Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 60.083
Filtrar
1.
Food Chem ; 400: 133980, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36084585

RESUMO

In the present study, the functionality of H2O2 and sodium hexametaphosphate (SHMP) on solubilization of whey protein hydrolysate (WPH) and isolate (WPI), resistant to sterilization temperature at various concentrations, was investigated. The physical state of the treated WPH and WPI dispersions at the presence of various concentrations of H2O2 and SHMP was related to their colloidal structures and thermal stability. Using optimum concentration of H2O2, both dispersions stabilized against heat treatment likely because free SH groups blocked by H2O2. The solubilization range by SHMP was comparably low (up to 6 and 15% w/w for WPI and WPH, respectively). Moreover, the desirable stability was reached when H2O2 and SHMP were simultaneously used. The pH adjustment (7.2), prior to sterilization, also improved the stability range. This research highlights the potential of these substances to restrain the denaturation of whey proteins. Further investigations are still required to elucidate the accurate mechanism of solubilization.


Assuntos
Peróxido de Hidrogênio , Hidrolisados de Proteína , Concentração de Íons de Hidrogênio , Fosfatos , Proteínas do Soro do Leite/química
2.
Food Chem ; 400: 134106, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36084601

RESUMO

The naive detection of scheduled H drug oxytocin is a vital requisite, owing to its deleterious impact on societal affluence prompted by unconstrained usage. Therefore, a reliable, cost-effective, and quick-to-respond analytic technique for this drug is in ample demand. In this work, we report electrochemical detection of oxytocin employing novel nitrogen, phosphorus co-doped coke-derived graphene (NPG) modified electrode. The electro-oxidation behavior of oxytocin was investigated on the NPG modified electrode by square wave stripping voltammetry (SWSV) in 0.1 M phosphate buffer of pH 7. The oxidation peak current was linear in two ranges, spanning from 0.1 nM to 10 nM and 15 nM to 95 nM. The limit of detection at the NPG electrode was calculated to be 40 pM. The practical application of developed sensor for the determination of oxytocin was examined in edible products and body fluids, hence signifying the possibility of having real-time surveillance over its misusage.


Assuntos
Coque , Grafite , Técnicas Eletroquímicas/métodos , Eletrodos , Limite de Detecção , Nitrogênio , Ocitocina , Fosfatos , Fósforo
3.
J Ethnopharmacol ; 300: 115752, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36174807

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Peganum harmala L. is a traditional medicinal plant used for centuries in folk medicine. It has a wide array of therapeutic attributes, which include hypoglycemic, sedative, anti-inflammatory, and antioxidant properties. The fruit decoction of this plant was claimed by Avicenna as traditional therapy for urolithiasis. Also, P. harmala seed showed a clinical reduction in kidney stone number and size in patients with urolithiasis. AIM OF THE STUDY: In light of the above-mentioned data, the anti-urolithiatic activities of the seed extracts and the major ß-carboline alkaloids of P. harmala were investigated. MATERIALS AND METHODS: Extraction, isolation, and characterization of the major alkaloids were performed using different chromatographic and spectral techniques. The in vivo anti-urolithiatic action was evaluated using ethylene glycol (EG)-induced urolithiasis in rats by studying their mitigating effects on the antioxidant machinery, serum toxicity markers (i.e. nitrogenous waste, such as blood urea nitrogen, uric acid, urea, and creatinine), minerals (such as Ca, Mg, P, and oxalate), kidney injury marker 1 (KIM-1), and urinary markers (i.e. urine pH and urine output). RESULTS: Two major alkaloids, harmine (P1) and harmalacidine HCl (P2), were isolated and in vivo evaluated alongside the different extracts. The results showed that P. harmala and its constituents/fractions significantly reduced oxidative stress at 50 mg/kg body weight, p.o., as demonstrated by increased levels of glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx), and catalase (CAT) in kidney homogenate as compared to the EG-treated group. Likewise, the total extract, pet. ether fraction, n-butanol fraction, and P1, P2 alleviated malondialdehyde (MDA) as compared to the EG-treated group. Serum toxicity markers like blood urea nitrogen (BUN), creatinine, uric acid, urea, kidney injury molecule-1 (Kim-1), calcium, magnesium, phosphate, and oxalate levels were decreased by total extract, pet. ether fraction, n-butanol fraction, P1, and P2 as compared to the EG-treated group. Inflammatory markers like NFκ-B and TNF-α were also downregulated in the kidney homogenate of treatment groups as compared to the EG-treated group. Moreover, urine output and urine pH were significantly increased in treatment groups as compared to the EG-treated group deciphering anti-urolithiatic property of P. harmala. Histopathological assessment by different staining patterns also supported the previous findings and indicated that treatment with P. harmala caused a gradual recovery in damaged glomeruli, medulla, interstitial spaces and tubules, and brown calculi materials as compared to the EG-treated group. CONCLUSION: The current research represents scientific evidence on the use of P. harmala and its major alkaloids as an effective therapy in the prevention and management of urolithiasis.


