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The main objective of this study was to produce, under pilot conditions, activated carbons (AC) from two different Caribbean by-products, specifically, sugarcane bagasse and vetiver roots. The produced activated
carbons under both physical and chemical activation processes were characterised with respect to their texture and surface chemistry. The...
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... physical characteristics are presented in Table 1. Specific surface-area measurements revealed that ''Bag- pilot'' has the greatest surface with 1,030 m 2 /g compared to 555 m 2 /g for ''Vet-pilot''. ...
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... these conditions, 1,248 tons of AC could be produced annually from vetiver roots in Haiti. This production would require a fixed investment of about 2.05 million $ (Table 10) and an annual operating cost of approximately $1,460,470 US (Table 10). Thus, the production of one kilogramme of AC from vetiver roots by phosphoric acid activation in Haiti is estimated at $ 1.17 US. ...
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... these conditions, 1,248 tons of AC could be produced annually from vetiver roots in Haiti. This production would require a fixed investment of about 2.05 million $ (Table 10) and an annual operating cost of approximately $1,460,470 US (Table 10). Thus, the production of one kilogramme of AC from vetiver roots by phosphoric acid activation in Haiti is estimated at $ 1.17 US. ...
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... this method leads to a low final yield compared to chemical activation. On the other hand, activation by phosphoric acid requires more materials and equipment, thereby leading to a heavier investment capital burden (Table 10) that is offset by a high final yield. Similar cost estimation work were realised by other researchers [14,15,21]. ...
Citations
... Various agro-industrial and domestic wastes have been used for preparation of activated carbons, for instance, luffa cylindrical [66], tobacco petiole [67], Sakura waste [68], worn tires [69], waste sludge [70], sugarcane bagasse [71][72][73][74][75][76], Bermuda grass [77], and bovine bone [78]. They all showed a good performance in removing pollutants from the aquatic environment. ...
In this work, low-cost microporous nano-activated carbon (MNSAC) was prepared from sugarcane bagasse using chemical activation with zinc chloride. The activated carbon prepared MNSAC was characterized using Brunauer-Emmett-Teller (BET), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) analyses, transmission electron microscopy (TEM), and energy-dispersive X-ray (EDX). MNSAC had BET, micropore analysis (MP), and t-plot surface area 1174.1, 1322.2, and 1401.5 m2/g, respectively, and was essentially microporous. Batch experiment was used to investigate the efficiency of MNSAC to remove toxic Cr(VI) ions from an artificial wastewater. Different adsorption behaviors towards toxic Cr(VI) ions have been studied to optimize adsorption status such as pH, initial concentration, absorbent dose, contact time, and temperature. Langmuir isothermal well fits experimental data compared to Freundlich isothermal model, which indicates that Cr(VI) ion adsorption process may be monolayer adsorption. The maximum adsorption capacity (Qm) of MNSAC obtained from Langmuir isotherm model was 277.78 mg/g. The regeneration of MNSAC was studied and the maximum removal of Cr(VI) ion was 93.61%, 82.38%, and 64.11% in the consequent three cycles. The pseudo-second-model kinetic well described the experimental data of hexavalent chromium adsorption (R2> 0.9900) compared to the other kinetic models studied. Thermodynamic parameters expose that adsorption process is endothermic, spontaneous, and appropriate in nature. A negative ∆G° value of Cr(VI) ion adsorption was found, which confirmed the spontaneous probability of the adsorption process.
... versus 1.46 $ per kg for steam-activated process). Physical activation was find to be more energy consumer [22]. ...
