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1.
Food Chem ; 368: 130841, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34425335

RESUMO

This study aimed to optimize an ion-exchange chromatography method for an accurate quantification of phosphates. Coelution of nucleotides was detected following the quantification of small amounts of di- and trimetaphosphates in hake fillets. In some samples, triphosphates were added to the glaze ice, therefore, defrosting waters (glaze ice + drip loss of fillets) should be analyzed for an effective assessment of the use of phosphates in seafood. Even low amounts of adenosine 5'-diphosphate (ADP) and inosine 5'-monophosphate (IMP) triggered false positive results for P2O74- and P3O93-. Keeping the initial isocratic conditions for longer was crucial for the separation of ADP from P2O74- and of IMP from P3O93-. The improved method showed that in general, hake fillets did not have diphosphates, and trimetaphosphates were residual. Triphosphates were clearly added in only four defrosting waters, and in most of the remaining ones, diphosphates and trimetaphosphates contents corresponded to false positive results.


Assuntos
Gadiformes , Fosfatos , Nucleotídeos de Adenina , Difosfato de Adenosina , Animais , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Difosfatos
2.
J Hazard Mater ; 421: 126758, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34352527

RESUMO

Organophosphorus compounds were proposed to impair immune surveillance and increase the total burden of pathogens. However, scarce attention has been paid to the effects of organophosphate flame retardants (OPFRs) on neutrophils. Previous literature outlined that neutrophil extracellular traps (NETs) death (NETosis) is associated with autophagy-related signaling. Here we found that 20 µM diphenyl phosphate (DPHP) could promote NETs formation via assessing markers of NETs and the morphological changes. Concurrently, flow cytometry and western blot analysis revealed that DPHP-triggered NETs formation was associated with reactive oxygen species (ROS) burst and activation of extracellular signal-regulated kinase (ERK) and p38. Additionally, the results revealed that autophagy occurred in DPHP-triggered NETs formation, manifested as enhanced LC3B protein expressions and reduced p62 protein expressions. Mechanism dissection revealed that inhibition of autophagy by 3-methyladenine (3-MA) alleviated the ROS burst and subsequent NETosis caused by DPHP. Conversely, autophagy enhancer Rapamycin (Rapa) augmented the above effects of DPHP, including the generation of ROS and NETosis. Collectively, these data suggested ERK/p38 signaling and ROS burst might be an important cause of DPHP-triggered NETs formation, while suppression of excessive autophagy could rescue these actions. These observations provided a theoretical basis for the treatment and prevention of OPFRs-induced immunotoxicity.


Assuntos
Armadilhas Extracelulares , Autofagia , Compostos de Bifenilo , MAP Quinases Reguladas por Sinal Extracelular , Organofosfatos , Fosfatos , Espécies Reativas de Oxigênio
3.
J Colloid Interface Sci ; 606(Pt 2): 2024-2037, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34749449

RESUMO

The remediation of non-reactive phosphate pollutants in the aquatic system is essential for protecting the ecological niche. In this work, a highly robust protein nanoparticles networked rare-earth metal carbonate-grafted bio-composite membrane (abbreviated as REMC) was fabricated via chemical crosslinking of three-dimensional (3D) hierarchical lanthanum carbonate (mREM) and casein nanoparticles (CsNPs) for selective rejection of non-reactive phosphates. The main components of the REMC membrane are mREM and CsNPs, which were prepared via SDS/CTAB templated homogeneous precipitation and the coacervation/desolvation hybrid method, respectively. The active lanthanum ion (La3+) on the 3D spherulitic surface of mREM exhibited excellent phosphate adsorption capacity (maximum adsorption capacity was 358 mg.g-1) across a wide pH range and in a multi-ionic environment. A series of batch testing and characterizations revealed that the active La3+ and dominating phosphate centers in the REMC membrane framework enable non-enzymatic phosphatase-like activity, cleaving the phosphate ester bond of organic phosphates and releasing free phosphate anions. These released phosphate ions are retained in the REMC membrane via an ion exchange mechanism, where they contribute to improved phosphate removal capacities. Furthermore, CsNPs have a dual function in the membrane, acting as a matrix in the REMC membrane framework and contributing to phosphate ion sequestrations in a synergistic manner. The catalysis of para-nitrophenyl phosphates (pNPP) to paranitrophenol (pNP) in a sequential dephosphorylation by REMC offers an estimate of reaction kinetics and elucidates the underlying mechanism of improved phosphate selectivity in a multi-ionic environment. Furthermore, phosphate specificity, homogeneous binding capacity, reusability, and visual observation of REMC membrane saturation binding direct it's useful economic, industrial applications in aqueous phosphate contaminant removal, which could be beneficial for the active recovery of the aquatic ecosystem.


