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1.
J Colloid Interface Sci ; 667: 32-43, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38615621

RESUMO

It has been a challenge to prepared polyether block amide (PEBA) fibrous membrane via solution electrospinning. The only few reported methods though involved hazardous solvents and surfactants which were against the principle of green chemistry. In this work, uniform fibrous membrane of PEBA was successfully fabricated by solution electrospinning with a bio-based solvent dihydrolevoglucosenone (Cyrene). To further improve the mechanical strength and adsorption performance of the PEBA membrane, a hierarchical magnesium hydrogen phosphate (MgHPO4·1.2H2O, MHP) was synthesized to blend evenly into the PEBA matrix. A Janus MHP/PEBA membrane with one side of hydrophobic surface and the other side of hydrophilic surface was subsequently prepared, which exhibited fast adsorption, high capacity, good selectivity and reusability towards ibuprofen, acetaminophen, carbamazepine and triclosan. In addition, the Janus membrane showed high removal efficiency of the above contaminants in secondary wastewater effluent with good long term stability. It demonstrated that this Janus MHP/PEBA membrane had a good potential in practical wastewater treatment.


Assuntos
Membranas Artificiais , Química Verde , Adsorção , Poluentes Químicos da Água/isolamento & purificação , Poluentes Químicos da Água/química , Fosfatos/química , Fosfatos/isolamento & purificação , Polímeros/química , Propriedades de Superfície , Preparações Farmacêuticas/química , Preparações Farmacêuticas/isolamento & purificação , Amidas/química , Amidas/isolamento & purificação , Tamanho da Partícula , Purificação da Água/métodos , Cosméticos/química , Cosméticos/isolamento & purificação
2.
Int J Biol Macromol ; 266(Pt 1): 131178, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38554905

RESUMO

Although adsorbents are good candidates for removing phosphorus and heavy metals from wastewater, the use of biosorbents for the sequential treatment of phosphorus and copper has not yet been studied. Porous chitosan (CS)-based biosorbents (CGBs) were developed to adsorb phytic acid (PA), a major form of organic phosphate. This first adsorbate (PA) further served as an additional ligand (P-type ligand) for the CGBs (N-type ligand) to form a complex with the second adsorbate (copper). After the adsorption of PA (the first adsorbate), the spent CGBs were recycled and used as a new adsorbent to adsorb Cu(II) ions (the second adsorbate), which was expected to have a dual coordination effect through P, N-ligand complexation with copper. The interactions and complexation between CS, PA and Cu(II) ions on the PA-adsorbed CGBs (PACGBs) were investigated by performing FTIR, XPS, XRD, and SEM-EDS analyses. The PACGBs exhibited fast and enhanced adsorption of Cu(II) ions, owing to the synergistic effect of the amino groups of CS (the original ligand, N-type) and the phosphate groups of PA (an additional ligand, P-type) on the adsorption of Cu(II) ions. This is the first time that sequential removal of phosphorus and heavy metals by biosorbents has been performed using biosorbents.


Assuntos
Quitosana , Cobre , Fosfatos , Purificação da Água , Quitosana/química , Cobre/química , Cobre/isolamento & purificação , Adsorção , Fosfatos/química , Fosfatos/isolamento & purificação , Purificação da Água/métodos , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Íons/química , Águas Residuárias/química , Ácido Fítico/química
3.
Artigo em Inglês | MEDLINE | ID: mdl-33678136

RESUMO

The physicochemical treatment (PT) of food industry wastewater was investigated. In the first stage, calcium magnesium acetate (CaMgAc4) was synthesized using eggshell (biocalcium), magnesium oxide and acetic acid in a 1:1:1 stoichiometric ratio. In the synthesis process, the thermodynamic parameters (ΔH, ΔS and ΔG) indicated that the reaction was endothermic and spontaneous. The samples were characterized by infrared spectroscopy (IR), scanning electronic microscopy (SEM), X-ray diffraction (XRD) and electron X-ray dispersive spectroscopy (EDS). CaMgAc4 was used to precipitate the phosphate matter. IR analysis revealed that the main functional groups were representative of the acetate compounds and the presence of OH- groups and carbonates. In the physicochemical treatment, a response surface design was used to determine the variables that influence the process (pH, t, and concentration), and the response variable was phosphorus removal. The treatments were carried out in the wastewater industry with an initial concentration of 658 mg/L TP. The optimal conditions of the precipitation treatment were pH 12, time 12 min, and a CaMgAc4 concentration of 13.18 mg/L. These conditions allowed the total elimination (100%) of total phosphorus and phosphates, 81.43% BOD5 and 81.0% COD, 98.9% turbidity, 95.01% color, and 92% nitrogen matter.


