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Landfills are sites for the disposal of waste over decades. The dynamics of contaminants during landfill treatment influence the functions and environmental risks of the landfill systems, but the patterns of these dynamics are not fully characterized, especially for antibiotic resistant genes (ARGs), an emerging contaminant of global concern. Here, seventeen typical ARG subtypes were quantitatively investigated in refuse samples from small and medium-sized landfills with ages of <3 years, ~5 years, and 8-10 years. The abundance of ARGs, including tetM, tetX, blaPER, emrB, sul1 and sul2, increased significantly (p < 0.05), approaching 8- to 304-fold on average, from refuse of < 3years to that of 8-10 years, while there was no obvious change (p > 0.05) in abundance for other ARGs, including tetQ, tetW, ampC, blaCTX-M, blaSHV, emrA, mefA, qnrD, qnrS, and mexF. Accordingly, resistance to tetracyclines, macrolides, and sulfonamides increased with landfill age, while resistance to ß-lactams and quinolones remained unchanged. The increase in ARG abundance with increasing refuse age was probably related with the increased horizontal gene transfer (HGT) (indicated by the increased abundance of mobile gene elements) and the enhanced co-selective pressure (suggested by the increased contents of heavy metals). These results indicated a potential risk from ARG enrichment with an increase in refuse age in small and medium-sized landfills, which should be managed to ensure landfill safety.
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Antibacterianos , Metales Pesados , Antibacterianos/toxicidad , Farmacorresistencia Microbiana/genética , Genes Bacterianos , Metales Pesados/análisis , Residuos Sólidos/análisis , Instalaciones de Eliminación de ResiduosRESUMEN
Biochar is the carbon-rich product of the pyrolysis of biomass under oxygen-limited conditions, and it has received increasing attention due to its multiple functions in the fields of climate change mitigation, sustainable agriculture, environmental control, and novel materials. To design a "smart" biochar for environmentally sustainable applications, one must understand recent advances in biochar molecular structures and explore potential applications to generalize upon structure-application relationships. In this review, multiple and multilevel structures of biochars are interpreted based on their elemental compositions, phase components, surface properties, and molecular structures. Applications such as carbon fixators, fertilizers, sorbents, and carbon-based materials are highlighted based on the biochar multilevel structures as well as their structure-application relationships. Further studies are suggested for more detailed biochar structural analysis and separation and for the combination of macroscopic and microscopic information to develop a higher-level biochar structural design for selective applications.
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Carbono , Carbón Orgánico , Biomasa , FertilizantesRESUMEN
Surface functional groups such as carboxyl play a vital role in the environmental applications of biochar as a soil amendment. However, the quantification of oxygen-containing groups on a biochar surface still lacks systematical investigation. In this paper, we report an integrated method combining chemical and spectroscopic techniques that were established to quantitatively identify the chemical states, dissociation constants (pK(a)), and contents of oxygen-containing groups on dairy manure-derived biochars prepared at 100-700 °C. Unexpectedly, the dissociation pH of carboxyl groups on the biochar surface covered a wide range of pH values (pH 2-11), due to the varied structural microenvironments and chemical states. For low temperature biochars (≤ 350 °C), carboxyl existed not only as hydrogen-bonded carboxyl and unbonded carboxyl groups but also formed esters at the surface of biochars. The esters consumed OH(-) via saponification in the alkaline pH region and enhanced the dissolution of organic matter from biochars. For high temperature biochars (≥ 500 °C), esters came from carboxyl were almost eliminated via carbonization (ester pyrolysis), while lactones were developed. The surface density of carboxyl groups on biochars decreased sharply with the increase of the biochar-producing temperature, but the total contents of the surface carboxyls for different biochars were comparable (with a difference <3-fold) as a result of the expanded surface area at high pyrolytic temperatures. Understanding the wide pKa ranges and the abundant contents of carboxyl groups on biochars is a prerequisite to recognition of the multifunctional applications and biogeochemical cycling of biochars.
