Removal of cadmium and zinc from water using sewage sludge-derived biochar

© 2024 The Authors. Published by Elsevier B V. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1016/j.scenv.2024.100118This research reveals the adsorption of cadmium (Cd2+) and zinc (Zn+2) from water using sewage sludge-derived biochar pyrolysed at 700 °C (SSB). The morphology and particle characteristics of SSB were characterised through scanning electron microscopy (SEM), particle size distribution (PSD), fourier transform infrared (FTIR), X-ray diffraction (XRD), and X-ray fluorescence (XRF). The adsorption study showed that the optimum contact times for removing Zn2+ and Cd2+ were 80 and 140 minutes, respectively. 95.51% Zn2+ and 97.54% Cd2+ could be removed from spiked solutions featuring 50 mg/L of Zn2+ and 50 mg/L Cd2+, each treated with 25 g/L biochar. The optimum pH of the solutions was 8–9 at a temperature of 40°C, indicating some precipitation of the metal ions at an alkaline pH. The highest adsorption capacity of SSB for Cd2+ and Zn2+ was found to be 3.02 and 2.51 mg/g, respectively, which compares favourably with other adsorbents. The isotherm studies confirmed experimental data to closely follow the Langmuir isotherm model at an R2 value of 0.9846 and 0.9816 for Cd2+ and Zn2+, respectively. The kinetic study confirmed the physical interaction between the adsorbents and the adsorbate. The spontaneous and exothermic nature of the process was confirmed by negative values of change in Gibbs free energy (ΔG) and enthalpy (ΔH). SSB could be regenerated for 6 cycles. Overall, this study explores sustainability, recycling, and waste management by offering SSB as a potentially cost-effective and environment-friendly solution to remove Cd2+ and Zn2+ from water.Published versio

Modification of banana stem fibers for efficient mercury (II) adsorption

The potential of banana stem fiber (BSF) and its modifications as a low cost adsorbent for Hg(II) adsorption was evaluated. In this study, three types of adsorbents were prepared; chemically treated BSFs, grafted BSFs and amine functionalized grafted BSFs. Chemically-treated BSFs were modified by HCl and NaOH pre-treatments. Grafted BSFs were prepared by grafting methacrylic acid (MAA) onto BSF using ß-radiation, microwave-radiation and conventional chemical initiation grafting methods. Subsequently, the grafted BSF was further functionalized using three types of amine, namely ethylenediamine (EDA, primary amine), N,N’- methylenebisacrylamide (MBA, secondary amine) and triethylamine (TEA, tertiary amine). Prior to adsorption, all the adsorbents were activated in vacuo at 373 K. The adsorbents were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, nitrogen physisorption, thermogravimetric analysis (TGA), field emission scanning electron microscopy-energy dispersive X-ray (FESEM-EDX), electron spin resonance (ESR) spectroscopy and pHzpc. Results of the study showed that HCl pre-treatment on BSF increased the cellulose accessibility, while activation process generated a large amount of structural defects on the BSF. Moreover, BSF grafted via ß-radiation (BSF-ß) was proved to have a higher grafting yield, which led to a higher Hg(II) adsorption capacity. In addition, the introduction of amines into BSF-ß significantly enhanced the Hg(II) uptake due to the stronger affinity towards Hg(II) ions. The functionalization of ethylenediamine onto BSF-ß (EDABSF) showed the highest Hg(II) adsorption capacity followed by MBA-BSF and TEABSF. These results indicate that the position of amine functional groups on BSF plays an important role in the adsorption process. Fitting of the adsorption data with the nonlinear Langmuir isotherms produced the maximum adsorption capacity of 372, 484 and 843 mg g-1 for activated BSF-HCl, BSF-ß and EDA-BSF, respectively. Besides, activation of BSF-HCl altered the activation energy from 3.5 to 76.9 kJ mol-1, which showed the increasing of Hg(II) chemisorption. On the other hand, the adsorption of Hg(II) onto BSF-ß and EDA-BSF were mainly via ion-exchange process, where their activation energy falls in the range of 13.7 to 19.2 kJ mol-1. It should be noted that BSF-HCl, BSF-ß and EDA-BSF adsorbents were effectively regenerated with 0.1 M HCl solution and exhibited good recyclability and reusability for a few cycles of Hg(II) adsorption. Furthermore, BSF-ß and EDA-BSF possessed an excellent adsorption capacity for cationic heavy metals (Hg2+, Pb2+ and Cd2+), offering potential applications in the recovery of cationic heavy metals from multi-metal aqueous systems. This study demonstrates an inexpensive yet effective material such as BSF from agricultural waste, has a great potential as adsorbent for the removal and recovery of Hg(II) ions from aqueous solutions

