Lignocellulose-based nanomaterials: synthesis, characterization, and sustainable applications in wastewater treatment

Wastewater treatment allows for the safe disposal of municipal and industrial wastewater to protect public health and the ecosystem[...]

The increasing global demand for clean water necessitates innovative and sustainable wastewater treatment technologies. Triboelectric nanogenerators (TENGs), particularly those utilizing polymers, have emerged as a promising self‐powered solution for environmental applications, offering the potential to drive wastewater treatment processes without external energy input. This review comprehensively examines the application of polymer‐based TENGs for sustainable wastewater treatment. It begins by classifying TENGs and outlining common fabrication methods, followed by a detailed discussion of the principles governing TENG operation in environmental contexts. A key focus is on the mechanisms of TENG‐powered dye degradation, highlighting the role of reactive species generated by the TENG. It is then delve into the specific advantages of polymer‐based TENGs as efficient energy harvesters for various wastewater treatment applications. This review addresses the current challenges in the field, including material durability, energy conversion efficiency, and scalability, and offers perspectives on future research directions aimed at realizing the full potential of polymer‐based TENG technology for sustainable wastewater treatment.

The crisis in clean water availability due to population growth, industrialization, and climate change has driven the need for more effective and sustainable wastewater treatment technologies. Plasma technology is emerging as a potential solution capable of overcoming the limitations of conventional methods, especially in the degradation of complex pollutants and new polluting compounds. Aim: This study aimed to identify trends, developments, and research gaps related to the application of plasma technology in wastewater treatment during the period 2000-2024. Methodology and results: A bibliometric analysis was conducted to map the publication trends, most influential sources, and research networks, while qualitative content analysis was used to classify research themes and highlight key findings from the selected papers. One hundred sixty-five papers on plasma technology application in wastewater treatment were retrieved from four databases and analyzed. The results show that research in this field is categorized into four main themes: plasma-based pollutant degradation, plasma-enhanced oxidation processes, energy-efficient non-thermal plasma reactors, and dielectric barrier discharge (DBD) for environmental treatment. Furthermore, the research focus has shifted from basic plasma exploration to applying plasma technology for water treatment and efficiency improvement. Conclusion, significance and impact study: This study provides recommendations for future research based on the findings of current research trends and themes, aiming to guide the development of more effective and sustainable plasma-based wastewater treatment technologies.

A comprehensive review of biochar in removal of organic pollutants from wastewater: Characterization, toxicity, activation/functionalization and influencing treatment factors

Biobased nanofibers are increasingly considered in purification technologies due to their high mechanical properties, high specific surface area, versatile surface chemistry and natural abundance. In this work, cellulose and chitin nanofibers functionalized with carboxylate entities have been prepared from pulp residue (i.e., a waste product from the pulp and paper production) and crab shells, respectively, by chemically modifying the initial raw materials with the 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) mediated oxidation reaction followed by mechanical disintegration. A thorough investigation has first been carried out in order to evaluate the copper(II) adsorption capacity of the oxidized nanofibers. UV spectrophotometry, X-ray photoelectron spectroscopy and wavelength dispersive X-rays analysis have been employed as characterization tools for this purpose. Pristine nanofibers presented a relatively low content of negative charges on their surface thus adsorbing a low amount of copper(II). The copper adsorption capacity of the nanofibers was enhanced due to the oxidation treatment since the carboxylate groups introduced on the nanofibers surface constituted negative sites for electrostatic attraction of copper ions (Cu2+). The increase in copper adsorption on the nanofibers correlated both with the pH and carboxylate content and reached maximum values of 135 and 55 mg g−1 for highly oxidized cellulose and chitin nanofibers, respectively. Furthermore, the metal ions could be easily removed from the contaminated nanofibers through a washing procedure in acidic water. Finally, the adsorption capacity of oxidized cellulose nanofibers for other metal ions, such as nickel(II), chromium(III) and zinc(II), was also demonstrated. We conclude that TEMPO oxidized biobased nanofibers from waste resources represent an inexpensive and efficient alternative to classical sorbents for heavy metal ions removal from contaminated water.

A review on conventional and novel materials towards heavy metal adsorption in wastewater treatment application

A novel network montmorillonite composite particle directly separated from water after adsorption pollutants

The metal ferrites (MFs) and their composites occupied a broad area of research in wastewater treatment because of their adsorptive, magnetic, and catalytic nature. This is due to their large surface area, high stabilities (for thermal, chemical, and mechanical stress), tuneable chemical composition, variety in size and shape, controllable magnetic properties, etc. The graphene (G) and graphene oxide (GO) (due to their exceptional electrical, mechanical, and thermal properties as well as extraordinary surface area) are performing excellently in wastewater treatment to remove/degrade several contaminants, both organic and inorganic. The composites of G/GO with metal ferrites are among the emerging candidates for wastewater treatment due to adsorption, photocatalytic degradation, and synergistic effect of adsorption-enhanced degradation, which offers excellent removal/degradation of contaminants along with easy magnetic separation. This chapter provides an excellent overview for the synthesis, characterization, and applications (in wastewater treatment) of metal ferrites and their graphene-based composites.

Magnetic nanoparticle-incorporated metal organic frameworks (MOF) are potential composites for various applications such as catalysis, water treatment, drug delivery, gas storage, chemical sensing, and heavy metal ion removal. MOFs exhibits high porosity and flexibility enabling guest species like heavy metal ions to diffuse into bulk structure. Additionally, shape and size of the pores contribute to selectivity of the guest materials. Incorporation of magnetic materials allows easy collection of adsorbent materials from solution system making the process simple and cost-effective. In view of the above advantages in the present review article, we are discussing recent advances of different magnetic material-incorporated MOF (Mg-MOF) composite for application in photocatalytic degradation of dyes and toxic chemicals, adsorption of organic compounds, adsorption of heavy metal ions, and adsorption of dyes. The review initially discusses on properties of Mg-MOF, different synthesis techniques such as mechanochemical, sonochemical (ultrasound) synthesis, slow evaporation and diffusion methods, solvo(hydro)-thermal and iono-thermal method, microwave-assisted method, microemulsion method post-synthetic modification template strategies and followed by application in waste water treatment.

An overview on nanostructured TiO2–containing fibers for photocatalytic degradation of organic pollutants in wastewater treatment

A review of carbon quantum dots and their applications in wastewater treatment

Current status of microwave application in wastewater treatment—A review

A comprehensive review on preparation, functionalization and recent applications of nanofiber membranes in wastewater treatment

The immobilization of biocatalysts or other bioactive components often means their transformation from a soluble to an insoluble state by attaching them to a solid support material. Various types of fibrous textiles from both natural and synthetic sources have been studied as suitable support material for biocatalysts immobilization. Strength, inexpensiveness, high surface area, high porosity, pore size, availability in various forms, and simple preparation/functionalization techniques have made textiles a primary choice for various applications. This led to the concept of a new domain called-biocatalysts immobilization on textiles. By addressing the growing advancement in biocatalysts immobilization on textile, this study provides the first detailed overview on this topic based on the terms of preparation, progress, and application in wastewater treatment. The fundamental reason behind the necessity of biocatalysts immobilized textile as well as the potential preparation methods has been identified and discussed. The overall progress and performances of biocatalysts immobilized textile have been scrutinized and summarized based on the form of textile, catalytic activity, and various influencing factors. This review also highlighted the potential challenges and future considerations that can enhance the pervasive use of such immobilized biocatalysts in various sustainable and green chemistry applications.

The application of nanoparticles for wastewater remediation