Perfluoroalkyl substances (PFAS) are pollutants with relevant accumulation in humans, and the enterohepatic circulation of PFAS secreted in bile sustains their persistence. A significant increase in fecal excretion has been experimentally assessed with the use of oral adsorbents with negligible gut absorption. Here, we evaluated in vitro the use of activated charcoal (AC) for human consumption, as sorption material for a panel of PFAS, such as, perfluoro-butanoic acid (PFBA), perfluoro-butanesulfonic acid (PFBS), perfluoro-hexanoic acid (PFHxA), perfluoro-hexanesulfonic acid (PFHxS), perfluoro-octanoic acid (PFOA), and perfluoro-octanesulfonic acid (PFOS), in an experimental simulated bile juice (SBJ). The aim was to obtain preliminary data for possible clinical applications to reduce PFAS blood levels in humans. PFAS concentrations in experimental samples were quantified by liquid chromatography-mass spectrometry. In kinetic tests, equimolar solutions of single PFAS in SBJ were incubated with AC at 37 °C up to 120 min, and the time-dependent reduction of PFAS concentration was monitored. In thermodynamic tests, PFAS solutions in SBJ were incubated at increasing concentrations with AC for 24 h at 37 °C and the concentrations at equilibrium evaluated. Results were finally fitted with available models in order to characterize the PFAS interaction with AC. All PFAS showed more than 80% sorption on activated charcoal from simulated bile juice within 120 min. This suggests rapid and nearly complete removal. Modeling analysis indicated that the pseudo-first-order kinetic model best described short-chain PFAS, while PFOS and PFOA fitted better with the Elovich model. Thermodynamic analysis showed a general fitting with the Freundlich model, presumptive of a heterogeneous binding model. PFOS binding was concentration-dependent and was better described by the Sips model. These data are suggestive of a potential noninvasive intervention strategy to increase fecal PFAS excretion through the dietary use of AC, in order to mitigate health issues associated with PFAS exposure.

In this study, we prepare N-doped biochar loaded with β-CD, using cotton stalks as a carbon source, and evaluate its removal efficiency for tetracycline (TC) and methylene blue (MB) from aqueous solutions. This composite uniquely integrates molten salt activation, nitrogen doping, and β-CD grafting, resulting in an exceptionally high specific surface area of 1943 m2/g and abundant active sites. The findings reveal that β-CD-NKBC-1.5 (5 g of N-doped biochar loaded with 1.5 g of β-CD) demonstrates remarkable capabilities for both TC and MB removal across an extensive pH spectrum, reaching peak adsorption levels of 1269.8 and 969.4 mg/g at 308.15 K, respectively-outperforming most previously reported biochar-based adsorbents. The adsorption process is well described by the pseudo-second-order and Langmuir models, indicating that monolayer chemisorption is the dominant mechanism. β-CD-NKBC-1.5 exhibits preferential adsorption for TC and MB and maintains high adsorption efficiency even with coexisting ions (Na+, K+, Ca2+, Mg2+, and SO42-) at concentrations up to 500 mg/L. The adsorption mechanism involves Lewis acid-base interactions, hydrogen bonding, π-π stacking, and pore filling.

Biochar is a carbon-based biosolid produced by pyrolysis of waste and biomasses. Given its physical-chemical properties, it is largely employed to ameliorate soil quality and retain contaminants from polluted waters. To date, only a few studies have explored the effects of biochar on living organisms and the potential risks also for human health, as a consequence of biochar environmental diffusion. Here, we investigated the biological effects of three biochar obtained from different raw biomasses (pruning chippings, almond shells, and stabilized organic fraction) on human keratinocyte and lung cell lines. We found that 24 h of treatment with biochar, even at low doses (1-10 μg/mL) caused a reduced cell viability, a cytoskeleton reorganization, and an increased apoptosis. Moreover, biochar seemed to perturb homeostatic physiologic responses, such as autophagy and antioxidant activity. Different properties of the three biochar, mainly particle dimension, composition, and roughness, could be responsible of differences in intensity of biological responses we registered. We also noticed that each cell line displayed an own intrinsic sensibility to each type of biochar. On the whole, our findings highlight that the large employment and the consequent diffusion of biochar in the environment might have detrimental consequences for living organisms, including humans.

