Global warming is widely recognized as one of humanity's most urgent challenges, making CO2 capture from the environment crucial to mitigating problems associated with climate change. In this study, ordered mesoporous silica SBA-15 was synthesized using the sol-gel process with Pluronic P123, a nonionic surfactant, and tetraethyl orthosilicate as the silica source, with hydrochloric acid serving as the catalyst. The results indicated that the CO2 adsorption capacity of SBA-15 was improved with higher CO2 feed concentration but decreased with increasing flowrate, temperature, and adsorbent loading. The Avrami model provided the best fit for the experimental kinetic data. The Thomas and Yoon-Nelson models were successful in predicting the CO2 adsorption performance of SBA-15 in the fixed-bed column system. The synthesized SBA-15 demonstrated its significant potential as a cost-effective CO2 adsorbent by maintaining a high adsorption capacity, even after multiple regeneration cycles.

The rapid industrialization relying on fossil fuel burning has escalated the greenhouse gases (GHGs) emissions issue impacting the environment and mankind negatively. Post-combustion capture (PCC) through fixed bed adsorption technology can participate in achieving the zero GHGs emissions goals by 2050 and stabilizing global interval temperature rise. This review explores the recent developments in the performance of carbonaceous and non-carbonaceous adsorbents in PCC fixed bed adsorption systems relying on the adsorbents' characterization properties, the breakthrough experiments, which were analyzed via their influential factors, such as the adsorption temperature, CO2 feed concentration, and feed flow rate, and the regeneration ability. Great advances have been recorded for PCC fixed bed adsorption, however, the capture of quite low concentrations of CO2 has not been illustrated comprehensively enough. Future studies need to offer more reliability to the suggested adsorbents for large-scale implementation via life cycle assessment and environmental impact assessment studies.

This study investigates the adsorption efficiency of Methylene Blue (MB) dye using tea waste as a cost-effective and environmentally friendly adsorbent. The impact of various parameters on MB removal was assessed, including solution pH, adsorbent dosage, pollutant concentration, and contact time. Optimal conditions were identified as pH 10, a dosage of 4 g/L, a concentration of 100 mg/L, and a contact time of 2 h, achieving nearly 99

This work aimed to develop a cost-effective, environmentally friendly, and sustainable adsorbent for CO2 capture using biomass waste, specifically oil palm ash (OPA), which is abundantly available as agricultural waste in Malaysia. Pristine OPA was first subjected to acid washing, followed by carbonization and chemical activation with KOH to enhance its physicochemical properties. Since machine learning (ML) can provide new insights into the design of adsorption processes and the understanding of CO2 adsorption mechanism, this paper presents a detailed comparative analysis of experimental and ML approaches. In this study, the surface and pore characteristics of OPA-KOH(1:2) were significantly enhanced through carbonization and KOH-functionalization, achieving an optimized mesoporous structure (average pore size: 72.71 Å), with a surface area of 30.95 m2/g. Despite having a moderate surface area, the tailored pore structure promoted efficient CO2 diffusion, thus enabling high CO2 adsorption capacity of 2.9 mmol/g, which was comparable or exceeds that some Acs with higher surface areas. Systematic analyses of adsorption isotherms, kinetics, and thermodynamics have confirmed that the CO2 adsorption onto OPA-KOH(1:2) occurred exothermically and was predominantly driven by a physisorption mechanism, supported by a weak chemisorption mechanism. ML-based models employed in this study have demonstrated that the bilayered neural network (NN) model could accurately predict CO2 adsorption onto OPA-KOH(1:2), with exceptionally high accuracy of R2 > 0.99. These findings have provided valuable insights into the capture, conversion, utilization, and storage (CCUS) technology, while highlighting OPA-KOH(1:2) as an affordable and environmentally friendly adsorbent for effective CO2 capture.

