Preparation and Application of Polymer-Metal Oxide Nanocomposites in Wastewater Treatment: Challenges and Potentialities

Introduction

Industrial and other anthropogenic activities have resulted to increased stress in access to clean water. These activities, though intended for beneficial purposes, are associated with release of toxic organic and inorganic chemicals in water systems posing a threat to the well-being of human, animal and aquatic life. In emerging economies mostly characterized with insufficient water treatment facilities and large populations are not connected to the municipally treated water and therefore depend on river and ground water, chemical and biological contamination of water is a serious problem whose solution needs no further delay. Similar trends are reported worldwide (Suriyaraj and Selvakumar, 2016). Indiscriminate disposal of agrochemicals and ad-hoc discharge of industrial effluents laden with chemicals such as dyes, pharmaceutical compounds, detergents, personal care products, the so called chemicals of emerging concern among others are among the leading causes of water pollution. The compounds have been demonstrated to cause of induce development of different illnesses and disorders in both human and aquatic life raising serious environmental concerns (Yang, 2011; Bottoni et al., 2010). These concerns have necessitated development of more stringent drinking water quality parameters by environmental and water resources management authorities. Unfortunately, most the chemical contaminants are recalcitrant to the conventional water treatment techniques such as coagulation and adsorption onto activated carbon only and the compounds find way to drinking and potable water (Shannon et al., 2008). Despite emergent technologies such as membrane technologies and chemical treatment being effecting in sequestering most contaminants from water, they generally invite high capital investment and have high operational costs hence are not widely used especially in developing countries (Jo et al., 2016). The search of low-cost, effective and sustainable technology (materials and processes) for production of potable drinking water is a subject of on-going research among scientists. Among the proposed alternative techniques for water treatment include the advanced oxidation processes (AOPs), such as the Fenton reaction, ozonation, and photocatalysis attributed to their simplicity, relatively low cost, high efficacy and ease of operation (Chong et al., 2010). Noteworthy, each of these techniques possess their inherent limitations. In the recent decades, metal oxide/polymer nanocomposites have been shown to be facile low cost and environmentally friendly materials for water treatment. They have been applied as adsorbents for various pollutants, as photocatalysts for degradation of organic compounds, as membrane filters and for bacteriological treatment of water. This chapter describes the synthesis and characterization techniques for development of metal oxide/polymer nanocomposites and their application for various water treatment processes namely, membrane technology, photocatalysis, biological treatment and adsorption. It is demonstrated that metal oxide/polymer nanocomposites are promising materials for water purification systems.