Engineering a Biopolymer-Based Ultrafast Permeable Aerogel Membrane Decorated with Task-Specific Fe-Al Nanocomposites for Robust Water Purification

Synthesis of aminopropyl triethoxysilane/melamine incorporated superhydrophilic membranes for simultaneous removal of oil, metals, and Salt ions from produced water

Water treatment has turned out to be more important in most societies due to the expansion of most economies and to advancement of industrialization. Developing efficient materials and technologies for water treatment is of high interest. Thin film nanocomposite membranes are regarded as the most effective membranes available for salts, hydrocarbon, and environmental pollutants removal. These membranes improve productivity while using less energy than conventional asymmetric membranes. Here, the polyvinylidene fluoride (PVDF) membranes have been successfully modified via dip single-step coating by silica-aminopropyl triethoxysilane/trimesic acid/melamine nanocomposite (Si-APTES-TA-MM). The developed membranes were evaluated for separating the emulsified oil/water mixture, the surface wettability of the membrane materials is therefore essential. During the conditioning step, that is when the freshwater was introduced, the prepared membrane reached a flux of about 27.77 L m-2 h-1. However, when the contaminated water was introduced, the flux reached 18 L m-2 h-1, alongside an applied pressure of 400 kPa. Interestingly, during the first 8 h of the filtration test, the membrane showed 90 % rejection for ions including Mg2+, and SO42- and ≈100 % for organic pollutants including pentane, isooctane, toluene, and hexadecane. Also, the membrane showed 98 % rejection for heavy metals including strontium, lead, and cobalt ions. As per the results, the membrane could be recommended as a promising candidate to be used for a mixture of salt ions, hydrocarbons, and mixtures of heavy metals from wastewater.

Recent Advancements in the Field of Chitosan/Cellulose-Based Nanocomposites for Maximizing Arsenic Removal from Aqueous Environment

Water remediation, acknowledged as a significant scientific topic, guarantees the safety of drinking water, considering the diverse range of pollutants that can contaminate it. Among these pollutants, arsenic stands out as a particularly severe threat to human health, significantly compromising the overall quality of life. Despite widespread awareness of the harmful effects of arsenic poisoning, there remains a scarcity of literature on the utilization of biobased polymers as sustainable alternatives for comprehensive arsenic removal in practical concern. Cellulose and chitosan, two of the most prevalent biopolymers in nature, provide a wide range of potential benefits in cutting-edge industries, including water remediation. Nanocomposites derived from cellulose and chitosan offer numerous advantages over their larger equivalents, including high chelating properties, cost-effective production, strength, integrity during usage, and the potential to close the recycling loop. Within the sphere of arsenic remediation, this Review outlines the selection criteria for novel cellulose/chitosan-nanocomposites, such as scalability in synthesis, complete arsenic removal, and recyclability for technical significance. Especially, it aims to give an overview of the historical development of research in cellulose and chitosan, techniques for enhancing their performance, the current state of the art of the field, and the mechanisms underlying the adsorption of arsenic using cellulose/chitosan nanocomposites. Additionally, it extensively discusses the impact of shape and size on adsorbent efficiency, highlighting the crucial role of physical characteristics in optimizing performance for practical applications. Furthermore, this Review addresses regeneration, reuse, and future prospects for chitosan/cellulose-nanocomposites, which bear practical relevance. Therefore, this Review underscores the significant research gap and offers insights into refining the structural features of adsorbents to improve total inorganic arsenic removal, thereby facilitating the transition of green-material-based technology into operational use.

A review on recent advances towards sustainable development of bio-inspired agri-waste based cellulose aerogels

Cellulose aerogel (CA) is considered to be the most promising material due to its extraordinary properties like unique microstructure, porosity, large specific surface area, biodegradability, renewable nature and lightweight. Cellulosic aerogels are thus found to have potential applications in different fields especially in water purification and biomedical field. Agricultural waste based cellulose aerogels are recently getting wider attention owing to its sustainability. The synthesis methods of agri-waste based cellulose aerogels, its properties and application in different fields especially in the field of water purification are detailed in a comprehensive manner. This review tries to bring light into the commercialization of value-added products from sustainable, cheap agricultural waste material and tries to motivate young researchers.

Biopolymeric Fibrous Aerogels: The Sustainable Alternative for Water Remediation

The increment in water pollution due to the massive development in the industrial sector is a worldwide concern due to its impact on the environment and human health. Therefore, the development of new and sustainable alternatives for water remediation is needed. In this context, aerogels present high porosity, low density, and a remarkable adsorption capacity, making them candidates for remediation applications demonstrating high efficiency in removing pollutants from the air, soil, and water. Specifically, polymer-based aerogels could be modified in their high surface area to integrate functional groups, decrease their hydrophilicity, or increase their lipophilicity, among other variations, expanding and enhancing their efficiency as adsorbents for the removal of various pollutants in water. The aerogels based on natural polymers such as cellulose, chitosan, or alginate processed by different techniques presented high adsorption capacities, efficacy in oil/water separation and dye removal, and excellent recyclability after several cycles. Although there are different reviews based on aerogels, this work gives an overview of just the natural biopolymers employed to elaborate aerogels as an eco-friendly and renewable alternative. In addition, here we show the synthesis methods and applications in water cleaning from pollutants such as dyes, oil, and pharmaceuticals, providing novel information for the future development of biopolymeric-based aerogel.

Bioinspired Superhydrophobic/Superhydrophilic Janus Copper Foam for On-Demand Oil/Water Separation

Superwettable Janus membranes with unique interfacial characteristics have versatile applications in oil/water separation, microfluid transportation, and membrane distillation. However, it remains a significant challenge to simply fabricate three-dimensional (3D) metallic foams with Janus superwettability using a facile and environment-friendly method. In this study, a novel method is present to construct a Janus copper foam (CF) by combining superhydrophobicity and superhydrophilicity into CF. Based on gravity, the water in the light oil (LO)/water mixture can be transported from the superhydrophilic (SHL) side to the superhydrophobic (SHB) side, while the heavy oil (HO) in the HO/water/mixture can be transported from the SHB side to the SHL side. Therefore, cylindrical Janus oil/water separation devices with superior separation efficiency and excellent repeatability can achieve on-demand oil/water separation effortlessly. This design and fabrication method offers a novel avenue for the preparation of Janus interface materials for practical applications in liquid transportation, sensor devices, energy materials, and oil spills.

Porous Aerogels and Adsorption of Pollutants from Water and Air: A Review

Aerogels are open, three-dimensional, porous materials characterized by outstanding properties, such as low density, high porosity, and high surface area. They have been used in various fields as adsorbents, catalysts, materials for thermal insulation, or matrices for drug delivery. Aerogels have been successfully used for environmental applications to eliminate toxic and harmful substances-such as metal ions or organic dyes-contained in wastewater, and pollutants-including aromatic or oxygenated volatile organic compounds (VOCs)-contained in the air. This updated review on the use of different aerogels-for instance, graphene oxide-, cellulose-, chitosan-, and silica-based aerogels-provides information on their various applications in removing pollutants, the results obtained, and potential future developments.