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The present dataset describes the entrained-flow pyrolysis of Microalgae Chlorella vulgaris and the results obtained during bio-char characterization. The dataset includes a brief explanation of the experimental procedure, experimental conditions and the influence of pyrolysis conditions on bio-chars morphology and carbon structure. The data show a...
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... under different temperatures and pressures at various magnifications, respectively. Swelling ratios of microalgae bio- chars under pressurized pyrolysis was measured from the SEM analysis data and are shown in Fig. 7. Fig. 8 shows the Raman spectra of microalgae and its bio-char samples prepared under different experimental conditions, while Fig. 9 shows the typical curve-fitted Raman spectra corresponding to D1, D2, D3, D4 and G1 bands, respectively. The FTIR curve-fitting analysis results of bio-chars are presented in Table ...
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... layers, functional groups and small aromatic clusters, and aromatic ethers, respectively [3,4]. The higher full width at half maximum (FWHM) of the defect bands (D2, D3, and D4) in Raman spectra suggested that the carbon structure of bio-chars was highly amorphous in nature. A typical curve-fitted Raman spectrum of bio-char is illustrated in Fig. ...
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The aim of the research was to study the development of Chlorella vulgaris at culturing on the modified Gromov 6 medium with high concentrations of nanostructured ferric citrate and also its effect on photosynthesis pigments accumulation. It was demonstrated that the highest intracellular iron content (15 mg/g of dry mass) in the culture cells was...
Urban wet weather discharge (UWWD) management is an important issue. UWWD often represents a significant source of pollution in all aquatic bodies. The occurrence of this pollution is difficult to predict due to the variability of storm events and the unknown contents of urban watershed leached out by rain. Previous studies have tried to demonstrat...
Chlorella ( vulgaris spp. ; CLV) is a genus of unicellular freshwater microalgae that are fit for human consumption and are used as additives with high nutritional value in feed for agriculturally important animals. Chlorella spp. are characterised by their simple cultivation, high productivity and levels of protein and other nutrients. Investigati...
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... Pressure engineering is one of the most important techniques used to tune the morphology of biochar. Maliutina et al. [27] studied the effect of pressurized entrained flow pyrolysis. It is well-known that lignocellulosic biomass transformation into fuels and chemicals is difficult due to its rigid structure. ...
... Here, there are mostly six components, namely SL (hydrogen circulation along the periphery of the biochar, S (alkyl-alkyl ether), D (defects, heteroatoms, etc.), V (sp 2 C), G (degree However, the B-MP biochar exhibited a D/G ratio < 1 indicating a high degree of graphitization as shown in Figure 9c,f. This is clear proof that biomass grinding using a mortar and pestle induced a mechanochemical reaction [27]. Basically, the pretreatment of BSG may result in the reorganization of the internal moieties, hence the obtaining of a more graphitized structure. ...
... It is worth noting that this same B-MP biochar had the highest However, the B-MP biochar exhibited a D/G ratio < 1 indicating a high degree of graphitization as shown in Figure 9c,f. This is clear proof that biomass grinding using a mortar and pestle induced a mechanochemical reaction [27]. Basically, the pretreatment of BSG may result in the reorganization of the internal moieties, hence the obtaining of a more graphitized structure. ...
The present work is based on the principle of biomass waste valorization. Brewer’s spent grains (BSG) come from breweries as by-products. Their huge amount of production on an industrial scale should focus our attention on their valorization, which creates challenges as well as opportunities. One way to valorize BSG by-products is to convert them into biochar, a functional material with multiple potential applications. With an emphasis on sustainable development and the circular economy, in this work, we focused on a comparative study of the different mechanical processes of BSG grinding and their effect on the resulting biochar formed after pyrolysis. Home appliances such as blenders, coffee mills, and mortar and pestles were used for this purpose. FESEM images confirmed the successful creation of five different morphologies from the same BSG under the same pyrolysis conditions. Interestingly, a novel Chinese tea leaf egg-like biochar was also formed. It was found that a series of physical pretreatments of the biomass resulted in the reduced roughness of the biochar surface, i.e., they became smoother, thus negatively affecting the quality of the biochar. XRD revealed that the biomass physical treatments were also reflected in the crystallinity of some biochar. Via a Raman study, we witnessed the effect of mechanical pressure on the biomass for affecting the biochar features through pressure-induced modifications of the biomass’s internal structure. This induced enhanced biochar graphitization. This is a good example of the role of mechanochemistry. DSC revealed the thermochemical transformation of the five samples to be exothermic reactions. This study opens up an interesting possibility for the synthesis of biochar with controlled morphology, crystallinity, degree of graphitization, and heat capacity.
