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1.
Braz. j. biol ; 84: e253555, 2024. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1355900

RESUMO

Abstract The aim of the present study is to assess the effects of selenium nanoparticles on the growth, hematology and nutrients digestibility of Labeorohita fingerlings. Fingerlings were fed with seven isocaloric sunflower meal-based diet supplemented with different concentrations of nanoparticles naming T1 to T7 (0, 0.5, 1, 1.5, 2, 2.5, and 3 mg/kg), with 5% wet body weight while chromic oxide was used as an indigestible marker. After experimentation for 90 days T3 treated group (1mg/kg -1Se-nano level) showed the best result in hematological parameters (WBC's 7.97 ×103mm-3, RBC's 2.98 ×106 mm-3 and Platelet count 67), nutrient digestibility (crude protein: 74%, ether extract: 76%, gross energy: 70%) and growth performance (weight gain 13.24 g, weight gain% 198, feed conversion ratio 1.5, survival rate 100%) as compared to the other treatment groups. Specific growth rates were found significantly higher in T5 than in other groups. The present study indicated positive effect of 1 mg/kg Se-nanoparticles on growth advancement, hematological parameters, and nutrients digestibility of L. rohita fingerlings.


Resumo O objetivo do presente estudo é avaliar os efeitos das nanopartículas de selênio no crescimento, hematologia e digestibilidade dos nutrientes de alevinos de Labeo rohita. Os alevinos foram alimentados com sete dietas isocalóricas à base de farinha de girassol suplementada com diferentes concentrações de nanopartículas, nomeando T1 a T7 (0, 0,5, 1, 1,5, 2, 2,5 e 3 mg / kg), com 5% do peso corporal úmido enquanto o óxido crômico foi usado como um marcador indigesto. Após a experimentação por 90 dias, o grupo tratado com T3 (nível 1mg / kg -1Se-nano) mostrou o melhor resultado em parâmetros hematológicos (WBC's 7,97 × 103mm-3, RBC's 2,98 × 106mm-3 e contagem de plaquetas 67), digestibilidade dos nutrientes (proteína bruta: 74%, extrato de éter: 76%, energia bruta: 70%) e desempenho de crescimento (ganho de peso 13,24 g, ganho de peso % 198, taxa de conversão alimentar 1,5, taxa de sobrevivência 100%) em comparação com os outros grupos de tratamento. As taxas de crescimento específicas foram encontradas significativamente mais altas em T5 do que em outros grupos. O presente estudo indicou efeito positivo de 1 mg / kg de nanopartículas de Se no avanço do crescimento, parâmetros hematológicos e digestibilidade de nutrientes de alevinos de L. rohita.


Assuntos
Animais , Nanopartículas , Helianthus , Nutrientes , Suplementos Nutricionais , Dieta , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal
2.
J Environ Sci (China) ; 124: 699-711, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36182175

RESUMO

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


Assuntos
Lagos , Fitoplâncton , China , Clorofila , Ecossistema , Nitrogênio/análise , Nutrientes , Fosfatos , Fósforo/análise
3.
J Environ Sci (China) ; 124: 769-781, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36182182

RESUMO

The seasonal changes in dissolved organic matter (DOM), and its correlation with the release of internal nutrients during the annual cycle of cyanobacteria in the eutrophic Lake Chaohu, China, were investigated from four sampling periods between November 2020 and July 2021. The DOM fluorescence components were identified as protein-like C1, microbial humic-like C2, and terrestrial humic-like C3. The highest total fluorescence intensity (FT) of DOM in sediments during the incubation stage is due to the decomposition and degradation of cyanobacteria remains. The lowest humification of DOM and the highest proportion of C1 in waters during the initial cyanobacterial growth indicate that fresh algae are the main source. The highest molecular weight of DOM and FT of the C2 in sediments during cyanobacterial outbreaks indicate the concurrent deposition of undegraded cyanobacterial remains and microbial degradation. The components of DOM are affected mainly by the dissolved total phosphorus in waters, while the temperature drives the annual cycle of cyanobacteria. The decreasing C1 in sediments and increasing nutrients in waters from the cyanobacterial incubation to outbreak indicate that mineralization of algal organic matter contributes importantly to the release of internal nutrients, with the strongest release of phosphorus observed during the early growth of cyanobacteria. The humic-like C2 and C3 components could also affect the dynamics of internal phosphorus through the formation of organic colloids and organic-inorganic ligands. The results show that the degradation of DOM leads to nutrients release and thus supports the continuous growth of cyanobacteria in eutrophic Lake Chaohu.