Assuntos
Alcaloides , Cálculos Renais , Peganum , Urolitíase , 1-Butanol , Alcaloides/farmacologia , Animais , Antioxidantes , Cálcio , Oxalato de Cálcio/urina , Catalase , Creatinina , Éteres , Etilenoglicol/uso terapêutico , Etilenoglicol/toxicidade , Glutationa , Glutationa Peroxidase , Glutationa Redutase , Harmina , Hipnóticos e Sedativos/uso terapêutico , Hipoglicemiantes/uso terapêutico , Cálculos Renais/tratamento farmacológico , Magnésio , Malondialdeído , Peganum/química , Fosfatos , Extratos Vegetais , Ratos , Fator de Necrose Tumoral alfa , Ureia , Ácido Úrico , Urolitíase/induzido quimicamente , Urolitíase/tratamento farmacológico , Urolitíase/patologia
4.
J Hazard Mater ; 441: 129886, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36088881

RESUMO

Mismanaged plastic waste interacts with secondary environmental pollutants, potentially aggravating their impact on ecosystems and human health. Here we characterized the natural and artificial radionuclides in polyethylene terephthalate (PET) bottles collected from the industrial littoral discharge of a phosphate fertilizer plant. The activity concentrations in littered bottles ranged from 0.47 (208Tl) to 12.70 Bq·kg-1 (226Ra), with a mean value of 5.30 Bq·kg-1. All the human health risk assessment indices (annual intake, annual effective dose, and excess lifetime cancer risk) estimated for radionuclides associated with ingestion and inhalation of microplastics were below international safety limits. Our results demonstrated that PET can be loaded with natural and artificial radionuclides, and potentially act as a carrier to transfer radionuclides to humans, posing a new potential health risk. Increased use, mismanagement and fragmentation of plastic waste, and continued interaction of plastic waste with radioelements may lead to enhanced radiation exposure in the future.


Assuntos
Poluentes Ambientais , Plásticos , Ecossistema , Fertilizantes , Humanos , Microplásticos , Fosfatos , Polietilenotereftalatos , Radioisótopos , Radioisótopos de Tálio
5.
Food Chem ; 400: 134001, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36084586

RESUMO

Flavonoids are associated with health benefits, but most of them have poor oral bioavailability due to their extremely low aqueous solubility. Flavonoid O-phosphorylation suggests a potent modification to solve the problems. Here, we isolated, identified and characterized an unprecedented phosphotransferase, flavonoid phosphate synthetase (BsFPS), from B. subtilis. The enzyme catalyzes the ATP-dependent phosphorylation of flavonoid to generate flavonoid monophosphates, AMP and orthophosphate. BsFPS is a promiscuous phosphotransferase that efficiently catalyzes structurally-diverse flavonoids, including isoflavones, flavones, flavonols, flavanones and flavonolignans. Based on MS and NMR analysis, the phosphorylation mainly occurs on the hydroxyl group at C-7 of A-ring or C-4' of B-ring in flavonoid skeleton. Notably, BsFPS is regioselective for the ortho-3',4'-dihydroxy moiety of catechol-containing structures, such as luteolin and quercetin, to produce phosphate conjugates at C-4' or C-3' of B-ring. Our findings highlight the potential for developing biosynthetic platform to obtain new phosphorylated flavonoids for pharmaceutical and nutraceutical applications.