... However, these peaks disappeared after pyrolysis and two wide peaks (G and D-band) appeared on the PBC spectrum (Fig. 2c). The G-band peak is assigned to graphite layers, and the D-band peaks can be related to aromatic clusters, graphene layers, and aromatic ethers (Maliutina et al., 2018). ...
Extensive use of pharmaceuticals in public health and animal husbandry has resulted in their frequent detection in a wide variety of environmental water matrices. Lincomycin (LIN) is a widely used lincosamide antibiotic that is relatively persistent in the environment given its chemically stable structure. Biochar-based adsorbents are eco-friendly and inexpensive materials that can be used to remove contaminants from water. This study investigated the interactions between LIN and a microwave-activated biochar (BC) in batch and dynamic adsorption processes. The BC activation process was optimized with consideration of the molarity of the activation agent (H3PO4), microwave heating time, and microwave power. The results indicated the effectiveness of the applied activation process in the BC production with a BET surface area of 1,452 m²/g at the optimized condition, exceeding 2 m²/g for the raw biomass. The maximum adsorption capacity of BC for LIN was 190 mg/g, with experiments suggesting that electrostatic interaction may be the dominant factor affecting the adsorption of LIN on BC. In addition, thermodynamic analyses indicated the thermodynamically spontaneous and favorable adsorption of LIN on BC. The results indicate that microwave pyrolysis is an efficient method for creating an effective BC-adsorbent for removing LIN from different water matrices.
... Peak fitting of Raman spectra to proximately estimate the carbonaceous structure of the associated biochars was conducted based on the method by (Sousa et al., 2020; Maliutina et al., 2018) and using Originpro 2018 (OriginLab Corporation, Northampton, Massachusetts, USA). Raman shifts at 1586, 1362, 1683, 1501, and 1174 cm − 1 were assigned to bands of G, D1, D2, D3, and D4, respectively (Maliutina et al., 2018). ...
... The TEM image (Fig. 2) also showed that the nano-structure of C layers of the four biochar was mainly amorphous, rather than any well-organized arrangement, such as graphite. Furthermore, Fig. S2 (Supplementary material) revealed that the defect D4 band (RH-BC, CS-BC, and CC-BC) and defect D2 band (LA-BC) from Raman spectra had a wider bandwidth than the D1 and G bands, respectively, indicating that the carbon structure of the four biochars was highly amorphous (Maliutina et al., 2018). The amorphous structure, presumably as a result of low pyrolysis temperature, may lead to greater adsorption of inorganic pollutants because of the presence of more oxygen-functional groups (Hassan et al., 2020). ...
Agricultural biomass wastes, which may pollute the environment yet are inefficiently managed worldwide, can be recycled into biochar, which is subsequently used to remediate salt-affected environments. This creates value-added or dual benefits of treating the wastes while reclaiming saline water/soil for sustainable development. Nevertheless, a lack of knowledge about the linkage between biochar characteristics and sodium adsorption capacity may restrict the wastes from being recycled. The current study aimed to examine physicochemical, nano/microstructural, and functional-group characteristics of biochar and to assess its sodium isothermal-adsorption properties. Four biochars made from rice husk (RH-BC), corn stalks (CS-BC), longan branch (LA-BC), and coconut coir (CC-BC) were used for an isothermal-adsorption experiment. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Brauner-Emmett-Teller surface area (BET area), pore size distribution, and Fourier Transform Infrared spectroscopy (FTIR) were used to characterize biochars, which were additionally analyzed for 9 parameters. RH-BC had the highest BET area (151 m² g⁻¹) and porosity, whereas LA-BC exhibited the lowest BET area (10.6 m² g⁻¹), and LA-BC was more condensed. Functional groups, necessary for cation adsorption, were found in biochars. The maximum adsorption capacity of RH-BC (33.9 mg g⁻¹), estimated by the Langmuir isotherm model, was the highest while that of CC-BC (15.5 mg g⁻¹) was the lowest. The Dubinin-Radushkevich isotherm model showed that the Na adsorption mechanism was dominantly a physical process. The current study provides a feasible value-added and sustainable strategy of recycling agricultural biomass wastes with dual benefits of waste treatment and salt-affected environment remediation, applicable worldwide.