Biochar application in Cd-contaminated paddy soils relies heavily on its inherent capacity for direct Cd adsorption. However, the long-term stability is critically challenged by Cd re-mobilization during biochar aging. Thus, we conducted a six-season pot experiment to investigate the temporal Cd release patterns under rice cultivation conditions from four types of Cd-loaded biochar: sewage sludge biochar (Cd-SSBC), palm fiber biochar (Cd-PFBC), pig manure biochar (Cd-PMBC), and rice straw biochar (Cd-RSBC). Our findings revealed three key phases of Cd release dynamics: (1) initial rapid Cd release (first growing season) exhibited strong material specificity, following the order: Cd-SSBC (61.59 %) > Cd-PFBC (48.10 %) > Cd-PMBC (27.82 %) > Cd-RSBC (28.90 %), (2) mid-term (second to the fourth growing season) slow release phase where pH decline (ΔpH = -0.55 to 0.81) showed significant positive correlation with Cd release (r = 0.75, p < 0.001), and (3) long-term equilibration phase after six seasons rice with cumulative Cd release reaching 85.56 %-93.92 %. Results also demonstrated distinct stability profiles among Cd-binding forms at initial aging phase: hydrogen bonding (Qhyd-Cd) and complexed (Qcom-Cd) species exhibited greater persistence compared to physically adsorbed (Qphy-Cd) and exchangeable (Qexc-Cd) fractions at initial aging phases. Notably, inter-biochar variability in total Cd release rates decreased from 33.8 % (S1) to 8.4 % (S6), while Cd form consistency increased across all biochar types. This study provides critical evidence for biochar aging-induced pH decline as the primary driver of Cd re-mobilization, and material-specific Cd release patterns. It also suggests that RSBC/PMBC may exhibit superior stability for extended applications in Cd-contaminated agroecosystems.

A large amount of red mud (RM) storage has been proven to have potential environmental risks, highlighting there is an urgent need to identify effective treatment technologies for this industrial waste. In this study, the ball milling peanut vine and RM biochar (BMPRBC) derived from waste RM and peanut vine was synthesized via a facile two-step approach (co-pyrolysis and ball milling treatment). BMPRBC exhibited remarkable adsorption performance for tetracycline antibiotics (TC) following the ball milling process, with maximum removal capacities for TC reaching 230.59 mg/g. The effects of the RM/peanut vine mixing ratio, ball milling duration, pH, initial TC concentration, anions, and humic acid on the adsorption capacity of BMPRBC were comprehensively investigated. The adsorption kinetics of BMPRBC for TC removal was well fitted by both the pseudo-second-order model and the intra-particle diffusion model, revealing that chemical adsorption determined the adsorption process. The Langmuir model provided a better fit than the Freundlich model for the adsorption isotherm, indicating monolayer adsorption of TC onto BMPRBC. The dominated adsorption mechanisms included pore filling, π-π stacking interactions, hydrogen bonding and complexation. Regeneration experiments showed that BMPRBC maintained a certain adsorption capacity for TC after four cycles. Overall, this work presents an effective and promising strategy that not only alleviates TC contamination in water but also promotes the resource utilization of RM and peanut vine.

Phosphorus is one of the main contributors to the eutrophication of water bodies; therefore, phosphorus recycling from agricultural wastewater represents a synergistic approach to achieve both phosphorus management and effective resource use. However, the specific removal pathway remains to be optimized. This study investigated the adsorption effect of lanthanum-modified biochar (La-BC) made from agricultural waste on dissolved phosphorus (DP). The maximum unit adsorption capacity of La-BC reached 41.09 mg P/g, representing a 215.35 % increase compared to the original biochar (BC) (C0: 500 mg/L; pH: 7). Further, the removal effect of La-BC on agricultural non-point source pollutants with different particulate phosphorus (PP) percentages was investigated through dynamic interception and adsorption simulation experiments. The results showed that PP was mostly intercepted by quartz sand while DP was mainly adsorbed by La-BC. Thus, La-BC could effectively remove DP and PP from agricultural wastewater and delay the adsorption depletion point of the dynamic adsorption device, subsequently prolonging its service life. Finally, the agricultural availability of La-BC after adsorption and filtration (La-BC-P) was further explored by soil and plant cultivation. The results indicated that La-BC-P with adsorption interception of fertilizer distribution water had higher plant availability. A higher DP percentage increased the beneficial effects on soil nutrients (available phosphorus increased by 12-16-fold) and plant growth (plant fresh weight increased by 33 %). This study innovatively verified the technical feasibility of the "agricultural waste-agricultural non-point source pollution treatment-carbon-based fertilizer" recycling model based on the characteristics of agricultural source wastewater.