The increased level of CO2 in the atmosphere has led to global warming and climate change. To mitigate these problems, solid adsorbents have become attractive materials for capturing excess CO2 in the post-combustion method. Molecularly imprinted polymer (MIP) can be applied to prepare highly selective adsorbents that could capture CO2 molecules. The MIP was prepared using the surface imprinted polymer technique in this preliminary work. Only two types of support materials were used (graphite and silica gel) to screen the best support material that could enhance the CO2 adsorption capacity of the resulting adsorbent, which was analyzed using a fixed-bed column reactor. Graphite-imprinted polymer (GMIP) was found to be a good potential for CO2 adsorption. The Avrami model best described the adsorption system, while the fixed-bed curve data fit the Yoon-Nelson model well. The semi-empirical method was used to assess the interaction mechanism of the molecularly imprinted polymer with CO2 during adsorption. This investigation involved testing four different ratios of the template complex to functional monomers. The ratio of 1:4 (CO2:Allylthiourea) demonstrated the highest binding energy, with a higher formation of hydrogen bonds. Film diffusion and intraparticle diffusion were the main rate-limiting steps that played vital roles at different stages of CO2 adsorption. This preliminary work has enhanced the development of MIP for CO2 adsorption and showcased the integration of computational approaches in tailoring specific MIPs.

This work has focused on the co-pyrolysis of sugarcane waste (SW) with polyethylene terephthalate (PET) to gain insight on its thermal decomposition, product distribution, kinetics, and synergistic effect. SW and PET were blended at different ratios (100:0, 80:20, 60:40, 40:60, and 0:100), and the Coats-Redfern method was used to determine the kinetics parameters. To ascertain the synergistic effect between SW and PET, product yields and composition of chemicals were compared with the synergistic effect of the individual components of pyrolysis. The bio-oil yield was significant at 60

Nutrient leaching and volatilization cause environmental pollution, thus the pursuit of developing controlled-release fertilizer formulation is necessary. Biochar-based fertilizer exhibits slow-release characteristic, howev-er the nutrient release mechanism needs to be improved. To overcome this limitation, the approach of applying encapsulation technology with biochar-based fertilizer has been implemented in this study. Black peppercorn waste was used to synthesize urea-impregnated biochar (UIB). Central composite design was used to investigate the effects of pyrolysis temperature, residence time and urea:biochar ratio on nitrogen content of UIB. The op-timum condition to synthesize UIB was at 400 degrees C pyrolysis temperature, 120 min residence time and 0.6:1 urea: biochar ratio, which resulted in 16.07% nitrogen content. The tapioca starch/palm oil (PO) biofilm formulated using 8 g of tapioca starch and 0.12 mu L of PO was coated on the UIB to produce encapsulated urea-impregnated biochar (EUIB). The UIB and EUIB pellets achieved complete release of nitrogen in water after 90 min and 330 min, respectively. The nutrient release mechanism of UIB and EUIB was best described by the Higuchi model and Korsmeyer-Peppas model, respectively. The improvement of water retention ratio of UIB and EUIB pellets was more significant in sandy-textural soil as compared to clayey-textural soil. The EUIB derived from peppercorn waste has the potential to be utilized as a sustainable controlled-release fertilizer for agriculture.

The goal of this research was to create a co-hydrochar (Co-HC) from styrofoam (SF) and sawdust (SD) using a co-hydrothermal carbonization (co-HTC) method and to investigate the physicochemical features of co-hydrochar. At various temperatures (180°C, 200°C, 220°C), the co-HTC procedure was carried out. The impact of process water recirculation during co-HTC at 200°C was also examined. TGA test was used to study the pyrolysis behavior of the co-hydrochar and the results showed that the Co-HC improved physicochemical properties, low O/C and H/C ratios, and high heating value (HHV) of 28.89 MJ/kg, making it suitable for use as a solid fuel. The results also indicated that recirculation of process water promoted dehydration and decarboxylation, increased Co-HC yield percent (73.85

