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1.
J Clin Pediatr Dent ; 44(1): 47-51, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31995417

RESUMO

Objective: The present study compared the mineral contents of enamel and dentin of primary teeth from children exposed to desalinated water with those from children drinking ground water. Study design: The study comprised of two groups of teeth, seven primary teeth from children living in areas supplied exclusively with desalinated water and seven primary teeth from children that have been exposed solely to ground water from in-utero until the teeth were either extracted or naturally shed. Mineral content of three tooth regions was determined by scanning electron microscopy with an energy dispersive X-ray spectrometer (EDS). The main ion content of each region was calculated. Results: Children exposed to ground water presented higher levels of magnesium in pre- and post- natal enamel than children living in areas supplied exclusively with desalinated water but without significant differences. The same was found for calcium levels. Excluding post-natal enamel calcium level (of borderline statistical significance), no significant differences were found in magnesium and calcium levels of primary teeth enamel and dentin of children exposed to desalinated water in comparison to children exposed to ground water. Conclusion: Mineral content of enamel and dentin in primary teeth is not affected by consuming desalinated water.


Assuntos
Cálcio , Magnésio , Criança , Esmalte Dentário , Dentina , Humanos , Minerais , Dente Decíduo
2.
Monogr Oral Sci ; 28: 22-31, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31940622

RESUMO

The foods in the diet contain a wide range of organic and inorganic compounds. Considering these from an elemental perspective, 5 so-called macroelements, calcium, potassium, sodium, phosphorus and chlorine, are contained in comparatively large quantities in foods compared to all other elements. This chapter attempts to review the importance of these dietary macroelements on oral health, and in particular their role in tooth loss, dental caries, erosive tooth wear and periodontal disease. Calcium and phosphate make up the bulk of the mineralized human tissues. Adequate intake of both is therefore of crucial importance in maintaining the health, function and retention of teeth and bones. Supplementation of the diet with calcium has also been shown to aid in maintaining and improving oral health. Several attempts have been made to lessen the erosive potential of beverages through calcium supplementation. Adequate calcium intake is also crucial for maintaining periodontal health. In many areas, however, the evidence is still emerging or controversial. Phosphate supplementation of the diet was once thought to decrease caries incidence, although studies in children were not successful. Furthermore, little attention has been paid to the other macroelements, highlighting the need for more well-controlled and comprehensive studies.


Assuntos
Cárie Dentária , Cálcio , Criança , Cloro , Dieta , Humanos , Minerais , Sódio
3.
Int J Oral Maxillofac Implants ; 35(1): 39-51, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31923288

RESUMO

PURPOSE: This study evaluated a novel injectable, self-setting, osteoconductive, resorbable adhesive that provides immediate implant stabilization. MATERIALS AND METHODS: Twenty-six large canines had the mandibular second through fourth premolars and the first molar removed bilaterally. After 3 months, oversized osteotomies were prepared with only the apical 2 mm of the implant engaging native bone. One site had a novel resorbable, self-setting, mineral-organic adhesive (TN-SM) placed around the implant, a second site received bone graft, and a third site received only blood clot. Removal torque, standardized radiography, and histology were used to evaluate implant stability and tissue contact after 24 hours, 10 days, and 4 months. RESULTS: Mean removal torque values after 24 hours were 1.4, 1.3, and 22.2 Ncm for the control, bone graft, and mineral-organic adhesive, respectively. After 10 days, these values were 5.7, 6.2, and 45.7 Ncm and at 4 months increased to 88.7, 77.8, and 104.7 Ncm, respectively. Clinical, radiographic, and histologic evaluations showed a lack of inflammatory reaction. Control defects were initially radiolucent in the coronal area; grafted sites revealed particles in the gap, with both conditions gradually filling with bone over time. At 10 days, histologic evaluation demonstrated excellent biocompatibility and intimate contact of mineral-organic adhesive to both the implant and bone, providing an osseointegration-like bond; control sites revealed no bone contact in the defect area, while the bone-grafted sites revealed unattached graft particles. At 4 months, much of the mineral-organic adhesive was replaced with bone; the control and grafted sites had some bone fill, and many of the defects demonstrated no bone-to-implant contact and were filled with soft tissue or isolated graft particles. CONCLUSION: The mineral-organic adhesive provides immediate (osseointegration-like) and continued implant stabilization over 4 months in sites lacking primary stability. Experimental sites demonstrated maintenance of crestal bone levels adjacent to the mineral-organic adhesive and soft tissue exclusion without the use of membranes in this canine model. These results demonstrate that this novel mineral-organic adhesive can enable implant osseointegration in a site where insufficient native bone exists to allow immediate implant placement.