Assuntos
Cálcio/química , Casca de Ovo/química , Indústria Alimentícia , Fosfatos/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/isolamento & purificação , Acetatos/química , Animais , Precipitação Química , Concentração de Íons de Hidrogênio , Óxido de Magnésio/química , Fosfatos/análise , Fosfatos/química , Águas Residuárias/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química
4.
J Parasitol ; 107(2): 141-146, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33662114

RESUMO

Early diagnosis of trichinellosis is still difficult because of the lack of specific symptoms and limited window for serological detection. Here we established an assay based on tracing phosphate ions generated during loop-mediated isothermal amplification (LAMP) to detect Trichinella spiralis DNA in rat feces during its early stage of infection. By targeting a 1.6-kb repetitive element of Tri. spiralis, the assay was able to detect Tri. spiralis DNA in the feces of all infected rats as early as 1 day postinfection (dpi). The positive detection lasted to 7 dpi in the rats infected with 250 muscle larvae, and 21 dpi in the rats infected with 5,000 larvae. The assay was highly sensitive, and could detect 1.7 femtograms (fg) of Tri. spiralis DNA with high specificity, and with no cross reactivity with the DNA from Anisakis pegreffii, Gnathostoma spinigerum, Angiostrongylus cantonensis, Enterobius vermicularis, Schistosoma japonicum, and Trypanosoma evansi. Our present study provided a reliable technique for the early diagnosis of trichinellosis with the advantages of simplicity and speed, as well as high sensitivity and specificity.


Assuntos
DNA de Helmintos/isolamento & purificação , Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico , Fosfatos/isolamento & purificação , Trichinella spiralis/isolamento & purificação , Triquinelose/parasitologia , Animais , Fezes/parasitologia , Fosfatos/metabolismo , Plasmídeos , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Sensibilidade e Especificidade , Trichinella spiralis/genética , Trichinella spiralis/crescimento & desenvolvimento , Triquinelose/diagnóstico
5.
Carbohydr Polym ; 255: 117335, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33436178

RESUMO

Nanocellulose has gained much attention because of its excellent properties. Cationic cellulose nanocrystals (cCNC) shows good adsorptivity toward negative ions and molecules. Phosphate binders are most used to treat hyperphosphatemia and it is significant to develop its alternatives with high specific and low cost in the clinic. Herein, we prepared cCNC and characterized it by FTIR, TEM, dynamic light scattering, and viscosity method. We simulated the binding process of cationic cellulose for phosphate and used it as phosphate binder for hyperphosphatemia therapy to study the phosphate binding effect and evaluate the oral toxicity. Cationic cellulose improved the conditions of mice models and efficiently decreased the level of phosphate in the serum. cCNC had a better binding effect than cationic microcrystalline cellulose both in vitro and in vivo. cCNC could be used as alternatives to phosphate binder for therapy of chronic renal failure and hyperphosphatemia.