Biochar (BC), an accessible and economic soil improvement, has influenced the biogeochemical cycling of iron and organic carbon (OC) in paddy soil. However, little is known about the effect of BC on iron-organic carbon (Fe-OC) associations, as well as how they regulate the associated microbial community in paddy soil. This study employed anoxic soil microcosms with distinct treatments including BC alone, ferrihydrite (Fh) alone, and BC combined with Fh. Results demonstrated that Fh alone significantly reduced CH₄ emission by suppressing key methanogens and stabilizing humic-like dissolved organic matter. BC alone slightly inhibited CH₄ while promoted CO₂ emission, consistent with its function as an electron shuttle promoting dissimilatory iron reduction and labile OC mineralization. Interestingly, the combined application of BC and Fh significantly suppressed the CH₄ emission. It might be due to that BC accelerated microbial iron reduction to divert electrons from methanogenesis and Fh preferentially sequestered humic-like organic components into mineral-associated complexes, which reduced substrate availability for methanogens (e.g., Methanosarcina) while enriched iron-reducing bacteria like Thermoleophilia and Desulfuromonadia. This study revealed that the BC and Fh together had significant effects on the OC stabilization, CH4 emission and microbial community, which provides fundamental information for future synergistic application of BC and Fh in rice paddy ecosystems.

The coastal palaeoenvironmental conditions of Utica ancient gulf area during the Holocene were reconstructed after a multidisciplinary study to identify natural variations and the influence of anthropic processes in the environmental evolution of this coastal area. For this purpose, a ca. 15 m-deep sedimentary core formerly drilled in the surroundings were studied. Amino acid racemization in ostracode valves and previously published radiocarbon ([14]C) datings of plant debris and charcoal were used for constructing the chronological scale using a bayesian age-model. Based on the sedimentological characteristics, lipid biomarkers and trace elements quantification both natural and anthropogenic variations were identified. The results reveal a chronological period ranging between the present and 8200 cal yr BP, in which marine and continental inputs occurred marking variations in the palaeoenvironmental conditions, being able to differentiate 2 units each one with 3 subunits (A1-A3; B1-B3). The human influence since the Chalcolithic, being noticeable during Phoenician and Roman times was also observed in the geological record. Lead, copper, zinc and silver concentrations along the sedimentary record revealed that the influence of anthropogenic factors predominated over lithogenic processes in the last three millennia, particularly linked to mining activities in the area especially in Phoenician times, with an important decrease after the conquest by Romans. In addition, the presence of faecal stanols, such as coprostanol, revealed the presence of human populations in the area since ca. 4200 cal yr BP, before the city of Utica was founded.

Per- and polyfluoroalkyl substances (PFAS) are synthetic chemicals widely used in consumer products, firefighting foams, and various industrial applications. These chemicals are pervasive, persistent, and degradation-resistant, posing a critical threat to human and environmental health. Currently, adsorption remains the most widely used technology for the remediation of PFAS. However, large-scale PFAS removal would require extensive usage of adsorbents such as activated carbon, which tends to be relatively expensive. Therefore, we investigated the upcycling of water hyacinth, an invasive aquatic plant, as a sustainable source for biochar production to remove perfluorooctanoic acid (PFOA), a type of PFAS. Different kinetic and isotherm models assessed PFOA adsorption to water hyacinth biochar. Pseudo-second-order kinetics and Langmuir isotherm models proved to be better fits in most experiments. Intra-particle diffusion and surface adsorption were determined to contribute to the rate-limiting step, and a monolayer distribution of PFOA through chemisorption was found to be the primary mechanism of adsorption. Water hyacinth biochar exhibited an adsorption capacity of 154.39 μg/g for PFOA removal at a solid-to-liquid ratio of 1 (in mg/mL). Experiments at different pH levels revealed that electrostatic interactions influenced PFOA adsorption, and, in acidic conditions, the removal capacity increased to 164.91 μg/g.