Lignocellulosic agricultural residues are worldwide used for the production of activated carbons with purpose of eliminate a large range of pollutants such as diuron, a very persistent herbicide found in streams. This work studies the adsorption of diuron in aqueous solution on two different activated carbons, a commercial activated carbon and a prepared one. Activated carbon has been produced from seed hulls of baobab (Andansonia digitata), as a valorization pathway for this waste. Precursors have been impregnated with potassium hydroxide and then carbonized under nitrogen flow. The porous structure of the carbon has been determined by methylen blue adsorption, iodine adsorption and nitrogen adsorption-desorption. The BET surface areas of the produced carbon was 1086 m² g‾¹ with an iodine and methylene blue values of 1854.2 mg•g⁻¹ and 26.66 mg•g⁻¹ respectively. Batch removal kinetics of diuron has been studied at 5, 13 and 20 ppm initial concentrations on the two activated carbons in a reconstituate solution. The results showed that adsorption of diuron can be modelled by Langmuir isotherm with a maximal adsorption capacity of 65.7 mg•g⁻¹ for baobab carbon and 151.8 mg•g⁻¹ for commercial activated carbon at 120 min equilibrium time. Speudo-second order reaction fits well with data collected during adsorption of diuron on carbons studied. Thus, Baobab seed hulls can be considered as good precursors for preparation of activated carbon with high specific surface area.
... Vetiver grass leaves and de-oiled roots are a suitable source for industrial production of activated carbon. De-oiled roots were used to generate high surface activated area (1000 m 2 g −1 ) and pore volume (up to 1.19 cm 3 g −1 ) using steam and H 3 PO 4 as activation agents (Altenor et al., 2013). Vetiver grass has also been applied in polymer composite industry (Methacanon et al., 2003;Ruksakulpiwat et al., 2007). ...
Plants and derivatives have been explored for unlimited purposes by mankind, from crop cultivation for providing food and animal feed, to the use for cosmetics, therapeutics and energy. Moringa tree and vetiver grass features, capabilities and applications were explored through a literature review. The suitability of these plants for the bioenergy industry products is evidenced, namely for bioethanol, biogas and biodiesel, given the lignocellulosic biomass content of these plants and characteristics of moringa seed oil. In addition, moringa leaves and pods are an important source for food and animal feed industries due to their high nutrient value. Thus, the co-cultivation of moringa and vetiver could provide energy and food security, and contribute to more sustainable agricultural practices and for the development of rural areas. Policymakers, institutions and scientific community must engage to promote the cultivation of multipurpose crops to cope with energy and food industries competition for biomass.
This study evaluates activated vetiver root powder as chloride ion adsorbent for saline water treatment. Experimental results demonstrate that activated vetiver root effectively removes chloride ions from saline solutions. Higher bed heights and lower flow rates improve efficiency by providing more adsorption sites and a longer contact time. However, higher concentrations lead to rapid bed exhaustion, highlighting the need for parameter optimization. Dynamic adsorption modeling using Thomas, Yoon–Nelson, and Clark models assesses the impact of bed height, flow rates, and initial concentration on chloride removal efficiency. Breakthrough equations closely fitted experimental data in the following order: Thomas model (R2 = 0.999) > Clark (R2 = 0.996) > Yoon–Nelson (R2 = 0.994). Scanning electron microscopy (SEM) analysis identifies pores and pockets as main surface components. Insights into adsorption mechanisms were gained through infrared and X-ray spectroscopies. A novel predictive algorithm for chloride removal in a continuous mode was developed using neural networks. Artificial neural network (ANN) prediction ability was assessed using MSE and R2 values. Future commercial applications of activated vetiver powder can be investigated using real salinity-induced wastewater. Additionally, assessing the adsorbent's regeneration and reusability is vital for confirming its cost-effectiveness and sustainability in longstanding use. This study offers perceptions for developing efficient water treatment strategies by understanding adsorption dynamics and surface characteristics for optimizing chloride removal processes.
The elimination of emerging contaminants (ECs) from aquatic environment has become a worldwide concern due to their widespread occurrence and consequent detrimental effects on aquatic life and humans. This review aims to highlight the applicability of carbonaceous materials including activated carbon, biochar, carbon nanofibers, graphene, carbon nanotubes (CNTs), and carbon aerogel for EC removal. This review depicts the versatility of carbonaceous material as an adsorbent, as a catalyst and as a catalyst support for EC removal. The mechanistic aspects involved in the adsorptive removal of ECs through π-π interactions, electrostatic interaction, n-π interactions, H-bonding, hydrophobic interaction, and pore filling were emphasized. An in-depth discussion on the catalytic properties of carbonaceous materials to activate peroxydisulfate (PS), peroxymonosulfate (PMS), and hydrogen peroxide leading to ECs degradation via radical and non-radical pathways were provided. The significance of carbonaceous materials when employed as catalyst support in photocatalysis, heterogeneous Fenton and catalytic ozonation was exemplified.