Assuntos
Celulose/farmacologia , Quelantes/farmacologia , Hiperfosfatemia/tratamento farmacológico , Rim/efeitos dos fármacos , Nanopartículas/química , Fosfatos/isolamento & purificação , Adenina/administração & dosagem , Adsorção , Animais , Biomarcadores/sangue , Celulose/química , Celulose/metabolismo , Quelantes/metabolismo , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Modelos Animais de Doenças , Fezes/química , Humanos , Hiperfosfatemia/induzido quimicamente , Hiperfosfatemia/metabolismo , Hiperfosfatemia/patologia , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/metabolismo , Rim/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas/administração & dosagem , Fosfatos/metabolismo , Resultado do Tratamento , Triglicerídeos/sangue
6.
Kidney Blood Press Res ; 46(1): 53-62, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33477164

RESUMO

BACKGROUND: Our research group has previously reported a noninvasive model that estimates phosphate removal within a 4-h hemodialysis (HD) treatment. The aim of this study was to modify the original model and validate the accuracy of the new model of phosphate removal for HD and hemodiafiltration (HDF) treatment. METHODS: A total of 109 HD patients from 3 HD centers were enrolled. The actual phosphate removal amount was calculated using the area under the dialysate phosphate concentration time curve. Model modification was executed using second-order multivariable polynomial regression analysis to obtain a new parameter for dialyzer phosphate clearance. Bias, precision, and accuracy were measured in the internal and external validation to determine the performance of the modified model. RESULTS: Mean age of the enrolled patients was 63 ± 12 years, and 67 (61.5%) were male. Phosphate removal was 19.06 ± 8.12 mmol and 17.38 ± 6.75 mmol in 4-h HD and HDF treatments, respectively, with no significant difference. The modified phosphate removal model was expressed as Tpo4 = 80.3 × C45 - 0.024 × age + 0.07 × weight + ß × clearance - 8.14 (ß = 6.231 × 10-3 × clearance - 1.886 × 10-5 × clearance2 - 0.467), where C45 was the phosphate concentration in the spent dialysate measured at the 45th minute of HD and clearance was the phosphate clearance of the dialyzer. Internal validation indicated that the new model was superior to the original model with a significantly smaller bias and higher accuracy. External validation showed that R2, bias, and accuracy were not significantly different than those of internal validation. CONCLUSIONS: A new model was generated to quantify phosphate removal by 4-h HD and HDF with a dialyzer surface area of 1.3-1.8 m2. This modified model would contribute to the evaluation of phosphate balance and individualized therapy of hyperphosphatemia.


Assuntos
Hemodiafiltração/métodos , Hiperfosfatemia/terapia , Fosfatos/isolamento & purificação , Diálise Renal/métodos , Idoso , Estudos Transversais , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade
7.
Int J Biol Macromol ; 168: 750-759, 2021 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-33232702

RESUMO

Phosphate and nitrate are commonly used industrial and agricultural nutrients that are of great anxiety because of their ubiquitous existence in water and wastewater sources and association with harmful health effects. Herein, we aimed to fabricate a novel and environmental-friendly chitosan encapsulated magnetic kaolin beads for the first time and applied for the adsorption of phosphate and nitrate ions from water. The physico-chemical properties of MK-chitosan beads were established by XRD, FTIR, and TGA-DSC techniques. Surface area (BET) analysis shows that MK-chitosan beads have a specific surface area of 2.12 m2/g. Surface morphology and elemental studies (SEM and EDAX) revealed the porous nature of MK-chitosan beads. The synthesized bead material employed as selective and effective adsorbent material for the remediation of phosphate and nitrate from water/ wastewater. The impact of external adsorption influencing effects likes, adsorbent dose, contact time, co-anions, pH of the solution, and temperature experiments have been performed. Adsorption isotherm and kinetic experiments have been studied and the data have been well tailored by the Freundlich isotherm and pseudo-second-order kinetic models. Thermodynamic parametric studies revealed endothermic and spontaneous nature of the overall sorption system. Besides, MK-chitosan beads were found to regeneration performance up to eight consecutive cycles. Furthermore, the adsorbent-adsorbate system implying that MK-chitosan beads could be a promising candidate for the removal of phosphate and nitrate ions from aqueous solutions.


