This work focused on the impacts of FeCl3 impregnation ratio on the properties of FeCl3-activated bermudagrass (BG)-derived biochars (IA-BCs), adsorption of sulfamethoxazole (SMX) onto IA-BCs and ...regeneration of SMX-spent IA-BC. Compared with the control BC (85.82 m2/g), IA-BCs made via pyrolysis with FeCl3 to BG mass ratio between 1 and 3 (1–3 g FeCl3/g BG) resulted in significantly enhancing surface area (1014–1035 m2/g), hydrophobicity, Fe content in IA-BCs (3.87–7.27%), and graphitized carbon. The properties of IA-BCs supported magnetic separation and higher adsorption (32–265 mg SMX/g BC) than the control BC (6–14 mg SMX/g BC) at various pH. Adsorption experiments indicated various adsorption mechanisms between SMX and IA-BCs via π-π EDA, hydrophobic interactions, and hydrogen bond with intraparticle diffusion limitation. The adsorption was also found to be spontaneous and exothermic. The IA-BC made at FeCl3 to BG mass ratio of 2 (IA-BC2.0) showed the maximum adsorption capacity for SMX (253 mg SMX/g BC) calculated from Langmuir isotherm model. Additionally, both NaOH desorption and thermal oxidation showed effective regeneration of SMX-saturated IA-BC2.0 over multiple cycles. After three cycles of adsorption-regeneration, 64% and 62% of regeneration efficiencies were still achieved under thermal treatment at 300 °C and desorption with 0.1 M NaOH solution, respectively, indicating a cost-efficient adsorbent for the elimination of SMX in water.
Display omitted
•Iron-activated bermudagrass (BG) biochars (BCs) were prepared.•Iron impregnation ratio affected the properties and adsorption capacity of BCs.•Iron impregnation ratio (FeCl3/BG) of 2 showed highest adsorption of SMX.•Mechanisms included hydrogen bond, non-covalent π-π, and hydrophobic interactions.•The activated BG BC was effectively regenerated by NaOH and thermal desorption.
The present study reports alfalfa (one of most abundant hays in U.S)-derived biochar for effective removal of emerging contaminants in water for the first time. The physicochemical properties of ...alfalfa-derived biochar (AF-BC) made at various pyrolysis temperatures were investigated, and correlated with the adsorption of bisphenol A (BPA) and sulfamethoxazole (SMX) in water. The increase in pyrolysis temperatures from 350 °C to 650 °C for the pyrolysis of AF led to a drastic increase in surface area and carbonization with the loss of functional groups. The AF-derived biochar made at 650 °C showed much higher adsorption capacities for BPA and SMX than those made at 350–550 °C, mainly owing to the hydrophobic and π-π interactions supported by its high surface area and degree of carbonization. The adsorption isotherms fitted the Freundlich for BPA and Temkin models for SMX well, respectively. The adsorption capacities of AF 650 for BPA and SMX were higher than those of other biochars but lower than those of commercial activated carbon. The pH-dependent desorption for AF 650 showed high efficiency for SMX, but low efficiency for BPA indicating needs for alternative regeneration methods for BPA.
•Alfalfa-derived biochar (AF-BC) was used for removal of BPA and SMX in water.•Pyrolysis temperature affected property and adsorption of AF-BC for BPA and SMX.•Adsorption of AF-BC at 650 °C for BPA and SMX was higher than other BCs.•Adsorption of BPA and SMX on AF-BC followed Freundlich and Temkin models.•Major mechanisms included hydrophobic and π-π interactions.
•Pinus taeda-derived activated biochar was used for removal of tetracycline.•Possible adsorption mechanisms were explained by kinetic and isotherm studies.•Significant increase in adsorption capacity ...was achieved after NaOH activation.•Intraparticle diffusion would be the major limitation for the adsorption.•Adsorption capacity of activated BC was compared to commercial activated carbons.
The objective of this study was to evaluate the adsorption of tetracycline (TC) on the Pinus taeda-derived activated biochar (BC). After NaOH activation, the well-developed porous surface structure was observed with a significantly increase in surface area (959.9 m2/g). The kinetic and isotherm studies indicated that hydrogen bonding and π-π interaction on the heterogeneous surface would be the possible mechanisms, while intra-particle diffusion was considered as the major limitation for the adsorption of TC on the activated BC. The maximum adsorption capacity of the activated BC (274.8 mg TC/g BC) was higher than those of various activated BCs from the previous studies while it was similar to those of commercial activated carbons. It indicated that the activated BC had the high potential for TC removal in water.
•Effects of manure-derived biochar on anaerobic digestion of manure were investigated.•Biochar addition increased maximum methane production rate and potential.•Biochar shortened the lag phase of ...anaerobic digestion (AD).•Alkaline content in the manure biochar played a significant role in AD of manure.