Environmental Biotechnology Research Group: Research Report.

Environmental biotechnology exploits living organisms (plant, bacteria, fungi, etc) in various applications of waste treatment and remediation of pollutants. The organisms that demonstrate the potential to utilize the wastes or pollutants as food are naturally found in the environment. Rapid development in genetic technology also assists in introducing genetically modified organisms with enhanced capability to degrade wastes or pollutants. It has been proven that environmental biotechnology can provide safer methods of cleaning hazardous wastes compared to conventional methods since it uses natural agents. Finally the utilization of biowastes and organic residues to useful value added product were also studie

The Design of Novel Functional Materials Based on Cellulose Nanocrystals/Nanofibrils

As the most abundant organic biomass on the planet, cellulose provides environmental, biocompatible and sustainable benefits. When treated by acid hydrolysis, highly crystalline nano-rods, called cellulose nanocrystals (CNCs), are generated. Besides the characteristics inherited from natural raw cellulose, this defect-free residue also displays unsurpassed physical properties, such as high tensile strength and ultrahigh specific surface area. The combination of these features makes CNC an excellent candidate for composite materials and building blocks. A partially sulfate esterified surface endows CNC aqueous suspensions with further properties. Dispersions of CNC with this modification are more stable and the abundant hydroxyl groups allow for various kinds of chemical modifications and polymer grafting. Another by-product of cellulose, called cellulose nanofibrils (CNFs), is produced through mechanical disintegration. CNFs have a lower crystallinity than CNCs and they deserve attention due to their flexibility, compressibility and ductility. It is well-known that CNF based foam possesses many attractive features, such as being ultralight, low-cost and ease of preparation. This kind of 3D structure with superior mechanical performance has potential applications in a broad range of fields. Carbon based materials, like graphene and fullerene, are used in a wide variety of applications due to their outstanding properties. For example, graphene enhanced supercapacitors and fullerene supported anti-oxidant agents are both attracting increasing attention. However, the inherent π-π stacking phenomenon hinders their processability in water, making them less environmentally friendly in design and manufacturing. The emergence of nanotechnology has offered an alternative-method of processing carbon based materials in aqueous phase, supporting their inclusion in environmentally friendly materials. This study involves the combination of fullerene and CNC to design an aqueous system with a high stability and free-radical scavenging properties. Both physical and chemical interactions between fullerene and CNC will be examined for their long-term stability. The morphology and structure of the system will be investigated and the conditions of synthesis will be optimized. Another focus is to incorporate CNF for the preparation of three-dimensional foam/aerogel with outstanding mechanical properties for waste water treatment. Non-toxic and water-soluble cross-linking agent ethylenediamine, will be used to form and enhance the mechanical properties of the structure. They will also confer chemically domains or grafting anchors on the inner and outer surface of the structure. CNF based foam could have compressible and twistable morphologies, both of which make it applicable to wearable/portable electronic devices. Porous 3D foam with a highly reactive surface could be able to coordinate with metal ions or bind with metal nanoparticles. Thus, CNF aerogels could be used to treat waste water contaminated with heavy metals and as a catalyst support or matrix for various metal oxide nanoparticles

Nanocellulose fibers: A Review of Preparation Methods, Characterization Techniques, and Reinforcement Applications