Assuntos
Lantânio , Poluentes Químicos da Água , Adsorção , Catálise , Ecossistema , Concentração de Íons de Hidrogênio , Troca Iônica , Cinética , Organofosfatos , Fosfatos
4.
Chemosphere ; 286(Pt 1): 131490, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34293561

RESUMO

Excessive phosphate run-off with total phosphorus concentration greater than 20 µg P L-1 triggers the growth of harmful algal species in waterbodies and potentially leads to eutrophication. This has severe negative implications on aquatic environment and impacts human health. The annual economic impact of harmful algal blooms is reported to be as high as $25 million for public health and commercial fishery sector, $29 million for recreation/tourism sector and $2 million for monitoring and management. Adsorption is widely considered as an effective and economic strategy to achieve extremely low concentration of phosphorus. The char produced by valorizing various waste biomasses have been gaining attention in phosphorus remediation owing to their availability, their ability to regenerate and reuse. This review paper exclusively focuses on utilizing hydrochar and biochar synthesized from waste biomass, respectively, through hydrothermal carbonization and slow pyrolysis to mitigate phosphorus concentration and potential strategies for handling the spent char. The key mechanisms involved in phosphate adsorption are electrostatic interaction, ion exchange and complexation. The maximum adsorption capacity of hydrochar and biochar ranges from 14-386 mg g-1 and 3-887 mg g-1, respectively. Hydrochar and biochar are cost-effective alternative to commercial activated carbon and spent char can be used for multiple adsorption cycles. Furthermore, extensive research studies on optimizing the feedstock, reaction and activation conditions coupled with technoeconomic analysis and life cycle assessment could pave way for commercialization of char-based adsorption technology.


Assuntos
Carvão Vegetal , Águas Residuárias , Adsorção , Biomassa , Humanos , Fosfatos
5.
Chemosphere ; 286(Pt 1): 131643, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34311395

RESUMO

In recent years, various phosphate nanoparticles (PNPs) have been synthesized and applied for in situ Pb remediation in laboratory investigations. Here, three kinds of PNPs, CMC-nClAP (carboxymethyl cellulose stabilized nano-chlorapatite), SDS-nClAP (sodium dodecyl sulfate stabilized nano-chlorapatite) and Rha-nClAP (rhamnolipid stabilized nano-chlorapatite) were used to investigate the influence of PNPs on Pb bioavailability, enzyme activities and bacterial community in Pb polluted sediment. Pb bioavailability can be reduced by the application of CMC-nClAP, SDS-nClAP and Rha-nClAP with the maximum increases of residual fraction to 57.2 %, 58.3 % and 61.4 %, respectively. Alternatively, catalase activity, urease activity and protease activity also changed with the remediation of PNPs. Microbes responded quickly to PNPs in different ways: bacterial richness was all increased while bacterial diversity was only increased with the application of SDS-nClAP. Three dominant species, Proteobacteria, Firmicutes and Bacteroidetes were redistributed differentially during the treatment of PNPs. Interestingly, PNPs didn't significantly change the bacterial community structure in treated samples and CMC-nClAP induced fewer changes in microbial activity and community as compared with SDS-nClAP and Rha-nClAP. Overall, our findings suggested that long-term exposure to PNPs would decrease Pb bioavailability, regulate enzyme activities and affect bacterial community in sediments. The Pb bioavailability, physical-chemical properties of PNPs and properties of chemical/bio-surfactant may determine the response of microorganisms to PNPs in Pb polluted sediment.