Assuntos
Quitosana/química , Caulim/química , Nitratos/isolamento & purificação , Fosfatos/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Recuperação e Remediação Ambiental , Concentração de Íons de Hidrogênio , Cinética , Fenômenos Magnéticos , Temperatura
8.
Ultrason Sonochem ; 71: 105379, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33157359

RESUMO

The objective of this study was to evaluate the effect of ultrasound treatments with different durations (15, 20, 25, 30, and 35 min) at a low static temperature (12 °C) controlled by an intelligent temperature control and monitoring system on the quality of 50% reduced-phosphate frankfurters. The results show that without ultrasound treatment, phosphate reduction caused some obvious deficits in the textural properties, sensorial parameters, and oxidative stability of frankfurters. Moreover, 25-min ultrasound treatment could significantly lower the cooking loss and enhance emulsion stability, textural properties, and sensorial parameters of reduced phosphate frankfurters, which was also verified by dynamic water distribution analysis and microstructural observation. Additionally, low constant temperature during ultrasound treatment was another crucial factor in retarding lipid oxidation during storage. Therefore, ultrasound treatment with moderate duration and stable low temperature could be considered a successful approach to obtain healthier reduced-phosphate frankfurters under the "clean label" concept.


Assuntos
Produtos da Carne/análise , Fosfatos/análise , Temperatura , Ondas Ultrassônicas , Cor , Culinária , Manipulação de Alimentos , Proteínas de Carne/química , Fosfatos/isolamento & purificação , Estrutura Secundária de Proteína , Paladar
9.
Chemosphere ; 262: 128357, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182098

RESUMO

The cost-effective recovery of phosphate is of great significance to the mitigation of phosphorus resource depletion crisis. The electrochemical-decomposition of dolomite was developed to recover phosphate and ammonium from aqueous solution. The dolomite ore is mainly composed of CaMg(CO3)2 (53.73%), CaCO3 (28.93%) and SiO2 (16.59%). The continuous release of Mg2+ and Ca2+ were achieved by electrochemically decomposing dolomite ore, accompanied by the generation of base solution (9.0-10.5). The main factors affecting the recovery performance of phosphate (PO4-P) and ammonium (NH4-N) are current, initial concentration of PO4-P and NH4-N, initial pH of feed solution and feed rate. For a 30-d operation, the recovery rate of PO4-P was maintained at 90-97% and that of NH4-N at 50-60% under optimized operating conditions. The recovered product had low water solubility but high citric-acid-soluble, and was proposed as a slow-release fertilizer for crops. The proposed process as a simple, effective and green route may serve as a new strategy for recovering PO4-P and NH4-N from wastewaters.


Assuntos
Compostos de Amônio/química , Carbonato de Cálcio/química , Técnicas Eletroquímicas/métodos , Magnésio/química , Fosfatos/química , Eliminação de Resíduos Líquidos/métodos , Compostos de Amônio/isolamento & purificação , Cálcio/química , Eletrodos , Fertilizantes , Concentração de Íons de Hidrogênio , Fosfatos/isolamento & purificação , Fósforo/química , Dióxido de Silício , Soluções , Águas Residuárias/química , Poluentes Químicos da Água/química
10.
Sci Rep ; 10(1): 17504, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-33060672

RESUMO

In renal failure, hyperphosphatemia is common and correlates with increased mortality making phosphate removal a key priority for dialysis therapy. We investigated phosphate clearance, removal and serum level, and factors associated with phosphate control in patients undergoing continuous ambulatory (CAPD), continuous cyclic (CCPD) and automated (APD) peritoneal dialysis (PD). In 154 prevalent PD patients (mean age 53.2 ± 17.6 year, 59% men, 47% anuric), 196 daily collections of urine and 368 collections of dialysate were evaluated in terms of renal, peritoneal and total (renal plus peritoneal) phosphorus removal (g/week), phosphate and creatinine clearances (L/week) and urea KT/V. Dialytic removal of phosphorus was lower in APD (1.34 ± 0.62 g/week) than in CAPD (1.89 ± 0.73 g/week) and CCPD (1.91 ± 0.63 g/week) patients; concomitantly, serum phosphorus was higher in APD than in CAPD (5.55 ± 1.61 vs. 4.84 ± 1.23 mg/dL; p < 0.05). Peritoneal and total phosphate clearances correlated with peritoneal (rho = 0.93) and total (rho = 0.85) creatinine clearances (p < 0.001) but less with peritoneal and total urea KT/V (rho = 0.60 and rho = 0.65, respectively, p < 0.001). Phosphate removal, clearance and serum levels differed between PD modalities. CAPD was associated with higher peritoneal removal and lower serum level of phosphate than APD.