Mercury (Hg) contamination in agricultural soils threatens crop productivity and ecosystem sustainability. This study investigates the synergistic effects of Pieris japonica-derived biochar and the Hg-resistant bacterium Bacillus cereus B2 in mitigating Hg toxicity in sorghum (Sorghum bicolor L.) grown in Hg-contaminated soils (0, 15, 20, and 25 mg Hg kg[-][1]). Hg stress significantly inhibited plant growth, gas exchange, and photosynthetic pigments, with the greatest reductions at 25 mg kg[-][1] Hg. The combined application of biochar (4%) and B. cereus B2 notably enhanced plant height (34.7%), stomatal conductance (50.1%), photosynthetic rate (24.5%), transpiration rate (60.2%), water-use efficiency (24.5%), chlorophyll a (75.8%), chlorophyll b (29.3%), carotenoids (27.0%), and total chlorophyll (59.5%) compared to individual treatments. This synergistic approach also stimulated antioxidant defenses, increasing activities of ascorbate peroxidase (20.1%), catalase (25.2%), superoxide dismutase (34.9%), and peroxidase (49.7%), while reducing reactive oxygen species (H2O2 and O2[-]) and lipid peroxidation (MDA). Furthermore, Hg accumulation in sorghum roots and shoots was significantly reduced under the combined treatment, indicating lower Hg bioavailability. These findings demonstrate the novel synergistic potential of P. japonica biochar and B. cereus B2 in enhancing Hg immobilization, improving plant physiological resilience, and strengthening antioxidant defenses in sorghum, providing an effective and sustainable strategy for Hg-contaminated soil remediation.

Different classes of chemical compounds including persistent, mobile chemicals (PMCs) often bypass the conventional treatment processes of common effluent treatment plants (CETPs), resulting in their unmonitored release into aquatic environments. In this study, an integrated treatment system comprising a microaerophilic fixed-film bioreactor (MFB) and an aerobic membrane bioreactor (Ae-MBR) was engineered to treat secondary CETP effluent. Two types of packing materials in the engineered MFBs were evaluated: one with wood charcoal (C-MFB) and another with 30% (w/w) biochar-augmented charcoal (BAC-MFB). The BAC-MFB showed better treatment efficiency, achieving 69.17% colour (Pt-Co units) removal and 93.01% COD removal at an optimal 3d hydraulic retention time (HRT). Integration with Ae-MBR further enhanced the treatment, achieving > 95% COD and > 94% colour removal, with an overall > 85% reduction in total number of parent chemical compounds and a specific > 83% reduction in PMCs from CETP effluent. At 3d HRT, bacterial community analysis revealed dominance of Campylobacterota and Bacillota in BAC-MFB under microaerophilic conditions, whereas Bacillota dominated in the Ae-MBR under aerobic conditions. The predicted metagenome analysis revealed significant enrichment of benzoate and aminobenzoate degradation pathways in the integrated system. While the BAC-MFB treatment alone achieved sufficient COD removal, its integration with Ae-MBR markedly enhanced the reduction in overall chemical complexity including PMCs from the CETP effluent. This study demonstrates that the engineered hybrid BAC-MFB-Ae-MBR system is a sustainable solution for the treatment of industrial CETP effluents.