Assuntos
Cianobactérias , Lagos , China , Matéria Orgânica Dissolvida , Eutrofização , Lagos/microbiologia , Ligantes , Nutrientes , Fósforo/análise , Espectrometria de Fluorescência
4.
J Hazard Mater ; 441: 129949, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36113346

RESUMO

Soil amendment products, such as biochar, with both sustained nutrient release and heavy metal retention properties are of great need in agricultural and environmental industries. Herein, we successfully prepared a new biochar material with multinutrient sustained-release characteristics and chromium removal potential derived from distiller grain by wet-process phosphoric acid (WPPA) modification without washing. SEM, TEM TG-IR, in situ DRIFTS and XRD characterization indicated that biochar and polyphosphate formed simultaneously and were tightly intertwined by one-step pyrolysis. The optimal product (PKBC-400) had the most stable carbon structure and an adequate P-O-P structure with less P loss. Batch experiments illustrated that 92.83% P (ortho-P), 85.94% K, 41.49% Fe, 78.42% Al and 65.60% Mg were continuously released in water from PKBC-400 within 63 days, and the maximum Cr removal rate reached 83.57% (50 mg/L K2Cr2O7, pH=3.0) with an increased BET surface area (304.0557 m2/g) after nutrient release. SEM, IC and 31P NMR analyses revealed that the dissolution and hydrolysis of polyphosphates not only realized the sustained release of multiple nutrients but also significantly improved the sustained release performance. The proposed resource utilization strategy provided new ideas for Cr hazard control, biomass waste utilization and fertilizer development.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Adsorção , Carbono , Carvão Vegetal/química , Cromo/química , Preparações de Ação Retardada , Fertilizantes , Nutrientes , Ácidos Fosfóricos , Polifosfatos , Solo , Água , Poluentes Químicos da Água/química
5.
J Biomech Eng ; 145(2)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36114163

RESUMO

Insights into the transport mechanisms of nutrients are essential for understanding the pathophysiology of menisci. In the present work, we focus on the modeling and numerical simulation of the transport of glucose molecules in mechanically stressed meniscus tissue. Therefore, a multifield model based on the theory of porous media is created. Due to a biphasic approach, the major phases of the solid and the fluid are represented. The description of the transport processes of the uncharged nutrient molecules, such as convection and diffusion, is given by three coupled partial differential equations valid for large deformations. Numerical simulations are performed for everyday types of stress such as (I) lying, (II) two-legged stance, (III) one-legged stance, (IV) level walking, and (V) stair descending using the finite element method. The results show that diffusion is the dominant process. However, in parts of the meniscus, the delivery of glucose can be improved by convection due to mechanical loading. Based on these basic insights, the model can now be adapted to individual patient's meniscus geometries. The model can thus give insights into the suitability of loading scenarios for rehabilitation after meniscus damage.


