Applications of Nano-Zeolite in Wastewater Treatment: An Overview

Abstract

Nano-zeolite is an innovative class of materials that received recognition for its potential use in water and tertiary wastewater treatment. These applications include ion-exchange/sorption, photo-degradation, and membrane separation. The aim of this work is to summarize and analyze the current knowledge about the utilization of nano-zeolite in these applications, identify the gaps in this field, and highlight the challenges that face the wide scale applications of these materials. Within this context, an introduction to water quality, water and wastewater treatment, utilization of zeolite in contaminant removal from water was addressed and linked to its structure and the advances in zeolite preparation techniques were overviewed. To have insights into the trends of the scientific interest in this field, an in-depth analysis of the variation in annual research distribution over the last decade was performed for each application. This analysis covered the research that addressed the potential use of both zeolites and nano-zeolites. For each application, the characterization, experimental testing schemes, and theoretical analysis methodologies were overviewed. The results of the most advanced research were collected, summarized, and analyzed to allow an easy visualization and comparison of these research results. Finally, the gaps and challenges that face these applications are concluded.

The adsorptive behaviour of electrospun hydrophobic polymers for optimized uptake of estrogenic sex hormones from aqueous media: kinetics, thermodynamics, and reusability study

“…For the remediation of environmental pollutants, numerous types of polymeric membranes have been synthesized, including polyvinylchloride, cellulose acetate, polysulfone, polycarbonate, polypropylene, and polydimethylsiloxane 26‐31 . Additionally, the polymer‐based nanofibers are functionalized with additive materials, such zeolite, graphene oxide, ammine groups, etc ., to impart unique features that achieve high removal efficiency and selectivity based on the type of target molecule and application 32‐34 . However, little work has gone into investigating the optimized parameters for removing estrogenic hormones using electrospun fibers to eradicate them properly.…”

“…[26][27][28][29][30][31] Additionally, the polymer-based nanofibers are functionalized with additive materials, such zeolite, graphene oxide, ammine groups, etc., to impart unique features that achieve high removal efficiency and selectivity based on the type of target molecule and application. [32][33][34] However, little work has gone into investigating the optimized parameters for removing estrogenic hormones using electrospun fibers to eradicate them properly.…”

Advanced Polymeric Nanocomposite Membranes for Water and Wastewater Treatment: A Comprehensive Review

“…Zeolites are a cost effective and green ceramic membrane precursor and have shown the potential to simultaneously have high rejection/selectivity and high-water flux [ 37 , 260 ]. Zeolites are three-dimensional porous crystalline structures of aluminosilicates with primary building units of alumina or silica tetrahedra that organize to form secondary building units that are responsible for the development of unique zeolite properties [ 261 ]. Zeolites are classified based on their origin (natural or synthetic), silicon-alumina ratio, pore size, crystal structure and composition, among other factors [ 262 ].…”

“…This gives rise to inter-crystalline defects, which eventually become a tradeoff for selectivity [ 268 ]. Zeolites with higher silica content showcase hydrophobicity and are better suited for removing emerging contaminants from drinking water [ 261 ]. Depending on the width of the flow channels, zeolites can act as molecular sieves, whereas the width can be tuned by changing the atoms in the framework.…”

The Potential Application of Natural Clinoptilolite-Rich Zeolite as Support for Bacterial Community Formation for Wastewater Treatment

“…Zeolites can be used successfully to improve the performance of wastewater treatment plants, and can provide a stabilizing effect, both in the short term and for the sedimentation of activated sludge and bacterial mass [ 21 , 22 ]. They not only act as agents that favor the settling of sludge but also as supports for the growth of bacteria, thus fulfilling a function similar to that of a suspended bacterial growth system.…”