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Carbón Orgánico , Oxígeno/química , Temperatura , Calor , Estiércol , Eliminación de Residuos/métodos , SueloRESUMEN
The adsorption of naphthalene, phenanthrene, and pyrene onto graphene (GNS) and graphene oxide (GO) nanosheets was investigated to probe the potential adsorptive sites and molecular mechanisms. The microstructure and morphology of GNS and GO were characterized by elemental analysis, XPS, FTIR, Raman, SEM, and TEM. Graphene displayed high affinity to the polycyclic aromatic hydrocarbons (PAHs), whereas GO adsorption was significantly reduced after oxygen-containing groups were attached to GNS surfaces. An unexpected peak was found in the curve of adsorption coefficients (Kd) with the PAH equilibrium concentrations. The hydrophobic properties and molecular sizes of the PAHs affected the adsorption of G and GO. The high affinities of the PAHs to GNS are dominated by π-π interactions to the flat surface and the sieving effect of the powerful groove regions formed by wrinkles on GNS surfaces. In contrast, the adsorptive sites of GO changed to the carboxyl groups attaching to the edges of GO because the groove regions disappeared and the polar nanosheet surfaces limited the π-π interactions. The TEM and SEM images initially revealed that after loading with PAH, the conformation and aggregation of GNS and GO nanosheets dramatically changed, which explained the observations that the potential adsorption sites of GNS and GO were unusually altered during the adsorption process.
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Grafito/química , Óxidos/química , Hidrocarburos Policíclicos Aromáticos/química , Adsorción , Microscopía Electrónica de Rastreo , Microscopía Electrónica de TransmisiónRESUMEN
Pachyonychia congenita (PC) is a group of rare hereditary disorders, characterised by hypertrophic nails and palmoplantar keratoderma (PPK), particularly localised to the pressure areas of the feet. At a molecular level, it is caused by mutations in genes encoding KRT6A, KRT6B, KRT6C, KRT16, or KRT17. To identify the underlying gene mutation in a Chinese family with PC presenting with disabling palmoplantar keratoderma and subsequent associated acral melanoma. Genomic DNA was extracted from peripheral blood samples of three available individuals in the Chinese family, which included the patient and his two unaffected sisters. The index patient presented with severe palmoplantar keratoderma as well as a newly diagnosed acral malignant melanoma (MM). Whole-exome sequencing (WES) was carried out with amplification of exon 1 of KRT16 by polymerase chain reaction (PCR). PCR products were then sequenced to identify potential mutations. We identified the proline substitution mutation p.Arg127Pro (c.380G>C) in our patient's 1A domain of KRT16. The same mutation was not found in his sisters or unrelated healthy controls. The mutation (p.Arg127Pro (c.380G>C)) in KRT16 has been reported in Dutch patients with PC. However, it is the first such report of a patient with a PC of Chinese origin. In addition, the acral MM occurred under the background of genetic PPK caused by KRT16 mutation in this patient.
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Decreasing bioaccessible antibiotics, heavy metals, and antibiotic resistance genes (ARGs) in soil by adsorption is an attractive, but unrealized, approach for ARG risk reduction. This approach has the potential to reduce the (co)selection pressure from antibiotics and heavy metals on bacteria and ARG horizontal gene transformation to pathogens. Here, a wet-state silicon-rich biochar/ferrihydrite composite (SiC-Fe(W)) synthesized by loading ferrihydrite onto rice straw-derived biochar was examined for i) adsorption of oxytetracycline and Cu2+ to reduce (co)selection pressure and ii) adsorption of extracellular antibiotic resistance plasmid pBR322 (containing tetA and blaTEM-1) to inhibit ARG transformation. SiC-Fe(W) gained the adsorption priority of biochar (for Cu2+) and wet-state ferrihydrite (for oxytetracycline and pBR322) and showed adsorptive enhancement (for Cu2+ and oxytetracycline) from a more wrinkled and exposed surface from biochar silica-dispersed ferrihydrite and a more negatively charged biochar, and the adsorption capacity for SiC-Fe(W) was 17-135 times that of soil. Correspondingly, 10 g/kg SiC-Fe(W) amendment increased the soil adsorption coefficient Kd by 31%-1417% and reduced the selection pressure from dissolved oxytetracycline, co-selection pressure from dissolved Cu2+, and transformation frequency of pBR322 (assessed with Escherichia coli). The development of Fe-O-Si bonds on silicon-rich biochar in alkaline enhanced ferrihydrite stability and adsorption capacity (for oxytetracycline), presenting a new potential strategy of biochar/ferrihydrite composite synthesis for adsorptive inhibition of ARG proliferation and transformation in ARG pollution control.