Invasive alien species (IAS) are one of the most serious environmental concerns for native biodiversity, as they can alter how the ecosystem functions through species homogenization. Invasive species can affect human health, disrupt ecosystem process, economic damage to agriculture. The conversion of invasive species through hydrothermal carbonization process can reduce the negative impact of invasive species. The objective of this study was to produce and characterize hydrochar as solid bio-energy derived from the invasive species Sphagneticola trilobata (ISST), an invasive plant species, specifically through hydrothermal carbonization. This technology can convert invasive species into biofuel by reducing their negative impact on the environment. The effect of different factors, namely temperature and reaction time towards the hydrochar yield (%) was optimized by central composite design (CCD) using statistical response surface methodology (RSM). Here the optimized conditions for hydrochar production have been identified. The optimized temperature was 180.31 °C and the time was 2.23 hours. The best yield of the hydrochar was 51.54%. To verify the hydrochar as an energy material, the physicochemical, structural and morphological properties were found using SEM, FTIR, TGA, elemental and proximate analysis. The calorific value of hydrochar increased from the calorific value of 13.41 MJ/Kg of Sphagneticola trilobata biomass to 17.03 MJ/Kg. The amounts of sulfur (S) and ash reduced dramatically. Moreover, a greater carbon content was present in the green biomass than oxygen content. Consequently, it is an advantageous technology for improving the characteristics of biomass of invasive species to hydrochar as fuel for energy generation.

A vital by-product of the petroleum industry, oily wastewater, presents a serious environmental problem owing to its complex composition and considerable volume. This includes a wide range of contaminants, such as oil, heavy metals, organic waste, and aromatic hydrocarbons. In order to tackle the issue at hand, this review article investigates new developments in adsorption technology as a potentially effective way to remediate oily refinery wastewater. It explores the numerous adsorbent materials, and the factors that affect the process in both batch and continuous systems, regeneration ability, mechanism of adsorption as well as the use of integrated processes. The review explores different adsorbent materials, including promising new options like nanomaterials and composites. Studies presented from literature show the modelling of isotherms onto Freundlich and Langmuir isotherms, and pseudo-second-order kinetics. Future studies ought to focus on developing affordable adsorbents as well as utilizing real wastewater samples to guarantee the adsorption process's viability from an economic and environmental standpoint for practical applications.

Tobacco (Nicotiana tabacum L.) is a significant crop widely planted worldwide. Its leaves have a special economical value as raw materials for the cigarette industry. During tobacco harvesting and cigarette production, a large amount of wastes that could not be used in the cigarette industry are generated such as tobacco stems, stalks, and low-grade leaves. The utilization of such agro-industrial wastes in raw or carbonaceous form as adsorbents for wastewater treatment is an economic and eco-friendly step for elimination of such waste. Tobacco waste can be directly applied as adsorbents for aquatic pollutants owing to its favorable lignocellulosic composition and functional groups enriched structure. Moreover, this waste has high volatile matters and thus can be an efficient precursor for high surface area carbonaceous adsorbents including biochar and activated carbon with high removal performance. This article is a recent and comprehensive review about the preparation of adsorbents (raw, biochar and activated carbon) from different tobacco wastes (stems, stalks, leaves, etc.) along with its characterization and regeneration. The adsorption behavior of different aquatic adsorbates on these adsorbents under specific conditions along with the isotherm, kinetic, thermodynamic, and mechanism studies is also considered. The highest uptakes for most tested pollutants were 399.0, 195.2, and 173.0 mg/g for lead, chromium, and cadmium, 517.5 mg/g for methylene blue, and 210.66 and 1.602 mg/g for phosphate and chlorpyrifos. Significant findings and future ideas for the studied adsorbate/adsorbent systems are finally given.

The potentials of mesoporous TiO2-ZnO (3TiZn) were explored on photocatalytic degradation of doxycycline (DOX) antibiotic, likewise the influence of adsorption on the photocatalytic process. The 3TiZn was characterized for physical and chemical properties. Stability, reusability, kinetic and the ability of 3TiZn to degrade high concentration of pollutant under different operating conditions were investigated. Photocatalytic degradation of DOX was conducted at varied operating conditions, and the best was obtained at 1 g/L catalyst dosage, solution inherent pH (4.4) and 50 ppm of DOX. Complete degradation of 50 ppm and 100 ppm of DOX were attained within 30 and 100 min of the reaction time, respectively. The stability and reusability study of the photocatalyst proved that at the tenth (10th) cycle, the 3TiZn is as effective in the degradation of DOX as in the first cycle. This may be attributed to the fusion of the mixed oxides during calcination. The 3TiZn is mesoporous with a pore diameter of 17 nm, and this boosts it potential to degrade high concentration of DOX. It was observed that the adsorption capacity of 3TiZn enhance the photocatalytic process. It can be emphasized that 3TiZn portrayed a remarkable catalyst stability and good potentials for industrial application.