Assuntos
Nanopartículas , Fosfatos , Bactérias , Disponibilidade Biológica , Chumbo/toxicidade
6.
Sci Total Environ ; 802: 149988, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34525699

RESUMO

Microalgae such Chlorella vulgaris can effectively absorb nitrate and phosphate from contaminated water. This work characterized nitrate and phosphate removal from simulated agricultural runoff using C. vulgaris. Statistically designed experiments were used to model the following responses: (1) algal growth; (2) nitrate removal; (3) phosphate removal; (4) protein in the algal biomass; (5) chlorophyll content of the biomass; (6) the biomass phenolics content; and (7) the free radical scavenging antioxidant activity of the biomass. These response were modelled for the following key experimental factors: initial nitrate concentration in the simulated runoff (1080-3240 mg L-1, as NaNO3), initial phosphate concentration (20-60 mg L-1, as K2HPO4), photoperiod (8-24 h of light/day) and culture duration (5-15 days). The validated models were used to identify the factor levels to maximize the various responses. Nitrate removal was maximized at 85.6% when initial nitrate and phosphate concentrations were 2322 mg L-1 and 38 mg L-1 (N:P atom ratio ≈ 125:1), respectively, with a 17.2 h daily photoperiod in a 13-day culture. Phosphate removal was maximized at 95% when the initial nitrate and phosphate concentrations were 1402 mg L-1 and 56.7 mg L-1 (N:P ≈ 51:1), respectively, with a 15.7 h daily photoperiod in a 14.7-day culture. At least ~14 h of a daily photoperiod and a ~11-day culture period were required to maximize all the studied responses. C. vulgaris is edible and may be used as animal feed. Nutritional aspects of the biomass were characterized. Biomass with more than 24% protein could be produced. Under the best conditions, the chlorophyll (potential food colorants) content of the biomass was 8.5% and the maximum level of total phenolics (antioxidants) in the biomass was nearly 13 mg gallic acid equivalent g-1.


Assuntos
Chlorella vulgaris , Microalgas , Biomassa , Nitratos , Fosfatos , Águas Residuárias , Água
7.
Chemosphere ; 287(Pt 2): 132177, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34826904

RESUMO

The carbonaceous materials have gained significant interest for the phosphorus species remediation and recovery in the last decade. Carbonaceous materials present many unique features, such as cost effective, availability, environmentally friendly, and high removal efficiency that make them a promising adsorbent. In this review, the recent application of carbonaceous materials including activated carbon (AC), graphene and graphene oxide (GO), lignin, carbon nanotubes (CNTs), and gC3N4 for phosphate removal and recovery were comprehensively summarized. The kinetics and isotherm models, removal mechanisms, and effects of operating parameters are reported. The reusability, lifetime of carbonaceous materials, and impact of modification were also considered. The modified carbonaceous materials have significantly high phosphate adsorption capacity compared to unmodified adsorbents. Namely, MgO-functionalized lignin-based bio-charcoal exhibited a 906.8 mg g-1 of capacity as the highest one among other reviewed materials. The modification of carbonaceous materials with various elements has been presented to improve the surface functional groups, surface area and charge, and pore volume and size. Among these loaded elements, iron has been effectively used to provide a prospect for magnetic recovery of the adsorbent as well as increase phosphate adsorption. Furthermore, the phosphate recovery methods, phosphate removal efficiency of carbonaceous materials, the limitations, important gaps in the literature, and future studies to enhance applicability of carbonaceous materials in real scale are also discussed.


