Herein, it was aimed to optimize, model, and forecast the biosorption of Congo Red onto biomass-derived biosorbent. Therefore, the waste-orange-peels were processed to fabricate biomass-derived ...carbon, which was activated by ZnCl2 and modified with cetyltrimethylammonium bromide. The physicochemical properties of the biosorbents were explored by scanning electron microscopy and N2 adsorption/desorption isotherms. The effects of pH, initial dye concentration, temperature, and contact duration on the biosorption capacity were investigated and optimized by batch experimental process, followed by the kinetics, equilibrium, and thermodynamics of biosorption were modeled. Furthermore, various artificial neural network (ANN) architectures were applied to experimental data to optimize the ANN model. The kinetic modeling of the biosorption offered that biosorption was in accordance both with the pseudo-second-order and saturation-type kinetic model, and the monolayer biosorption capacity was calculated as 666.67 mg g−1 at 25 °C according to Langmuir isotherm model. According to equilibrium modeling, the Freundlich isotherm model was better fitted to the experimental data than the Langmuir isotherm model. Moreover, the thermodynamic modeling revealed biosorption took place spontaneously as an exothermic process. The findings revealed that the best ANN architecture trained with trainlm as the backpropagation algorithm, with tansig-purelin transfer functions, and 14 neurons in the single hidden layer with the highest coefficient of determination (R2 = 0.9996) and the lowest mean-squared-error (MSE = 0.0002). The well-agreement between the experimental and ANN-forecasted data demonstrated that the optimized ANN model can predict the behavior of the anionic dye biosorption onto biomass-derived modified carbon materials under various operation conditions.
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•MOP, CTAB-modified waste-orange peel-derived biosorbent, was fabricated.•ZnCl2 activation and CTAB-modification enlarged the specific surface area.•MOP was utilized as a biomass-derived biosorbent for Congo Red removal.•The ANN model was optimized for forecasting of Congo Red removal efficiency.•The optimized ANN model can be used to predict dye removal efficiency of biosorbent.
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•CO2 emission and climate change are urgent, universal crises.•CCU technologies have developed to utilize CO2 as precursors to fine chemicals.•Conventional carbon capture techniques ...are compatible with microalgal bio-CCU.•CO2 is incorporated into valuable biochemical compounds via photosynthesis.•Microalgal bio-CCU decreases carbon footprint and increases carbon handprint.
The continuously rising emission of carbon dioxide (CO2) is a universal hazard which urgently requires collaborative action between policymakers and scientists. International treaties such as the Paris Agreement (with 196 signatories) reflect the importance of anthropogenic climate change as a truly global public concern. Towards the aim of climate recovery, the most broadly utilized CO2 reduction strategies, including carbon capture and storage (CCS); carbon capture, utilization, and storage (CCUS); and carbon capture and utilization (CCU) are reviewed herein. Of these methods, CCU shows the greatest potential by recycling captured CO2 and harnessing it as a resource to generate emissions-neutral or -negative value-added products (VAPs). Within CCU methodologies, biologically-mediated CCU (bio-CCU) by microalgae is a promising biotechnology to drastically reduce CO2 emissions. This review therefore details the mechanisms of photosynthesis to sequester CO2 and incorporate it into valuable biomolecules. Microalgal cells utilize CO2 as precursors of macromolecules, including lipids, proteins, carbohydrates, and pigments; all of which are discussed within the frame of industrial relevance and market value. The biofixation potential of microalgae is clearly demonstrated by the carbon content of the myriad VAPs they produce. Moreover, pathways towards decreasing carbon footprint (via carbon capture prior to emission to the atmosphere) and increasing carbon handprint (reducing carbon emissions by consuming CO2-neutral or -negative products) related to bio-CCU are presented herein. Finally, existing challenges and knowledge gaps are acknowledged and described, and future research needs are recommended.
Herein, it is aimed to develop a high-performance monolithic adsorbent to be utilized in methyl orange (MO) adsorption. Therefore, amino-functionalized three-dimensional graphene networks (3D-GNf) ...fulfilling the requirements of reusability and high capacity have been fabricated via hydrothermal self-assembly approach followed by a double-crosslinking strategy. The potential utilization of 3D-GNf as an adsorbent for removal MO has been assessed using both batch-adsorption studies and an artificial neural network (ANN) approach. Graphene oxide sheets have been amino-functionalized and cross-linked, by ethylenediamine (EDA) during hydrothermal treatment, following the glutaraldehyde has used as a double-crosslinking agent to facilitate the crosslinking of architecture. The successful fabrication of 3D-GNf has been confirmed by field-emission scanning electron microscopy (FESEM), Fourier transform infrared (FT-IR), Raman and X-ray photoelectron spectroscopy (XPS). Moreover, N2 adsorption/desorption isotherms have revealed the high specific surface area (1015 m2 g−1) with high pore volume (1.054 cm3 g−1) and hierarchical porous structure of 3D-GNf. The effect of initial concentration, contact time, and temperature on adsorption capacity have been thoroughly studied, and the kinetics, isotherms, and thermodynamics of MO adsorption have been modelled. The MO adsorption has been well defined by the pseudo-second-order kinetic model and Langmuir isotherm model with a monolayer adsorption capacity of 270.27 mg g−1 at 25 °C. The thermodynamic findings have revealed MO adsorption has occurred spontaneously with an endothermic process. The Levenberg-Marquardt backpropagation algorithm has been implemented to train the ANN model, which has used the activation functions of tansig and purelin functions at the hidden and output layers, respectively. An optimum ANN model with high-performance metrics (coefficient of determination, R2 = 0.9995; mean squared error, MSE = 0.0008) composed of three hidden layers with 5 neurons in each layer was constructed to forecast MO adsorption. The findings have shown that experimental results are consistent with ANN-based data, implying that the suggested ANN model may be used to forecast cationic dye adsorption.