Assuntos
Implantes Dentários , Cimentos Dentários , Implantação Dentária Endo-Óssea , Mandíbula , Minerais , Osseointegração
4.
J Environ Manage ; 258: 110013, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31929055

RESUMO

The effect of competition between isolated petroleum-degrading bacteria (PDB) and indigenous compost microorganisms (ICM) on the efficiency of composting process in bioremediation of petroleum waste sludge (PWS) was investigated. After isolating two native PDB (Acinetobacter radioresistens strain KA5 and Enterobacter hormaechei strain KA6) from PWS, their ability for growth and crude oil degradation was examined in the mineral-based culture (MBC). Then, the PDB isolate were inoculated into the composting experiments and operated for 12 weeks. The results showed that the PDB degraded 21.65-68.73% of crude oil (1-5%) in the MBC after 7 days. The PDB removed 84.30% of total petroleum hydrocarbon (TPHs) in the composting bioreactor containing the initial TPH level of 20 g kg-1. Removal of petroleum hydrocarbons (PHCs) in the composting experiments proceeded according to the first-order kinetics. The computed values of degradation rate constants and half-lives showed a better performance of the PDB than ICM for TPHs removal. This finding suggests that simultaneous application of the PDB and ICM in the composting reactors resulted in a decline in the effectiveness of the PDB which is due to competition between them. The study also verified that the capability of PDB in degrading PHCs can be successfully scaled-up from MBC to composting process.


Assuntos
Compostagem , Petróleo , Poluentes do Solo , Biodegradação Ambiental , Hidrocarbonetos , Minerais , Esgotos , Microbiologia do Solo
5.
Chemosphere ; 242: 125273, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31896195

RESUMO

Atmospheric processing may significantly increase solubility of iron in mineral dust, but the effects of heterogeneous reactions on iron solubility have been poorly understood. In this work, we investigated heterogeneous reaction of NO2 (15 ±â€¯1 and 2.5 ±â€¯0.1 ppmv, equal to ∼3.7 × 1014 and ∼6.2 × 1013 molecule cm-3) with hematite, magnetite and goethite at different relative humidities (RH, 0-90%), and changes in particulate nitrate and soluble iron due to heterogeneous reaction with NO2 were quantified as a function of time (up to 24 h). After reaction with 2.5 ±â€¯0.1 ppmv NO2 for 24 h (or less time), hematite and magnetite were fully saturated, while goethite was only partly deactivated. Nitrate yield was largest for goethite, and the mass ratio of formed nitrate to unreacted mineral only reached ∼1% or less after 24 h reaction. All the three minerals showed low reactivities towards NO2, and the average reactive uptake coefficients of NO2 in the first 3 h were found to be < 5 × 10-8. In addition, the increase in iron solubility was found to be small and in some cases even insignificant for the three minerals after heterogeneous reaction with NO2 for 24 h. Overall, the impacts of heterogeneous reaction of NO2 with hematite, magnetite and goethite on nitrate aerosol formation and iron solubility could be very limited.


Assuntos
Compostos Férricos/química , Óxido Ferroso-Férrico/química , Compostos de Ferro/química , Ferro/química , Minerais/química , Nitratos/análise , Óxidos de Nitrogênio/química , Aerossóis , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/química , Poeira/análise , Modelos Químicos , Solubilidade
6.
Environ Technol ; 41(3): 296-308, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29974819

RESUMO

In France, the road construction sector is the greatest consumer of granular materials, with a yearly consumption of about 200 million tons. With the shortage of standard materials, the valorisation of dredged sediments for road construction could constitute an interesting solution. Dredged sediments generally consist of a mineral phase, an organic phase (in various forms) and a liquid phase (water). The presence of organic matter (OM) in sediments, even in small amounts, affects their engineering properties. The main objective of this study is to investigate the effects of organic matter content on the engineering properties of dredged sediments. For this purpose, a specific methodology to reconstitute samples with different amounts of organic matter contents is proposed. The evaluation of the effects of organic matter content in term of compressibility, shear strength, compaction and bearing capacity show that even for high amount of organic matter the performances of the studied samples are compatible with the use in road construction sector.