Assuntos
Menisco , Simulação por Computador , Difusão , Análise de Elementos Finitos , Glucose , Humanos , Modelos Biológicos , Nutrientes
6.
Food Chem ; 402: 134351, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36162174

RESUMO

Food nutrients and bioactive compounds have been widely explored due to the increased prevalence of chronic non-communicable diseases. Antioxidant supplementation might be a crucial non-pharmacological strategy against oxidative stress. However, although some assays evaluate the antioxidant potential of a particular food or food compound, in vivo responses related to oxidative stress in the body may not be reproduced or directly correlated with in vitro values. Therefore, this review aims to discuss the relationship between data obtained in vitro for the antioxidant potential of food/food compounds and the effects observed in vivo. More specifically, we examined in vitro methods for evaluating antioxidant potential, their limitations, and the effects of consuming food rich in antioxidants on oxidative stress biomarkers. This review will help to understand the effects of antioxidant compounds on oxidative stress biomarkers (usually measured in vivo) and their use as health parameters to explain the effects of dietary antioxidants.


Assuntos
Antioxidantes , Estresse Oxidativo , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Dieta , Biomarcadores , Nutrientes
7.
J Sci Food Agric ; 103(1): 48-56, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-35794785

RESUMO

BACKGROUND: Intensive olive (Olea europaea L.) orchards are fertilized, mostly with the macronutrients nitrogen (N), phosphorus (P) and potassium (K). The effects of different application levels of these nutrients on olive oil composition and quality were studied over 6 years in a commercial intensively cultivated 'Barnea' olive orchard in Israel. RESULTS: Oil quality and composition were affected by N, but not P or K availability. Elevated N levels increased free fatty acid content and reduced polyphenol level in the oil. Peroxide value was not affected by N, P or K levels. The relative concentrations of palmitoleic, linoleic and linolenic fatty acids increased with increasing levels of N application, whereas that of oleic acid, monounsaturated-to-polyunsaturated fatty acid ratio and oleic-to-linoleic ratio decreased. CONCLUSION: These results indicate that intensive olive orchard fertilization should be carried out carefully, especially where N application is concerned, to avoid a decrease in oil quality due to over-fertilization. Informed application of macronutrients requires leaf and fruit analyses to establish good agricultural practices, especially in view of the expansion of olive cultivation to new agricultural regions and soils. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Olea , Azeite de Oliva/química , Olea/química , Frutas/química , Ácidos Graxos Monoinsaturados , Nutrientes , Fertilização , Ácidos Graxos/química , Óleos Vegetais/química
8.
Bioresour Technol ; 367: 128301, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36370937

RESUMO

Microalgae cannot meet the bait demand for aquaculture due to light intensity limitation and other disadvantageous conditions. This research selected 6 mixotrophic microalgae, and the optimal strains and organic carbon were screened. The results showed that Thalassiosira pseudonana and Chlorella sp. are suitable for mixotrophic culture. The maximum cell density of Thalassiosira pseudonana was found to be 1.67 times than that of the photoautotrophic group when glycerol was added. The maximum cell density of Chlorella sp. with acetic acid was 1.69 times than that of the photoautotrophic group. When the concentration of acetic acid was 5.0 g·L-1 and the concentration of KNO3 was 0.2 g·L-1, the maximum biomass of Chlorella sp. could reach 3.54 × 107 cells·mL-1; the maximum biomass of Thalassiosira pseudonana was 5.53 × 106 cells·mL-1 with 10.0 g·L-1 glycerol and 0.2 g·L-1 KNO3. Metabolomic analysis further revealed that mixotrophic bait microalgae could promote the accumulation of lipids and amino acids.


Assuntos
Chlorella , Microalgas , Microalgas/metabolismo , Biomassa , Chlorella/metabolismo , Carbono/metabolismo , Glicerol/metabolismo , Nutrientes , Acetatos/metabolismo
9.
Sci Total Environ ; 855: 158894, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36155045