Assuntos
Falência Renal Crônica/terapia , Diálise Peritoneal/métodos , Fosfatos/isolamento & purificação , Insuficiência Renal/terapia , Adulto , Idoso , Creatinina/sangue , Estudos Transversais , Soluções para Diálise , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Diálise Peritoneal Ambulatorial Contínua , Peritônio , Diálise Renal , Ureia/sangue
11.
IET Nanobiotechnol ; 14(6): 527-536, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32755963

RESUMO

Montmorillonite (MMT) clay modified with lanthanum (La) ions and Fe3O4 nanoparticles was proposed for the effective removal of phosphate ions from aqueous solution. Characterisation of the adsorbent using FTIR, SEM, XRD, XPS, XRF, BET and VSM techniques were carried out. The effects of initial phosphate concentration, contact time, dosage and pH on the phosphorus adsorption were investigated. La-MMT/Fe3O4 exhibited an excellent adsorption capacity of up to 14.35 mg/g, with 97.8% removal within 60 min. Langmuir isotherm model fits well with the equilibrium isotherm data, with a maximum adsorption capacity of 15.53 mg/g at room temperature. The kinetic study was well fitted with pseudo-second-order kinetics, and the adsorption rate was mainly controlled by liquid-film diffusion. The manufactured adsorbent was effectively regenerated using 0.1 M NaOH solutions, with 90.18% adsorption efficiency remaining after six adsorption/desorption cycles. These results demonstrate that La-MMT/Fe3O4 provides an example of regenerable high-performance adsorbents for removal of PO43- from wastewater.


Assuntos
Bentonita/química , Lantânio/química , Nanopartículas de Magnetita/química , Fosfatos , Poluentes Químicos da Água , Difusão , Cinética , Fosfatos/análise , Fosfatos/química , Fosfatos/isolamento & purificação , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos
12.
Int J Biol Macromol ; 154: 188-197, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32171829

RESUMO

Nitrate and phosphate are primary pollutants of water/wastewaters for eutrophication and methemoglobinemia diseases, harshly threatening the security of aquatic environments and human health as well as all living beings. The present work investigates the adsorption performance and mechanism of lanthanum encapsulated chitosan-kaolin clay (LCK) hybrid composite was prepared and utilized for the remediation of nitrate and phosphate from water. The fabricated LCK hybrid composite was characterized using XRD, SEM, BET, EDAX, TGA-DTA and FTIR analysis. The removal of nitrate and phosphate onto the LCK composite defined by pseudo-second-order kinetic model whereas the isotherms are described by Freundlich adsorption isotherm model and thermodynamic experiments showed spontaneous and exothermic nature of the adsorption process. Results also demonstrated that the LCK hybrid composite exhibited extremely high nitrate and phosphate adsorption capacity and stability which followed the mechanisms by ion exchange, complexation and electrostatic interactions. Adsorption-desorption experiments revealed that the LCK hybrid composite could be potentially reused with maintaining high adsorption efficiency. This study highlights the novel low-cost, eco-friendly and promising adsorbent for efficient denitrification and dephosphorization from water/ wastewater.


Assuntos
Quitosana/química , Caulim/química , Lantânio/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água , Adsorção , Argila , Cinética , Nitratos/isolamento & purificação , Fosfatos/isolamento & purificação
13.
Chemosphere ; 247: 125799, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31951952