Assuntos
Materiais de Construção , Sedimentos Geológicos , França , Minerais , Água
7.
Waste Manag ; 102: 624-634, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31785522

RESUMO

The use of solid recovered fuels (SRF) is often associated with an increased risk of chloride corrosion because these fuels can be high in chlorine and alkali. One way to reduce the risk of chloride corrosion is the co-combustion of fuel mixtures in the presence of a mineral additive containing chemical compounds that bind the emitted chlorides. This paper concerns the influence of mineral additives - constituting waste material, on the process of the binding of emitted chlorides. One of these waste materials could be a halloysite, not yet used in power industry. The research has shown its high chloride binding effectiveness, comparable to that of kaolin (known in literature as a mineral additive effectively binding chloride). Moreover, the studies have shown that SRF combustion in the presence of stabilized, dried and granulated sewage sludge, with a 25% mass fraction of sewage sludge, allows reducing chloride emissions. Studies are based on tests in a calorimetric bomb.


Assuntos
Cloro , Incineração , Cloretos , Minerais , Esgotos , Resíduos
8.
Water Res ; 169: 115240, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31706122

RESUMO

Advanced oxidation treatment processes used in various applications to treat contaminated soil, water, and groundwater involve powerful radical intermediates, including hydroxyl radicals (•OH). Inefficiency in •OH-driven treatment systems involves scavenging reactions where •OH react with non-target species in the aqueous and solid phases. Here, •OH were generated in iron (Fe)- and UV-activated hydrogen peroxide (Fe-AHP, UV-AHP) systems where the loss of rhodamine B served as a quantitative metric for •OH activity. Kinetic analysis methods were developed to estimate the specific •OH surface scavenging rate constant (k≡S). In the Fe-AHP system, k≡S for silica (2.85 × 106 1/m2 × s) and alumina (3.92 × 106 1/m2 × s) were similar. In the UV-AHP system, estimates of k≡S for silica (4.50 × 106 1/m2 × s) and alumina (7.45 × 106 1/m2 × s) were higher. k≡S for montmorillonite (MMT) in the UV-AHP system was ≤4.22 × 105 1/m2 × s. Overall, k≡S,silica ∼ k≡S, alumina > k≡S,MMT indicating k≡S is mineral specific. Radical scavenging was dominated by surface scavenging at 10-50 g/L silica, alumina, or MMT, in both Fe-AHP and UV-AHP systems. The experimentally-derived surface •OH scavenging rate constants were extended to in-situ chemical oxidation (ISCO) treatment conditions to contrast •OH reaction rates with contaminant and aqueous phase reactants found in aquifer systems. •OH reaction was dominated by solid surfaces comprised of silica, alumina, and montmorillonite minerals relative to •OH reaction with trichloroethylene, the target compound, and H2O2, a well-documented radical scavenger. These results indicate that solid mineral surfaces play a key role in limiting the degradation rate of contaminants found in soil and groundwater, and the overall treatment efficiency in ISCO systems. The aggressive •OH scavenging measured was partially attributed to the relative abundance of scavenging sites on mineral surfaces.


Assuntos
Peróxido de Hidrogênio , Radical Hidroxila , Cinética , Minerais , Oxirredução , Estresse Oxidativo
9.
Bioresour Technol ; 297: 122388, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31734064

RESUMO

After the co-combustion of tobacco stem/black bean straw/wheat straw/millet straw/corn stalk/rice straw and coal, it was found that all tested biomass in this study could inhibit arsenic release, but only rice straw promoted arsenic release. When the acid washed biomass was mixed with coal during combustion, the release of arsenic increased. When mineral metals (Na, K, Mg, Ca, Al and Fe) and Si elements were added to the coal, the mineral metals inhibited arsenic release. However, the release of arsenic was increased when the silicon content in biomass was high. The volatiles in the biomass also promoted the release of arsenic during co-combustion. The arsenic in the ash generated from co-combustion was mainly in the sulphide-bound state. Co-combustion of biomass and coal reduced the occurrence of an exchangeable state in the ash, and also significantly reduce the possibility of leaching.


