Black Wattle Bark Research Articles

Condensed tannins from black wattle as a promising nutritional additive for Nile tilapia: Growth, immune and antioxidant responses, and gut morphology

The present study aimed to investigate the potential of condensed tannins (CT), derived from black wattle (Acacia mearnsii) tree bark, as a nutritional additive for Nile tilapia (Oreochromis niloticus) juveniles. CT are known for their antioxidant and immune-modulating properties, and their inclusion in aquafeeds may enhance fish health and performance. In this study, six diets were formulated: one control diet (Con) with no additives, and five experimental diets supplemented with CT extract at concentrations of 150, 250, 500, 750, and 1000 mg/kg (CT150, CT250, CT500, CT750, CT1000, respectively). The selection of these doses was based on previous studies indicating that lower concentrations (below 1000 mg/kg of diet) of tannins may offer benefits, while higher concentrations could exhibit antinutritional effects. After a 90-day feeding trial, fish fed the CT150 diet exhibited significantly higher growth compared to the control group. Additionally, fish in the CT150 group showed higher plasma lysozyme activity, while myeloperoxidase activity and hemolytic activity of the complement system were significantly higher in all tannin-fed groups compared to the control. Notably, CT150-fed fish demonstrated liver antioxidant responses comparable to or better than the control group, with no significant increase in lipid peroxidation, suggesting antioxidant protection. Histological analysis revealed a significant increase in intestinal villi density in the CT150 and CT500 groups compared to the control. While all groups showed an increase in absorption surface area (ASA), this increase was statistically significant only in the CT250, CT500, and CT750 groups when compared to the control. Furthermore, the CT150 diet led to the highest survival rate (80 %) following a bacterial challenge. These findings suggest that dietary supplementation with 150 mg/kg of CT from black wattle bark provides the most beneficial effects on growth, immune response, and survival in Nile tilapia juveniles.

Evaluating black wattle bark industrial residue as a new feedstock for bioenergy via pyrolysis and multicomponent kinetic modeling

This work presents an evaluation of the industrial residue from exhausted black wattle bark after the extraction of tannin for use as a new feedstock for biofuel production, without competing with food production. The physicochemical and thermodynamic properties, the influence of temperature on pyrolysis products and multicomponent kinetics were evaluated. Principal component analysis showed that sugars, carboxylic acids, ethers/esters, furans and aldehydes were formed as primary products of pyrolysis at 450 °C. At 550 °C, phenols and mainly ketones were favored, especially acetone and 2,3-butanedione. Pyrolysis at 650 °C favored the production of aldehydes, alcohols, and 1-alkene, polyene and alkane hydrocarbons. After an upgrade, the series of 1-alkenes produced, with carbons C7 to C16, could be suitable for a range of gasoline and jet fuels. Kinetic modeling was based on the deconvolution of the mass loss of three events of the pseudo-components: hemicellulose (DE-HC), cellulose (DE-CL) and lignin (DE-LG). The activation energy for kinetic models Friedman, Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose and Starink presented average values of ∼141.4–149.4 for DE-HC, ∼190.5–200.9 for DE-CL and ∼237.2–252.3 kJ mol−1 for DE-LG. This study encourages using agro-industrial waste to produce second-generation drop-in biofuels and bio-based chemicals, aiming at industrial decarbonization.

Tannin Industry Waste-Derived Porous Carbon: An Effective Adsorbent from Black Wattle Bark for Organic Pollutant Removal

In Brazil, a significant part of the biomass is unused, contributing to environmental pollution. The tannin industry commonly extracts tannins from the bark of Acacia mearnsii or black wattle, leaving a significant residue of 70% (w w−1). This study investigates the conversion of black wattle bark into a porous carbonaceous material to efficiently remove organic pollutants. Using ZnCl2 as a chemical activation reagent, the experiments varied the impregnation time, carbonization rates, and temperatures. Additional experiments aimed to increase the specific surface area (SSA). X-ray diffraction (XRD) analysis showed the formation and removal of ZnO, which increased porosity. Scanning electron microscopy (SEM) showed an irregular morphology with pores. Fourier-transform infrared (FTIR) spectroscopy indicated characteristic bands, and electron paramagnetic resonance (EPR) detected organic free radicals. The SSAs exceeded 1000 m2 g−1, averaging 1360 m2 g−1, with a maximum of 1525 m2 g−1. Micropores (1.4 nm) were consistent. The structure of the material and the high SSA suggest a potential for efficient removal of aromatic impurities by π–π interactions. This approach addresses the issue of biomass waste, provides a solution for environmental remediation, and represents a transformative strategy for biomass utilization.