RESUMO

The biochemical properties of selected microorganisms (Bacillus pumilus, Brevibacterium antiquum, Myxococcus xanthus, Halobacterium salinarum and Idiomarina loihiensis), known for their ability to produce struvite through biomineralisation, were investigated. All five microorganisms grew at mesophilic temperature ranges (22-34 °C), produced urease (except I. loihiensis) and used bovine serum albumin as a carbon source. I. loihiensis was characterised as a facultative anaerobe able to use O2 and NO3 as an electron acceptor. A growth rate of 0.15 1/h was estimated for I. loihiensis at pH 8.0 and NaCl 3.5% w/v. The growth rates for the other microorganisms tested were 0.14-0.43 1/h at pH 7-7.3 and NaCl ≤1% w/v. All the microorganisms produced struvite, as identified by morphological and X-ray Powder Diffraction (XRD) analysis, under aerobic conditions. The biological struvite yield was between 1.5 and 1.7 g/L of media, the ortho-phosphate removal and recovery were 55-76% and 46-54%, respectively, the Mg2+ removal and recovery was 92-98% and 83-95%, respectively. Large crystals (>300 µm) were observed, with coffin-lid and long-bar shapes being the dominant morphology of biological struvite crystals. The characterisation of the biochemical properties of the studied microorganisms is critical for reactor and process design, as well as operational conditions, to promote phosphorus recovery from waste streams.


Assuntos
Bactérias/metabolismo , Biomineralização , Nutrientes/isolamento & purificação , Estruvita/metabolismo , Magnésio/isolamento & purificação , Fosfatos/química , Fosfatos/isolamento & purificação , Fósforo/química , Fósforo/isolamento & purificação , Eliminação de Resíduos Líquidos , Águas Residuárias/química
14.
Chemosphere ; 240: 124889, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31563102

RESUMO

This study explores the use of an engineered char produced from the pyrolysis of anaerobically digested fiber (ADF) to adsorb phosphate from aqueous solutions. Two series of engineered chars were produced. The first series was a CO2 activated (CA) char produced via slow pyrolysis between 350 and 750 °C. The second series was a nitrogen doped (ND) char activated in the presence of ammonia at comparable temperatures. Proximate analysis, elemental composition, gas physisorption, Inductively coupled plasma mass spectrometry (ICP-MS), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray powder diffraction (XRD) techniques were used to characterize properties of resulting products. The surface area of the carbon product increased after nitrogen doping through ammonization (166.6-463.1 m2/g) compared to CO2 activated chars (156.5-413.1 m2/g). Phosphate adsorption isotherms for both CO2 activated and nitrogen doped chars can be described by the Langmuir- Freundlich and Redlich Peterson adsorption models. Nitrogen doped carbon phosphate sorption capacity in aqueous solutions was twice compared to CO2 activated carbons. As carbonization/activation temperature increased the sorption capacity increased from 3.4 to 33.3 mg g-1 for CA char and 6.3-63.1 mg g-1 for nitrogen doped char.


Assuntos
Carvão Vegetal/química , Nitrogênio/química , Fosfatos/análise , Fosfatos/isolamento & purificação , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação
15.
Environ Int ; 134: 105322, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31739135

RESUMO

The separation of urine at source for phosphorus (P) recovery is attractive taking into account the high P concentration and small volume. However, the treatment of urine is still challenging due to its unpleasant odor and hygiene problems. Because the above problems could be solved by acidification to keep the pH of urine below 4, we propose a novel strategy to recover P from acidified urine using tailored hydrous zirconia-coated magnetite nanoparticles (Fe3O4@ZrO2). This strategy involves the selective adsorption of phosphate by easily separable and reusable Fe3O4@ZrO2, the desorption of adsorbed phosphate, and the precipitation of desorbed phosphate as calcium phosphate fertilizer. The results indicated that at pH 4, the P in synthetic urine was selectively adsorbed and could be exhausted using Fe3O4@ZrO2. Nearly all (>97.5%) of the sequestered P on the Fe3O4@ZrO2 nanoparticles was stripped using ≥1 M NaOH solution and ~100% of the stripped P was then successfully transformed into calcium phosphate, upon adding CaCl2 at pH >12 and a Ca/P molar ratio of 3. The liquid/solid (Fe3O4@ZrO2 particles) mixture could be conveniently separated for reuse using an external magnetic field. The reusability of the Fe3O4@ZrO2 nanoparticles in the extraction of P from synthetic urine was confirmed using five cycles of the adsorption-desorption process and their performance validated using real urine samples. The mechanism of phosphate adsorption was investigated using XPS, FTIR and zeta potential measurements, showing that phosphate was chemically adsorbed on the surface through direct coordination to zirconium atom via ligand exchange.