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Metales Pesados , Oxitetraciclina , Contaminantes del Suelo , Antibacterianos/farmacología , Silicio/farmacología , Adsorción , Contaminantes del Suelo/análisis , Metales Pesados/análisis , Carbón Orgánico/farmacología , Carbón Orgánico/química , Suelo/química , Farmacorresistencia Microbiana/genética , Proliferación CelularRESUMEN
The char component of biochar can act as an electron shuttle and redox agent to accelerate the transformation of ferrihydrite, but how the silicon component of biochar affects ferrihydrite transformation and pollutant removal remains unclear. In this paper, infrared spectroscopy, electron microscopy, transformation experiments and batch sorption experiments were conducted to examine a 2-line ferrihydrite formed by alkaline precipitation of Fe3+ on a rice straw-derived biochar. Fe-O-Si bonds were developed between the precipitated ferrihydrite particles and biochar silicon component, increasing mesopore volume (for mesopores with diameters of 10-100 nm) and surface area of ferrihydrite as the Fe-O-Si formation probably alleviated the aggregation of ferrihydrite particles. The Fe-O-Si bonding-contributed interactions blocked the transformation to goethite for ferrihydrite precipitated on biochar in a 30-day ageing and a 5-day Fe2+ catalysis ageing. Moreover, there was an increase of oxytetracycline adsorption capacity onto ferrihydrite-loaded biochar, which reached amazingly 3460 mg/g at the maximum, due to the Fe-O-Si bonding-contributed increase of surface area and oxytetracycline coordination sites. Ferrihydrite-loaded biochar as a soil amendment enhanced oxytetracycline adsorption and reduced the bacterial toxicity of dissolved oxytetracycline better than ferrihydrite did. These results provide new perspectives for the role of biochar (especially its silicon component) as an iron-based material carrier and a soil additive in the environmental effects of iron (hydr) oxides in water and soil.
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Oxitetraciclina , Silicio , Adsorción , Compuestos Férricos/química , Hierro/química , Carbón Orgánico/química , SueloRESUMEN
The bisolute sorption and thermodynamic behavior of organic pollutants on low temperature biochars (LTB) at 300 °C and high temperature biochars (HTB) at 700 °C were determined to elucidate sorptive properties of biochar changed with pyrolytic temperatures. The structural characteristics and isotherms shape of the biochar were more dependent on the pyrolytic temperature than on the biomass feedstocks, which included orange peel, pine needle, and sugar cane bagasse. For LTB, the thermally altered organic matter colocalized with the carbonized matter, and the visible fine pores of the fixed carbons were plugged by the remaining volatile carbon. For HTB, most of the volatile matter was gone and the fixed matter was composed of fully carbonized adsorptive sites. Monolayer adsorption of 1-naphthol to HTB was dominant but was suppressed by phenol. In comparison, LTB displayed exceptional sorption behavior where partition and adsorption were concurrently promoted by a cosolute and elevated temperature. In addition to monolayer surface coverage, pore-filling mechanisms may contribute to the increase of adsorption fraction. Moreover, the entropy gain was a dominant force driving the partition and adsorption processes in LTB. Thus, the colocalizing partition phase and adsorptive sites in LTB are proposed to be in interencased states rather than in physical separation.
