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Cost-effective CO2 adsorbents are gaining increasing attention as viable solutions for mitigating climate change. In this study, composites were synthesized by electrochemically combining the post-gasification residue of Macadamia nut shell with copper benzene-1,3,5-tricarboxylate (CuBTC). Among the different composites synthesized, the ratio of 1:1 between biochar and CuBTC (B 1:1) demonstrated the highest CO2 adsorption capacity. Under controlled laboratory conditions (0°C, 1 bar, without the influence of ambient moisture or CO2 diffusion limitations), B 1:1 achieved a CO2 adsorption capacity of 9.8 mmol/g, while under industrial-like conditions (25°C, 1 bar, taking into account the impact of ambient moisture and CO2 diffusion limitations within a bed of adsorbent), it reached 6.2 mmol/g. These values surpassed those reported for various advanced CO2 adsorbents investigated in previous studies. The superior performance of the B 1:1 composite can be attributed to the optimization of the number of active sites, porosity, and the preservation of the full physical and chemical surface properties of both parent materials. Furthermore, the composite exhibited a notable CO2/N2 selectivity and improved stability under moisture conditions. These favorable characteristics make B 1:1 a promising candidate for industrial applications.
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Dióxido de Carbono , Estructuras Metalorgánicas , Dióxido de Carbono/química , Adsorción , Estructuras Metalorgánicas/química , Contaminantes Atmosféricos/química , Carbón Orgánico/químicaRESUMEN
Erythromycin fermentation residue (EFR) represents a typical hazardous waste produced by the microbial pharmaceutical industry. Although electrolysis is promising for EFR disposal, its microbial threats remain unclear. Herein, metagenomics was coupled with the random forest technique to decipher the antibiotic resistance patterns of electrochemically treated EFR. Results showed that 95.75% of erythromycin could be removed in 2 hr. Electrolysis temporarily influenced EFR microbiota, where the relative abundances of Proteobacteria and Actinobacteria increased, while those of Fusobacteria, Firmicutes, and Bacteroidetes decreased. A total of 505 antibiotic resistance gene (ARG) subtypes encoding resistance to 21 antibiotic types and 150 mobile genetic elements (MGEs), mainly including plasmid (72) and transposase (52) were assembled in EFR. Significant linear regression models were identified among microbial richness, ARG subtypes, and MGE numbers (r2=0.50-0.81, p< 0.001). Physicochemical factors of EFR (Total nitrogen, total organic carbon, protein, and humus) regulated ARG and MGE assembly (%IncMSE value = 5.14-14.85). The core ARG, MGE, and microbe sets (93.08%-99.85%) successfully explained 89.71%-92.92% of total ARG and MGE abundances. Specifically, gene aph(3')-I, transposase tnpA, and Mycolicibacterium were the primary drivers of the resistance dissemination system. This study also proposes efficient resistance mitigation measures, and provides recommendations for future management of antibiotic fermentation residue.
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Eritromicina , Fermentación , Metagenómica , Antibacterianos/farmacología , Farmacorresistencia Microbiana/genética , Farmacorresistencia Bacteriana/genéticaRESUMEN
In this paper, a novel ratiometric fluorescent probe based on silicon quantum dots (SiQDs) has been developed for the sensitive detection of methyl parathion pesticide residues. The silicon quantum dots were prepared by a simple hydrothermal reaction process using 3-Aminopropyltriethoxysilane (APTES) as silicon resource and were characterized by the analysis of transmission electron microscopy, FTIR spectroscopy, and X-ray photoelectron spectroscopy. The silicon quantum dots displayed characteristic blue fluorescence emission at 440 nm. Tyrosinase can catalyze the oxidation of tyramine to form dopamine. Then, dopamine can interact with silicon quantum dots and effectively change the position of its fluorescence emission for redshifting to 540 nm. In the presence of organic phosphorus pesticides (OPPs), the activity of tyrosinase was inhibited, resulting in the inability to generate dopamine and the fluorescence emission at 440 nm remaining unchanged. As a model of organic phosphorus pesticides, methyl parathion (MP) was determined using this method, and the fluorescence intensity response values showed a good linear relationship with methyl parathion concentration in the range of 50-90 nM, with a detection limit of 0.149 nM. Due to its good performance of relative low detection limit, good selectivity and high reproducibility, this sensing system has been successfully applied to the detection of methyl parathion in environmental water samples and potato samples, which showed good prospects for application in the detection of organic phosphorus pesticide residues in more real samples.