... This band (D 1 ) can also be attributed to aromatic clusters having more than 6 rings (amorphous carbon structure). The D 2 band centered at ca. 1500 cm − 1 was observed for Ni-FA H , Ni-FA Na/H , and Ni-FA Na , and is suggested to originate from amorphous sp 2 -bonded forms of carbon (represented as functional groups and small aromatic clusters) [67,69]. Based on Raman peak intensities, the coke formed on the used catalysts follows quantitatively the order of Ni-FA H > Ni-FA Na/H > Ni-FA Na > Ni-FA H/Na > Ni-FA. ...
Application of coal fly ash (FA) residues as catalyst support is mainly restricted because of low surface area and high sulfur content. In the present work, the physicochemical properties of a low-efficiency FA were significantly improved via simple acid/alkali treatments consisting of one-step (HNO3 or NaOH) or two-step (NaOH/HNO3 or HNO3/NaOH) leaching-partial-dissolution (LPD). As a result, as compared to Ni-FA, the catalytic activity of the Ni-FA(treated) catalysts for glycerol steam reforming was considerably enhanced. Alkali-LPD is more effective than acid-LPD in simultaneously improving FA’s surface area and regulating FA’s elemental distribution. Ni-FA(HNO3/NaOH) has the best performance with high glycerol conversion to gas (99.2%) and H2 yield (74.5%), attributed to i) removal of sulfur-containing species by acid-LPD, ii) upgrading specific surface area, iron-exposure, and Ni dispersion via alkali-LPD, iii) diminishment of coke using acid/alkali-LPD sequence treatment, and iv) enhancement of catalytic stability due to the formation of NiFe alloys.
... An upsurge in the I D /I G ratio was stated with an increase in the hydropyrolysis temperature. A similar change in G and D band was reported by Maliutina et al. (2018) in microalgal biochar (Maliutina et al., 2018). An increase in I D /I G value with a rise in pyrolysis temperature from 300-600 • C was also reported by Rhim et al. (2010). ...
... An upsurge in the I D /I G ratio was stated with an increase in the hydropyrolysis temperature. A similar change in G and D band was reported by Maliutina et al. (2018) in microalgal biochar (Maliutina et al., 2018). An increase in I D /I G value with a rise in pyrolysis temperature from 300-600 • C was also reported by Rhim et al. (2010). ...
In this study, hydropyrolysis was carried out using sodium carbonate to convert the green algal bloom into bio-oil, biochar, aqueous solution, and gases. The effect of supercritical conditions (400, 450, 500 °C) on the product yield, bio-oil composition, and structure, and functionalities of the biochar was determined. The high yield of biochar and bio-oil was reported at 400 °C. A significant reduction in bio-oil and increment in hydrocarbon content was reported on the elevation of temperature from 450 °C to 500 °C. After that, kinetic and isotherm analysis was investigated simultaneously to remove four heavy metals viz. Cu(II), Ni(II), Co(II), and Cd(II) from the mixture solution. Results show that kinetics data follow a pseudo-second-order kinetics model and adsorption isotherm is in better agreement with the Langmuir model, not with the Freundlich model. The maximum adsorption capacity was found 10.90, 5.74, 5.80, and 16.28 mg/g with the biochar prepared at 500 °C for Cu(II), Ni(II), Co(II), and Cd(II) metals, respectively. The current investigation provided a promising way for the utilization of freshwater algal bloom biomass for renewable products and simultaneously heavy metal removal from the water.
... While the microcrystalline structure of the bio-chars revealed the appearance of two broad bands centered at 1351 cm -1 (D band) and 1585 cm -1 (G band) in MB-OB and 1335 cm -1 (D band) and 1580 cm -1 (G band) in MB-DOB, demonstrating the amorphous structure. The D band structures are interpreted as aromatic clusters having more than 6 rings and a higher FWHM suggests a highly amorphous nature of the carbon structure, while the G band attributes to the E 2 g symmetry of the graphite layers in the bio-chars (Maliutina et al., 2018;Sudhakar et al., 2018). G bands in microalgae bio-chars conform to sp 2 hybridized C atoms, and D bands originate as defects generated in the carbon lattice. ...