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Carbón Orgánico/química , Dinitrobencenos/química , Naftalenos/química , Naftoles/química , Fenol/química , Adsorción , Biomasa , Celulosa/química , Carbón Orgánico/análisis , Citrus sinensis/química , Entropía , Microscopía Electrónica de Rastreo , Pinus/química , Saccharum/química , Soluciones , Temperatura , Termodinámica , TermogravimetríaRESUMEN
This study investigated the sorption kinetics of a model solute (naphthalene) with a series of biochars prepared from a pine wood at 150-700 °C (referred as PW100-PW700) to probe the effect of the degree of carbonization of a biochar. The samples were characterized by the elemental compositions, thermal gravimetric analyses, Fourier transform IR spectroscopy, scanning electron microscopy, Brunauer-Emmett-Teller-N(2) surface areas (SA), and pore size distributions. Naphthalene exhibited a fast rate of sorption to PW150 owning a high oxygen content and a small SA, due supposedly to the solute partition into a swollen well-hydrated uncarbonized organic matter of PW150. The partial removal of polar-group contents in PW250/PW350, which increased the compactness of the partition medium, decreased the diffusion of the solute into the partition phase to result in a slow sorption rate. With PW500 and PW700 displaying low oxygen contents and high SA, the solute sorption rates were fast, attributed to the near exhaustion of a partition phase in the sample and to the fast solute adsorption on the carbonized biochar component. The results illustrate that the sorption rate of a solute with biochars is controlled largely by the solute's diffusivity in the biochar's partition phase, in which the medium compactness affects directly the solute diffusivity.
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Carbón Orgánico/química , Incineración , Naftalenos/química , Contaminantes del Suelo/química , Adsorción , Restauración y Remediación Ambiental , Cinética , Modelos Químicos , Naftalenos/análisis , Pinus , Temperatura , MaderaRESUMEN
Pyrogenic char (biochar) with a high sorption capacity (B-HSC) can sequester hazardous chemicals (e.g., phenanthrene). However, when sorption inhibits bioavailability of some functional chemicals (e.g., the herbicidal efficacy of diuron in soil), biochar with a low sorption capacity (B-LSC) is required to prevent sorption effects. The pyrolytic B-HSC generation has been reported, but information on B-LSC formation is scarce. How fast B-HSC and B-LSC could be generated is unknown until now. Here, biochars were rapidly prepared (the shortest heating time reached 5 min and the cooling time reached < 30 min) by a direct-pyrolysis method by directly exposing packaged rice straw and pine wood to 350 °C, 500 °C and 700 °C and out-of-furnace cooling at room temperature. The sorption of diuron, phenanthrene, and twelve other chemicals was investigated. B-HSCs were obtained within 30 min of rice straw pyrolysis, and the biochar Kd values quickly increased to 7-730-fold that of the raw biomass as -OH and C-O-C in (hemi)cellulose of rice straw rapidly degraded, increasing hydrophobic interactions between the char and chemicals (solubility ≤ 82.8 g/L). In contrast, B-LSCs were generated within 30 min of PW pyrolysis, and the Kd values of the biochars were 0.2-3.0-fold that of the raw biomass, as the surface area development and hydrophobicity-driven sorption were probably delayed by the late degradation of lignin aromatic C-O and phenolic -OH. Biochar amendment revealed an enhancement effect of B-HSC but not of B-LSC on soil sorption. The fast formation of B-LSC and B-HSC provides a guide to develop time- and cost-effective technique in pyrolytically producing weakly or strongly sorbing biochars for organic chemical management.