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Organic farming utilizes farmyard manure, compost, and organic wastes as sources of nutrients and organic matter. Soil under organic farming exhibits increased microbial diversity, and thus, becomes naturally suppressive to the development of soil-borne pathogens due to the latter's competition with resident microbial communities. Such soils that exhibit resistance to soil-borne phytopathogens are called disease-suppressive soils. Based on the phytopathogen suppression range, soil disease suppressiveness is categorised as specific- or general- disease suppression. Disease suppressiveness can either occur naturally or can be induced by manipulating soil properties, including the microbiome responsible for conferring protection against soil-borne pathogens. While the induction of general disease suppression in agricultural soils is important for limiting pathogenic attacks on crops, the factors responsible for the phenomenon are yet to be identified. Limited efforts have been made to understand the systemic mechanisms involved in developing disease suppression in organically farmed soils. Identifying the critical factors could be useful for inducing disease suppressiveness in conducive soils as a cost-effective alternative to the application of pesticides and fungicides. Therefore, this review examines the soil properties, including microbiota, and assesses indicators related to disease suppression, for the process to be employed as a tactical option to reduce pesticide use in agriculture.
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Some strains of lactic acid bacteria can regulate the host's intestinal immune system. Bacterial cells and membrane vesicles (MVs) of Limosilactobacillus antri JCM 15950T promote immunoglobulin A (IgA) production in murine Peyer's patch cells via toll-like receptor (TLR) 2. This study aimed to investigate the role of lipoteichoic acid (LTA), a ligand of TLR2, in the immunostimulatory activity of these bacterial cells and their MVs. LTA extracted from bacterial cells was purified through hydrophobic interaction chromatography and then divided into fractions LTA1 and LTA2 through anion-exchange chromatography. LTA1 induced greater interleukin (IL)-6 production from macrophage-like RAW264 cells than LTA2, and the induced IL-6 production was suppressed by TLR2 neutralization using an anti-TLR2 antibody. The LTAs in both fractions contained two hexose residues in the glycolipid anchor; however, LTA1 was particularly rich in triacyl LTA. The free hydroxy groups in the glycerol phosphate (GroP) repeating units were substituted by d-alanine (d-Ala) and α-glucose in LTA1, but only by α-glucose in LTA2. The dealanylation of LTA1 slightly suppressed IL-6 production in RAW264 cells, whereas deacylation almost completely suppressed IL-6 production. Furthermore, IL-6 production induced by dealanylated LTA1 was markedly higher than that induced by dealanylated LTA2. These results indicated that the critical moieties for the immunostimulatory activity of L. antri-derived LTA were the three fatty acid residues rather than the substitution with d-Ala in GroP. LTA was also detected in MVs, suggesting that the triacyl LTA, but not the diacyl LTA, translocated to the MVs and conferred immunostimulatory activity. IMPORTANCE: Some lactic acid bacteria activate the host intestinal immune system via toll-like receptor (TLR) 2. Lipoteichoic acid (LTA) is a TLR2 ligand; however, the moieties of LTA that determine its immunostimulatory activity remain unclear because of the wide diversity of LTA partial structures. We found that Limosilactobacillus antri JCM 15950T has three types of LTAs (triacyl, diacyl, and monoacyl LTAs). Specifically, structural analysis of the LTAs revealed that triacyl LTA plays a crucial role in immunostimulation and that the fatty acid residues are essential for the activity. The three acyl residues are characteristic of LTAs from many lactic acid bacteria, and our findings can explain the immunostimulatory mechanisms widely exhibited by lactic acid bacteria. Furthermore, the immunostimulatory activity of membrane vesicles released by L. antri JCM 15950T is due to the transferred LTA, demonstrating a novel mechanism of membrane vesicle-mediated immunostimulation.