Assuntos
Flavanonas , Flavonas , Flavonolignanos , Isoflavonas , Monofosfato de Adenosina , Trifosfato de Adenosina , Bacillus subtilis , Catecóis , Flavonoides/química , Ligases , Luteolina , Fosfatos , Fosfotransferases , Quercetina
6.
J Environ Sci (China) ; 124: 429-439, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36182151

RESUMO

Antibiotic pollution imposes urgent threats to public health and microbial-mediated ecological processes. Existing studies have primarily focused on bacterial responses to antibiotic pollution, but they ignored the microeukaryotic counterpart, though microeukaryotes are functionally important (e.g., predators and saprophytes) in microbial ecology. Herein, we explored how the assembly of sediment microeukaryotes was affected by increasing antibiotic pollution at the inlet (control) and across the outlet sites along a shrimp wastewater discharge channel. The structures of sediment microeukaryotic community were substantially altered by the increasing nutrient and antibiotic pollutions, which were primarily controlled by the direct effects of phosphate and ammonium (-0.645 and 0.507, respectively). In addition, tetracyclines exerted a large effect (0.209), including direct effect (0.326) and indirect effect (-0.117), on the microeukaryotic assembly. On the contrary, the fungal subcommunity was relatively resistant to antibiotic pollution. Segmented analysis depicted nonlinear responses of microeukaryotic genera to the antibiotic pollution gradient, as supported by the significant tipping points. We screened 30 antibiotic concentration-discriminatory taxa of microeukaryotes, which can quantitatively and accurately predict (98.7% accuracy) the in-situ antibiotic concentration. Sediment microeukaryotic (except fungal) community is sensitive to antibiotic pollution, and the identified bioindicators could be used for antibiotic pollution diagnosis.


Assuntos
Compostos de Amônio , Antibacterianos , Biomarcadores Ambientais , Fosfatos , Tetraciclinas , Águas Residuárias
7.
J Environ Sci (China) ; 124: 50-60, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36182158

RESUMO

Phosphorus (P) in sediments plays an important role in shallow lake ecosystems and has a major effect on the lake environment. The mobility and bioavailability of P primarily depend on the contents of different P forms, which in turn depend on the sedimentary environment. Here, sediment samples from Baiyangdian (BYD) lake were collected and measured by the Standards, Measurements, and Testing procedure and Phosphorus-31 nuclear magnetic resonance spectroscopy (31P NMR) to characterize different P forms and their relationships with sediment physicochemical properties. The P content in the sediments varied in different areas and had characteristics indicative of exogenous river input. Inorganic P (334-916 mg/kg) was the dominant form of P. The 31P NMR results demonstrated that orthophosphate monoesters (16-110 mg/kg), which may be a source of P when redox conditions change, was the dominant form of organic P (20-305 mg/kg). The distribution of P forms in each region varied greatly because of the effects of anthropogenic activities, and the regions affected by exogenous river input had a higher content of P and a higher risk of P release. Principal component analysis indicated that P bound to Fe, Al, and Mn oxides and hydroxides (NaOH-P) and organic P were mainly derived from industrial and agricultural pollution, respectively. Redundancy analysis indicated that increases in pH lead to the release of NaOH-P. Organic matter plays an important role in the organic P biogeochemical cycle, as it acts as a sink and source of organic P.


Assuntos
Fósforo , Poluentes Químicos da Água , China , Ecossistema , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Óxidos/análise , Fosfatos/análise , Fósforo/análise , Hidróxido de Sódio , Poluentes Químicos da Água/análise
8.
J Environ Sci (China) ; 124: 699-711, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36182175

RESUMO

Numerous studies support that biodiversity predict most to ecosystem functioning, but whether other factors display a more significant direct impact on ecosystem functioning than biodiversity remains to be studied. We investigated 398 samples of the phytoplankton phosphorus resource use efficiency (RUEP = chlorophyll-a concentration/dissolved phosphate) across two seasons in nine plateau lakes in Yunnan Province, China. We identified the main contributors to phytoplankton RUEP and analyzed their potential influences on RUEP at different lake trophic states. The results showed that total nitrogen (TN) contributed the most to RUEP among the nine lakes, whereas community turnover (measured as community dissimilarity) explained the most to RUEP variation across the two seasons. Moreover, TN also influenced RUEP by affecting biodiversity. Species richness (SR), functional attribute diversity (FAD2), and dendrogram-based functional diversity (FDc) were positively correlated with RUEP in both seasons, while evenness was negatively correlated with RUEP at the end of the rainy season. We also found that the effects of biodiversity and turnover on RUEP depended on the lake trophic states. SR and FAD2 were positively correlated with RUEP in all three trophic states. Evenness showed a negative correlation with RUEP at the eutrophic and oligotrophic levels, but a positive correlation at the mesotrophic level. Turnover had a negative influence on RUEP at the eutrophic level, but a positive influence at the mesotrophic and oligotrophic levels. Overall, our results suggested that multiple factors and nutrient states need to be considered when the ecosystem functioning predictors and the biodiversity-ecosystem functioning relationships are investigated.