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INTRODUCTION: Psoriasis is a common skin disease, with chronic inflammation and a complex etiology. It has long been recognized that chronic skin conditions and mental health disorders are often co-morbid. Thus, the concept of the gut-brain-skin axis emphasized in mental health disorders may also regulate the health of skin. RESULTS: The gut microbiota has been found to be the bridge between the immune system and nervous system. By leveraging clinical cases and animal models of psoriasis, an important communication pathway has been identified along the gut-brain-skin axis that is associated with the modulation of neurotransmitters from the microbiota. Furthermore, mammalian neurotransmitters, including dopamine, serotonin, or γ-aminobutyric acid (GABA), can be produced and/or consumed by several types of bacteria. Other studies suggest that manipulating these neurotransmitters by bacteria may have an effect on host physiology, and the levels of neurotransmitter can be altered by microbiota-based interventions. CONCLUSIONS: Nonetheless, it is unknown whether or not the manipulation of neurotransmitter levels by bacteria can affect the occurrence and development of psoriasis. Notably, preliminary experiments found that oral consumption of probiotics improves the clinical symptoms in patients with psoriasis, perhaps correlated with the gut microbiome-mediated crosstalk between the immune system and the nervous system by secreting neurotransmitters in psoriasis. In this review, the communication along the gut-brain-skin axis is discussed.
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As an important part of biochar, surface functional group is the key interface between biochars and other phases, as well as an essential source of biochar's alkalinity and buffer abilities. However, due to the intricate organic and inorganic structures within biochars, the contribution from organic and inorganic matters to the functional groups remains unknown. In this work, the proton uptake curves were applied to study the functional groups of biochars via titration. Pine needle (PN) derived biochars with low inorganic content was selected for analyzing the organic functional groups variation under different pyrolysis temperatures. While rice straw (RS) derived biochars and the double-acid treated rice straw (DRS) derived biochars were compared for understanding the contributions from inorganic matters. The results indicate that the sorption behavior of proton onto biochars is surface adsorption, and the functional groups variation within PN biochars keeps consistent with reactions happened during pyrolysis. The inorganic matters within RS biochars contributed significantly to the buffering ability of biochars, and it is noteworthy to find that the contribution of inorganic matters of RS350, RS500, and RS700 on the total proton uptake stabilized at 67%, 84%, and 84% in the pH range of 2-8, respectively. As far as we know, this is the first report on separating the proton uptake ability of the organic and inorganic matters for biochars. The study on the interaction between biochars and proton will improve the estimation of the fate of ionizable pollutants, and the differentiation on the organic and inorganic matter contributions would benefit the understanding of biochar organic structures and inorganic structures.
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Carbón Orgánico , Pirólisis , Adsorción , Protones , TemperaturaRESUMEN
The adsorptive performance of carbonaceous materials (CMs) for the removal and sequestration of ionizable organic contaminants (IOCs) is heavily dependent on the pH-controlled speciation of the objective chemicals. To date, there is no effective method for measuring the sorption of IOC species at a solution pH near the IOC pKa, which is usually of environmental relevance and essential for validating sorption models. In this study, a unique "pH dynamics method" was developed. The method relates the uptake of the IOC species with the solution pH changes during sorption on the basis of the proton mass balance in the adsorptive process. The effectiveness of the method to quantify the sorption of IOC species at a pH near the pKa was validated by determining the extents and mechanisms of the pH change in a series of sorption systems employing graphite, biochar, carbon nanotube and activated charcoal as representative CMs, and 4-methylbenzoic acid, 2,4,6-trichlorophenol, 4-methylaniline and quinoline as model IOCs. Moreover, with the derived species uptake using the pH dynamics method, the effectiveness of already-reported speciation models for predicting species sorption at a pH around the pKa was verified for the first time. It was shown that the speciation models, including the linear speciation model and nonlinear speciation model, were convincing for estimating the sorption of individual species at the pH around the chemical pKa when the collected uptake of individual species could be reliably predicted. This research advances the application of pH dynamics for quantifying the uptake of individual species of IOCs and enhances the understanding of the speciation models and carbonaceous materials in managing risks of IOCs.