Every year millions of oil barrels enter the water bodies. These oil spills have a devastating impact on the marine environments and their wildlife. Hence, it is necessary to clean-up these oil spills. Chitosan is cheap, renewable and eco-friendly polysaccharide. Therefore, chitosan-based materials have caught the attention of researchers as absorbents for oil spills cleanup and to separate oil/water mixtures. In their studies, chitosan was modified to improve its mechanical and physical properties, hence improving its adsorption capabilities. This paper is a comprehensive review on the application of chitosan and chitosan derivatives such as sponges, aerogels, carbon nanotubes fibers, foams, and polymers in the field of oil spill cleanup. Furthermore, this review lists the different parameters, such temperature, salinity, and pH, which affect the adsorption process and adsorption isotherms. Finally, the challenges and prospects of this type of adsorbent are discussed and summarized.

Date palm stones are regarded as possible alternatives to activated carbon (AC) precursors with high potential for various environmental applications. In this research study, date palm stones derived activated carbon (DPSAC) was used as adsorbent for removing toxic remazol brilliant blue R (RBBR). The synthesis of DPSAC involved a chemical treatment using KOH and NaOH (1:1). Characterization of DPSAC revealed that it exhibited a BET surface area of 715.30 m 2 /g, Langmuir surface area of 1061.93 m 2 /g, total pore volume of 0.39 cm 3 /g, and average pore diameter of 2.15 nm. Adsorption uptake of RBBR increased (from 24.54 to 248.54 mg/g), whereas the removal percentage decreased (from 98.16 to 82.85%) when the initial RBBR concentration increased (from 25 to 300 mg/L). The adsorption process performed best under acidic conditions (pH 3), with an RBBR uptake of 98.33 mg/g. Because of the high R 2 values (0.9906 and 0.9779) and low average errors (6.24 and 13.95%), this adsorption process followed the Freundlich isotherm and pseudo-first-order (PFO) models, respectively. The Langmuir adsorption capacity (Q m ) was 319.63 mg/g. Thermodynamic parameters were − 11.34 kJ/mol for ∆H° (exothermic in nature), 0.05 kJ/mol K for ∆S° (increasing randomness level at solid–liquid interface), − 27.37 kJ/mol for ∆G° (spontaneous), and 6.84 kJ/mol for E a (controlled by physisorption).

Regeneration of base oil from spent engine oil (spent SAE W50) for transfer oil production has been investigated using the solvent extraction-adsorption method. Solvent treated base oil regenerated from spent SAE W50 was treated with activated carbon (AC) from Penthaclatra macophylla pod (PMP) and activated clay (ACL) from Ukpor clay. The oil was characterized before and after treatment for heavy metals content, kinematic viscosity, viscosity index, specific gravity, and pour point. The carbon and clay were characterized using FTIR, BET, SEM-EDX, XRF, and XRD. Characterization results revealed the required properties of the adsorbents that make them capable of adhering impurities to their active sites. Results obtained showed that the optimum conditions for the regeneration of base oil from spent SAE W50 was a temperature of 110 degrees C, an adsorbent dosage of 5% w/v and a contact time 60 min, with 98% removal of impurities using the mixture of AC and ACL (AC-ACL). The transfer oil was obtained using a blend of the recovered base oil and virgin oil (150 N) at the ratio of 1:1.2. The blend gave the required properties for a transfer oil of similar quality to ISO VG 46. (c) 2023 The Authors. Published by Elsevier B.V. on behalf of African Institute of This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

[This corrects the article DOI: 10.1021/acsomega.2c03755.].