Assuntos
Lagos , Fitoplâncton , China , Clorofila , Ecossistema , Nitrogênio/análise , Nutrientes , Fosfatos , Fósforo/análise
9.
Chemosphere ; 310: 136796, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36228722

RESUMO

Increased production and usage of organophosphate esters (OPEs) as flame retardants and plasticizers has trended towards larger and 'novel' (oligomeric) OPEs, although there is a dearth of understanding of the environmental fate, stability, toxicokinetics, biotransformation and bioaccumulation of novel OPEs in exposed biota. The present study characterized in vitro biotransformation of the novel OPE bisphenol-A bis(diphenyl phosphate) (BPADP) using Wistar-Han rat and herring gull liver based microsomal assays. Hypothesized target metabolites bisphenol-A (BPA) and diphenyl phosphate (DPHP) and other metabolites were investigated by applying a lines of evidence approach. In silico modelling predicted both BPA and DPHP as rat metabolites of BPADP, these metabolites were quantified via UHPLC-QQQ-MS/MS. Additional non-target metabolites were determined by UHPLC-Q-Exactive-Orbitrap-HRMS/MS and identified by Compound Discoverer software. Mean BPADP depletion of 44 ± 10% was quantified with 3.9% and 2.6% conversion to BPA and DPHP, respectively, in the rat assay. BPADP metabolism was much slower when compared to the well-studied OPE, triphenyl phosphate (TPHP). BPADP depletion in gull liver assays was far slower relative to the rat. Additional non-target metabolites identified included two Phase I, O-dealkylation products, five Phase I oxidation products and one Phase II glutathione adduct, demonstrating agreement between lines of in vitro and in silico evidence. Lines of evidence suggest that BPADP is biologically persistent in exposed mammals or birds. These findings add to the understanding of BPADP stability and biotransformation, and perhaps of other novel OPEs, which are factors highly applicable to hazard assessments of exposure, persistence and bioaccumulation in biota.


Assuntos
Retardadores de Chama , Fosfatos , Ratos , Animais , Fosfatos/metabolismo , Espectrometria de Massas em Tandem , Ratos Wistar , Organofosfatos/análise , Retardadores de Chama/análise , Biotransformação , Aves/metabolismo , Fígado/metabolismo , Ésteres/análise , Mamíferos/metabolismo
10.
Chemosphere ; 310: 136852, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36241115

RESUMO

Iron (Fe) salt was applied extensively to remove phosphorus (P) in wastewater treatment plants (WWTPs). Exploring the formation mechanism of iron-phosphorus compounds (FePs) during the chemical P removal (CPR) process is beneficial to P recovery. In this study, the performance of P removal, FePs speciation analysis and the kinetics of P removal under different conditions (pH, Fe/P molar ratio (Fe/Pmol), type of Fe salt, dissolved organic matters) were comprehensively investigated. More than 95% of P was removed under the optimal conditions with pH = 4.7, Fe/Pmol = 2, FeCl3 or polymeric ferric sulfate (PFS) as the coagulant. The FePs formation mechanism was considerably influenced by reaction conditions. Iron-phosphate compounds were the dominant FePs species (>76%) at pH < 6.2, while more iron oxides were formed at pH ≥ 6.2 with decreased P removal efficiency. When the initial Fe/Pmol was 2, iron-phosphate compound was the only product that was formed by the reaction between PO43- and Fe(III) or Fe(II) ions directly. More iron oxides were generated when the initial Fe/Pmol was 1 or 3. At Fe/Pmol = 1, the Fe(III) was hydrolyzed to form iron oxides and trapped PO43-, while at Fe/Pmol = 3, iron-phosphate compounds were produced firstly and the remaining Fe(III) was hydrolyzed to form iron oxides. The pseudo-second-order kinetic model simulated the chemical P removal process well. The reaction rate of P with Fe(II) was slower than that with Fe(III), but complete removal was still achieved when the reaction time was more than 30 min. Poly-Fe salt exhibited a fast P removal rate, while the removal efficiency depended on its iron content. Organic matters in wastewater with large molecular weight and multiple functional groups (such as humic acids) inhibited P removal rate but hardly affect the removal amount. This study provides an insight into CPR by Fe salts and is beneficial for P recovery in WWTPs.


