Functionalized Silica Gel as Green Material for Metal Remediation

Abstract

Advancement in industrialization and urbanization is a good indicator of the progress of humanity. However, it has an evil side as well. This advancement is identified as being responsible for deleterious effects on the health of human beings and aquatic biodiversity. Anthropogenic activities like mining and disposal of treated/untreated waste effluents containing toxic metals have resulted in severe deterioration of water quality, rendering serious environmental problems. The basic problem is that the wastewater generated through industries is not given the necessary pretreatment and is discharged directly into water resources. The metals beyond their permissible limits cause maximum negative impacts owing to their long biological half-lives and nondegradable nature. The condition is further worsening in economically deprived countries, where this metal-contaminated wastewater is directly used in various agricultural and day-to-day practices. As a solution to this, the extraction and removal of toxic metal ions from these polluted water resources at an industrial level is of paramount importance. This chapter provides the enthusiastic efforts of the scientific community to disseminate the fundamentals and practices of green analytical methods for metal removal. These methods are based on solid-phase extraction using functionalized silica gel for the separation and preconcentration of metal ions in polluted water resources. Ease of synthesis and extensive application of these organic-inorganic hybrid materials helps to fulfil the commitment of continual environmental improvement by remediating the wastewater.

Folic Acid-Polyaniline Hybrid Hydrogel for Adsorption/Reduction of Chromium(VI) and Selective Adsorption of Anionic Dye from Water

“…In this century, worldwide water pollution is a serious challenge to human civilization. The necessity of wastewater treatment has been increasing over the past decades, especially in developing countries, where many manufacturing industries are located . Because of the increasing concern on global environmental pollution problems, more and more researchers have dedicated their efforts to find suitable approaches to obtain good quality drinking water free from heavy metal ions, organic dye, and pathogenic bacteria, etc. − Chromium ions and organic dyes are omnipresent in industrial processes, such as electroplating, textile production, leather tanning, metal finishing, dyeing, and so forth. , Consequently, huge amounts of aqueous chromium­(VI) and organic dye wastes are discharged, posing profound threat to human health and environment. − Cr­(VI) is carcinogenic and is also harmful to lungs, liver, and kidney .…”

Dual bioimprinting of Thermomyces lanuginosus lipase for synthesis of biodiesel

“…It is inexpensive and an abundantly available material. It is also considered as a green material [42] . Hence 20% (w/w of oil) silica was added to the reaction mixture.…”