Assuntos
Nanotubos de Carbono , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Cinética , Fosfatos , Poluentes Químicos da Água/análise
8.
Chemosphere ; 287(Pt 2): 132193, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34826906

RESUMO

In order to remove and recover uranium from acidic uranium-bearing wastewater in uranium mining and metallurgy. Herein, a novel chitosan/Chlorella pyrenoidosa composite adsorbent bearing phosphate ligand (CSP/CP) was designed and synthesized, demonstrating a high uranium adsorption capacity at a pH of 5 and excellent selectivity in an aqueous solution with eight coexisting ions. The CSP/CP exhibits a maximum adsorption capacity (1393.338 mg g-1) and selectivity (Su = 80.53%) for uranium, which is higher than many reported adsorbents. Mechanism analysis shows that the surface of CSP/CP is rich in hydroxyl, amino, phosphate and carboxyl groups, resulting in an excellent three-dimensional structure with active sites for high-performance uranium adsorption; U(VI) is selectively bound via ion exchanges with -COOH and -OH and through surface complexation with NH2 and PO. Furthermore, by desorption with 0.1 M Na2CO3 + 2% H2O2 at 318 K, CSP/CP can be recycled more than five times. It provides a new scientific basis for the preparation of high selectivity composite adsorbent by chitosan.


Assuntos
Quitosana , Chlorella , Urânio , Adsorção , Peróxido de Hidrogênio , Cinética , Ligantes , Fosfatos
9.
Chemosphere ; 287(Pt 2): 132209, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34826911

RESUMO

Soil cadmium (Cd) mobilized with phosphate-solubilizing bacteria (PSB), especially for strains effectively colonized in rhizosphere, is an important pathway for promoting its accumulation by Cd-hyperaccumulators. In this study, screened PSB strains, Acinetobacter pittii (AP) and Escherichia coli (EC), were used to evaluate their effects on Cd mobilization in rhizosphere, Cd accumulation by Solanum nigrum L., and rhizobacterial community and metabolic function under different colonization condition. Results indicated that AP or EC inoculated in soils significantly promoted plant growth, and simultaneously motivated Cd accumulation in S. nigrum L. by 119% and 88%, respectively, when compared with that of uninoculated treatment. Higher efficiency colonization of AP contributed to more organic acids (malic, l-proline, l-alanine, and γ-aminobutanoic) production in the rhizosphere soil and Cd accumulation by S. nigrum L., when compared with that of EC treatment. Taxonomic distribution and co-occurrence network analyses demonstrated that inoculation of AP or EC enriched dominant microbial taxa with plant growth promotion function and keystone taxa related to Cd mobilization in the rhizosphere soil, respectively. Inoculated strains up-regulated the expression of genes related to bacterial mobility, amino acid metabolism, and carbon metabolism among rhizobacterial community. Overall, this study provided a feasible method for soil Cd phytoremediation by promoting Cd mobilization with the enhancement of keystone taxa and organic acid secretion based on the high-efficiency colonization of PSB.


Assuntos
Poluentes do Solo , Solanum nigrum , Acinetobacter , Bactérias , Biodegradação Ambiental , Cádmio/análise , Fosfatos , Raízes de Plantas/química , Solo , Poluentes do Solo/análise
10.
Chemosphere ; 287(Pt 2): 132235, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34826926

RESUMO

Lead (Pb) pollution has become one of the most serious environmental problems in recent decades. However, there are few remediation technologies for insoluble cerussite (PbCO3), which are common in the environment and have high bioavailability. In this study, the immobilisation of Pb(II) released from PbCO3 by Pseudomonas rhodesiae HP-7 isolated from Pb-contaminated soil was studied. The results showed that hydroxyapatite and PbCO3 were dissolved by the organic acids secreted by the HP-7 strain, and then the dissolved Pb2+ and H2PO4- reacted to form low bioavailable Pb5(PO4)3Cl precipitate. XRD and mass conservation calculations showed that 85.7% of PbCO3 was transformed to Pb5(PO4)3Cl when P:Pb was 9:5. Our research showed that the HP-7 strain and hydroxyapatite could reduce the bioavailability of Pb(II) in PbCO3, which could be used for the remediation of Pb-polluted environments.