Thermochemical transformation of microalgae biomass into graphitic bio-chars entices as proficient bio-adsorbents for heavy metal contaminants. This study explores the synergistic impact of Chlorella sorokiniana on biomass generation and wastewater remediation in high rate algae pond (HRAP). Biomass produced was applied for hydrothermal carbonization-co-liquefaction (HTCL). The structural and morphological characteristics of HTCL products (i.e. bio-chars and bio-oils) have been systematically studied by XRD, Raman, FTIR, elemental analyzer, SEM, BET, and ¹H-NMR spectroscopy. The crystallite size of the graphite 2H indexing planes was to be 4.65 nm and 14.07 nm in the bio-chars of oiled biomass (MB-OB) and de-oiled biomass (MB-DOB), respectively. The increase in the ID/IG ratio of MB-DOB indicated the highly disordered graphitic structure due to the appearance of carbonyl, hydroxyl, and epoxy functionalities in the line of high C/N and low C/H ratio. Also, the multiple heavy metals remediation of MB-DOB revealed better efficiency as ~100% in 720 min. The kinetics analysis shows the correlation coefficient of pseudo-second-order is well fitted compared to the pseudo-first-order. The Langmuir adsorption model signifies the adsorption of heavy metal ions in a monolayer adsorption manner. The study proposes the microalgae bio-char potential for multiple heavy metals remediation alongside bio-oils.
... It also suggests the formation of aromatic compounds in GBC during the pyrolysis (McDonald-Wharry et al., 2013). The Raman data concluded that the pyrolysis temperature has affected the properties of GBC, and their amorphous carbonaceous materials (Maliutina et al., 2018). ...
The present study aimed to envisage the effect of physicochemical properties on the performance of Gliricidia sepium biochar (GBC) pyrolyzed at 300, 500, and 700 °C in the removal caffeine (CFN); a pharmaceutical and personal care product, from water. The physicochemical properties of GBC were characterized by proximate and ultimate analysis, BET, SEM, FTIR, and Raman spectroscopy. The adsorption batch experiment was carried out at various pH values (pH 3–10), mixing times (up to 24 h), and initial CFN concentration (10–500 mg/L). The FTIR analysis revealed the loss of polar functional groups on the surface of GBC derived at high temperatures. The red-shifted and blue-shifted Raman peaks indicate the condensation of small molecules on GBC. The GBC derived at 700 °C demonstrated high CFN adsorption capacity (16.26 mg/g) due to its high surface area and aromaticity. The highest adsorption of CFN was occurred at acidic pH range from 3.5 to 4.5 due to the existence of non-specific attraction between CFN and GBC. The kinetics and isotherm experimental data were fitted with Elovich and fractional power kinetic regression, Freundlich, and Temkin isotherm models, which suggested the adsorption of CFN on the GBC by mixed mechanisms; physisorption and chemisorption including π–π interactions, hydrogen bonding, n–π interactions, electrostatic attraction, and electron donor-acceptor attraction. Moreover, both surface area and aromaticity index have demonstrated a high positive correlation for CFN adsorption, signifying the importance of controlling physicochemical properties based on the end-user purpose of biochar.
... The group of S L , S and S R bands represent the aryl-alkyl ether, paraaromatics, C(aromatic)C-(alkyl), C-H in aromatic rings and sp 3 of hexagonal diamond carbon (Feng et al., 2016;Maliutina et al., 2018). The two bands of V and G L represent the amorphous carbon structures and aromatic carbon structures consisting with few aromatic rings (Pusceddu et al., 2016). ...
The CO2 concentration in the atmosphere is increasing and threatening the earth's climate. Selective CO2 capture at large point sources will help reduce the CO2 emissions to the atmosphere. Biochar with microporous structure could be a potential material to capture CO2. The impact of feedstock type, pyrolysis temperature and steam activation of biochars were evaluated for CO2 adsorption capacity. Pine sawdust biochars were produced at 550 °C, and steam activated for 45 min at the same temperature after completing the pyrolysis (PS550 and PSS550). Paper mill sludge biochars were produced at 300 and 600 °C (PMS300 and PMS600). The CO2 adsorption capacity of biochars was tested at 25 °C using a volumetric sorption analyzer. Pine sawdust biochars showed significantly higher CO2 adsorption capacity than paper mill sludge biochars due to high surface area and microporosity. Pine sawdust biochars were then evaluated for dynamic adsorption under representative post-combustion flue gas concentration conditions (15% CO2, 85% N2) using a breakthrough rig. Both materials showed selective CO2 uptake over N2 which is the major component along with CO2 in flue gas. PSS550 had slightly higher CO2 adsorption capacity (0.73 mmol/g vs 0.67 mmol/g) and CO2 over N2 selectivity (26 vs 18) than PS550 possibly due to increase of microporosity, surface area, and oxygen containing basic functional groups through steam activation. Pine sawdust biochar is an environmentally friendly and low-cost material to capture CO2.
