Embedded Metals and Metal Oxides/Hydroxides ........................................... 386
19.4.2.1 Natural Polymers as Support Matrix ................................................... 387
19.4.2.2 Synthetic Polymers as Support Matrix ................................................ 388
19.4.2.3 Inorganic Metal Oxide as Support Matrix .......................................... 389
19.4.3 Carbon-Based Materials ........................................................................................ 390
19.5 Summary ............................................................................................................................. 391
References ..................................................................................................................................... 392
19.1 Introduction to Groundwater Pollution
Water is an essential and the most critical natural resource on Earth on which all social, eco-
nomic, and ecosystem functions depend. It is currently being threatened by development,
overuse, and other human activities. The scarcity and quality of the freshwater are likely to
be the most challenging issues to be faced by mankind in the near future. Among various
available freshwater resources, groundwater often provides a water supply that is more
reliable in terms of quantity and quality as compared with surface water. Groundwater
drawn from deep aquifers was assumed to be free from microbial contamination and has
economic and operational advantages owing to reduced treatment requirements [1]. Thus,
it accounts for a signiicant portion of drinking water supply in many countries worldwide
[2]. In India, >80% of the rural water supplies are obtained from groundwater. Over the
years, a number of quantitative and qualitative changes have occurred in groundwater
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