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•3D-GNf, a monolith adsorbent, was fabricated by facile method.•3D-GNf was utilized as a high-performance adsorbent for methyl orange removal.•Effect of operational parameters on removal efficiency was investigated via batch-adsorption studies.•The ANN model was optimized for forecasting of methyl orange removal efficiency.
Wastewater is water that has already been contaminated by domestic, industrial and commercial activity that needs to be treated before it could be discharged into some other water bodies to avoid ...even more groundwater contamination supplies. It consists of various contaminants like heavy metals, organic pollutants, inorganic pollutants and Emerging contaminants. Research has been doing on all types of contaminates more than a decade, but this emerging contaminants is the contaminants which arises mostly from pharmaceuticals, personal care products, hormones and fertilizer industries. The majority of emerging contaminants did not have standardized guidelines, but may have adverse effects on human and marine organisms, even at smaller concentrations. Typically, extremely low doses of emerging contaminants are found in the marine environment and cause a potential risk to the aquatic animals living there. When contaminants emerge in the marine world, they are potentially toxic and pose many risks to the health of both man and livestock. The aim of this article is to review the Emerging contaminate sources, detection methods and treatment methods. The purpose of this study is to consider the adsorption as a beneficial treatment of emerging contaminants also advanced and cost effective emerging contaminates treatment methods.
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•Sources and causes of Emerging Contaminants has been discussed.•Treatment methods and the Detection of Emerging Contaminants has been explained.•Different types of emerging contaminants and advancement in its treatment were reviewed.•Latest advances and further improvements in Adsorption of emerging contaminants were addressed.
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•Evaluations on the factors, composition, and growth mode of microalgae cultivation.•Various potential algae-based bioproducts implemented in different countries.•Comparison on the ...demand and supply gap of microalgae biomass in the global market.•Critical discussion on the challenges and future outlooks of microalgae industry.
Microalgae have been a promising alternative source of high-value compounds to replace the non-sustainable fossil fuels resource. The recent research development of algae-based bioproducts has remarkable impact various industries section for its renewability, efficiency, and environmentally friendly crops over those synthetic-made product. However, by utilizing microalgae biomass toward their full potential is still limited due to lack of research funding, social acceptability and challenges in policy implementation. This present review highlights the various microalgae biotechnology with consideration of economical aspect for the global potential of algae market, comparison between the microalgae market in Malaysia and international countries. In addition, the cultivation technologies and feasibility of microalgae biomass production globally, followed by insightful challenges and future development of microalgae industry are mentioned. The current study will contribute to the understanding of upstream and downstream of microalgae processing along with technical economical understandings for the successful commercialisation of microalgae products.
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•Recent development on seaweed-based plastics is summarized.•Biorefinery concept and impediment of microalgae-based plastics is discussed.•Algal application for biocomposites and ...additives is provided.
There is a growing interest in developing bio-based biodegradable plastics to reduce the dependence on depleting fossil fuels and provide a sustainable alternative. Bio-based plastics can usually be produced from lipids, proteins or carbohydrates, which are major components of microalgae. Despite its potential for algal plastics, little information is available on strain selection, culture optimization and bioplastics fabrication mechanism. In this review, we summarized the recent developments in understanding the utilization of seaweed polysaccharides, such as alginate and carrageenan for bio-based plastics. In addition, a conceptual biorefinery framework for algal plastics through promising components (e.g., lipids, carbohydrates and proteins) from microalgae is comprehensively presented. Moreover, the reasons for variations in bioplastics performance and underlying mechanism of various algal biocomposites have been critically discussed. We believe this review can provide valuable information to accelerate the development of innovative green technologies for improving the commercial viability of algal plastics.
Heavy metal pollution is one of the most pervasive environmental problems globally. Novel finely tuned algae have been proposed as a means to improve the efficacy and selectivity of heavy metal ...biosorption. This article reviews current research on selective algal heavy metal adsorption and critically discusses the performance of novel biosorbents. We emphasize emerging state-of-the-art techniques that customize algae for enhanced performance and selectivity, particularly molecular and chemical extraction techniques as well as nanoparticle (NP) synthesis approaches. The mechanisms and processes for developing novel algal biosorbents are also presented. Finally, we discuss the applications, challenges, and future prospects for modified algae in heavy metal biosorption.