Wood, a sustainable and ubiquitous natural structural material, has been widely used in various fields. A bottleneck perplexing its applications is the inevitable flammability. Traditional anti-flammability methods, such as surface coating and internal decoration, still suffer from the possibility of wood combustion upon exposure to extreme flames, owing to the complexity imposed by the challenge to integrate the spatially localized flame retardants into the entire solid wood. Here, we develop a super retarding-flame wood, denoted as Surf-wood, that enables effective distribution of flame retardant metal salts in the hierarchical structures of wood cell walls through a facile molecular-scale cell wall engineering strategy. The Surf-wood exhibits a remarkable high limiting oxygen index of ∼100%, as well as 80% and 96% reduction in the peak of heat release rate and total smoke production compared with natural wood, suppresses combustion even when placed in harsh charcoal fire, and withstands 12 min-continuous burning at 1300 °C without structural collapse. This new material is scalable in production while maintaining the esthetics and other desirable properties of natural wood, which would open a new avenue for numerous functional applications.

This study aimed to investigate the equilibrium and kinetics of adsorption of diclofenac on non-activated and activated charcoal made from dragon fruit peel at a carbonization temperature of 500 °C. The experiments were carried out in agitated flasks containing the adsorbents and diclofenac solutions at initial adsorbate concentrations from ∼20 to 307 mg L[-1] at ∼25 °C and pH 5.7. The highest adsorption capacity of the adsorbent was 64.54 mg g[-1] by charcoal activation with inorganic acids. Using activated charcoal as adsorbent, the highest equilibrium yield of removal of diclofenac from the liquid was close to 91% in approximately 1 hr. At the examined pH, the deprotonation of activated charcoal and the almost complete dissociation of diclofenac indicate physical adsorption of the conjugate anion of diclofenac. These explanations are consistent with results of point of zero charge of activated charcoal, pKa of diclofenac, Brunauer-Emmett-Teller analysis, energy dispersive X-ray and Fourier transform infrared spectroscopy of the adsorbents. The equilibrium and kinetic results were described by the Langmuir and Freundlich isotherms and simplified kinetic models involving empirical pseudo first- and second-order adsorption rate expressions.

Zinc (Zn) deficiency in calcareous soils is a global issue that affects agricultural yields and threatens nutrient availability worldwide. The present study examined optimization of elements influencing synthesis of a slow-release fertilizer (SRF) of Zn and compared it with commercial ZnSO4 fertilizer. In this study, response surface methodology (RSM) optimization technique was used to reduce costs and time. Organic (pectin, biochar), inorganic (layer double hydroxide (LDH), layer double hydroxide (LDO)), and microbial (bacterial inoculation) treatments were utilized, leading to production of 12 slow-release fertilizers. Ultimately, optimization and modeling were carried out. Based on RSM findings, three fertilizers exhibiting highest Zn levels and greatest desirability (SRF-LDH, SRF-LDO-bacterial, SRF-biochar-LDO-bacterial) were recognized as most efficient fertilizers. LDH increased Zn concentration by 75% and 50% compared to LDO and biochar, respectively. Based on the results, biochar increased Zn concentration by 40% compared to pectin. Additionally, combining biochar with LDH increased Zn concentration by 60% compared to biochar alone. The highest Zn concentration of SRFs (93.48 mg g -1) was related to run 3 (organic material: 0, inorganic material: LDH, inoculation bacteria with fertilizer: 1 W/V), which is 3.9-fold higher than the lowest run (24.54 mg g -1) (run 9: organic material: pectin, inorganic material: 0, inoculation bacteria with fertilizer: 0). In comparing all runs, where biochar is used instead of pectin in SRFs, the Zn concentration increased. The highest swelling ratio was related to SRF1 (4.4 g g -[1]). The swelling ratio of SRF3 (LDO-biochar-bacterial) was 3.81 g g -[1], which was higher than that of ZnSO4 (2.41 g g -[1]). The slow-release behavior of Zn from SRFs demonstrated three phases, comprising an initial phase of steady Zn release and a concluding phase of diminishing Zn release rates. First-order and Higuchi models were appropriate for characterizing slow-release nutrient processes of SRFs, suggesting external environment can affect gradual release of Zn from SRFs. Based on the RSM optimization results, three formulations-SRF-LDH, SRF-LDO-bacterial, and SRF-biochar-LDO-bacterial-were identified as the most efficient among the twelve synthesized SRFs, exhibiting the highest Zn loading and desirability values.