Development of MoS2/cellulose aerogels nanocomposite with superior application capability for selective lead(II) capture

MoS2-based nanocomposites and aerogels for antibiotic pollutants removal from wastewater by photocatalytic degradation process: A review

Photocatalytic technologies based on molybdenum disulfide (MoS2) catalysts are effective, eco-friendly, and promising for antibiotic pollutants treatment. The technologies used by MoS2-based nanocomposites and aerogels for efficient degradation of antibiotics are reviewed in detail for the first time in this paper. The fundamental aspects of MoS2 were comprehensively scrutinized, encompassing crystal structure, optical properties, and photocatalytic principle. Then, the main synthesized methods and advantages/disadvantages for the preparation of MoS2-based nanocomposites and aerogels were systematically presented. Besides, a comprehensive overview of diverse MoS2-based nanocomposites and aerogels photo-degradation systems that enhanced the degradation of antibiotic pollutants were revealed. Meanwhile, the photo-degradation mechanism concentrated on the photoelectron transfer pathways and reactive oxygen species (ROS) were systematically evaluated. Finally, the challenges and perspectives for deeply development of MoS2-based nanocomposites and aerogels were discussed. This review may help researchers to deeply understand the research status of MoS2-based nanocomposites and aerogels for antibiotics removal, and makes clear the photo-degradation mechanism from photoelectron transfer pathways and ROS aspects of MoS2-based nanocomposites and aerogels.

Recent advances in cellulose-based sustainable materials for wastewater treatment: An overview

Water pollution presents a significant challenge, impacting ecosystems and human health. The necessity for solutions to address water pollution arises from the critical need to preserve and protect the quality of water resources. Effective solutions are crucial to safeguarding ecosystems, human health, and ensuring sustainable access to clean water for current and future generations. Generally, cellulose and its derivatives are considered potential substrates for wastewater treatment. The various cellulose processing methods including acid, alkali, organic & inorganic components treatment, chemical treatment and spinning methods are highlighted. Additionally, we reviewed effective use of the cellulose derivatives (CD), including cellulose nanocrystals (CNCs), cellulose nano-fibrils (CNFs), CNPs, and bacterial nano-cellulose (BNC) on waste water (WW) treatment. The various cellulose processing methods, including spinning, mechanical, chemical, and biological approaches are also highlighted. Additionally, cellulose-based materials, including adsorbents, membranes and hydrogels are critically discussed. The review also highlighted the mechanism of adsorption, kinetics, thermodynamics, and sorption isotherm studies of adsorbents. The review concluded that the cellulose-derived materials are effective substrates for removing heavy metals, dyes, pathogenic microorganisms, and other pollutants from WW. Similarly, cellulose based materials are used for flocculants and water filtration membranes. Cellulose composites are widely used in the separation of oil and water emulsions as well as in removing dyes from wastewater. Cellulose's natural hydrophilicity makes it easier for it to interact with water molecules, making it appropriate for use in water treatment processes. Furthermore, the materials derived from cellulose have wider application in WW treatment due to their inexhaustible sources, low energy consumption, cost-effectiveness, sustainability, and renewable nature.

Adsorption of Rhodamine B and Pb(II) from aqueous solution by MoS2 nanosheet modified biochar: Fabrication, performance, and mechanisms

Mediated by polydopamine, MoS2 nanosheets were immobilized on the porous biochar derived from fungus residue, forming a novel biochar-based nanocomposite (MoS2-PDA@FRC) for the removal of Rhodamine B(RhB) and Pb(II) from water. Utilizing MoS2 nanosheets with abundant active adsorption sites, MoS2-PDA@FRC showed higher adsorption capacities than raw biochar, with 2.76 and 1.78 times higher capacities for RhB and Pb(II) respectively. MoS2-PDA@FRC also exhibited fast adsorption kinetics for RhB (120 min) and Pb (180 min) removal, as well as satisfactory adsorption selectivity in the presence of coexisting substances. The underlying removal mechanism was explored via Fourier transform infrared and X-ray photoelectron spectroscopies. Furthermore, during cyclic adsorption-regeneration and the fixed-bed adsorption experiments, the nanocomposite removed RhB and Pb(II) with high effectiveness and stability. Collectively, the results demonstrated the bright prospects of MoS2-PDA@FRC as a highly efficient decontamination agent of RhB and Pb(II) from water.