Assuntos
Compostos Férricos , Compostos de Ferro , Compostos Férricos/química , Fósforo/química , Ferro/química , Fosfatos , Compostos Ferrosos/química , Óxidos/química
11.
Methods Mol Biol ; 2555: 103-114, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36306081

RESUMO

Phosphate release from inorganic and organic phosphorus compounds can be enzymatically mediated. Phosphate-releasing enzymes, comprising acid and alkaline phosphatases, are recognized as useful biocatalysts in applications such as plant and animal nutrition, bioremediation, and diagnostic analysis. Here, we describe a functional metagenomics approach enabling rapid identification of genes encoding these enzymes. The target genes are detected based on small- and large-insert metagenomic libraries derived from diverse environments. This approach has the potential to unveil entirely new phosphatase families or subfamilies and members of known enzyme classes that hydrolyze phosphomonoester bonds such as phytases. Additionally, we provide a strategy for efficient heterologous expression of phosphatase genes.


Assuntos
6-Fitase , Metagenômica , Metagenoma , Monoéster Fosfórico Hidrolases/genética , Monoéster Fosfórico Hidrolases/metabolismo , 6-Fitase/genética , Fosfatos
12.
J Environ Manage ; 325(Pt A): 116452, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36257228

RESUMO

Shrimp farming wastewater includes high amounts of phosphate and microbiological contaminants, necessitating further treatment before release into receiving water bodies. After 24 h of shrimp wastewater treatment, alginate beads containing the blue-green algal Synechocystis strain lacking the phosphate regulator gene (mutant strain ΔSphU) at 150 mg L-1 reduced phosphate content from 17.5 mg L-1 to 5.0 mg L-1, representing 71.5% removal efficiency, with phosphate removal rate reaching 6.9 mg gDW-1 h-1 during photobioreactor operation. For short-term treatment, removal rates of nitrate, ammonium and nitrite were 42.7, 48.5 and 92.9%, respectively. Microalgal encapsulated beads also impacted the bacterial community composition dynamics in shrimp wastewater. Next-generation sequencing targeting the V3-V4 region of the 16S rDNA gene showed significant differences in bacterial community composition after 24 h of treatment. Proteobacteria are the most abundant phylum in shrimp wastewater. After 24 h of bioremediation, reductions of harmful bacteria in the Cellvibrionaceae and Pseudomonadaceae families were recorded at 5.85 and 3.18%, respectively. Engineered microalgal immobilization under optimal conditions can be applied as an alternative short-term bioremediation strategy to remove phosphate and other harmful microbial contamination from shrimp farming wastewater.


Assuntos
Microalgas , Purificação da Água , Humanos , Águas Residuárias/microbiologia , Fosfatos , Bactérias/genética , Biomassa
13.
J Environ Manage ; 325(Pt B): 116424, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36283167

RESUMO

The effective removal of radioactive strontium (especially 90Sr) from nuclear wastewater is crucial to environmental safety. Nevertheless, materials with excellent selectivity in Sr removal remain a challenge since the similarity with alkaline earth metal ions in the liquid phase. In this work, a novel titanium phosphate (TiP) aerogel was investigated for Sr(II) removal from the radioactive wastewater based on the sol-gel method and supercritical drying technique. The TiP aerogel has amorphous, three-dimensional and mesoporous structures with abundant phosphate groups, which was confirmed by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), atomic force microscope (AFM) and Fourier transform infrared spectroscopy (FT-IR). The adsorbent exhibited high efficiency and selectivity for the removal of Sr(II) with an extensive distribution coefficient up to 4740.03 mL/g. The adsorption equilibrium reached within 10 min and the maximum adsorption capacity was 373.6 mg/g at pH 5. And the kinetics and thermodynamics data fitted well with the pseudo-second-order model and Langmuir model respectively. It can be attributed to the rapid trapping and slow intraparticle diffusion of Sr(II) inside the mesoporous channels of the TiP aerogel. Furthermore, TiP aerogel exhibited over 80% removal for 50 mg/L Sr2+ in real water systems (seawater, lake water and tap water). X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy revealed that strong ionic bonding formed during Sr(II) adsorption with the phosphate group on TiP aerogel. These results indicated that TiP aerogel is a promising high-capacity adsorbent for the effective and selective capture of Sr(II) from radioactive wastewater.