Assuntos
Nanopartículas de Magnetita , Fósforo/urina , Ácidos , Adsorção , Fracionamento Químico/métodos , Humanos , Concentração de Íons de Hidrogênio , Fosfatos/isolamento & purificação
16.
Chemosphere ; 243: 125380, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31760293

RESUMO

This work aims to evaluate the effect of new contaminant diclofenac (DCF) in sewage on the performance of Enhanced Biological Phosphorus Removal (EBPR) and its mechanism. The results showed that low-level DCF had no significant effect on EBPR. However, when the concentration of DCF was 2.0 mg/L, the removal efficiencies of chemical oxygen demand (COD), NH4+-N and soluble orthophosphate (SOP) decreased significantly to 71.2 ± 4.2%, 78.6 ± 2.9%, and 64.3 ± 4.2%, respectively. Mechanisms revealed that DCF promoted the ratio of protein to polysaccharide in activated sludge extracellular polymers and inhibited anaerobic phosphorus release and oxic phosphorus uptake. Intracellular polymer analysis showed that when the DCF content was 2.0 mg/L, the maximum content of polyhydroxyalkanoates (PHA) was only 2.5 ± 0.4 mmol-C/g VSS, which was significantly lower than that in the blank. Analysis of key enzyme activities indicated that the presence of DCF reduced the activities of exopolyphosphatase and polyphosphate kinase.


Assuntos
Diclofenaco/farmacologia , Fósforo/isolamento & purificação , Eliminação de Resíduos Líquidos/métodos , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos , Fosfatos/análise , Fosfatos/isolamento & purificação , Fósforo/química , Fósforo/farmacocinética , Poli-Hidroxialcanoatos/análise , Esgotos/química
17.
Sci Rep ; 9(1): 18083, 2019 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-31792245

RESUMO

Hyperphosphatemia is a secondary issue associated with chronic kidney disorder. Use of phosphate binders and dialysis are the treatments for hyperphosphatemia, albeit with harmful side effects and high cost, respectively. A safer and healthier approach is attempted to administer phosphate-accumulating organisms (PAOs) from probiotics to prevent hyperphosphatemia. However, screening and isolation of PAOs are limited by inefficient enrichment of relevant metabolism and contamination. Therefore, we devised a novel strategy to isolate elite PAOs from Lactobacillus casei JCM 1134 and Bifidobacterium adolescentis JCM 1275 (previously reported PAOs). PAOs were first enriched for phosphate uptake and incubated in low-pH phosphate-free media to dormant non-PAOs, and then purified using Percoll density gradient centrifugation. Subsequently, elite PAOs were isolated from centrifuged pellet on a toluidine blue O-supplemented agar-based media. Using this technique, elite PAOs could not only be isolated, but also semi-quantitatively scored for their phosphate accumulation capabilities. Additionally, these scores correlated well with their accumulated phosphate values. The elite PAOs isolated from L. casei and B. adolescentis showed 0.81 and 0.70 [mg-phosphate/mg-dry cell], respectively (23- and 4.34-fold increase, respectively). Thus, our method can be used to successfully isolate elite PAOs, which might be of use to prevent hyperphosphatemia at early stages.


Assuntos
Bifidobacterium adolescentis/metabolismo , Lacticaseibacillus casei/metabolismo , Fosfatos/metabolismo , Probióticos/metabolismo , Bifidobacterium adolescentis/isolamento & purificação , Técnicas de Cultura de Células , Centrifugação com Gradiente de Concentração , Humanos , Hiperfosfatemia/metabolismo , Hiperfosfatemia/terapia , Lacticaseibacillus casei/isolamento & purificação , Fosfatos/isolamento & purificação , Probióticos/isolamento & purificação
18.
Huan Jing Ke Xue ; 40(7): 3179-3185, 2019 Jul 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854716