Assuntos
Chumbo , Poluentes do Solo , Carbonatos , Durapatita , Minerais , Fosfatos , Pseudomonas , Poluentes do Solo/análise
11.
Chemosphere ; 287(Pt 3): 132320, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34826951

RESUMO

Phosphate solubilizing bacteria (PSB) that can withstand high cadmium (Cd) stress is a desired combination for bioremediation. This study evaluated the Cd bioremediation potential of four PSB strains isolated from the contaminated soils of a municipal solid waste (MSW) discarding site (Guwahati, India). PSB strains were cultured in Pikovskaya (PVK) media, which led to higher acid phosphatase (ACP) activity and the release of organic acid. Optical density (OD) measurements were performed to determine the growth pattern of PSB; furthermore, Cd uptake by PSB was evaluated using infrared spectroscopy (IR) and X-Ray Diffraction (XRD) analyses. The 16S rRNA taxonomic analysis revealed that all the four promising PSB strains belonged to either Bacillus sp. or Enterobacter sp. One strain (SM_SS8) demonstrated higher tolerance towards Cd (up to 100 mg L-1). Flow cytometry analysis revealed 70.92%, 46.93% and 20.4% viability of SM_SS8 in 10, 50 and 100 mg L-1, respectively in PVK media containing Cd. This study has therefore substantiated the bioremediation of Cd from polluted soil by the PSB isolates. Thus, experimental results revealed a potential combo benefit, phosphate solubilization along with Cd remediation.


Assuntos
Poluentes do Solo , Solo , Bactérias , Biodegradação Ambiental , Cádmio/análise , Fosfatos , RNA Ribossômico 16S/genética , Microbiologia do Solo , Poluentes do Solo/análise , Instalações de Eliminação de Resíduos
12.
Ann Anat ; 239: 151836, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34563672

RESUMO

Soy isoflavone genistein interplays with numerous physiological or pathophysiological processes during ageing. However, its protective role and underlying mechanisms of action in the regulation of calcium (Ca2+) and phosphate (Pi) homeostasis in an animal model of the andropause are yet to be fully clarified. Wistar male rats (16-month-old) were divided into sham-operated, orchidectomized, orchidectomized estradiol-treated (0.625 mg/kg b.m./day) and orchidectomized genistein-treated (30 mg/kg b.m./day) groups. Treatments were administered subcutaneously for 3 weeks, while the controls received vehicle alone. Estradiol treatment increased the expression level of fibroblast growth factor receptor (FGFR) and parathyroid hormone 1 receptor (PTH1R), and activated mitogen - activated protein kinase kinase 1/2 (MEK 1/2) signaling pathway in the kidneys. Genistein application induced a prominent gene and protein expression of Klotho and downregulated the expression of FGFR and PTH1R in the kidney of andropausal rats. Activation of protein kinase B (Akt) signalling pathway was observed, while MEK 1/2 signaling pathway wasn't altered after genistein treatment. The increase of 25 (OH) vitamin D in the serum and decrease in Ca2+ urine content was observed after genistein application. Our findings strongly suggest genistein as a potent biocompound with beneficial effects on the regulation of Ca2+ and Pi homeostasis, especially during aging process when the balance of mineral metabolism is impaired. These novel data provide closer insights into the physiological roles of genistein in the regulation of mineral homeostasis.


Assuntos
Andropausa , Genisteína , Animais , Cálcio , Modelos Animais de Doenças , Genisteína/farmacologia , Homeostase , Masculino , Quinases de Proteína Quinase Ativadas por Mitógeno , Orquiectomia , Fosfatos , Ratos , Ratos Wistar , Transdução de Sinais
13.
Chemosphere ; 287(Pt 4): 132382, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34597641