Cellulose, which occurs naturally in abundance, has the benefit of being the most widely used biomass material on a global scale. It is generated from natural fibers and can be processed to produce various types of nanocellulose fibers, each with its hierarchical configuration. This review summarizes current advances in the production of nanocellulose particles, focusing on the analytical techniques most widely used for their preparation, extraction, and characterization. These techniques include FT-IR, TGA, FESEM, and XRD. The review also demonstrates that research into nanocellulose fibers has progressed exponentially over the last decade (over 400 references). Many manufacturing techniques have been developed to use nanofibers in multiple applications as advanced sustainable materials. The presented data will reinforce the applications of nanocellulose fibers for various purposes

Water Quality Engineering and Wastewater Treatment

Clean water is one of the most important natural resources on earth. Wastewater, which is spent water, is also a valuable natural resource. However, wastewater may contain many contaminants and cannot be released back into the environment until the contaminants are removed. Untreated wastewater and inadequately treated wastewater may have a detrimental effect on the environment and has a harmful effect on human health. Water quality engineering addresses the sources, transport and treatment of chemical and microbiological contaminants that affect water. Objectives for the treatment of wastewater are that the treated wastewater can meet national effluent standards for the protection of the environment and the protection of public health. This book, which is based on the Special Issue, includes contributions on advanced technologies applied to the treatment of municipal and industrial wastewater and sludge. The book deals with recent advances in municipal wastewater, industrial wastewater, and sludge treatment technologies, health effects of municipal wastewater, risk management, energy efficient wastewater treatment, water sustainability, water reuse and resource recovery

竹由来リグニン：バイオマス由来グラフェン誘導体の作製とその機能性

九州工業大学博士（工学）1 Introduction and Literature Review| 2 Lignin Extraction from Bamboo Biomass Via Autoclave-Assisted Organosolv Treatment| 3 Synthesis of Graphene Derivatives Utilizing Bamboo Fractionated Lignin as a Precursor| 4 Practical Application of Bio-Derived Graphene Derivatives in The Fabrication of Nanofiltration Membranes and as Bioadsorbents for Pollutant Removal| 5 Practical Application of Bio-Derived Graphene Derivatives in the Preparation of Sulphonated Catalysts for Biodiesel Production Using Microwave-Assisted Transesterification Method| 6 Conclusion and RecommendationsLignocellulosic biomass has been the subject of thorough investigation due to the increasing need for sustainable materials, specifically as a potential feedstock for advanced bio-based materials. As a novel source for graphene production, this present thesis scrutinizes the prospective applications of fractionated lignin from bamboo biomass, which is renowned for its carbon-dense structure and renewable nature. Chapter 2 examines lignin extraction via autoclave-assisted methods utilizing a variety of acid catalysts and solvents, revealing that HCl has a lower purity but a higher recovery rate than H2SO4. The utilization of structural analysis improves understanding and offers valuable insights for optimizing extraction procedures. Chapter 3 of the paper delves into the synthesis of graphene derivatives from bamboo lignin using metal-catalyzed catalytic pyrolysis. The superior properties of Fe-catalyzed graphitic carbons are emphasized. Furthermore, the process of sequential conversion into bio-based graphene products, such as carbon quantum dots (CQDs) featuring distinctive structures, is clarified. Chapter 4 explores into the utilization of graphene derivatives derived from bamboo lignin for the purpose of removing pollutants through the implementation of bioadsorbents and nanofiltration membranes. The results exhibit notable water permeability and effective expulsion of saline solutions and organic pigments. The successful elimination of phenol and tannic acid is observed to occur under particular conditions. In Chapter 5, an examination is conducted on bio-based graphene derivatives utilized as catalyst supports in microwave-assisted biodiesel production. The results demonstrate improved catalytic activity, increased efficiency, decreased consumption, and shortened reaction time. In particular, efficacy is validated by kinetic and thermodynamic analyses conducted at elevated temperatures. This study introduces bamboo fractionated lignin as a sustainable and adaptable precursor for bio-graphene derivatives, providing significant knowledge regarding its synthesis, potential applications, and far-reaching implications in various disciplines.九州工業大学博士学位論文 学位記番号:生工博甲第495号 学位授与年月日:令和6年9月25日令和6年度doctoral thesi

Production of laccases by the white-rot fungus trametes pubescens for their potential application to synthetic dye treatment