Obtaining of a rich-cellulose material from black wattle (Acacia mearnsii De Wild.) bark residues.

Black wattle (Acacia mearnsii De Wild.) barksare residues produced by tannin industries in huge quantities, which are normally discharged on environmental or used for energy production. Therefore, this study aimed to evaluate the use of black wattle bark residues as a raw material on obtaining of a rich-cellulose material by alkaline (MET1), acetosolv (MET2), and organosolv (MET3) procedures. The results obtained indicated that the alkaline methodology, followed by a bleaching step (MET1), promoted klason lignin and hemicellulose removals more efficiently. It was possible to observe that better results were achieved using NaOH concentration of 6% (wt%), at 65 °C for 2.5 h, presenting a yield of 63.24 ± 1.25%, and a reduction on klason lignin content of almost 90.45%. Regarding the bleaching step, it was possible to obtain a material free of non-cellulosic compounds with a yield of 78.28 ± 1.48%. Thermogravimetric analysis indicated the removal of lignin and hemicellulose as well as an increase in cellulose degradation temperature, due to changes in crystalline phases. According toX-ray diffraction (XRD), the procedures employed have led to an increase in crystallinity from 66.27 to 91.78% due to the removal of non-cellulosic compounds. Scanning electron microscopy (SEM) showed morphological alterations in accordance with the removal of non-cellulosic compounds.

Flocculation performance and evaluation of a sulfur-containing tannin flocculant for Cu2+ removal

To introduce sulfur compounds into tannin-based flocculants, thiosemicarbazide (TC) was selected as a raw material to react with black wattle bark tannin and formaldehyde through the Mannich reaction in order to synthesize a sulfur-containing tannin flocculant (TFA) with the functions of chelation, flocculation and precipitation. The physicochemical characteristics of TFA were characterized by elemental analysis (EA), Fourier transform infrared spectroscopy (FT-IR), 13C solid-state nuclear magnetic resonance (13C NMR) and zeta potential to identify the successful synthesis. The flocculation performance of TFA was evaluated by measuring the Cu2+ removal rate. The effects of pH, initial Cu2+ concentration, TFA dosage, coexisting inorganic compounds and organic complexing agents on the Cu2+ removal rate were investigated through flocculation experiments. The results showed that the Cu2+ removal rate increased with increasing pH and the maximum Cu2+ removal rate for 5, 10 and 25 mg/L initial Cu2+ reached 100 % by raising the TFA dosage. Coexisting inorganic compounds, such as KCl, NaCl, CaCl2, MgCl2, NaNO3, and Na2SO4, had a negligible impact on Cu2+ removal, while the presence of organic complexing agents (humic acid, disodium ethylenediamine tetraacetate, citric acid and aminoacetic acid) had a significant influence on Cu2+ removal. The flocculation mechanisms of Cu2+ by TFA mainly involved a combination of bridge-aggregation and chelating precipitation, accompanied by a sweeping effect.

Influence of Temperature and Residence Time in the Hydrothermal Carbonization of Rice Husk and Exhausted Black Wattle Bark

Influence of Temperature and Residence Time in the Hydrothermal Carbonization of Rice Husk and Exhausted Black Wattle Bark

Low temperature production of biochars from different biomasses: Effect of static and rotary lab reactors and application as soil conditioners

Abundant renewable resources, such as biomass, can acquire added value when applied in industrial processes, such as slow pyrolysis to produce biochar. The type of biomass and the pyrolysis conditions are factors that determine the characteristics of the resulting biochars, influencing their potential applications. In this work, biochars were produced at 350 °C from sugarcane bagasse (SB), exhausted black wattle bark (EH), and elephant grass (EG). The materials were characterized considering the effects of different pyrolysis methods: (1) tube (laboratory scale), (2) rotary, and (3) muffle furnace (industrial scale). Despite using the same temperature, the formation of structures with condensed aromatic rings, the order of the processes that tended to form this type of structure was (3) ≥ (2) > (1). Pyrolysis method (3) tended to carbonize the constituents of biomass, than the other processes, which was promising for the production of biochar on an industrial scale. Besides, an investigation was made of the effects of applying BEG3 and BEH3 biochars as soil conditioners to mitigate emissions of N2O (a major greenhouse gas) and improve productivity in the cultivation of black oats. The BEG3 reduced the release of N2O from the soil, mainly affecting its peak emission, in addition to increasing the productivity of black oats by a factor of 1.22, compared to the control, being statistically significant results. It could be concluded that elephant grass biochar produced on an industrial scale is suitable for application to soils.