Assuntos
Estrôncio , Poluentes Químicos da Água , Estrôncio/análise , Águas Residuárias/química , Espectroscopia de Infravermelho com Transformada de Fourier , Adsorção , Poluentes Químicos da Água/química , Água/química , Cinética , Fosfatos , Concentração de Íons de Hidrogênio
14.
J Environ Manage ; 325(Pt A): 116553, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36283197

RESUMO

This study investigated the effects of different carbon-based additives including biochar, woody peat, and glucose on humic acid, fulvic acid, and phosphorus fractions in chicken manure composting and its potential for phosphorus mobilization in soil. The results showed that the addition of glucose effectively increased the total humic substance content (90.2 mg/g) of composts, and the fulvic acid content was significantly higher than other groups (P < 0.05). The addition of biochar could effectively improve the content of available phosphorus by 59.9% in composting. The addition of carbon-based materials to the composting was beneficial for the production of more stable inorganic phosphorus in the phosphorus fraction. The highest proportion of soluble inorganic phosphorus components of sodium hydroxide was found in group with woody peat addition (8.7%) and the highest proportion of soluble inorganic phosphorus components of hydrochloric acid was found in group with glucose addition (35.2%). The compost products with the addition of biochar (humic acid decreased by 17.9%) and woody peat (fulvic acid decreased by 72.6%) significantly increased soil humic acid mineralization. The compost products with the addition of biochar was suitable as active phosphate fertilizer, while the compost products with the addition of glucose was suitable as slow-release phosphate fertilizer.


Assuntos
Compostagem , Substâncias Húmicas/análise , Solo , Carbono/metabolismo , Fósforo , Fertilizantes , Esterco , Fosfatos , Glucose
15.
J Environ Manage ; 325(Pt A): 116548, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36308786

RESUMO

With the exacerbating water eutrophication globally, it is important to recover nitrogen (N) and phosphorus (P) from sewage for recycle. In this study, coconut shell biochar and ethylene diamine tetraacetic acid (EDTA) were added into the designed fluidized bed reactor (FBR) to create struvite-biochar. N and P released from struvite-biochar and the recovery efficiency of N and P from concentrated sludge supernatant were analyzed. Results showed that the optimal operation condition for hydraulic retention time (HRT), pH, Mg/P molar ration, and addition amount EDTA were 90 min, 9.5, 1.2, and 0.2 g/L, respectively. The recovery efficiency of NH4+-N and PO43--P, and purity struvite for FBR were 34.41%-38.05%, 64.95-68.40%, and 84.15%, respectively. The recovery efficiency of NH4+-N and PO43--P were respectively increased by 7.23% and 5.36% when FBR with addition of 0.33 g/L coconut shell biochar, but purity struvite from struvite-biochar decreased by 45.70%. Contents of As, Cd, Pb, and Cr in struvite and struvite-biochar were all lower than Chinese Standard Limits of Fertilizer. Compared to commercial chemical fertilizer, such as superphosphate and urea, struvite-biochar and struvite have slowly released N and P. The amounts of released P, NO3--N and NH4+-N from struvite-biochar were higher than struvite during the five leaching times. Compared with struvite, the total amounts of released P, NO3--N and NH4+-N from struvite-biochar increased by 4.9%, 3.5% and 8.3%, respectively. Therefore, it is valuable to add biochar into FBR to recovery N and P from concentrated sludge supernatant and make struvite-biochar as a slow-release fertilizer.