RESUMO

Activation is an effective method to improve adsorption capacity of coal gangue, however, most activated gangues reported have limited adsorption capacity for phosphate because of the electronegativity, affecting their use in agricultural production and environmental protection. In order to enhance the phosphate absorption capacity of coal gangue through alkali-activation, three alkali-activated silicate coal gangue according to fine-size (AS-FCG1), medium-size (AS-MCG2), and large-size (AS-LCG3) were prepared through grinding, calcining (800 °C) and stimulating with Ca(OH)2 solution (0.1 M), and raw coal gangue (RCG4) was used as control. The results revealed that AS-FCG has the best modified effects, its maximum phosphate adsorption capacity, according to Langmuir model, was 11.796 mg g-1, which was 4.41, 8.16 and 73.73 times higher than that of AS-MCG, AS-LCG and RCG, respectively. The adsorption penetration time of AS-FCG packed column was over 30 h, which was longer than that of other samples. Besides, when the AS-FCG packed column loaded with phosphate was desorbed with distilled water, the phosphate concentration of filtrate was low and rapidly tended to 0 mg L-1, while when it was desorbed with NaHCO3 solution, the concentration remained high sustainably. The best adsorption performance of AS-FCG were associated with generation of calcium silicate hydrate gel and ettringite, which provided more Ca2+, Al3+, hydroxyl and larger specific surface area. It is suggested that alkali-activation is able to truly realize the recycling of solid waste, AS-FCG is an inexpensive, durable and eco-friendly material, which could not only be used to hold phosphate, but also release it slowly as fertilizer.


Assuntos
Carvão Mineral , Fosfatos , Adsorção , Álcalis , Cinética
14.
Chemosphere ; 287(Pt 4): 132396, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34597644

RESUMO

Activating peroxides to produce active substances is the key to advanced oxidation processes (AOPs), but this usually requires energy or is accompanied by additional contaminants. In this study, diclofenac (DCF) was effectively removed by peracetic acid (PAA) in phosphate buffer (PBS). According to the results of radical scavenging experiments and electron paramagnetic resonance (EPR), hydroxyl radical (•OH) and organic radicals (i.e., CH3C(=O)OO• and CH3C(=O)O•) generated from PBS-activated PAA might be the dominant reactive species responsible for DCF degradation. At neutral pH, PBS/PAA system exhibited the best degradation efficiency on DCF. Presence of NO3-, SO42- and Cl- had little effect on the removal of DCF, while HCO3- and natural organic matter (NOM) significantly inhibited DCF degradation in PBS/PAA system, resulting in the lower degradation efficiency of DCF in natural waters than that in ultrapure water. Finally, four possible degradation pathways, including hydroxylation, formylation, dehydrogenation and dechlorination, were proposed based on the detected reaction products. This study suggests that PBS used to control solution pH should be applied cautiously in PAA-based AOPs.


Assuntos
Diclofenaco , Poluentes Químicos da Água , Peróxido de Hidrogênio , Cinética , Ácido Peracético , Fosfatos , Poluentes Químicos da Água/análise
15.
Sci Total Environ ; 804: 149896, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34798712

RESUMO

Improving phosphorus (P) use efficiency is a challenge to promote a circular economy and greening the phosphorus cycle towards planetary sustainability. The disruptive innovation for phosphate fertilizers may help to reduce some unwelcome reactions that occur to P in soils. Monoammonium phosphate (MAP) coating with biodegradable organic polymers and the addition of magnesium (Mg) - a nutrient with a synergistic effect on the uptake of P, zinc (Zn), and boron (B) - emerge as a smart strategy to applying these micronutrients uniformly in soils. The objectives of this study were: to characterize the coated-MAP with biodegradable organic polymers, quantify the diffusion and availability of P in the soil, and evaluate the corn crop nutrition and yield during two crop seasons. The treatments were: MAP, MAP coated with biodegradable organic polymer (BOP), MAP + BOP + 1.3% of Zn + 0.33% of B, and MAP + BOP + 1.76% of Mg. The laboratory tests showed that the diffusion of MAP-based fertilizers was: MOMg (7.86 mm) = MO (8.82 mm) = MAP (8.84 mm) = MOM (8.51 mm) after 432 h. Coatings did not cause delays in the P-release in water at 25 °C since more than 95% of P was released within 24 h. In the field trials, the application of Mg, Zn, and B in the MAP coating did not increase nutrient leaf concentration. In the summer crop season, grain yield increased up to the P-rates of 85 kg of P2O5 ha-1, reaching the value of 6731 kg ha-1. Physical and chemical characteristics of MAP-fertilizers tend to improve with the coatings. The addition of biodegradable organic polymers, Mg, B, and Zn, as MAP-coatings did not enhance P diffusion, release, and availability in the soil and the crop nutrition. Coated-MAP improved corn yield only in the 2nd crop season.


