Volume 9, Issue 11

Xenobiotics, hazardous compounds, and emerging contaminants contribute risk to the ecosystem, and the most effective way to reduce their harmful effects is to utilize different carbon-based composites and carbon adsorbents. Adsorption is considered a highly effective approach for eliminating pollutants. Various adsorbent materials, such as nanomaterials, natural materials, and biological biomasses, have been recognized as effective adsorbents for different contaminants. Carbon-based adsorbents are often highly flexible for cleanup because of their exceptional physical and chemical characteristics. This review presents the various forms of carbon composites as an adsorbent and their production strategies. The selection of synthesis methods and the operational parameters are found to be the key factors in determining the nature of the adsorbent and its adsorption efficiency. The pretreatment, activation, and coupling of other agents in the production of carbon composites are found to increase the adsorption efficiency of the material. The study extensively concentrated on the advancements in synthesizing carbon-sourced composites and sorbents. The research gap and the -utilization possibilities of diverse carbon composites in the removal of pollutants are also discussed.

Pollutants in water bodies is a major threat, which affects both flora and fauna, including humans. The environmental impact on pollutants due to increase in industrialization and growing populations has been increasing every year. The efficient removal of pollutants from aqueous solutions is a significant challenge in environmental remediation. In recent years, the application of nanomaterials has emerged as a promising strategy to address this issue. Of these nanomaterials, carbon nanotubes (CNTs), carbon nanofibers (CNFs), and nano-gels have attracted considerable attention due to their unique properties and their versatile functionalities. In this review, we have discussed about the recent advances in CNTs, CNFs, nanogels in eliminating pollutants from aqueous solution. CNTs possess a notable aspect ratio and demonstrate outstanding mechanical strength, enabling them to effectively adsorb a wide range of contaminants including heavy metals, organic compounds, and gases, CNFs have improved adsorption and catalytic characteristics. These entities exhibit efficacy in the elimination of contaminants from aquatic ecosystems and atmospheric currents, hence aiding in the restoration of polluted settings, and nano-gels, which are composed of cross-linked polymers arranged in three dimensions, offer a flexible framework for the encapsulation of pollutants and the precise delivery of substances. Functionalized nano-gels provide the targeted adsorption of particular contaminants, hence providing customised approaches for the management and mitigation of pollution. The utilisation of nanomaterials holds significant promise in the advancement of water treatment technologies, necessitating the enhancement of their practical applications.

Water and wastewater treatment is crucial to meet the global demand for clean drinking water and attaining environmental sustainability. Using graphene oxide (GO) and reduced graphene oxide (rGO) membranes for wastewater and water treatment is innovative in tackling water pollution and water scarcity worldwide. Graphene-based membranes have been proven advantageous and effective in water purification due to their unique qualities such as increased surface area, mechanical and thermal durability, adsorbability, and antifouling and antibacterial capabilities. This chapter discusses the synthesis of graphene oxide and reduced graphene oxide membranes and their hybrid derivatives. It also discusses their applicability and challenges in wastewater purification. Ongoing research is necessary to optimize these membranes, as challenges persist in the large-scale cost-effective production for widespread use in water treatment plants.

Adsorption processes are crucial in various applications, especially water and wastewater treatment. The research is focused on improving and developing adsorbent materials. An in-depth evaluation of a recently suggested adsorbent is essential to determine its characteristics, confirm its suitability, and understand its effectiveness in the intended process. Various approaches can be engaged to collect multiple physico-chemical data, with the selection of the methodology contingent on the substance under investigation and the instruments at hand. The accessible procedures include, FTIR, Raman, XPS, EDX, XRD, SEM/FESEM, TEM, AFM, VSM, DLS, and thermoanalytical techniques (TGA, DSC). These methods aid in identifying, locating, and quantifying chemical components. They also enable the analysis of the structure, topography, morphology, magnetic properties, and size, as well as other physical characteristics of materials. This information is valuable for assessing the manufacturing and modification of adsorbent materials and studying the adsorption process by examining the interactions between the adsorbent and the adsorbate. This work aims to offer an inclusive resource for investigators exploring adsorbent resources. It attempts to help them choose the most suitable characterization methods according to their specific needs.

The growing concern regarding various environmentally hazardous pollutants has arisen due to their potential hazards to public health. Managing ecological concerns has become a pressing global priority. The utilisation of biochar in wastewater treatment to remove various hazardous substances impeded by its limited adsorption capacity, despite its low cost and good effectiveness. To enhance the efficiency of biochar in eliminating multiple pollutants, mixed methods have been used to change biochar and give it different physical and chemical properties; this results in distinctive adsorption outcomes, behaviours, and mechanisms. This study comprehensively analyses the efficient techniques, impacts, and mechanisms of modified biochar in eliminating hazardous substances, such as emerging contaminants, in the ecosystem. Modified biochar has enhanced efficacy in removing these substances, with removal processes mainly using adsorption and catalytic degradation pathways. Future endeavours should prioritise the development of uniform assessment standards for cost, efficacy, and environmental hazards while utilising emerging technologies to expand the potential uses of modified biochar to remove emerging contaminants.