... The most common bacteria found in the atmosphere are Bacillaceae, Actinobacteria, Proteobacteria, and Bacteroidetes (Dasgupta and Poruthoor 2002;Górny et al. 1999;Núñez 2016). Similarly, several fungal bioaerosols (1.5-30 lm) such as Cryptococcus, Histoplasma, Alternaria, Aureobasidium, Chaetomium, Cladosporium, and Mucor are abundant in the atmosphere adapted from previously published articles provided in Ref (Golding et al. 2016;Maliutina et al. 2018;Sharma Ghimire et al. 2016;Wu et al. 2015) Fig. 2 Overall illustration about bioaerosol emission, cycling, transformation, and measurement 123 regardless of their exposure to severe UV light conditions and probability of desiccation at high altitudes (Elbert et al. 2007;Lee et al. 2010;Löndahl 2014). The activity of fungal spore is high in a condition of high humidity. ...
Bioaerosols are biologically originated particles present in the atmosphere that can be formed from any process involving biological materials. They comprise of both living and non-living components including organisms, dispersal methods of organisms, and excretions. Bioaerosols such as airborne bacteria, fungal spores, pollen, and others possess diverse characteristics and effects. A large gap exists in the scientific understanding of the overall physical characteristics and measurement of bioaerosols. Consequently, this review aims to devise an appropriate approach to generate more scientific knowledge of bioaerosols. In addition to comparisons and discussions about the various factors affecting bioaerosols, sampling, handling, and the application of various devised analytical techniques, this review offers insight into the current state of bioaerosol research. The review focuses on instrumental and methodical strategies to understand bioaerosol measurement. Numerous studies have investigated conventional methods, advanced methods, and real-time methods that can be applied for bioaerosol monitoring. Each method is different in terms of working principle, characteristics, sensitivity, and efficiency. For the first time, this review explains and compares different methods of conventional, offline, online, and real-time detection methods of bioaerosols based on their working principles, sensitivity, and efficiency on a single platform. This will provide a clear concept and better options for selecting the appropriate method based on the research proposal. Furthermore, recent advances are summarized, and future outlooks are emphasized for bioaerosol identification and categorization. This study also encourages developing affordable and standardized methods to avoid the inter-laboratory and sampling variability to obtain a better understanding and comparison of bioaerosol measurements worldwide. Nevertheless, this work can assist researchers in selecting appropriate methods for bioaerosol measurement and investigation.
... Thus, as Fig. 5 illustrates, that the char particles appear to be cenospheric and possess large cavities with thin walls. The fact that rapidly heated small biomass particles (where heat conduction to the particle interior is effective) undergo melting has already been reported for different types of biomass by Panahi et al. [89] , Cetin et al. [60] , Gill et al. [104] , Reed and Williams [105] , Lèdè et al. [106] and Narayan and Antal [107] , Dall'Ora et al. [54] , Maliutina et al. [108] among others. The particle structure and surface details of the char shown in Fig. 5 confirm recent findings of fusion and spherodization of biomass particles of sizes relevant to pulverized fuel combustion [89] . ...
A unique approach and proposed methodology was implemented to determine char burning rates in conjunction to their prevailing structure from detailed results on the combustion histories of small biomass fuel particles, exposed to elevated temperatures (>1000 K) at very high heating rates (104–105 K/s). Analogous conditions typically prevail in pulverized fuel utility boilers for power generation. Individual particles of pre-measured size, shape, aspect ratio and mass from five different types of raw and torrefied biomass were selected for this study. The particles were injected into a transparent drop-tube furnace, electrically heated to 1400 K, where they were rapidly heated, ignited and burned in air. Temperature-time histories of the individual particles were recorded pyrometrically and were used to assess their individual combustion rates. These particles burned in distinct volatile and char phases. A published phenomenological combustion model for carbonaceous fuel particles was enhanced and applied to the experimental data to calculate the char burning rates. Important information on the nature of these chars, which formed inside volatile matter envelope flames, was obtained by juxtaposition of the knowledge of their original properties with the pyrometric observations and the numerical simulations. It was concluded that, under the conditions of these experiments, chars of most types of biomass consisted of thin-wall cenospherical particles. The modeling results show that this predominant particle structure needs to be considered for reliable burnout predictions.