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The burgeoning accumulation of spent lithium-ion batteries (LIBs), a byproduct from the widespread adoption of portable electronics and electric vehicles, necessitates efficient recycling strategies. Direct recycling represents a promising strategy to maximize the value of LIB waste and minimize harmful environmental outcomes. However, current efforts to large-scale direct recycling face challenges stemming from heterophase residues (e.g., Li2CO3, LiOH) in the recycled products and uncontrolled interfacial instability, often requiring repeated washing that generates significant wastewater. Here, a refined direct recycling process is proposed to improve cathode interface stability by leveraging in situ reaction between surface residual lithium species and a weak inorganic acid to form a conformal Li+ conductive coating that stabilizes the regenerated Ni-rich cathodes with significantly reduced water footprint. The findings reveal that the conductive coating also prevents direct contact between contaminants and the cathode surface, thus improving the ambient storage stability. By eliminating the need for extensive washing, this intensified recycling process offers a more sustainable approach with the potential to transition from laboratory to industrial-scale applications, improving both product quality and environmental sustainability.
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The widespread application of pesticides in China has led to the accumulation of residues in soil. However, few regional studies have fully elucidated the characteristics of pesticide residues in soil (PRS) and the associated risks to the ecosystem and human health on a national level. Therefore, this study aims to compile a dataset on PRS in China from 2006 to 2020 and analyze the interactions and impacts between PRS and the environment. The average concentration of PRS in China was 243.96 µg/kg which was lower than the levels reported in Euro-Americans and other nations. This study revealed PRS in China predominantly originates from organochlorine pesticide residues, with DDTs and HCHs being significant contributors. Despite the high intensity of pesticide application in the Southeast China, PRS concentrations were comparable to those in the Northeast, due to environmental factors that favor pesticide degradation in the Southeast. Both legacy and in-use pesticides were transported by surface runoff or air current, resulting in their accumulation in soil of the lower Yangtze River basin or the piedmont soil of Qinling Mountains, respectively. The average soil environment carrying capacity of PRS in China was -69.5 kg. The ecological risk contributed by PRS in China was mainly at a negligible level. Carcinogenic risks of PRS to adults (4.6 ×10-4) and children (6 ×10-4) exceeded the tolerable thresholds (10-5) by a small margin.
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Composting is widely applied in recycling ever-increasing sewage sludge. However, the insufficient elimination of antibiotics and antibiotic resistance genes (ARGs) in conventional compost fertilizer poses considerable threat to agriculture safety and human health. Here we investigated the efficacy and potential mechanisms in the removal of antibiotics and ARGs from sludge in hyperthermophilic composting (HTC) plant. Our results demonstrated that the HTC product was of high maturity. HTC led to complete elimination of antibiotics and potential pathogens, as well as removal of 98.8 % of ARGs and 88.1 % of mobile genetic elements (MGEs). The enrichment of antibiotic-degrading candidates and related metabolic functions during HTC suggested that biodegradation played a crucial role in antibiotic removal. Redundancy analysis (RDA) and structural equation modelling (SEM) revealed that the reduction of ARGs was attributed to the decline of ARG-associated bacteria, mainly due to the high-temperature selection. These findings highlight the feasibility of HTC in sludge recycling and provide a deeper understanding of its mechanism in simultaneous removal of antibiotics and ARGs.
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Pesticide residues pose a significant threat to food safety and human health, necessitating the development of novel detection tools. Pesticides can inhibit the activity of certain biological enzymes, so enzyme inhibition is one of the methods of pesticide detection. In this study, we developed a novel near-infrared fluorescent probe named TCFCl-CES based on the tricyanofuran structure, for ultrasensitive detection of carboxylesterase (CES). TCFCl-CES exhibits strong and stable fluorescence, excellent specificity. Notably, the fluorescence intensity of TCFCl-CES shows a linear relationship with CES concentration, achieving an exceptionally low detection limit of 4.41 × 10-5 u/mL. This ultrasensitive probe can also effectively detect pesticide residues in vegetables and monitor CES activity in cells and liver tissues. TCFCl-CES stands out for its rapid and accurate detection capabilities, making it an essential tool for accurately monitoring pesticide residue. It also has great potential for tracking CES activity in biological systems. Additionally, it offers a robust solution for food safety and improving pesticide residue analysis.