Approximately 10,000 different dyes and pigments are produced annually worldwide and used extensively in the dye and printing industries. This has resulted in the generation of large volumes of highly polluted wastewater. Apart from the aesthetic deterioration of the natural water bodies, dyes also cause harm to the flora and fauna in the natural environment. Therefore, wastewater containing dyes must be treated prior to their discharge into the environment.Different methods can be applied for the treatment of synthetic dyes from aqueous solutions, such as ozonation, coagulation, flocculation, reverse osmosis and adsorption. However, biological treatments are promising alternatives with different approaches going from the complete immobilization of microorganisms to the pure enzyme utilization. Among all enzymes, laccases are an interesting alternative for the dye degradation due to their low affinity and wide specificity for the substrates. Laccases are multicopper oxidases found in higher plant and microorganisms, like white-rot-fungi; and carry out one-electron oxidation of phenolic and related compounds, and reduce O2 to water. Thus, this work proposes different strategies based on the use of laccases for the discoloration of synthetic dyes from aqueous solutions. These strategies include studies in different fields to promote eco-friendly solutions for different assets of the whole process. These studies include: the selection of substrates for the production of laccase by the white-rot fungus Trametes pubescens, the possible reutilization of these substrates in the discoloration process, the optimization of the laccase production per culture, the scale up of the laccase production, the use of free and immobilized laccase in the discoloration of dyes and the use of different immobilization techniques to increase the reutilization of the immobilized laccase for the treatment of synthetic dyes.Aproximadamente 10,000 tintes y pigmentos diferentes son producidos anualmente y tienen un uso extendido en las industrias de teñido e impresión. Esto ha generado grandes cantidades de aguas residuales altamente contaminadas. A parte del deterioro estético que sufren los cuerpos de agua, los tintes también causan daño a la flora y fauna presentes en el medio ambiente. Por ello, las aguas residuales que contienen tintes deben ser tratadas antes de su descarga al ambiente.Distintos métodos pueden ser empleados para el tratamiento de tintes sintéticos en soluciones acuosas, tales como la ozonización, coagulación, floculación, osmosis inversa y la adsorción. Sin embargo, los tratamientos biológicos resultan una alternativa prometedora con distintas aproximaciones que van desde la inmovilización de microorganismos hasta el uso de las enzimas puras. Entre todas estas enzimas, las lacasas resultan ser muy interesantes para la degradación de tintes debido a su baja afinidad y amplia especifidad por los substratos. Las lacasas son oxidasas de multicobre que se encuentran en plantas, microorganismos, como los hongos de putrefacción-blanca, y llevan a cabo la oxidación del fenol y compuestos relacionados, y reducen el O2 a agua.Debido a esto, en este trabajo se proponen distintas estrategias basadas en la utilización de las lacasas para la decoloración de tintes sintéticos en medios acuosos. Estas estrategias incluyen estudios en distintas áreas para promover soluciones amigables con el medio ambiente en las distintas etapas del proceso. Estos estudios incluyen: la selección de substratos para la producción de lacasa con el hongo de putrefacción-blanca Trametes pubescens, la posible reutilización de estos substratos en los procesos de decoloración, la optimización de la producción de la lacasa por cultivo, el escalado de la producción de la lacasa, el uso de lacasa libre e inmovilizada en la decoloración de tintes y el uso de distintas técnicas de inmovilización para incrementar la reutilización de la lacasa inmovilizada en el tratamiento de tintes sintéticos

Sustainable Development and Application of Renewable Chemicals from Biomass and Waste

Advancements in efficient energy sources have played a pivotal role in determining the present world energy structure. Renewable biomass energy has been incorporated in industrial regulations and policies in many European countries. Based on the statistics, more than one-seventh of the total world energy consumption is generated from biomass.The renewable energies movement was prompted by two important factors: a) growing world energy consumption and b) the abundance of generated biomass residues, especially in agriculture. In the case of the first, batteries containing different metals are considered, as is the production of items for human consumption (food, clothing, home comfort, etc.). In the second case, the biomass waste from plants and animals, as byproducts of cultivating and production processes, is the main source of generated waste