Assuntos
Fertilizantes , Esgotos , Estruvita/química , Esgotos/química , Ácido Edético , Fósforo/química , Nutrientes , Fosfatos
16.
J Environ Manage ; 325(Pt B): 116570, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36308964

RESUMO

Struvite is a value-added by-product recovered from phosphorus-rich wastewater treatment by adding magnesium. Struvite is mainly used as slow-release fertilisers containing phosphate that can form insoluble salts with certain heavy metals. Hence, struvite may have potential application as a phosphate remediation agent for the immobilisation of heavy metals in contaminated soil, while the related study is limited. Similarly, an analogue compound of struvite, K-struvite, may also have this value but has not been reported elsewhere. This study investigated the effect of struvite and K-struvite on the remediation of Cr-spiked and Pb-spiked soil. To evaluate the feasibility, the agent dosage and two quality parameters (particle size and purity) of struvite and K-struvite were considered for the experimental design and statically analysed by principal component analysis (PCA) and partial least squares (PLS). The results show that the dosage significantly impacts the immobilisation process, while the effect of particle size and purity are negligible. Struvite and K-struvite have similar performance on heavy metals immobilisation, and both are significant in Pb immobilisation (up to 96% of F5, stable fraction) and are beneficial for reducing the most mobilised fractions (F1 and F2) of Cr to lesser than 3%. Struvite and K-struvite share similar performance due to their similar atomic radius, and the different performance between Cr and Pb immobilisation can be explained by the strong hydrolysis trend of chromium ion, which may inhibit the binding of the phosphate and chromium. The kinetic study finds that all three variables positively impact the free chromium ion, and the immobilisation process is fast so unlikely to be kinetically limited. These findings of this project will provide insight into how the immobilisation process changes in response to the dosage and quality of struvite compounds.


Assuntos
Metais Pesados , Poluentes do Solo , Estruvita/química , Chumbo , Metais Pesados/química , Solo/química , Poluentes do Solo/análise , Cromo , Fosfatos/química
17.
J Colloid Interface Sci ; 630(Pt B): 193-201, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36327722

RESUMO

The specific effects of salts (strong electrolytes) on biomolecular properties have been investigated for more than a century. By contrast, the specific role of pH buffers (weak electrolytes and their salts) has usually been ignored. Here, specific buffer effects on DNA thermal stability were evaluated by measuring the melting curve of calf thymus DNA through UV-vis spectroscopy. The study was carried out using phosphate, Tris, citrate and cacodylate buffers at fixed pH 7.4 at concentrations varying systematically in the range 1-600 mM. DNA stability increases with buffer concentration and is influenced specifically by buffer type. To interpret empirical data, a theoretical model was applied with parameters quantifying the impact of buffer on the DNA backbone charge. Comparing the buffer effects via buffer ionic strength rather than buffer concentration, we find that the buffers stabilize DNA in the order Tris > cacodylate > phosphate > citrate.


Assuntos
Ácido Cacodílico , Sais , Tampões (Química) , Ácido Cacodílico/química , DNA/química , Eletrólitos , Fosfatos/química , Citratos , Concentração de Íons de Hidrogênio
18.
Sci Total Environ ; 856(Pt 1): 158779, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36116658

RESUMO

In this study, brominated flame retardants (BFRs), phthalates, and organophosphate flame retardants (PFRs) were analyzed in indoor household dust collected during the COVID-19 related strict lockdown (April-July 2020) period. Floor dust samples were collected from 40 households in Jeddah, Saudi Arabia. The levels of most of the analyzed chemicals were visibly high and for certain chemicals multifold high in analyzed samples compared to earlier studies on indoor dust from Jeddah. Bis (2-ethylhexyl) phthalate (DEHP) was the primary chemical in these dust samples, with a median concentration of 769,500 ng/g of dust. Tris (2-butoxy ethyl) phosphate (TBEP) and Decabromodiphenyl ether (BDE 209) contributed the highest among PFRs and BFRs with median levels of 5990 and 940 ng/g of dust, respectively. The estimated daily exposure in the worst case scenario (23,700 ng/kg bw/day) for Saudi children was above the reference dose (20,000 ng/kg bw/day) for DEHP, and the hazardous index (HI) was also >1. The long-term carcinogenic risk was above the 1 × 10-5, indicating a risk to the health of Saudi young children from getting exposed to DEHP from indoor dust. This study draws attention to the increased indoor pollution during the lockdown period when all of the daily activities by adults and children were performed indoors, which negatively impacted human health, as suggested by the calculated risk. However, the current study has limitations and warrants more monitoring studies from different parts of the world to understand the phenomenon. At the same time, this study also highlights another side of COVID-19 related to our lives.