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Dimetridazole (DMZ) is a broad-spectrum anti-anaerobic and antiprotozoal drug extensively used for the control of blackhead disease in poultry (especially turkeys). The presence of DMZ and its metabolites in animal food poses potential risks to human health. In this study, we developed a high-performance liquid chromatography tandem mass spectrometry (HPLC/MS-MS) method for the precise detection of DMZ and its metabolite 2-hydroxymethyl-1-methyl-5-nitroimidazole (HMMNI). Our results demonstrate a strong linear relationship (r2 > 0.99) between the concentrations of DMZ and HMMNI in tissues and egg within the range of 1~100 ng/g. The limits of detection (LOD) were determined to be 0.5 ng/g, with corresponding limits of quantification (LOQ) at 1.0 ng/g. Furthermore, average recoveries in tissues and egg fell within the range of 84.90% to 103.01%, with coefficients of variation below 15% for both intra-day and inter-day analyses. To investigate the residue elimination pattern of DMZ and HMMNI, diets containing 500 mg/kg DMZ were fed to healthy SanHuang chicken and Hy-line Gray laying hens for 10 consecutive days. The results indicated that the concentration of HMMNI consistently exceeded that of DMZ during the same period, in both broiler tissues and egg. Sebum showed the slowest elimination of DMZ and HMMNI, becoming undetectable after 168 h of withdrawal. In egg, residues of both substances peaked on the first day after drug withdrawal, followed by slow elimination with half-lives of 0.45 days for DMZ and 0.66 days for HMMNI. Based on these findings, WT1.4 software was used to calculate a withdrawal time of 11 days for broilers and an egg abandonment period of 14 days after withdrawal for laying hens, providing a scientific basis for the safe and rational use of DMZ in poultry farming.
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Rice intake represents a significant pathway through which humans accumulate heavy metals. This study presents a comprehensive analysis of heavy metal and pesticide contamination in rice cultivars irrigated with industrial wastewater near Dhaka, Bangladesh, a region heavily influenced by industrial activities. This study employed a unique methodology that not only quantified the concentrations of heavy metals and pesticide residues in rice grains but also extended to evaluating the physicochemical properties of rice stems, husks, soil, and irrigation water. The findings revealed alarmingly high levels of heavy metals such as lead, cadmium, chromium, nickel, and mercury in the soil and irrigation water, with concentrations in some cases exceeding the World Health Organization safety thresholds by 2 to 15 times. Notably, the rice grains also exhibited significant contamination, including substantial amounts of diazinon and fenitrothion pesticides, exceeding the established safety limits. The study employed hazard quotients (HQs) and cancer risk (CR) assessments to evaluate the potential health risks associated with the consumption of contaminated rice. The results indicated HQ values were greater than 1 for rice grains across the sampled fields, suggesting a considerable non-carcinogenic health risk, particularly from lead exposure, which was found at levels twice the standard limit in all the sampling fields. Moreover, the CR values for As, Pb, Cd, Co, and Mn highlighted a significant carcinogenic risk in several instances.
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Riego Agrícola , Monitoreo del Ambiente , Metales Pesados , Oryza , Plaguicidas , Contaminantes del Suelo , Metales Pesados/análisis , Oryza/química , Bangladesh , Medición de Riesgo , Plaguicidas/análisis , Contaminantes del Suelo/análisis , Contaminación de Alimentos/análisis , Humanos , Contaminantes Químicos del Agua/análisisRESUMEN
The utilisation of coated controlled-release fertilizers (CRFs) leads to the persistence of residual plastic films in agricultural soils, posing a potential threat to crop health. This study investigates the impacts of four residual films (0.39â¯%, w/w) derived from CRFs in soil, including petrochemical polyether, bio-based polyether, castor oil polyester, and wheat straw polyester polyurethane on wheat growth. This study found that PecPEUR significantly reduced wheat plant height, stem diameter, leaf area, and aboveground fresh weight by 24.8â¯%, 20.2â¯%, and 25.7â¯%. Through an in-depth exploration of transcriptomics and metabolomics, it has been discovered that all residual films disrupted glycolysis-related metabolic pathways in wheat roots, affecting seedling growth. Among them, PecPEUR significantly reduced the fresh weight of aboveground parts by 20.5â¯%. In contrast, polyester polyurethane residue had no discernible impact on aboveground wheat growth. This was attributed to the enrichment of wheat root genes in jasmonic acid and γ-aminobutyric acid metabolic pathways, thus mitigating oxidative stress, enhancing stress resistance, and ensuring normal plant growth. This study, for the first time, provides comprehensive insights into the effects of polyurethane film residue on wheat seedling growth, underscoring its potential as a promising alternative to conventional plastics in soil.