Cellulose/inorganic nanoparticles-based nano-biocomposite for abatement of water and wastewater pollutants

Nanostructured materials offer a significant role in wastewater treatment with diminished capital and operational expense, low dose, and pollutant selectivity. Specifically, the nanocomposites of cellulose with inorganic nanoparticles (NPs) have drawn a prodigious interest because of the extraordinary cellulose properties, high specific surface area, and pollutant selectivity of NPs. Integrating inorganic NPs with cellulose biopolymers for wastewater treatment is a promising advantage for inorganic NPs, such as colloidal stability, agglomeration prevention, and easy isolation of magnetic material after use. This article presents a comprehensive overview of water treatment approaches following wastewater remediation by green and environmentally friendly cellulose/inorganic nanoparticles-based bio-nanocomposites. The functionalization of cellulose, functionalization mechanism, and engineered hybrid materials were thoroughly discussed. Moreover, we also highlighted the purification of wastewater through the composites of cellulose/inorganic nanoparticles via adsorption, photocatalytic and antibacterial approach.

Renewable cellulose aerogel embedded with nano-HFO for preferable phosphate capture from aqueous solution

Excess phosphate in water can cause eutrophication, which must be addressed. Despite many efforts devoted to the adsorptive removal of phosphate from water, the development of new adsorbents with high adsorption capacity is highly desirable. Herein, a novel nanocomposite was proposed for phosphate removal by confining hydrated ferric oxide (HFO) nanoparticles into a cellulose aerogel (CA) network named as HFO@CA. Benefiting from the characteristics of the low density and porous structure of CA, the internal surface of the nanocomposite is more accessible and thus improves the utilization of the HFO nanoparticles. Batch adsorption experiments were carried out to evaluate the phosphate uptake by the prepared adsorbent. The maximum adsorption capacity of HFO@CA occurs at near-acidic pH. With increasing temperature, the composite adsorbent is more favorable for phosphate adsorption. Moreover, the hybrid aerogel exhibited fast kinetic behavior for phosphate removal, which could be accurately depicted by pseudo-second-order model. HFO@CA shows excellent adsorption selectivity in solutions containing competitive anions at higher levels. In addition, five cycles of the phosphate adsorption experiments without obvious capacity loss indicated that HFO@CA has great regenerability. These results demonstrate that HFO@CA has a wide field of application with good prospects in phosphate removal from wastewater, which also provides a new strategy to prepare adsorbents with excellent performance using renewable cellulose resources.

Recent advancements in engineered biopolymeric-nanohybrids: A greener approach for adsorptive-remediation of noxious metals from aqueous matrices

Industrial wastewater is causing serious health problems due to presence of large concentrations of toxic metals. Removal of these metals is still a big challenge using pristine natural biopolymers due to their low surface area, water solubility, and poor recovery. Developing biopolymeric composites with other materials has attained attention because they possess a high surface area and structural porosity, high reactivity, and less water solubility. In simple words, biopolymeric nanohybrids have great adsorption capacity for heavy metals. Biopolymeric materials are abundant, low cost, biodegradable, and possess different functional moieties (carboxyl, amine, hydroxyl, and carbonyl) which play a vital role to adsorb metal ions through various inter-linkages (i.e., electrostatic, hydrogen bonding, ion exchange, chelation, etc.). Biopolymeric nanohybrids have been proven a potent tool in environmental remediation such as the abatement of heavy metal ions from polluted water. Herein, we have reported the adsorption potential of various biopolymers (cellulose, chitosan, pectin, gelatin, and silk proteins) for the removal of heavy metals. This review discusses the suitability of biopolymeric nanohybrids as an adsorbent for heavy metals, their synthesis, modification, adsorption potential, and adsorption mechanism along with best fitted thermodynamic and kinetic models. The influence of pH, contact time, and adsorbent dose on adsorption potential has also been discussed in detail. Lastly, the challenges, research gaps and recommendations have been presented. This review concludes that biopolymers in combination with other materials such as metal-based nanoparticles, clay, and carbon-based materials are excellent materials to remove metallic ions from wastewater. Significant adsorption of heavy metals was obtained at a moderate pH (5-6). Contact time and adsorbent dose also affect the adsorption of heavy metals in certain ways. The Pseudo-first order model fits the data for the initial period of the first step of the reaction. Kinetic studies of different adsorption processes of various biopolymeric nanohybrids described that for majority of bionanohybrids, Pseudo-second order fitted the experimental data very well. Functionalized biopolymeric nanohybrids being biodegradable, environment friendly, cost-effective materials have great potential to adsorb heavy metal ions. These may be the future materials for environmental remediation.