Fundamentals and mechanism of adsorption

Demand for freshwater, as well as a limited source of freshwater, has resulted in adopting technologies for treating and recycling wastewater. With rising awareness of environmental protection, there is a need for treatment technologies that are sustainable, environmentally friendly, and of low cost. Adsorption has been documented to have all such features and is widely adopted for removing diverse pollutants from varied waste streams. The attractive feature of this technology is that no secondary pollutants are generated, and the process requires no tedious setup or operational cost. Compared to technologies like chemical oxidation, membrane technologies, and biological treatment processes involving toxic sludge generation, lengthy set-up operations are not cost-effective. The success of the adsorption technology depends on the fabrication of low-cost and effective adsorbents. The study of different types of adsorbents and the study of specific adsorbent-adsorbate interactions have helped to understand the mechanism of binding. The chapter aims to introduce to the readers the fundamentals of adsorption, different methods used to fabricate the adsorbents, the Physico-chemical characteristics of the adsorbents, and the binding mechanisms. An updated literature study would help to bring forth the latest knowledge on the adsorbents used, the emerging contaminants that have been eradicated from water samples, and the nature of binding.