Assuntos
Arsênico , Carvão Mineral , Biomassa , Cinza de Carvão , Minerais
10.
Water Res ; 169: 115265, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31710914

RESUMO

Extracellular polymeric substances (EPS) in wastewater sludge form a network structure that is highly hydrophilic and compressible. Thus chemical conditioning is always required to improve sludge dewaterability by changing the gelatinous structure of sludge flocs. Layered double hydroxides (LDH) are generally characterized by large surface area and high anion exchange capacity, so we prepared three types of hydrotalcite-like compounds (Ca/Mg/Al-LDHs) from a typical solid waste, blast furnace slag, using NaOH precipitation (giving LDHa), a hydrothermal method (LDHb), and NaOH-Na2CO3 precipitation (LDHc). The physicochemical properties of the three LDH were comprehensively characterized, and their effectiveness as sludge conditioners was evaluated. The results showed that LDH conditioning was able to promote sludge dewaterability, and conditioning efficiency was strongly dependent on LDH structural properties. LDH neutralized the negative charges onto sludge particles and interacted with EPS to increase floc strength. LDH also formed a skeletal structure that reduced sludge compressibility. In addition, there were interactions between the LDH surfaces and the OC-OH in EPS proteins, which altered the secondary structure of protein molecules, consequently increasing sludge dewaterability. The biomolecules of low-molecular-weight fractions (such as peptides and humic acids) in soluble EPS intercalated LDH. Both the surface complexation of organic matter containing carboxyl groups and the intercalation of small molecules in soluble EPS were responsible for EPS-LDH interactions. The combination of skeleton formation, electrostatic interaction, and EPS-LDH interactions resulted in compression of gel-like structure and improved sludge dewatering performance. We finally suggested a novel sludge treatment process that increases sludge dewaterability using slag-derived Ca/Mg/Al-LDH to condition the sludge, and it could be combined with pyrolysis to prepare multi-functional materials or bio-oil.


Assuntos
Esgotos , Águas Residuárias , Hidróxido de Alumínio , Filtração , Hidróxido de Magnésio , Minerais , Eliminação de Resíduos Líquidos , Água
11.
J Sci Food Agric ; 100(3): 1294-1300, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31742701

RESUMO

BACKGROUND: Maize (Zea mays L.) is a staple cereal crop and feed crop throughout the world. In this article, a mineral element fingerprinting technique was applied to single out suitable element indicators to determine the geographical origin of maize. A total of 90 fresh maize samples were collected in 2107 from Jilin, Gansu, and Shandong provinces in China. The contents of 25 mineral elements in all maize samples were measured by inductively coupled plasma mass spectrometry (ICP-MS). The composition of mineral elements was analyzed by multivariate statistical analysis, including one-way analysis of variance (one-way ANOVA), principal component analysis (PCA), k-nearest neighbor (KNN) analysis, and stepwise linear discriminant analysis (SLDA). RESULTS: As compared by one-way ANOVA, the contents of 19 mineral elements in maize samples were significantly different among three provinces. Principal component analysis based on these 19 elements could obtain preliminary visual classification groups of maize samples. K-nearest neighbor analysis produced a total correct classification rate of 83.9% on the training set, and 82.2% on the prediction set. The SLDA model, based on eight indicative elements (Na, Cr, Rb, Sr, Mo, Cs, Ba, and Pb) obtained a total correct classification rate of 92.2% with cross-validation. CONCLUSION: The mineral element fingerprinting technique combined with multivariate statistical analysis could be a helpful method to identify the geographical origin of maize. © 2019 Society of Chemical Industry.


Assuntos
Minerais/análise , Oligoelementos/análise , Zea mays/química , China , Análise Discriminante , Geografia , Análise de Componente Principal , Análise Espectral
12.
Clin Oral Implants Res ; 31(1): 10-17, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31529644

RESUMO

OBJECTIVES: Deproteinized bovine bone mineral (DBBM) is not resorbable. However, the behavior of DBBM under inflammatory conditions remains unclear. Aim of the study was therefore to evaluate the resorption of DBBM under local inflammatory conditions in vivo using the calvarial osteolysis model. METHODS: In thirty adult BALB/c mice, DBBM was implanted into the space between the elevated soft tissue and the calvarial bone. Inflammation was induced either by lipopolysaccharides (LPS) injection or by polyethylene particles (Ceridust) mixed with DBBM. Three modalities were randomly applied (n = 10 each): (a) DBBM alone (control), (b) DBBM + LPS, and (c) DBBM + polyethylene particles (Ceridust). Mice were euthanized on day fourteen, and each calvarium was subjected to histological and µCT analysis. Primary outcome was the size distribution of the DBBM particles. Secondary outcome was the surface erosion of the calvarial bone. RESULTS: Histological and µCT analysis revealed that the size distribution and the volume of DBBM particles in the augmented site were similar between DBBM alone and the combinations with LPS or polyethylene particles. Moreover, histological evaluation showed no signs of erosions of DBBM particles under inflammatory conditions. µCT analysis and histology further revealed that LPS and the polyethylene particles, but not the DBBM alone, caused severe erosions of the calvarial bone as indicated by large voids representing the massive compensatory new immature woven bone formation on the endosteal surface. CONCLUSIONS: Local calvarial bone but not the DBBM particles undergo severe resorption and subsequent new bone formation under inflammatory conditions in a mouse model.