Evaluation of the vermicomposting of Acacia mearnsii De Wild bark bagasse with bovine manure

The main goal of this article is to study the vermicomposting and composting process of black wattle bark bagasse with bovine manure mixed in different proportions and to evaluate if the composts generated have physicochemical and toxicological aspects suitable for its use as fertilizers. The physicochemical tests of the studied residues and their composts demonstrated that bovine manure and black wattle bark bagasse are sources of macro and micronutrient, but none of the composts showed relevant differences between nutrient concentrations. The final pH of the composts remained acidic, varying between 4.6 and 5.80. During composting the maximum temperature reached by the composts was 29.5 °C, reached by the 20% black wattle bark bagasse compost. The germination test and root elongation performed with Lactuca sativa showed that the black wattle bark bagasse and bovine manure presented toxic effects, but the composting process was capable to reduce their toxicity to safe levels in the composts V5 and C5. Chronical and acute toxicity tests revealed no toxic effect of the composts on Eisenia fetida; the same happened with the avoidance test, which indicated negative avoidance of earthworms. Thus, it is concluded that the biotransformation of black wattle bark bagasse in organic fertilizer is viable through composting process and that composts V5 and C5 have adequate physical, chemical and toxicological characteristics for use as agricultural fertilizer. However, application to Cu-sensitive crops should be avoided due to the high concentration of this element on the composts.

Preparation of activated carbon from black wattle bark waste and its application for phenol adsorption

Black wattle bark waste is generated in large amounts by tannin extraction industries, which leads to an environmental problem. In literature there are few reports about reusing this waste, mainly in adsorption processes. An activated carbon from black wattle bark waste was produced, characterized and applied for phenol adsorption. Activated carbon was produced under different carbonization and activation conditions, being characterized and applied as an adsorbent for phenol removal from aqueous solution. The results showed that phenol adsorption capacity increased with the increase of carbonization temperature and of activating agent ratio and, decreased with the increase of carbonization time. Activated carbon presented a micro/mesoporous structure and the surface area was 414.97 m2 g−1. FTIR analysis showed that lactone and quinone groups compose the surface chemistry of the activated carbon. The adsorption kinetics followed the pseudo-second order model. The Weber-Morris model showed that the adsorption occurred by film and intra-particle diffusion, and the increase in stirring rate led to an increase in film diffusion. Temperature increase led to an increase in phenol adsorption capacity, and the highest value was around 98.57 mg g−1, obtained at 55 °C. The Freundlich isotherm model was the more suitable to represent the equilibrium data. Thermodynamic study indicated that phenol adsorption onto the developed activated carbon was a spontaneous, favorable, endothermic and entropy-controlled process. The activated carbon can be used in two cycles with a slight decrease in the equilibrium adsorption capacity and presented a good efficiency to remove phenolic compounds in a simulated industrial effluent.

Evaluation of the Coagulating Potential of the Crude Extract from the Barbatimão Bark for the Treatment of Dairy Effluents

The coagulating potential of the crude extract from the barbatimao bark for the treatment of dairy effluent was assessed and compared with industrial coagulants such as aluminum sulfate (inorganic coagulant), the crude extract of black wattle bark (used in the manufacture of natural organic coagulants), and gallic acid (the main constituent of condensed tannins). The aqueous extract of barbatimao was obtained by refluxing for 12 h, and the black wattle was provided by a producer of natural coagulants. The determinations of total phenolic compounds and tannins in the extracts were performed by the Folin-Ciocalteu method and precipitation with casein, respectively. The treatment of the effluent with coagulant was performed by the Jar-Test. After testing, the effluent was evaluated for turbidity, total solids, and biochemical oxygen demand (BOD). A higher content of phenolic compounds (19.81% mg of gallic acid/g extract) was observed in the barbatimao extract than in the black wattle extract (14.24% mg of gallic acid/g extract). However, the extracts contained the same amount of tannins, 13.95% for the barbatimao extract and 12.89% for the black wattle extract. A 63%, reduction in BOD was observed for the effluent treated with barbatimao extract, 35% for the black wattle extract, 58% for gallic acid and 60.59% for the treatment with aluminum sulfate. Treatment with gallic acid caused a 98% reduction in the turbidity of the effluent; with aluminum sulfate, a 97% reduction was obtained; with barbatimao extract, 96%, and with black wattle extract, 93%. The barbatimao extract was shown to be a potential coagulant for dairy effluents.