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Chlorpyrifos is one of the most widely used broad-spectrum insecticides in agriculture. Given its potential toxicity and residue in food (e.g., tea), establishing a rapid and reliable method for the determination of chlorpyrifos residue is crucial. In this study, a strategy combining surface-enhanced Raman spectroscopy (SERS) and intelligent variable selection models for detecting chlorpyrifos residue in tea was established. First, gold nanostars were fabricated as a SERS sensor for measuring the SERS spectra. Second, the raw SERS spectra were preprocessed to facilitate the quantitative analysis. Third, a partial least squares model and four outstanding intelligent variable selection models, Monte Carlo-based uninformative variable elimination, competitive adaptive reweighted sampling, iteratively retaining informative variables, and variable iterative space shrinkage approach, were developed for detecting chlorpyrifos residue in a comparative study. The repeatability and reproducibility tests demonstrated the excellent stability of the proposed strategy. Furthermore, the sensitivity of the proposed strategy was assessed by estimating limit of detection values of the various models. Finally, two-tailed paired t-tests confirmed that the accuracy of the proposed strategy was equivalent to that of gas chromatography-mass spectrometry. Hence, the proposed method provides a promising strategy for detecting chlorpyrifos residue in tea.
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This study aimed to investigate the efficacy of biochar, produced from different agricultural residues varying in lignin and cellulose content and subjected to different pyrolysis temperatures, in removing cadmium ions (Cd (II)) from an aqueous solution. This removal process is crucial for protecting human health and the environment. Specifically, the study focused on the adsorption behaviors of Cd (II) by the biochars made from rice husk biochar (RHB), maize straw biochar (MSB), peanut shell biochar (PSB), cottonseed shell biochar (CHB), and mulberry leaf biochar (MLB), which were prepared at 300 °C and 600 °C. The results indicated that the type of agricultural residue used to produce biochar significantly influenced the adsorption of Cd (II). Notably, mulberry leaf biochar prepared at 300 °C (MLB-300) demonstrated the highest adsorption efficiency, achieving a maximum adsorption capacity of 42.2 mg g-1. Batch adsorption experiments assessed the impact of various factors, including system pH, NO3- concentration, and adsorption duration. The adsorption kinetics were better described by the pseudo-second-order model than the pseudo-first-order model. Moreover, the study found that the lignin content of the biochar plays a major role in determining the adsorption capacity. The surface characteristics of biochar, influenced by the types of agricultural residues and preparation temperature, directly impact its adsorption mechanism and capacity. While biochar produced at 300 °C showed optimal Cd(II) adsorption, those processed at 600 °C were less effective, likely due to the loss of functional groups at higher temperatures.