RESUMO

In a cyclic alternating O/A operation mode, phosphorus accumulating organisms (PAOs) can undertake phosphate removal and enrichment as the main process in wastewater treatment plants. The effects of the concentration of carbon sources during the aerobic stage on phosphate removal and enrichment performance of PAO biofilms, and the microbial population structure in the biofilms, were investigated. The results showed that the aerobic COD concentration decreased from 200 mg·L-1 to 0 mg·L-1, the phosphorus uptake rate improved by 1.29 times, the phosphorus concentration in effluent stabilized below 0.5 mg·L-1, the phosphorus release rate increased by 3.56 times, and the phosphate concentration in the circulating solution increased from 27.125 mg·L-1 to 55.91 mg·L-1. With respect to the change in microbial communities, the identification showed that the abundance of Proteobacteria increased by approximately two times, and the enrichment effects of Rhodocyclaceae and Anaerolineaceae increased by 2.28 and 5 times, respectively. Reducing the concentration of the carbon source in the aerobic section was beneficial to the screening and enrichment of PAOs, strengthening the removal of phosphate in the aerobic section and the release of phosphate in the anaerobic section. This resulted in an enriched phosphate solution. These observations provide a theoretical basis for future urban sewage treatment plants seeking to reduce their carbon demand.


Assuntos
Biofilmes , Carbono , Fosfatos/isolamento & purificação , Eliminação de Resíduos Líquidos , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos/microbiologia , Fósforo , Proteobactérias , Rhodocyclaceae , Esgotos
19.
Chemosphere ; 235: 1015-1021, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31561290

RESUMO

Phosphate is one of the main contaminations in water, so an effective method of decreasing or removing phosphate is needed. The main purpose of this paper is to synthesize CaFe-LDHs and MgFe-LDHs from the mixture of calcined dolomite and ferric chloride to remove orthophosphate and pyrophosphate. The study showed that removal of orthophosphate was attributed to the precipitation by Ca2+ and adsorption by MgFe-LDHs, where the former played a main role. As for pyrophosphate, it was mainly removed by precipitation at the initial pyrophosphate concentration ranging from 3.228 to 17.04 mmol/L. When the initial concentrations became relatively higher, the removal efficiency of pyrophosphate decreased because the complexation effects by Fe3+, Ca2+ and Mg2+ took place.


Assuntos
Carbonato de Cálcio/química , Cloretos/química , Difosfatos/análise , Compostos Férricos/química , Hidróxidos/química , Magnésio/química , Fosfatos/análise , Poluentes Químicos da Água/análise , Difosfatos/isolamento & purificação , Fosfatos/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos
20.
Int J Biol Macromol ; 141: 1199-1209, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31518621

RESUMO

The eutrophication of water bodies resulting from the excessive amounts of phosphate and nitrate ions in the water systems will cause serious environmental problems. This study deals with the adsorptive removal of toxic anions from aqueous medium using zirconium entrenched chitosan-starch membrane (Zr-CS-ST). The optimization of several influencing key factors like adsorbent dosage, shaking time, solution pH, aggressive ions, zero point charge and temperature were examined by batch mode adsorption experiments. In addition, Freundlich isotherm model showed an outstanding fit with the experimental data's, yielding the maximum adsorption capacities of 86.28 and 70.88 mg/g for phosphate and nitrate, respectively. Thermodynamic parameters, including the Gibbs free energy, entropy and enthalpy change indicated that the removal of both anions by Zr-CS-ST membrane was feasible, spontaneity and endothermic in nature. The diffusion and reaction based kinetic models were exposed to study about the kinetics and adsorption process were followed by pseudo-second-order and intra-particle diffusion kinetic models. The removal mechanism involved by different types of interactions such as complexation, ion exchange and electrostatic interaction, which were adopted for the removal mechanisms. We exposed that, Zr-CS-ST was successfully developed and will be effectively employed for the remediation of phosphate and nitrate ions in field/practical applications.


Assuntos
Quitosana/química , Membranas Artificiais , Nitratos/química , Fosfatos/química , Amido/química , Água/química , Zircônio/química , Adsorção , Estudos de Viabilidade , Água Subterrânea/química , Concentração de Íons de Hidrogênio , Cinética , Nitratos/isolamento & purificação , Fosfatos/isolamento & purificação , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
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