Analysis of commercial proanthocyanidins. Part 4: Solid state 13C NMR as a tool for in situ analysis of proanthocyanidin tannins, in heartwood and bark of quebracho and acacia, and related species

(13)C NMR is an effective method of characterizing proanthocyanidin (PAC) tannins in quebracho (Schinopsis lorentzii) heartwood and black wattle (Acacia mearnsii) bark, before and after commercial extraction. The B-rings of the constituent flavan-3-ols, catechols (quebracho) or pyrogallols (wattle), are recognized in unprocessed source materials by "marker" signals at ca. 118 or 105ppm, respectively. NMR allows the minimum extraction efficiency to be calculated; ca. 30%, and ca. 80%, for quebracho heartwood and black wattle bark, respectively. NMR can also identify PAC tannin (predominantly robinetinidin), and compare tannin content, in bark from other acacia species; tannin content decreases in the order A. mearnsii, Acacia pycnantha (87% of A. mearnsii), Acacia dealbata and Acacia decurrens (each 74%) and Acacia karroo (30%). Heartwood from an underexploited PAC tannin source, Searsia lancea, taxonomically close to quebracho, shows abundant profisetinidin and catechin PACs. NMR offers the advantage of being applicable to source materials in their native state, and has potential applications in optimizing extraction processes, identification of tannin sources, and characterization of tannin content in cultivar yield improvement programmes.

Manejo dos resíduos da colheita de acácia-negra (<i>Acacia mearnsii</i> De Wild) e a sustentabilidade do sítio.

A acácia-negra se adapta a inúmeras condições ambientais por ser uma espécie pioneira de crescimento rápido. Este trabalho foi realizado em povoamentos comerciais puros de acácia-negra de propriedade da TANAGRO S.A., no município de Piratini, RS, em cinco classes de solos, com plantas de mesma procedência, constituindo cada qual um tratamento. Em cada solo, foram avaliados o crescimento em DAP, altura e produção de biomassa aérea. Os solos foram caracterizados química, física e morfologicamente em seus horizontes superficiais. Nas plantas, foram determinado o estado nutricional dos diferentes compartimentos, o teor de tanino na casca e o teor de lignina e extrativos totais no tronco. O Neossolo Litólico eutrófico produziu o maior volume de troncos comerciais, enquanto o Neossolo Litólico álico foi o menos produtivo, mostrando a grande importância da fertilidade do solo na produtividade da acácia negra, sobretudo, o teor de P e as saturações por bases e por alumínio trocável. Se os resíduos não forem queimados, a quantidade de macronutrientes devolvida ao solo (por galhos, flor, folhas e vagens) é maior que a quantidade de macronutrientes exportada, com a retirada apenas do tronco comercial e casca, nos solos menos produtivos, confirmando que se trata de espécie recuperadora de solo. Nos solos com maior volume de troncos comerciais produzidos, a quantidade de cálcio e magnésio exportada foi maior do que a devolvida ao solo pelos resíduos da colheita. A concentração de tanino na casca da acácia-negra foi maior em condições adversas de solo, mas a maior produção de casca em solos melhores compensa esse fato.

Preparation and adsorption properties of macroporous tannin resins

In this paper, a new kind of adsorption resin with multi-phenolic hydroxyl was created by immobilizing black wattle bark tannins to chloromethyl polystyrene resin. Its adsorption capacity to cation dye was tested. With an orthogonal test the optimal conditions of synthesis were determined: the concentration of sodium hydroxide solution 1.0 mol·L−1; the reaction time is one hour and the mass concentration of tannins 5%. With single factorial experiment the optimal conditions of adsorption were confirmed: a solidified pH of 5.0; an adsorption temperature of 25°C and a cation dye concentration of 100 mg·L−1. The adsorption for cation dye can be similar to Langmuir isotherms.

Condensed tannins: direct synthesis, structure, and absolute configuration of four biflavonoids from black wattle bark (‘mimosa’) extract

Optically pure (+)-2,3-trans-3,4-trans-flavan-3,3′,4,4′,7-pentaol [(+)-mollisacacidin] and (+)-2,3-trans-flavan-3,3′,4′,5,7-pentaol [(+)-catechin] condense rapidly in 0·1 M HCl to give good yields of 4,8-linked diastereoisomeric biflavonoid proanthocyanidins of all-trans and 2,3-trans-3,4-cis-2,3-trans configurations, and also the 4,6-linked all-trans isomer; c.d. comparison thus enables confirmation of the absolute configurations of three known 4,8-linked all-trans biflavonoids from black wattle bark as 2R,3S,4S–2R,3S, and also identification of a fourth as 2R,3S,4R–2R,3S.

Condensed tannins. 3. Isolation and estimation of (−)-7:3′:4′:5′-tetrahydroxyflavan-3-ol, (+)-catechin and (+)-gallocatechin from black-wattle-bark extract

Condensed tannins. 3. Isolation and estimation of (−)-7:3′:4′:5′-tetrahydroxyflavan-3-ol, (+)-catechin and (+)-gallocatechin from black-wattle-bark extract