Novel finely tuned algae can improve the selectivity and performance of heavy metal adsorption.Molecular modification can be used to display metal-binding proteins at the cell surface via gene overexpression or by introducing exogenous DNA to generate transgenic algae.The performance of chemical modification has been highly variable, and more studies will be necessary to overcome its limitations.The extraction approach is promising because of the strong metal-binding properties of algae that have been attributed to alginate.Algae-based nanoparticles show better performance in heavy metal removal compared with raw algae.
Summary
With the increasing demand and depleting trend of commercial energies, it has forced the researchers all over the world to accelerate research and development in the area of renewable energy. ...Currently, unique and interesting features of binary compounds have gained more attention by researchers, and it became a favourite research topic among various groups of researchers around this world. It was noticed that strontium titanate (SrTiO3) consists of several extraordinary properties that can apply for miscellaneous applications especially for energy storage, fuel cells, as well as to generate hydrogen fuel via photocatalysis process. Besides that, it was noticed that SrTiO3 can be synthesised in different pathways. The method of preparation and amount of precursors can affect the surface properties of SrTiO3. Thus, this article presents a critical review on how SrTiO3 synthesis methods affect its surface morphology and the applications of SrTiO3 in various fields.
SrTiO3 can be synthesised by hydrothermal, solvothermal, SSR, MSR, and sol‐gel reaction. Hydrothermal and solvothermal can synthesise uniform nanoparticles. It also controls the morphology of SrTiO3 with different parameters. SrTiO3 can be applied in photocatalysis, fuel cell anode, sensors, and storage.
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•Valorization of date pulp waste for production of ZnO nanoparticles (DP-ZnO-NPs).•Easy, energy efficient & ecofriendly biosynthetic process for DP-ZnO-NPs synthesis.•Rapid and ...complete photocatalytic degradation of hazardous dyes by DP-ZnO-NPs.•DP-ZnO-NPs exhibited competent inhibitory effects against pathogenic bacteria.•DP-ZnO-NPs are promising and potential industrial wastewater treatment agents.
Production of multi-functional zinc oxide nanoparticles (ZnO-NPs) for wastewater treatment through green-approaches is a desirable alternative for conventional synthesis routes. Biomass waste valorization for nanoparticles synthesis has received increased research attention. The present study reports date pulp waste (DPW) utilization as an effective bio-reductant for green-synthesis of ZnO-NPs. A simple and eco-friendly process with low reaction time and calcination temperature was adopted for DPW mediated ZnO-NPs (DP-ZnO-NPs) synthesis. Microscopic investigations of DP-ZnO-NPs confirmed the non-agglomeration and spherical nature of particles with mean diameter of 30 nm. EDX and XPS analysis defined the chemical composition and product purity of DP-ZnO-NPs. UV and photoluminescence studies exhibited surface plasmonic resonance at 381 nm and fluorescent nature of DP-ZnO-NPs. FTIR studies established a formation mechanism outline for DP-ZnO-NPs. XRD and Raman investigations confirmed the crystalline and hexagonal wurtzite phase of DP-ZnO-NPs. DSC/TG analysis displayed the thermal stability of DP-ZnO-NPs with <10 wt% loss upto 700 °C. Photocatalytic degradation of hazardous methylene blue and eosin yellow dyes using DP-ZnO-NPs, showed rapid decomposition rate with 90 % degradation efficiency. Additionally, DP-ZnO-NPs demonstrated significant antibacterial effects on various pathogenic bacteria in terms of zone-of-inhibition measured by disc-diffusion method. Thus, the as-prepared DP-ZnO-NPs is suitable for industrial wastewater treatment.
•Microalgae contains various nutritious and bio-active compounds.•Microalgae is capable of preventing or curing various acute and chronic diseases.•Microalgae is under-exploited crop due to its ...capital-intensive nature.•Microalgal biorefinery approach can enable sustainable growth in the market.
Microalgae has been consumed in human diet for thousands of years. It is an under-exploited crop for production of dietary foods. Microalgae cultivation does not compete with land and resources required for traditional crops and has a superior yield compared to terrestrial crops. Its high protein content has exhibited a huge potential to meet the dietary requirements of growing population. Apart from being a source of protein, presence of various bio-active components in microalgae provide an added health benefit. This review describes various microalgal sources of proteins and other bio-active components. One of the heavily studied group of bio-active components are pigments due to their anticarcenogenic, antioxidative and antihypertensive properties. Compared to various plant and floral species, microalgae contain higher amounts of pigments. Microalgal derived proteins have complete Essential Amino Acids (EAA) profiles and their protein content is higher than conventional sources such as meat, poultry and dairy products. However, microalgal based functional foods have not flooded the market. The lack of awareness coupled with scarce incentives for producers result in under-exploitation of microalgal potential. Application of microalgal derived components as dietary and nutraceutical supplements is discussed comprehensively.
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