Carbon polymer nanocomposite is a type of composite material that combines carbon-based materials with polymers and nanoparticles to achieve enhanced properties. These materials are designed to take advantage of the unique properties of each constituent to create a new material with superior performance compared to individual components. Nanocomposites composed of carbon-based polymers are the wonder and novel materials of contemporary research. At the forefront of a more recent scientific revolution, both material science and composite science are involved. Polymer science and nanotechnology are inextricably linked in today’s modern science. The subjects of environmental engineering science and nanotechnology require focused attention since these professions currently offer limited solutions for the increasingly pressing problems of groundwater contaminated with heavy metal and drinking water purification. Carbon polymer composites play a significant role in numerous modern applications due to their excellent electrical, mechanical, chemical, and thermal capabilities. Carbon polymer composites are viewed as desirable candidates for the manufacture of nanocomposite materials due to their nanoscale geometries, high aspect ratio, and specific surface area. Due to the shape-dependent nature of their physical and chemical characteristics as well as their thickness, carbon polymer nanocomposites have demonstrated excellent catalytic activity in organic chemical processes. It has been discovered that the catalytic product from the usage of carbon polymer nanocomposites is of tremendous utility in a variety of sectors, inclusive of material sciences, medicinal, and nutritional for biotechnology. As a result, the demand for carbon nanocomposites has grown quickly and the creation of new preparation techniques elevates a higher level of interaction.

The pervasive issue of micro and nanoplastics (MNPs) in the environment has escalated into a global concern, necessitating the exploration of innovative and efficient removal strategies. This review paper provides a comprehensive analysis of the application of carbon composites in mitigating MNPs, drawing upon a wide array of studies and technological advancements in the field. Carbon composites, known for their high surface area, porosity, and functional ability, offer a promising avenue for the adsorption, degradation, and removal of MNPs from various environmental matrices. We delve into the mechanisms underlying the interaction between carbon composites and MNPs, including physical adsorption, chemical binding, and photocatalytic degradation, highlighting the factors that influence these interactions, such as composite structure, surface chemistry, and environmental conditions. The review further categorizes carbon composites, such as activated carbon, carbon nanotubes, graphene, and biochar-based composites, examining their efficacy, limitations, and potential environmental impacts. A critical analysis of recent field and laboratory studies provides insights into these composites’ practical applications and performance in real-world scenarios. Additionally, we discuss the challenges and future directions for developing carbon composites, including scalability, regeneration, and the sustainable production of these materials. Carbon composites hold significant potential for efficient mitigation of MNPs, offering a viable solution to one of our time’s most pressing environmental challenges. However, further research is needed to optimize these materials for widespread application, enhancing their selectivity, capacity, and durability while minimizing unintended environmental consequences. This review aims to catalyze further investigation and innovation in the field, paving the way for developing more effective and sustainable technologies for mitigating micro and nanoplastics.

Depletion of potable water availability is threatening the whole biota, owing to the presence of anthropogenic compounds and hazardous chemicals above the permissible levels. Although many conventional methods exist, the development of innovative technologies is critical for wastewater treatment and recycling. Carbon composites have recently seen widespread use across a variety of industries due to their distinctive and superior properties. These carbon composites are easily integrated into many stages of the treatment process, making them efficient, cost-effective, and environmentally friendly. This chapter discusses the importance and effectiveness of carbon-based composite materials in removing toxic dyes and heavy metal contaminants from the environment. Carbon composites are classified according to their sources, preparation methods, and applications. This chapter also discusses various research perspectives on carbon composites, particularly from an environmental and financial standpoint.

Pollution in the water bodies has been on the rise for several decades. To address this issue, many technologies involving physical, chemical, biological, and electrochemical processes are being utilised. Nevertheless, their commercial use is limited by a number of inherent drawbacks. Here, nanotechnology combined with material science has offered practical and economical ways to remove organic pollutants from the wastewater. This review will provide a detailed overview of the efficiency and applicability of various carbon-metal nanoparticle adsorbents such as heavy metals (mercury, lead, and cadmium), organic contaminants (benzene, insecticides, and polycyclic aromatic hydrocarbon), and nitrogen and sulfur compounds from the wastewater by the adsorption process. The future research direction and the encouraging future of carbon composites loaded with metal nanoparticles for environmental applications are also discussed.

Emerging contaminants are the outcome of the widespread usage of manufacturing advancements facilitating human life. These are found in various solid and liquid wastes discharged into nature. Sewage treatment plants across the globe receive a maximum quantity of various emerging contaminants from diverse sources. These contaminants reach soil, surface, and groundwater, affecting their quality. They also enter into the food web through different levels. This article thoroughly discusses the adverse effects of emerging contaminants and possible methods of remediation using activated carbon prepared from different materials. The review highlights the utilization of activated carbon for pharmaceutical and personal care products, pesticides, and a specific observation of caffeine removal. An in-depth online search for research and review articles gave an overview of technologies used and their reports with reference to the applicability of activated carbon as an adsorbent for emerging contaminants. Adsorption is considered to be one of the green methodologies for reducing contamination and making the resultant water of reusable quality. Biowaste materials are used for the preparation of activated carbon by chemical or physical modifications. These adsorbents can be used for removing emerging contaminants from wastewater/contaminated water. Many advantages of this method make it suitable for the treatment of effluent generated from various sources. The activated carbon quality, surface area for adsorption, and kinetics are of significance to ensure the quality and efficiency of the adsorbent.