This study aims to assess the thermal properties of mixtures of sugarcane bagasse and iron(III) nitrate in the following proportions (mass/mass): 1/2, 1/1, and 2/1, using thermogravimetry/differential thermogravimetry and differential thermal analysis. These thermoanalytic techniques were performed to assess the best temperatures for the heat treatment of the mixtures for the subsequent production of the carbonaceous material/iron oxide composites and their behavior at different temperatures. According to thermal analysis, the decomposition profile of the mixture depends on the ratio of sugarcane bagasse to iron nitrate (BC/NF). The synthesized composites were characterized by X-ray diffraction, proving the formation of phases established from thermal analyses performed at 400, 500, and 600 °C. It was concluded that composites of the precursor mixtures may be produced to have different and interesting properties according to their application in sewage treatment processes such as adsorption.
Several samples of activated carbon were prepared by physical (CO2) and chemical (H3PO4) activation of aspen wood and tested for the adsorption of organic compounds from water generated during the recovery of bitumen using steam assisted gravity drainage. Total organic carbon removal by the carbon samples increased proportionally with total pore volume as determined from N2 adsorption isotherms at -196 °C. The activated carbon produced by CO2 activation had similar removal levels for total organic carbon from the water (up to 70%) to those samples activated with H3PO4, but lower yields, due to losses during pyrolysis and activation. A method to increase the yield when using CO2 activation was proposed and consisted of recycling bio-oil produced from previous runs to the aspen wood feed, followed by either KOH addition (0.48%) or air pretreatment (220 °C for 3 h) before pyrolysis and activation. By recycling the bio-oil, the yield of CO2 activated carbon (after air pretreatment of the mixture) was increased by a factor of 1.3. Due to the higher carbon yield, the corresponding total organic carbon removal, per mass of wood feed, increased by a factor of 1.2 thus improving the overall process efficiency.
Mining and smelting have a history of centuries. Once nature was predominant and human interference was negligible. Now, due to population explosion and increased demand for materials and energy, pollution from mine waste is glaringly visible. Coal and a variety of minerals are explored in different countries. Opencast mining generates large quantities of waste "overburden." The intermediate layers of sandstone, shale, and gravel that are usually present between two coal seams constitute this overburden. Pollution monitoring of abandoned coal mine sites and their reclamation are some of the emerging areas of environmental science and pollution research. In this chapter two cases of phytostabilization are presented: (1) the overburdens in the West Bokaro Coalfields, India, using mulberry, and (2) the Mae Sot, Padaeng zinc mine waste stabilization using vetiver grass in Thailand. Morus alba (mulberry) cultivation on coal mine overburden and vetiver cultivation on zinc mine waste accelerated the natural attenuation processes. These two examples of plants for phytostabilization are beneficial to locals and environmental protection.
Activated carbon from sugarcane residues, bagasse and straw was obtained with phosphoric acid activation. All samples were characterized by N2 adsorption-desorption isotherm, scanning electron microscopy, coupled with energy dispersive microscopy, X-ray photoelectron spectroscopy and thermal analysis. The advantages of using a ball or hammer milling process were investigated, together with the effect of the impregnation ratio and its influence on the final activated carbon porosity. The results show that all samples exhibit a high surface area and well developed porosity, but those which were ball-milled have a greater gas adsorbed amount, especially those which had straw (1415 m2/g) as precursor material. Furthermore, the results suggest that the process may have an optimum impregnation ratio, which should be around 2 or 3, irrespectively of the lignocellulosic source material. The mechanochemical process seems to be more relevant than the percentage of cellulose in the raw material. According with spectroscopy results, the homogeneous distribution of phosphorus throughout the sample was verified, even after repeated washing steps. Surface phosphate linkages like C-O-PO3 and C-PO3 were also detected.