Effects of dairy manure-derived biochar (M-BC) on methane production in anaerobic digestion (AD) of dry dairy manure were investigated with three different concentrations of biochar (0, 1 and 10 g/L) and temperatures (psychrophilic, 20 °C; mesophilic, 35 °C; thermophilic, 55 °C). Compared with the AD without any biochar, the cumulative methane and yield in the AD with 10 g/L biochar were increased to 27.65% and 26.47% in psychrophilic, 32.21% and 24.90% in mesophilic and 35.71% and 24.69% in thermophilic digestions. The addition of M-BC shortened the lag phases of AD at all temperatures in the study while it lowered the concentration of total VFAs and propionic acid. It was suggested that the high nutrients and alkalinity potential of M-BC (i.e. 9.1% Ca, 3.6% Mg, 1.3% N, 0.14% P) would play significant roles in enhancing methane production and shortening lag phases from the AD of dairy manure.
Display omitted
•PHA production from biowaste is an economic and ecofriendly approach.•Microbes are able to recover resource from waste and produce PHA.•C, N, P and dissolved oxygen are the main ...factors that affect PHA production.•The downstream process has a big impact on whole cost of PHA production.•Functionalization of PHA has potential to improve their applications.
Biowaste management is a challenging job as it is high in nutrient content and its disposal in open may cause a serious environmental and health risk. Traditional technologies such as landfill, bio-composting, and incineration are used for biowaste management. To gain revenue from biowaste researchers around the world focusing on the integration of biowaste management with other commercial products such as volatile fatty acids (VFA), biohydrogen, and bioplastic (polyhydroxyalkanoates (PHA)), etc. PHA production from various biowastes such as lignocellulosic biomass, municipal waste, waste cooking oils, biodiesel industry waste, and syngas has been reported successfully. Various nutrient factors i.e., carbon and nitrogen source concentration and availability of dissolved oxygen are crucial factors for PHA production. This review is an attempt to summarize the recent advancements in PHA production from various biowaste, its downstream processing, and other challenges that need to overcome making bioplastic an alternate for synthetic plastic.
We evaluated the production of Spirulina sp. (microalgae)-derived biochars (SPAL-BCs) at different pyrolysis temperatures for the removal of an emerging water contaminant, tetracycline (TC). ...Physicochemical properties of SPAL-BCs were characterized and related with their capacity to adsorb TC. Increasing pyrolysis temperatures led to higher aromaticity, higher hydrophobicity, and higher specific surface area. In particular, SPAL-BC750 possessed the highest hydrophobicity, various strong crystallizations (i.e., calcite, hydroxyapatite, and rhenanite) and functional groups (i.e., CH2, CN, CO, and CO32−), which may be associated with high TC adsorption. SPAL-BC750 also presented the highest TC adsorption capacity (132.8 mg TC/g biochar) via batch experimentation because of hydrophobic, π-π interactions, functional groups, and metal complexation. The best fitting isotherm and kinetic models of TC adsorption by SPAL-BC750 were the Langmuir and pseudo-first order models, respectively. SPAL-BCs obtained as a by-product of pyrolysis may be an economical and potentially valuable adsorbent for aqueous antibiotic removal.
Display omitted
•Microalgae (Spirulina sp.) were successfully applied for biochar production.•High pyrolysis temperatures led to low O/C and H/C and high SSA and pHpzc values.•SPAL-BC750 had the highest hydrophobicity, crystallizations, and functional groups.•SPAL-BC750 had the highest TC adsorption capacity (132.8 mg TC/g biochar).•SPAL-BCs are economical and potentially valuable adsorbents.
Display omitted
•Cork biochar produced at temperature 600 °C has porous structure.•Conc. H2SO4 activated biochar able to transesterify WCO into biodiesel.•A:O ratio (25:1) at catalyst loading 1.5% ...w/v results in 98% FAME conversion.•Produced biodiesel has CN (50.56), HHV (39.5), ʋ (3.9) and (ρ) 0.87.
In this study, a heterogeneous catalyst prepared by pyrolysis of waste cork (Quercus suber) was used for the transesterification of waste cooking oil (WCO). Physicochemical properties of the synthesized biochar catalyst were studied using BET, SEM, FTIR, and XRD. The experiment results demonstrate that heterogeneous catalyst synthesized at 600 °C showed maximum fatty acids methyl esters (FAMEs) conversion (98%) at alcohol:oil (25:1), catalyst loading (1.5% w/v) and temperature 65 °C. Biodiesel produced from WCO (Canola oil) mainly composed of FAMEs in following order C18:1 > C18:2 > C16:0 > C18:0 > C20:0. Properties of produced biodiesel were analysed as cetane number (CN) 50.56, higher heating value (HHV) 39.5, kinematic viscosity (ʋ) 3.9, and density (ρ) 0.87.