Assuntos
Substitutos Ósseos , Animais , Regeneração Óssea , Bovinos , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos BALB C , Minerais , Crânio
13.
Water Environ Res ; 92(2): 173-176, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31529657

RESUMO

Iron oxides facilitated anaerobic digestion process has been attracted more and more attention in the renewable energy production area. In the current study, goethite was added into the continuous stirred tank reactor with glucose as the substrate. Effect of the influent organic loading rate (OLR) on the reactor performances was explored. Results showed that goethite promoted the methane production significantly (p < 0.05) when OLR was changed between 1.20 and 1.80 g glucose L-1  day-1 . Compared to the control reactor, addition of goethite improved the methane production by13.4%-22.9%. The iron reduction rate had a positive correlation with the methane production rate. Microbial community analysis results showed that OLRs influenced the dominant methanogenic species in the both reactors. Methanothrix, Methanobacterium, Methanosarcina, and Methanocella were dominant under various OLR levels. PRACTITIONER POINTS: Goethite could promote the methanogenic process of glucose in the CSTRs under certain levels of OLRs. Iron reduction rate had a positive correlation with the methane production rate. OLRs influenced the dominant methanogenic species in the goethite-dosed reactors.


Assuntos
Reatores Biológicos , Metano , Anaerobiose , Compostos de Ferro , Minerais , Veículos Automotores
14.
Glob Chang Biol ; 26(1): 261-273, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31587451

RESUMO

Managing soil organic matter (SOM) stocks to address global change challenges requires well-substantiated knowledge of SOM behavior that can be clearly communicated between scientists, management practitioners, and policy makers. However, SOM is incredibly complex and requires separation into multiple components with contrasting behavior in order to study and predict its dynamics. Numerous diverse SOM separation schemes are currently used, making cross-study comparisons difficult and hindering broad-scale generalizations. Here, we recommend separating SOM into particulate (POM) and mineral-associated (MAOM) forms, two SOM components that are fundamentally different in terms of their formation, persistence, and functioning. We provide evidence of their highly contrasting physical and chemical properties, mean residence times in soil, and responses to land use change, plant litter inputs, warming, CO2 enrichment, and N fertilization. Conceptualizing SOM into POM versus MAOM is a feasible, well-supported, and useful framework that will allow scientists to move beyond studies of bulk SOM, but also use a consistent separation scheme across studies. Ultimately, we propose the POM versus MAOM framework as the best way forward to understand and predict broad-scale SOM dynamics in the context of global change challenges and provide necessary recommendations to managers and policy makers.


Assuntos
Minerais , Solo , Carbono , Plantas
15.
Clin Oral Implants Res ; 31(1): 93-102, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31724239

RESUMO

OBJECTIVES: This study histologically analyzed biopsy samples obtained from sites of damaged extraction socket grafting using deproteinized bovine bone mineral (DBBM) or deproteinized porcine bone mineral (DPBM) with coverage by a collagen membrane. MATERIAL AND METHODS: One hundred patients participated in this randomized controlled clinical trial of extraction socket grafts performed in cases of periodontally compromised teeth. All participants were blinded to their group allocations, and each material was grafted with coverage by collagen membranes after extraction of the tooth and removal of granulation tissue. At implant placement at 4 months, a biopsy was harvested at the implant site using a trephine was analyzed histologically. RESULTS: Eighty-five biopsy samples were acquired, of which 81 were finally included in the histologic analysis (42 in DBBM and 39 in DPBM group). Both DBBM and DPBM groups showed comparable proportions of residual biomaterial (12.37 ± 5.67% and 12.21 ± 5.75%, respectively), newly formed bone (15.07 ± 10.52% and 18.47 ± 11.47%, respectively), and nonmineralized tissue (72.56 ± 10.07% and 71.55 ± 15.47%, respectively). There were no significant differences in these histologic parameters between the two groups with different biomaterials. CONCLUSION: Comparable histologic bone formation was found in both socket grafted groups with DBBM or DPBM covered by collagen membranes in periodontally damaged extraction sockets. However, a wide variation in new bone formation was found after 4 months of postsurgical healing and a tendency of higher new bone formation was shown at damaged sockets that had an intact unilateral residual wall regardless of buccal or lingual side.