RESUMO

The tributaries flowing through Leamington, Ontario are unique in the Canadian Lake Erie watershed due to the broad spatial extent of greenhouse operations, which more than doubled in size and density from 2011 to 2022. These greenhouse operations are considered to be potential nutrient point sources with respect to observed nutrient concentrations in tributaries adjacent to greenhouse stormwater retention ponds (GSWPs). Identifying causal factors of nutrient release, whether this be chemical or biological, within these ponds may be critical for mitigating their impact on the watershed and ultimately the receiving waters of Lake Erie. Specifically, phosphorus and nitrogen accumulation in freshwater ponds can contribute to environmental damage proximal to adjacent streams, serving as a potential catalyst for algal blooms and eutrophication. This study compared correlations between the water column N:P stoichiometry, sediment nutrient retention capacity, and drivers of microbial metabolism within GSWP sediments. Correlations between water column TN:TP ratios and sediment nutrient retention capacity were observed, suggesting an interplay between N and P in terms of nutrient limitation. Further, clear shifts were observed in the bacterial metabolic pathways analyzed through metatranscriptomics. Specifically, genes related to nitrogen fixation, nitrification and denitrification, and other metabolic processes involving sulfur and methane showed differential expression depending on the condition of the respective pond (i.e., naturalized wetland vs. dredged, eutrophic pond). Collectively, this research serves to highlight the interconnected role of chemical-biological processes particularly as they relate to significant ecosystem processes such as nutrient loading and retention dynamics in impaired freshwater systems.


Assuntos
Lagoas , Poluentes Químicos da Água , Ontário , Ecossistema , Poluentes Químicos da Água/análise , Fósforo/análise , Nitrogênio/análise , Lagos , Nutrientes , Água , Monitoramento Ambiental
10.
Sci Total Environ ; 856(Pt 1): 159018, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36167139

RESUMO

Increasing the overall use efficiency of nitrogen (N) and phosphorus (P) resources in food production while minimizing losses to the environment are required to meet the dual challenge of food security and sustainability. Yet studies quantifying the overall performance of different agro-system types and how these have changed over time remain rare, although they are essential to propose solution pathways. Here, we reconstructed fluxes of N and P within 78 watersheds of the St. Lawrence Basin (SLB) of eastern Canada between 1901 and 2011, using the Generalized Representation of Agro-Food System model (GRAFS). This analysis allowed us to classify different agro-food system types and to evaluate how agricultural specialization influenced nutrient efficiencies and potential losses to the environment over time. Using a cluster analysis, we identified four agro-food system types with different overall outcomes in efficiencies and losses. We show that agricultural practices in the SLB were similar until the 1950's and deemed unsustainable in several watersheds by depleting agricultural soils of their nutrients (particularly N). With the advent of manufactured fertilizers and the intensification of livestock farming, the SLB then rapidly shifted through the 1970s and 1980s to more intensified and highly unsustainable agro-food system types, where, in 2011, ~77 % of N and ~ 94 % of P inputs were lost to the environment. We also show that nutrient pollution continued to increase despite gains in the nutrient use efficiency of animal farming due to higher nutrient throughput from intensive production. The increased proportion of confined animals, disconnected from croplands, indeed resulted in inefficient nutrient recycling. While nutrient use efficiency may mitigate nutrient pollution, reducing the absolute nutrient flux through agro-food systems should be a priority, likely through a reconnection of crop and animal farming and an overall reduction of meat production, specifically from concentrated, intensive livestock systems.


Assuntos
Agricultura , Fósforo , Animais , Agricultura/métodos , Fertilizantes , Nitrogênio , Gado , Nutrientes
11.
Sci Total Environ ; 857(Pt 1): 159220, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36209876