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It remains a challenge to precisely predict and control environmental behaviors of ionizable organic contaminants (IOCs) due to their species change relative to pH and because of the lack of appropriate models to illustrate the underlying pH-dependent mechanisms. We studied the pH-dependent sorption behavior of five sulfonamide antibiotics (SAs) as typical IOCs with different pKa values towards a series of biochars as representative sorbents with well-characterized surface structures. After subtracting the contribution of the speciation effect using a classical speciation model, up to three unexpected enhanced sorption peaks could be found and regulated by the pKa,SA of the SAs and the pKa, BC of the biochars. The mono H-bond formation between the two pKa,SA of the SAs (pKa,SA1 is from NH2, pKa,SA2 is from SO2NH), and the biochar surface functional groups with comparable pKa values generated two peaks. Another peak around the middle between pKa,SA1 and pKa,SA2 appeared due to the aromatic π bonding-enhanced dual H-bond. All of these peaks were quantitatively separated by a novel two-compartment model, which was developed by capturing the characteristics of pH-dependent sorption. The quantified hydrogen bonding among different SAs elucidates the effectiveness and limits of the pKa equalization principle to predict the strengthening of hydrogen bonding at the solid-aqueous interface. This work recognizes the quantitative relationship among the structure, sorption, and H-bond interaction of biochars and guides the prediction of the fate of IOCs in the environment and the development of remediation options.
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Antibacterianos/química , Carbón Orgánico/química , Restauración y Remediación Ambiental/métodos , Sulfonamidas/química , Adsorción , Enlace de Hidrógeno , Concentración de Iones de Hidrógeno , Agua/químicaRESUMEN
Solar steam generation is considered to be a promising strategy for sustainable clean water supply. An easily made and robust solar still can practically meet any contingency in wilderness survival, compared to high-cost and delicate solar thermal materials, for example, plasmonic metals, carbon nanotubes, or graphene-based materials. Inspired by rice plants with high transpiration, we develop a universal solar steam-generation device from wasted rice straw for robust clean water production. The upper leaves of rice straw are carbonized and composited with bacterial cellulose to function as a superior light absorber and the lower culms are designed as excellent water pumps. The unique capillary structures and multilevel geometrical structures of the rice culms contribute to their outstanding water pumping capacity for surface evaporation, resulting in an evaporation rate of 1.2 kg m-2 h-1 with 75.8% conversion efficiency. The rice straw-derived solar still has a daily clean water yield of 6.4-7.9 kg m-2 on sunny days and 4.6-5.6 kg m-2 on cloudy days over 14 days of operation. More attention-grabbing aspect is that this evaporation device is applicable to various water-bearing media, for example, sand, soil, and seawater, to collect clean water with a stable evaporation performance, and the unique multilevel structures of the culms make great contribution to the unimpeded water channels. By turning "waste" to "wealth," this project shines significant light on a facilely fabricated, robust, and efficient solar still, especially designed for urgent priority in wilderness survival.
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Biochar is increasingly gaining attention due to multifunctional roles in soil amelioration, pollution mitigation and carbon sequestration. It is a significant challenge to compare the reported results from world-wide labs regarding the structure and sorption of biochars derived from various precursors under different pyrolytic conditions due to a lack of a simple linkage. By combining the published works on various biochars, we established a quantitative relationship between H/C atomic ratio and pyrolytic temperature (T), aromatic structure, and sorption properties for naphthalene and phenanthrene. A reverse sigmoid shape between T and the H/C ratio was observed, which was independent of the precursors of biochars, including the ash contents. Linear correlations of Freundlich parameters (N, log Kf) and sorption amount (log Qe, log QA) with H/C ratios were found. A rectangle-like model was proposed to predict the aromatic cluster sizes of biochars from their H/C ratios, and then a good structure-sorption relationship was derived. These quantitative relationships indicate that the H/C atomic ratio is a universal linkage to predict pyrolytic temperatures, aromatic cluster sizes, and sorption characteristics. This study would guide the global study of biochars toward being comparable, and then the development of the structure-sorption relationships will benefit the structural design and environmental application of biochars.