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Cadmio , Carbón Orgánico , Carbón Orgánico/química , Cadmio/análisis , Cadmio/química , Adsorción , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/química , Agricultura/métodos , Cinética , Concentración de Iones de Hidrógeno , Agua/química , Purificación del Agua/métodos , Temperatura , SolucionesRESUMEN
The improper application of pesticides in cultivating vegetables has resulted in the buildup of pesticide residues on vegetables. This study evaluated organophosphate pesticide residue levels in cabbage with specific objectives of investigating the varieties of organophosphate pesticides employed by farmers and their awareness, assessing residue levels on cabbage using semi-structured questionnaires, and determining the distribution of pesticide residues within the layers of the cabbage head using 50 cabbage samples randomly collected from farmers from 14 cabbage-producing communities. The findings indicated that 98 % of the farmers applied pesticides in the morning, whereas 24 % preferred evening application. Meanwhile, 22 % applied pesticides twice in a day. Also, 18 % combined pesticides, 40 % applied 20 ml during the application, 72 % chose a particular pesticide based on the expected efficiency, 46 % applied pesticides between 1 and 5 times in a season and 66 % sprayed between 7 and 14 days. Pyrinex 48 EC and Perferthion emerged as the predominant organophosphates, with usage rates of 10 % and 12 % respectively. Also, eleven (11) organophosphate pesticide residues were identified in the cabbage samples. Profenofos and chlorpyrifos exhibited the highest concentrations of pesticide residues, with levels reaching 0.02 mg/kg, with 56.6 % of the samples containing chlorpyrifos pesticide residue. Nevertheless, all the identified pesticide residues did not exceed the maximum residue limits for cabbage. The study analysis disclosed the presence of various organophosphate pesticide residues in the first 10 layers of cabbage. However, it was noted that the innermost layers might not contain any detectable pesticide residues. The findings highlight the need for farmers to use pesticides judiciously and follow recommended application practices to minimize vegetable residues.
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Fireworks play a vital role in festive celebrations and entertainment. These fireworks industries are administered by the Petroleum and Explosives Safety Organisation (PESO), Nagpur, Government of India. Even though PESO prescribed the standard composition for various fireworks products, concerns persist regarding the potential deviation from these standards, particularly in the pursuit of increased noise levels to attract consumers. This change in the burning and reactive properties of chemicals could potentially lead to accidents and environmental pollution. The current work investigated the combustion characteristics of two unknown market flash powder samples and a PESO standard sample. The samples were openly ignited in a controlled atmosphere, and video recordings of the resulting chemical flames were analyzed to determine fire area, flame intensity, and motion magnitude. The residues were also collected for EDAX and SEM analysis. Fire pixels from video frames are segmented to create a comprehensive database detailing flame area and motion magnitude under different circumstances. From the flame area profile, motion magnitude and SEM/EDAX analysis, it is found that PESO standard sample combustion is better than the unknown flash powder combustion.
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Pesticide residues may enter the human body through the food chain when livestock and poultry consume pesticide-contaminated feed. Therefore, monitoring and limiting pesticide residues in animal feed and animal-origin foods is necessary. Carbendazim is one of the most frequently detected pesticides in food and feed and has various toxic effects on non-target animals. This study investigated the effects of varying concentrations of carbendazim contamination in feed on broiler chicken growth performance, serum biochemical indicators, histopathology, and carbendazim residues in broiler muscles and livers. The results demonstrated that contamination of 5-100 mg/kg carbendazim in feed did not affect broiler growth performance or health. Carbendazim contamination in feed at 200-800 mg/kg slightly reduced growth performance. Broiler kidneys showed minor histopathological alterations after 400 mg/kg carbendazim exposure. Furthermore, when the carbendazim content in feed was less than 25 mg/kg, the residual carbendazim in the muscles and livers of broilers did not exceed the maximum residue level set by the European Union and China. Based on the above findings, carbendazim residues in the feed of less than 25 mg/kg can be considered safe for chicken products.
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Postconsumer household food residues can act as useful substrates for other industries, but transporting high-moisture material corresponds to high fuel use and associated greenhouse gas production. Drying food residues at the household level reduces transportation weight, increases stability, and preserves the nutritional quality of recovered material. Mitigating foodborne microbiological safety risks is crucial to encourage the development of novel methods to rapidly dry and stabilize food residues. The objective of this study was to improve the prediction of bacterial pathogen inactivation under various thermal and drying processes in a synthetic mixture of residual food material (RFM). The log reduction rate was measured for Escherichia coli, Enterococcus faecium, and Listeria innocua (surrogates of common foodborne pathogens) in RFM under different moisture contents (12% and 25% by fresh weight) and temperatures (50, 55, and 60°C). Inactivation data were used to determine D- and z-values and to fit a multiple regression model to predict log(D-values) in response to temperature and moisture content. Across conditions, D-values were measured to be 5.1-120, 4.6-123, and 32-545 min for E. coli, L. innocua, and E. faecium, respectively. Temperature sensitivities were significantly higher in lower moisture RFM for E. coli and L. innocua. Applying E. coli inactivation models during RFM at 55°C yielded inactivation rates that aligned with experimental values after 5 min (0.1 vs. 0-0.1 logs), 30 min (2.1 vs. 1.3-2.3 logs), and 90 min (7.2 vs. 7.1-8.9 logs). These results can inform the design of RFM drying and stabilization processes to promote pathogen inactivation and safety in downstream applications of dried material.