Assuntos
Fertilizantes , Fosfatos , Fertilizantes/análise , Nitrogênio/análise , Fósforo , Solo , Zea mays
16.
J Environ Manage ; 301: 113923, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34634722

RESUMO

Phosphate is a major pollutant that deteriorates water quality and causes eutrophication, a novel calcium silicate hydrate composite cryogel (Cry-CSH) was thus successfully prepared for phosphate removal and recovery in this work. Calcium silicate hydrate (C-S-H) was mixed with the gel precursor (7.5% w/w) prepared from native starch and limewater (saturated calcium hydroxide solution as the cross-linker). The mixture was frozen and thawed for 3 cycles giving an interconnected macroporous composite. This had C-S-H nanoparticles (75 mg) immobilized on a monolithic floatable cryogel network (2.5 cm diameter × 1.0 cm height) enabling an easier recovery and without the losses that occur when using C-S-H nanoparticles. The phosphate adsorption reaches equilibrium at 120 min with adsorption capacity of 2.50 mgPO43-/gCry-CSH (65.42 mgPO43-/gC-S-H) under optimum conditions. Adsorption equilibrium data were well fit by the Freundlich isotherm model, while kinetic results were well fit by the pseudo second-order model. The calculated activation energy (Ea) of 43.9 kJ/mol indicates chemical adsorption, while a positive change in enthalpy (ΔH0, 19.3 kJ/mol) indicates the endothermic nature of phosphate adsorption. Cry-CSH can remove phosphate from wastewater and effluent samples with excellent removal efficiency (>98%). It can float on water surface for at least 105 days without damage, while its phosphate adsorbed form can be biodegraded within 10 days under soil buried conditions. Thus, this work demonstrated the significant potential of Cry-CSH for practical and environmentally friendly phosphate removal and recovery.


Assuntos
Fosfatos , Poluentes Químicos da Água , Adsorção , Compostos de Cálcio , Criogéis , Cinética , Silicatos , Amido
17.
J Colloid Interface Sci ; 606(Pt 1): 736-747, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34419814

RESUMO

Recently, biochar-related phosphate sorbents have been extensively investigated and achieved significant progress; however, there is still much room for enhancement on capturing performance and recovery of powdery ones after sorption. Herein, a new kind of adsorbent, in which biochar/Mg-Al spinel encapsulated in carboxymethyl cellulose-La hydrogels with cationic polymeric layers, was fabricated, aiming for integrating multi-advantages of each component for enhanced phosphate capture. Batch static experiments were correlated to the phosphate adsorption performance of the adsorbent. The maximum phosphate adsorption capacity of the adsorbent was 89.65 mg P/g at pH = 3. The Langmuir isotherm model and the pseudo-second-order kinetic model fitted well with the adsorption behavior of the adsorbent. More importantly, this composite adsorbent that integrated with biochar, Mg-Al spinel, cationic polymeric components exhibited favorable selectivity over coexisting anions (Cl-, SO42-, HCO3- and NO3-) and performed good reusability after five consecutive cycles. By virtue of the bead-like feature, fixed-bed column experiments demonstrated that the Thomas model fitted the breakthrough curves well under varied experimental conditions. The adsorption mechanism of phosphate on the designed composite adsorbent with multi-components could be described as the electrostatic attraction, ligand exchange and inner-sphere complexation, which might account for the efficient phosphate capturing performance.


Assuntos
Fosfatos , Poluentes Químicos da Água , Adsorção , Óxido de Alumínio , Carboximetilcelulose Sódica , Carvão Vegetal , Hidrogéis , Cinética , Óxido de Magnésio , Poluentes Químicos da Água/análise
18.
Chemosphere ; 286(Pt 3): 131786, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34411927