Assuntos
Substitutos Ósseos , Alvéolo Dental , Animais , Bovinos , Colágeno , Humanos , Minerais , Suínos , Extração Dentária
16.
Chemosphere ; 240: 124961, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31574433

RESUMO

Acid mine drainage (AMD) is a sulfuric discharge containing metals and particulates that can spread to nearby water sources, imposing toxicity and physical stress to living things. We have shown that vetiver grass (Chrysopogon zizanioides) is capable of tolerating and treating AMD-impacted water from the abandoned Tab-Simco mining site from southern Illinois, though little is known about its tolerance mechanisms. We conducted metabolomic analyses of vetiver shoots and roots after relatively short- and long-term periods of exposure to Tab-Simco AMD. The metabolic shift of vetiver shoots was dramatic with longer-term AMD exposure, including upregulation of amino acid and glutathione metabolism, cellular respiration and photosynthesis pathways, with downregulation of phosphorylated metabolites. Meanwhile, the roots demonstrated drastic downregulation of phospholipids and phosphorylated metabolites, cellular respiration, glyoxylate metabolism, and amino acid metabolism. Vetiver accumulated ornithine and oxaloacetate in the shoots, which could function for nitrogen storage and various intracellular functions, respectively. Organic acids and glutathione were secreted from the roots for rhizospheric metal-chelation, whereas phosphorylated metabolites were recycled for phosphorus. These findings reveal AMD-induced metabolic shifts in vetiver grass, which are seemingly unique in comparison to independent abiotic stresses reported previously.


Assuntos
Biodegradação Ambiental , Vetiveria/metabolismo , Poluentes do Solo/análise , Ácidos Sulfúricos/análise , Aminoácidos/metabolismo , Vetiveria/química , Glutationa/metabolismo , Illinois , Metais/análise , Metais/toxicidade , Minerais/metabolismo , Mineração , Ornitina/metabolismo , Ácido Oxaloacético/metabolismo , Fosfolipídeos/biossíntese , Fotossíntese , Raízes de Plantas/metabolismo , Poluentes do Solo/toxicidade , Ácidos Sulfúricos/toxicidade
17.
Bioresour Technol ; 295: 122223, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31623921

RESUMO

Although for the past 100 years, fertilizer technologies have increasingly used renewable resources, the majority of manufactured products are still based on mineral deposits and fossil fuels. The European Commission has set a goal of 30% reduction of non-renewable resources in fertilizer production. This can only be accomplished if there are incentives for wastes valorization and fines for making use of non-renewable raw materials. This will enable the reduction of eutrophication of surface waters due to the presence of nitrogen and phosphorus, originating from agricultural fields fertilizers. The use of biological waste is a practical solution to recover valuable fertilizer components. In order to effectively implement technologies based on biological resources, it is necessary to construct small wastes solubilization or fertilizer installations at the site of waste generation, which will solve the problem of waste transport or sanitary hazards.


Assuntos
Fertilizantes , Fósforo , Minerais , Nitrogênio
18.
Water Res ; 168: 115151, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31630019