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This study presents a novel approach to producing activated carbon from agro-industrial residues, specifically cocoa fruit peel, using solid-state fermentation (SSF) with Aspergillus niger. The process effectively degrades lignin, a major impediment in traditional activated carbon production, resulting in a high-quality carbon material. This carbon was successfully utilized for enzyme immobilization and aroma synthesis, showcasing its potential as a versatile biocatalyst. The study meticulously evaluated the physical and chemical attributes of activated carbon derived from fermented cocoa peel, alongside the immobilized enzymes. Employing a suite of analytical techniques-electrophoresis, FTIR, XRD, and TG/DTG the research revealed that fermentation yields a porous material with an expansive surface area of 1107.87 m2/g. This material proves to be an excellent medium for lipase immobilization. The biocatalyst fashioned from the fermented biomass exhibited a notable increase in protein content (13% w/w), hydrolytic activity (15% w/w), and specific activity (29% w/w), underscoring the efficacy of the fermentation process. The significant outcome of this research is the development of a sustainable method for activated carbon production that not only overcomes the limitations posed by lignin but also enhances enzyme immobilization for industrial applications. The study's findings have important implications for the agro-industrial sector, promoting a circular economy and advancing sustainable biotechnological processes.
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Constructing a restoration strategy from bauxite residue to Technosols is a cost-effective and sustainable strategy for addressing the ecological and environmental issues caused by high alkalinity, salinity, and fine-grained bauxite residues. However, the quantitative contribution of restoration strategies on the upper bauxite residue-derived Technosols to the underlying untreated bauxite residue in the short term remains poorly understood. This study investigated the mediating mechanisms of vegetation and microbial metabolic effects on the alkalinity, nutrient content, and structure of the underlying bauxite residue (20-50 cm) through a simulated ecological reconstruction of the bauxite residue stockpile. Results indicated that implementing plant restoration strategies resulted in the content of polyphenolic compounds, lipids, tannins, and carbohydrates in bauxite residue dissolved organic matter (DOM) increased significantly from 52.5, 8.2, 3.3, and 2.0 % to 54.4, 10.4, 5.6, and 2.8 %, respectively, while the content of condensed aromatics, unsaturated hydrocarbons, and proteins/amino sugars decreased significantly from 15.5, 12.0, and 6.5 % to 12.1, 9.7, and 5.1 %, respectively. The newly produced molecules were concentrated in regions with low O/C and high H/C ratios, suggesting that short-term vegetation restoration strategies facilitate the transformation of substrate DOM towards easily decomposable and highly bioavailable substances. This led to the migration of the newly produced molecules to the underlying bauxite residue, and as a result, the protein and soluble microbial products of the underlying bauxite residue increased significantly, as well as the pH, exchangeable Na, and < 0.054 mm particles decreased from 10.2, 44.2 cmol kg-1, and 28.1 % to 9.7, 27.1 cmol kg-1, and 19.4 %, respectively, available nitrogen, urease, and 1-2 mm particles increased from 7.3 mg kg-1, 0.2 U mg-1, and 14.5 % to 7.6 mg kg-1, 0.3 U kg-1, and 21.7 %, respectively. Results of the structural equation model further confirmed that plant biomass, proteins/amino sugars, and condensed aromatics in the upper Technosol were the main factors controlling the aggregate formation of the underlying bauxite residue by mediating the protein-dominated biogenic organic matter produced by microbial metabolism.