RESUMO

To gain insight in the environmental impacts of crop, soil and nutrient management, an integrated model framework INITIATOR was developed predicting: (i) emissions of ammonia (NH3) and greenhouse gases (GHG) from agriculture, including animal husbandry and crop production and (ii) accumulation, leaching and runoff of carbon, nutrients (nitrogen, N, phosphorus, P, and base cations) and metals in or from soils to groundwater and surface water in the Netherlands. Key processes in soil are included by linear or non-linear process formulations to maintain transparency and to enable data availability for spatially explicit application from field up to national level. Calculated national trends in nutrient losses over 2000-2020 compared well with independent estimates and showed a reduction in N and P input of 26 to 33 %, whereas the surplus declined by 33 % for N and 86 % for P due to increased crop yields and reduced inputs. This was accompanied by a reduction of 30-35 % in atmospheric emissions of ammonia and nitrous oxide as well a decline in N and P runoff of 35 and 10 %, respectively, whereas the emission of methane increased with 4 %. Model results compared well with (i) large scale observations of ammonia concentrations in air and nitrate concentrations in upper groundwater and ditch water, (ii) with nitrous oxide emissions and phosphorus adsorption in experiments at field scale and (iii) with metal adsorption in large scale soil datasets. Various mitigation measures were evaluated in view of policy ambitions for climate, soil and environmental quality for 2030, i.e. a reduction of 50 % for NH3, 11-17 % for GHG, 20 % for N runoff and 40 % for P runoff and an ambition of 50 % GHG emission reduction for 2050. The measures focused on a combination of animal feeding, low emission housing and application technologies, improved crop, soil and nutrient management, all being applied with an effectiveness of 100 % and 50 %, respectively. In addition, we evaluated impacts of 50 % livestock reduction, and combination scenarios of measures and livestock reduction. Full implementation of all measures can reduce NH3 emission, N leaching and N runoff by approximately 40-50 % and GHG emissions by approximately 30 %, but there is less potential to reduce P runoff, being <10 %. The combination of a more likely 50 % implementation/effectiveness of measures with 25 % livestock reduction leads to a comparable reduction. Required reductions from Dutch agriculture seem not possible with improved management only, but also requires livestock reduction, especially when the NH3 ambitions at the short term (2030) and the climate ambitions for the long term (2050) should be attained.


Assuntos
Gases de Efeito Estufa , Metais Pesados , Animais , Amônia/análise , Óxido Nitroso/análise , Esterco , Fertilizantes , Água , Agricultura/métodos , Solo , Gado , Criação de Animais Domésticos , Nutrientes , Fósforo
12.
Braz. j. biol ; 83: e246568, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1278537

RESUMO

Abstract Fishmeal; being a limited and costly feed ingredient is continuously been substituted with locally available plant proteins. However, the occurrence of anti-nutritional factors in plant meal suppresses its potential to be fully replaced. Therefore, in this study we aimed to study the synergistic effects of dietary additives like citric acid and phytase enzyme supplementation on growth performance and nutrient digestibility of Cirrhinus mrigala fingerlings. Canola meal (CM) was used as a test ingredient to replace fishmeal (FM) as; 0%, 25%, 50% and 75%. These four diets were further supplemented by varying levels of phytase (0 and 750 FTU kg-1) and citric acid (0% and 2.5%) to formulate total sixteen test diets as T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15 and T16. Each treatment contained three replicates; applied to fish groups having 15 fingerlings each; following 3×3 factorial arrangement. 1% of chromic oxide was added as an inert marker. Maximum weight gain% (288%) and the lowest value of FCR (1.07) were recorded when fish was fed on diet T12 as compared to fish fed control diet (T1). Similarly, optimum nutrient digestibility values such as crude protein (77%), crude fat (84%) and gross energy (70%) were noted on same level. It was concluded that 50% canola meal can optimally replace fishmeal when supplemented with phytase and citric acid at the levels of 750 FTU kg-1 and 2.5%, respectively.