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Biochar derived from agricultural biomass waste is increasingly recognized as a multifunctional material for agricultural and environmental applications. Three novel magnetic biochars (MOP250, MOP400, MOP700) were prepared by chemical co-precipitation of Fe3+/Fe2+ on orange peel powder and subsequently pyrolyzing under different temperatures (250, 400 and 700 °C), which resulted in iron oxide magnetite formation and biochar preparation in one-step. The MOP400 was comprised of nano-size magnetite particles and amorphous biochar, and thus exhibited hybrid sorption capability to efficiently remove organic pollutants and phosphate from water. For organic pollutants, MOP400 demonstrated the highest sorption capability, and even much larger than the companion non-magnetic biochar (OP400). For phosphate, magnetic biochars, especially MOP250, demonstrated much higher sorption capability than the companion non-magnetic biochars. No significantly competitive effect between organic pollutant and phosphate was observed. These suggest that the magnetic biochar is a potential sorbent to remove organic contaminants and phosphate simultaneously from wastewater.
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Carbón Orgánico/química , Magnetismo/métodos , Naftalenos/aislamiento & purificación , Fosfatos/aislamiento & purificación , Tolueno/análogos & derivados , Contaminantes Químicos del Agua/aislamiento & purificación , Adsorción , Elementos Químicos , Microscopía Electrónica de Transmisión , Porosidad , Análisis de Regresión , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Tolueno/aislamiento & purificaciónRESUMEN
A pot experiment was conducted to study the effect of spent mushroom compost (SMC) in alleviating greenhouse soil secondary salinization and cabbage salt stress. With the amendment of SMC, the salinized soil after 60 day cabbage cultivation had a pH value close to 7.0, its organic matter and available phosphorous contents increased significantly, and the increment of total water-soluble salt content reduced, compared with the control. When the amendment amount of SMC was 10 g x kg(-1), the increment of soil water soluble salt content was the least, suggesting that appropriate amendment with SMC could reduce the salt accumulation in greenhouse soil. Amendment with SMC increased the cabbage seed germination rate, plant height, plant fresh mass, chlorophyll SPAD value, and vitamin C content, and decreased the proline content significantly. All the results indicated that SMC could improve the growth environment of greenhouse cabbage, and effectively alleviate the detrimental effect of salt stress.
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Agricultura/métodos , Brassica/crecimiento & desarrollo , Sales (Química)/análisis , Suelo/análisis , Agaricales , Ambiente Controlado , Eliminación de Residuos/métodos , Estrés FisiológicoRESUMEN
Biochars, derived from biomass, are increasingly recognized as an environmental-friendly sorbent to abate organic pollutants. Sorption variations of biochars with their pyrolytic temperatures are evaluated. Nine biochars of orange peels with different pyrolytic temperatures (150-700 degrees C, referred as OP150-OP700) were characterized via elemental analysis, BET-N(2) surface area, and Fourier transform infrared spectroscopy. Sorption of naphthalene and 1-naphthol by the biochars in water are compared. Sorption isotherms varied from linear to Freundlich with increasing pyrolytic temperature. The respective contributions of adsorption and partition to total sorption were correlated with biochars' structural parameters. For OP150-OP600, sorption of 1-naphthol was significantly larger than naphthalene due to the former owning additional specific interactions. For 1-naphthol with high concentrations, the OP200 exhibited the maximal sorption capacity due to its largest partition and high adsorption among nine biochars. For 1-naphthol with low concentrations and naphthalene, the OP700 displayed the maximal sorption capacity. These observations provide a reference to the use of biochars as engineered sorbents for environmental applications.