Display omitted
•Maple leaf-derived biochars were prepared at the different pyrolytic temperature.•Biochar produced at 750 °C showed BET surface area of 191.1 m2/g.•Selected biochar presented maximum ...adsorption capacity of 361 mg/g.•Adsorption of tetracycline followed pseudo-second-order and Freundlich models.
The present study evaluates the physicochemical properties of maple leaf-derived biochars (M-BCs) produced at different pyrolytic temperatures (i.e., 350, 550, and 750 °C) and their adsorptive properties for tetracycline onto M-BCs. The increase in pyrolysis temperature to produce M-BCs led to a significant increase in the biochar’s hydrophobicity, surface area, and calcite (CaCO3) crystallization. The M-BC750 produced without functionalization or activation possessed a high calcite composition and a hydrophobic nature with lower O/C and H/C, hydroxyl groups (–OH) on the surface, and functional groups (i.e., O-containing) as H-bond acceptors. Among M-BCs, the M-BC750 present a highest TC adsorption capacity owing to possible mechanisms such as metal complexation, H-bonding, and hydrophobic interactions. The isotherm and kinetic models for TC adsorption followed the Freundlich models and pseudo-second-order models, respectively. M-BCs produced from the waste fallen maple leaves could be applied as low-cost environmental adsorbents for TC removal.
Abstract In neurodegenerative diseases like AD, tau forms neurofibrillary tangles, composed of tau protein. In the AD brain, activated caspases cleave tau at the 421th Asp, generating a ...caspase-cleaved form of tau, TauC3. Although TauC3 is known to assemble rapidly into filaments in vitro , a role of TauC3 in vivo remains unclear. Here, we generated a transgenic mouse expressing human TauC3 using a neuron-specific promoter. In this mouse, we found that human TauC3 was expressed in the hippocampus and cortex. Interestingly, TauC3 mice showed drastic learning and spatial memory deficits and reduced synaptic density at a young age (2–3 months). Notably, tau oligomers as well as tau aggregates were found in TauC3 mice showing memory deficits. Further, i.p. or i.c.v . injection with methylene blue or Congo red, inhibitors of tau aggregation in vitro , and i.p. injection with rapamycin significantly reduced the amounts of tau oligomers in the hippocampus, rescued spine density, and attenuated memory impairment in TauC3 mice. Together, these results suggest that TauC3 facilitates early memory impairment in transgenic mice accompanied with tau oligomer formation, providing insight into the role of TauC3 in the AD pathogenesis associated with tau oligomers and a useful AD model to test drug candidates.
The present study aimed towards adsorptive removal of the toxic azo dye onto biochar derived from Eucheuma spinosum biomass. Characterization of the produced biochar was performed using X-ray ...diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET). Eucheuma spinosum biochar (ES-BC) produced at 600 °C revealed a maximum adsorption capacity of 331.97 mg/g towards reactive red 120 dye. The adsorption data fitted best to the pseudo-second order kinetics (R2 > 0.99) and Langmuir isotherm (R2 > 0.98) models. These adsorption models signified the chemisorption mechanism with monolayer coverage of the adsorbent surface with dye molecules. Furthermore, the adsorption process was mainly governed by electrostatic interaction, ion exchange, metal complexation, and hydrogen bonding as supported by the solution pH, FTIR, XPS, and XRD investigation. Nevertheless, alone adsorption technology could not offer a complete solution for eliminating the noxious dyes. Therefore, the bioelectrochemical system (BES) equipped with previously isolated marine Shewanella marisflavi BBL25 was intended for the complete remediation of azo dye. The BES II demonstrated highest dye decolorization (97.06%) within 48 h at biocathode where the reductive cleavage of the azo bond occurred. Cyclic voltammetry (CV) studies of the BES revealed perfect redox reactions taking place where the redox mediators shuttled the electrons to the dye molecule to accelerate the dye decolorization. Besides, the GC-MS analysis revealed biotransformation of the dye into less toxic metabolites as tested using a phyto and cytogenotoxicity.
Display omitted
•Macroalgae derived biochar showed excellent performance for azo dye adsorption.•Pseudo-second order and Langmuir isotherm were the best suited adsorption model.•Shewanella marisflavi BBL25 attained >97% dye decolorization at biocathode.•Cyclic voltammetry revealed direct and mediator driven electron transfer mechanism.•This study provides a suitable and sustainable approach for remediation of azo dyes.
PDF