Resumo A farinha de peixe, por ser um ingrediente alimentar limitado e caro, é continuamente substituída por proteínas vegetais disponíveis localmente. No entanto, a ocorrência de fatores antinutricionais na farinha de plantas suprime seu potencial de ser totalmente substituída. Portanto, neste estudo objetivamos estudar os efeitos sinérgicos de aditivos dietéticos como ácido cítrico e suplementação com enzima fitase sobre o desempenho de crescimento e digestibilidade de nutrientes de alevinos de Cirrhinus mrigala. A farinha de canola (CM) foi usada como ingrediente de teste para substituir a farinha de peixe (FM) como: 0%, 25%, 50% e 75%. Essas quatro dietas foram suplementadas por níveis variados de fitase (0 e 750 FTU kg-1) e ácido cítrico (0% e 2,5%) para formular um total de 16 dietas de teste como T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15 e T16. Cada tratamento continha três repetições; aplicado a grupos de peixes com 15 alevinos cada; seguindo o arranjo fatorial 3 × 3. 1% de óxido crômico foi adicionado como um marcador inerte. % de ganho de peso máximo (288%) e o valor mais baixo de FCR (1,07) foram registrados quando os peixes foram alimentados com dieta T12 em comparação com peixes alimentados com dieta controle (T1). Da mesma forma, valores ótimos de digestibilidade de nutrientes, como proteína bruta (77%), gordura bruta (84%) e energia bruta (70%) foram anotados no mesmo nível. Concluiu-se que 50% da farinha de canola pode substituir de forma ideal a farinha de peixe quando suplementada com fitase e ácido cítrico nos níveis de 750 FTU kg-1 e 2,5%, respectivamente.


Assuntos
Animais , 6-Fitase , Nutrientes , Galinhas , Ácido Cítrico , Suplementos Nutricionais , Dieta/veterinária , Digestão , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal
13.
Sci Total Environ ; 856(Pt 1): 158972, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36179838

RESUMO

In the recent decades, the area of seasonal water (SEW) has substantially increased at the global scale. To evaluate nutrient dynamics in aquatic ecosystems, previous studies have analyzed the determining factors of sediment nutrient content and stoichiometry on whole sediment profiles without depth separation on SEW sites. Such a methodology assumes that SEW sediment is a uniform unit and its nutrient dynamics are regulated by the same mechanism at various depths (uniformity assumption). We tested this assumption using sediment samples from six depth increments of 154 sediment profiles (1 m depth) on SEW sites at Shengjin Lake in subtropical China. We measured sediment total nitrogen (STN), total phosphorus (STP), nutrient fractions, and the molar ratio of STN to STP (RSNP), and investigated their determining factors at various depths. STN, STP, and RSNP were averaged at 1.34 g/kg, 0.55 g/kg, and 5.43, respectively, and all gradually decreased with depth. STN was positively affected by moisture and flooding duration in all depth increments. Instead, the major determining factors of STP changed from particle size at 0-20 cm of depth to pH and electrical conductivity at 30-100 cm of depth. These vertical patterns have close connections with sediment nutrient fractions since sediment N fractions did not shift along profile depths (i.e., over 99 % of STN was organic N) but sediment P fractions did (the percentage of Fe-P and Al-P decreased by 6.25 % but those of Ca-P increased by 4.31 % along the sediment depth gradient). The major determining factors of RSNP showed no obvious vertical patterns because they frequently varied along depth gradients. The results demonstrate that SEW sediment is not a uniform unit and the determining factors of nutrient dynamics change with depth. Our study highlights the importance of improved methodological reflection in studies addressing sediment nutrient dynamics on SEW sites.


Assuntos
Ecossistema , Sedimentos Geológicos , Sedimentos Geológicos/química , Água , Estações do Ano , Fósforo/análise , Lagos/química , Nitrogênio/análise , Nutrientes , China
14.
Sci Total Environ ; 856(Pt 1): 159093, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36183766