Date palm trees generate large amounts of various types of waste, including leaf sheath fibres, which can be used as a low-cost precursor for the production of biochar, including activated carbon (AC), which can be employed for the adsorption of contaminants. In the current study, activated carbon was produced from leaf sheath fibres of date palms (LSDPFAC) by the use of chemical activation with K2CO3 combined with microwave irradiation, and it was characterised and evaluated for its adsorptive capacity of lead ions (Pb2+). The Brunauer–Emmett–Teller (BET) surface area, Langmuir surface area, total pore volume and average pore diameter of the LSDPFAC were 560.20 m2/g, 744.31 m2/g, 0.29 cm3/g and 2.47 nm, respectively. A greater adsorption of Pb2+ was observed when its concentration was higher in the solution, and the greatest adsorption capacity of 5.67 mg Pb/g was observed at the highest pH. The results of isotherm and kinetic studies demonstrated that the adsorption of Pb2+ onto the LSDPFAC was best described by the Freundlich isotherm and pseudo-second-order (PSO) models. The Langmuir ΔG° and Ea were 6.39 kJ/mol, 0.12 kJ/mol K, −31.28 kJ/mol and 15.90 kJ/mol, respectively, which demonstrated that the adsorption of Pb2+ by the LSDPFAC was endothermic, spontaneous and governed by physisorption.

Hydroxyapatite-zeolite (HAP-ZE) catalyst prepared from steel waste was utilised in co-catalytic pyrolysis of sugarcane bagasse (SB) and high-density polyethylene (HDPE) for bio-oil production. The highest bio-oil yield (71.19 wt%) was obtained at HAP-ZE to SB/HDPE ratio of 1:6, and mass ratio of SB to HDPE of 40:60. HAP-ZE favoured the production of hydrocarbon and alcohol and inhibited the production of acid. The acid sites promoted the hydrogenation and deoxygenation via hydrocarbon pool while the basic sites promoted the deoxygenation reactions via decarboxylation and decarbonylation. HAP-ZE large pores facilitates access of bulky pyrolyzates to active sites, promoting deoxygenation and hydrocarbons formation.

Chitosan/bentonite beads (CsB) composites were prepared from chitosan (Cs) and bentonite (B) and cross-linked with epichlorohydrin for removal of reactive orange 16 (RO16) and methylene blue (MB). The adsorption results have shown that the (Cs20B80), 20 % wt of (Cs) and 80 % (B), was selected as the best adsorbent for (MB) and (RO16) dyes. SEM, EDX, FTIR, BET, and pHpzc were implemented to investigate the features of Cs, B, and Cs20B80 samples. The influence of contact time (0-72 h), initial RO16 concentration (15-300 mg/L), temper-ature (30, 40, and 50 degrees C), the quantity of adsorbent (1-4 g/L), ion strength (0.1-1 M), and solution pH (3-10) on RO16 adsorption onto Cs20B80 were explored. The pseudo-second-order and the Langmuir models fit adequately the adsorption kinetic results and the isotherms ones respectively. Also, the maximal monolayer capacities calculated using the non-linear form of the Langmuir isotherm are 55.27, 55.29, and 70.80 mg/g, at 30, 40 and 50 degrees C. Based to the statistical physics model, the RO16 could be retained on the surface of Cs20B80 through a non-parallel orientation. The RO16 adsorption process is endothermic and natural, as demonstrated by ther-modynamic studies. After three regeneration cycles, the Cs20B80 composite has shown an adsorption capacity of around 20 % compared to the initial one. The adsorption energy of RO16 onto Cs, B, and Cs20B80 examined using the Monte Carlo simulation method (MC) ranged from-164.8 to-303.7 (kcal/mol), showing the potential of the three adsorbants for RO16 dye. Also, the process of adsorption of RO16 dye on the surface of Cs20B80 composite indicates several kinds of physical interactions, involving electrostatic interaction, hydrogen bonding, and 7C-7C interactions, this finding was proved theoretically via molecular dynamic simulations.