Assuntos
Poluição do Ar em Ambientes Fechados , COVID-19 , Dietilexilftalato , Retardadores de Chama , Criança , Adulto , Humanos , Pré-Escolar , Retardadores de Chama/análise , Poeira , Organofosfatos/análise , COVID-19/epidemiologia , Poluição do Ar em Ambientes Fechados/análise , Exposição Ambiental/análise , Controle de Doenças Transmissíveis , Éteres Difenil Halogenados/análise , Compostos Organofosforados/análise , Fosfatos
19.
Sci Total Environ ; 856(Pt 1): 159050, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36174683

RESUMO

BACKGROUND: Evidence from in vitro and rodent studies suggests that organophosphate esters (OPEs) may disrupt sex steroid hormone homeostasis, but no human studies, to date, have examined the effects of in utero exposure to OPEs on offspring reproductive development. OBJECTIVE: Anogenital distance (AGD) is a sensitive biomarker of fetal hormonal milieu and has been used to assess reproductive toxicity. We evaluated the longitudinal effects of prenatal exposure to OPEs on the AGD of offspring from birth to 4 years. METHODS: Based on Shanghai-Minhang Birth Cohort Study, pregnant women provided urine samples at a gestational age of 12-16 weeks, which were analyzed for eight OPE metabolites. AGD was measured in offspring at birth and 0.5, 1, and 4 years of age. We used generalized estimating equations (GEE) and Bayesian kernel machine regression (BKMR) models to estimate the associations of prenatal exposure to individual OPE metabolites and OPE mixtures with AGD stratified by sex. RESULTS: A total of 733 mother-infant pairs were analyzed. Prenatal exposure to diphenyl phosphate and bis-(2-ethylhexyl) phosphate was associated with decreased AGD in boys in GEE models. Bis-(1-chloro-2-propyl) phosphate (BCIPP) showed a similar but marginally significant effect. Prenatal exposure to most OPE metabolites was associated with decreased AGD in girls, with the most profound association observed for bis (2-butoxyethyl) phosphate (BBOEP) and alkyl-OPEs. The OPE mixture was also inversely associated with AGD in both sexes. The single-exposure effects of BKMR models were largely consistent with those observed in the GEE models. In addition, alkyl-OPEs, particularly BBOEP, contributed the most to the decreased AGD in girls, while BCIPP contributed the most to the decreased AGD in boys. CONCLUSIONS: This study provides the first human evidence that prenatal exposure to OPEs is associated with decreased AGD in offspring. The magnitude of these effects may vary depending on the structure of OPEs.


Assuntos
Efeitos Tardios da Exposição Pré-Natal , Masculino , Lactente , Recém-Nascido , Humanos , Feminino , Gravidez , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Estudos de Coortes , Teorema de Bayes , China , Organofosfatos/toxicidade , Organofosfatos/urina , Fosfatos
20.
Sci Total Environ ; 856(Pt 1): 159091, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36191718

RESUMO

Accurate on-site profiling of the pollutants is of vital significance for estimating environmental pollution. Herein, we propose a paper-based fluorescence-sensing system to precisely report the level of multiple pollutants. A high-performance fluorescence-sensor for apparatus-free and visual on-site tandem precisely reporting phosphate ions (Pi), o-phenylenediamine (OPD), and benzaldehyde (BA) levels have been fabricated successfully by introducing synthesized red emission (>600 nm) fluorescent chromophore 10-(diethylamino)-3-hydroxy-5,6-dihydrobenzo [c]xanthen-12-ium (HTD) into the environment of CoZn zeolitic imidazolate framework (CoZn ZIF) by a simple stirring method. CoZn ZIF@HTD with the bimetallic nodes not merely provided main Zn2+ sites for specific recognition of Pi to generate an enhanced red fluorescent optical signal, Co3+/Co2+ exhibited excellent peroxidase-like activity for the catalytic oxidation of OPD substrate in the presence of H2O2 resulting in color changing from red to yellow. Subsequently, the obvious yellow fading of the OPDox species took place with the addition of BA. By virtue of the sensitively visual tandem detection of Pi, OPD, and BA, the sensor can be applied to real wastewater samples. Meanwhile, this fluorescent sensor was further adopted for practical application in confocal cell imaging and security inks. Overall, this work established a fluorescent sensing system with integrated multifunctional applications for environmental and biological samples, implying the great potential for simultaneous real-time cascade detection of various important pollutants with the merit of low-cost, time-saving, and easy-to-use.


Assuntos
Poluentes Ambientais , Zeolitas , Peróxido de Hidrogênio , Benzaldeídos , Fosfatos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...