RESUMO

This study investigated nutrient removal characteristics and the related pathways in aerobic granular reactors using three pilot-scale granular sequencing batch reactors (GSBRs) treating wastewaters of diverse carbon and nutrient strength. The GSBRs were operated with alternating (AN/O/AX/O_SBR and AN/O_SBR) and purely-aerobic (O_SBR) operation modes. Mineral-rich aerobic granules with hydroxyapatite (HAp) core were cultivated in all the three GSBRs. The highest nitrogen removal efficiency (75%) was achieved in AN/O/AX/O_SBR and O_SBR and the lowest (22%) in AN/O_SBR, establishing a quasi-linear relationship with organic loading rate (OLR). Phosphorus removal efficiencies of 55-63% were achieved in the GSBRs despite different influent PO4-P concentrations. Heterotrophic nitrification and biologically-induced phosphate precipitation (BIPP) became the dominant nutrient depletion pathways, contributing 61-84% and 39-96% to overall ammonium nitrogen and phosphorus removal, respectively. A direct relation was noted between heterotrophic nitrification efficiency (ηHeterotrophic nitrification) and nutrient availability, as nitrification efficiencies of 18 and 64% were observed for COD:Ninf of 5 and 20, respectively. Whereas, BIPP efficiency (ηBIPP) established inverse relation with (COD:P)inf and (Ca:P)inf and direct relation with phosphorus concentration beyond microbial growth requirement. Core heterotrophic nitrifiers and bio-calcifying species were identified as {Thauera and Flavobacterium} and {Flavobacterium, Acinetobacter, Pseudomonas, and Corynebacterium}, respectively. Ca-P crystallization was proposed to be via phosphate precipitation on calcite surfaces. Granulation mechanism was proposed as crystallization on bio-aggregates' periphery and then crystal growth toward the core.


Assuntos
Nutrientes , Esgotos , Aerobiose , Reatores Biológicos , Minerais , Nitrificação , Nitrogênio , Fósforo , Eliminação de Resíduos Líquidos
19.
Food Chem ; 305: 125452, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514050

RESUMO

Flakes are an assortment of grain products mainly consumed for breakfast. Most of them are important source of nutrients including minerals. Twenty commercial flakes from different raw materials were included in this study, both gluten (barley, rye, spelt, wheat) and gluten-free (amaranth, buckwheat, corn, quinoa, millet, oat, rice, teff). The content of minerals (Ca, Fe, K, Mg, Mn, Na and Zn), dietary fiber (total, soluble and insoluble), tannins and phytates was determined. Moreover, the phytates:mineral molar ratios and the percentage of the realization of mineral requirements were calculated. For the first time the mineral bioavailability from the gluten and gluten-free flakes was evaluated and compared. It allowed indicating amaranth and teff products as flakes with the highest impact on the realization of daily requirements for minerals, especially for magnesium and iron. This aspect is particularly important for people on a gluten-free diet who often represent mineral deficiencies.


Assuntos
Fibras na Dieta/análise , Minerais/análise , Ácido Fítico/análise , Taninos/análise , Disponibilidade Biológica , Chenopodium quinoa/química , Chenopodium quinoa/metabolismo , Grão Comestível/química , Fagopyrum/química , Fagopyrum/metabolismo , Glutens/metabolismo , Hordeum/química , Hordeum/metabolismo , Milhetes/química , Milhetes/metabolismo , Espectrofotometria Atômica , Triticum/química , Triticum/metabolismo
20.
Chemosphere ; 240: 124938, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31574444

RESUMO

Clearwater Mesa (James Ross Island, northeast Antarctic Peninsula) provides a unique opportunity to study solute dynamics and geochemical weathering in the pristine lacustrine systems of a high latitude environment. In order to determine major controls on the solute composition of these habitats, a geochemical survey was conducted on 35 lakes. Differences between lakes were observed based on measured physico-chemical parameters, revealing neutral to alkaline waters with total dissolved solids (TDS) < 2500 mg L-1. Katerina and Trinidad-Tatana systems showed an increase in their respective TDS, total organic carbon values, and finner sediments from external to internal lakes, indicating an accumulation of solutes due to weathering. Norma and Florencia systems exhibited the most diluted and circumneutral waters, likely from the influence of glacier and snow melt. Finally, isolated lakes presented large variability in TDS values, indicating weathering and meltwater contributions at different proportions. Trace metal abundances revealed a volcanic mineral weathering source, except for Pb and Zn, which could potentially indicate atmospheric inputs. Geochemical modelling was also conducted on a subset of connected lakes to gain greater insight into processes determining solute composition, resulting in the weathering of salts, carbonates and silicates with the corresponding generation of clays. We found CO2 consumption accounted for 20-30% of the total species involved in weathering reactions. These observations allow insights into naturally occurring geochemical processes in a pristine environment, while also providing baseline data for future research assessing the impacts of anthropogenic pollution and the effects of climate change.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Lagos/química , Minerais/análise , Compostos Orgânicos/análise , Oligoelementos/análise , Regiões Antárticas , Carbonatos/análise , Mudança Climática , Ecossistema , Camada de Gelo/química , Chumbo/análise , Trinidad e Tobago , Tempo (Meteorologia) , Zinco/análise
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