RESUMO

Phosphate rock (PR) is the main source of phosphorous used in fertilizers for Colombian soils. In many regions of Colombia, PR is applied directly to the soil, which affects eutrophication problems and phosphorus losses due to runoff, because to the low solubility of phosphorus in this georesource. In this article, phosphate rock samples from Colombia were treated with ethylenediamine tetra-acetic acid disodium salt dihydrate (2Na-EDTA) at different concentrations. PR obtained from the Media Luna Mine, located in Aipe, Huila (Colombia), was characterized using Infrared Spectroscopy, X-ray Diffraction and Scanning Electron Microscopy. Carbonate fluorapatite Ca9.74(PO4)5.45F2.05(CO3)0.53 (0.5%-61.5 %), hydroxyapatite - Ca5(PO4)3OH (26.6 %-84.0 %) and quartz- SiO2 (13.2 %) were the minerals found in the largest composition in the two samples of PR. The PR was crushed to powder (~125 µm) and it was treated with disodium EDTA dihydrate solutions at different concentrations [0.0025-0.1000 M]. Water-soluble phosphate was determined by UV-Vis spectrophotometry based on the ASTM -4500P method. The modified absolute solubility index (ASI*) was calculated for each EDTA treatment used in the phosphate rock, considering the total phosphorus solubilized in H2SO4 (40 % v/v) at 30 °C. The statistical analysis showed that there were significant differences between the treatments used, where (16.87 %) was presented highest ASI* for the treatment with 2Na-EDTA (0.353 M).


Assuntos
Fosfatos , Dióxido de Silício , Colômbia , Durapatita , Ácido Edético , Fósforo , Solo , Solubilidade
19.
Sci Total Environ ; 803: 149888, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34482146

RESUMO

In the present study, lanthanum hydroxide (La OH)-engineered sewage sludge biochar (La-SSBC) was utilized for efficient phosphate elimination from an aqueous medium. A high adsorption capacity of 312.55 mg P/g was achieved using La-SSBC at 20 °C, which was an excellent adsorbent performance in comparison to other biochar-based adsorbents. Additionally, the performance of La-SSBC was stable even at wider range of pH level, the existence of abundant active anions, and recycling experiments. Statistical physics modeling with the fitting method based on the Levenberg-Marquardt iterating algorithm, as well as various chemical characterizations, suggested the unique double-layered mechanism of phosphate capturing: one functional group of La-SSBC adsorbent describing a prone direction of the PO4 ions on the stabilize surface in a multi-ionic process, forming the first layer adsorption. Additionally, SSBC played an important role by releasing positively charged cations in solution, overcoming the electronic repulsion to form a second layer, and achieving excellent adsorption capacity. The calculation of multiple physicochemical parameters including adsorption energy further evidenced the process. This two-layered mechanism sheds light on the complex interaction between phosphate and biochar. Moreover, the management of sewage sludge associated with the requirement of cost-effectively and environmentally acceptable mode. Therefore, the present investigation demonstrated an efficient approach of the simultaneous sewage sludge utilization and phosphate removal.


Assuntos
Esgotos , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Cinética , Lantânio , Fosfatos , Poluentes Químicos da Água/análise
20.
Sci Total Environ ; 803: 150087, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34500276

RESUMO

We reported a new strategy for efficient phosphate removal from wastewaters, it relies on the discarded Artemia Cyst-shell in-situ growth of Al(OH)3 nanocluster, the charged amino-acids components of skeleton make available for the small size of Al(OH)3 formation (< 10 nm) with high activity, and the three-dimensional porous structure of discarded matrix provides fast kinetics and efficient Al(OH)3 nanoparticles utilization. These hybrid adsorbents exhibit ultrahigh capacity (850.5 mg/g) and fast kinetics (~2 min) by recent ten-years (2011-2020) survey, the superior selectivity against various foreign ions, with a distribution coefficient (Kd) as high as 4820 mL/g, the porous structure and fast kinetics also accelerate the phosphate accessibility, yielding a satisfactory capacity of ~3000 L/kg sorbent (Artemia CS-Al) for the application, even varying at high feeding-speeds. The saturated adsorbent can be readily regenerated and reused without decrease in performance, this technology is promising for mitigating the contamination problem of excess phosphate worldwide.


Assuntos
Cistos , Nanopartículas , Poluentes Químicos da Água , Adsorção , Animais , Artemia , Fosfatos , Água , Poluentes Químicos da Água/análise
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