RESUMO

Chronic exposure of coral reefs to elevated nutrient conditions can modify the performance of the coral holobiont and shift the competitive interactions of reef organisms. Many studies have now quantified the links between nutrients and coral performance, but few have translated these studies to directly address coastal water quality standards. To address this management need, we conducted a systematic review of peer-reviewed studies, public reports, and gray literature that examined the impacts of dissolved inorganic nitrogen (DIN: nitrate, nitrite, and ammonium) and dissolved inorganic phosphorus (DIP: phosphate) on scleractinian corals. The systematic review resulted in 47 studies with comparable data on coral holobiont responses to nutrients: symbiont density, chlorophyll a (chl-a) concentration, photosynthesis, photosynthetic efficiency, growth, calcification, adult survival, juvenile survival, and fertilization. Mixed-effects meta-regression meta-analyses were used to determine the magnitude of the positive or negative effects of DIN and DIP on coral responses. Zooxanthellae density (DIN & DIP), chl-a concentration (DIN), photosynthetic rate (DIN), and growth (DIP) all exhibited positive responses to nutrient addition; maximum quantum yield (DIP), growth (DIN), larval survival (DIN), and fertilization (DIN) exhibited negative responses. In lieu of developing specific thresholds for the management of nutrients as a stressor on coral reefs, we highlight important inflection points in the magnitude and direction of the effects of inorganic nutrients and identify trends among coral responses. The responses of corals to nutrients are complex, warranting conservative guidelines for elevated nutrient concentrations on coral reefs.


Assuntos
Antozoários , Animais , Antozoários/fisiologia , Clorofila A , Recifes de Corais , Nitrogênio/farmacologia , Nutrientes
15.
Sci Total Environ ; 856(Pt 2): 159283, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36208738

RESUMO

Global food security, which has emerged as one of the sustainability challenges, impacts every country. As food cannot be generated without involving nutrients, research has intensified recently to recover unused nutrients from waste streams. As a finite resource, phosphorus (P) is largely wasted. This work critically reviews the technical applicability of various water technologies to recover macro-nutrients such as P, N, and K from wastewater. Struvite precipitation, adsorption, ion exchange, and membrane filtration are applied for nutrient recovery. Technological strengths and drawbacks in their applications are evaluated and compared. Their operational conditions such as pH, dose required, initial nutrient concentration, and treatment performance are presented. Cost-effectiveness of the technologies for P or N recovery is also elaborated. It is evident from a literature survey of 310 published studies (1985-2022) that no single technique can effectively and universally recover target macro-nutrients from liquid waste. Struvite precipitation is commonly used to recover over 95 % of P from sludge digestate with its concentration ranging from 200 to 4000 mg/L. The recovered precipitate can be reused as a fertilizer due to its high content of P and N. Phosphate removal of higher than 80 % can be achieved by struvite precipitation when the molar ratio of Mg2+/PO43- ranges between 1.1 and 1.3. The applications of artificial intelligence (AI) to collect data on critical parameters control optimization, improve treatment effectiveness, and facilitate water utilities to upscale water treatment plants. Such infrastructure in the plants could enable the recovered materials to be reused to sustain food security. As nutrient recovery is crucial in wastewater treatment, water treatment plant operators need to consider (1) the costs of nutrient recovery techniques; (2) their applicability; (3) their benefits and implications. It is essential to note that the treatment cost of P and/or N-laden wastewater depends on the process applied and local conditions.


Assuntos
Fertilizantes , Águas Residuárias , Estruvita/química , Águas Residuárias/química , Eliminação de Resíduos Líquidos/métodos , Inteligência Artificial , Fósforo/análise , Fosfatos/química , Nutrientes , Minerais , Segurança Alimentar
16.
J Environ Manage ; 325(Pt A): 116372, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36252327

RESUMO

Although lakes dominated by macrophytes are conducive to ecological balance, this balance is easily disrupted by excessive nutrients flowing into the lake. However, knowledge of whether excessive nutrients lead to different microbial environmental vulnerabilities in the lake sediment between macrophyte-dominated areas and macrophyte-free areas is a prerequisite for the implementation of targeted protection measures. In this study, we investigated bacterial communities in sediments using high-throughput sequencing of 16S rRNA genes. Our results showed that the sources of total nitrogen (TN) and organic matter (OM) were related to the macrophytes. The structure, drivers, and interspecific associations of bacterial community, which were more susceptible to increased changes in TN and OM, differed significantly between macrophyte-dominated areas and macrophyte-free areas. More precisely, the lake edge, where was occupied by macrophytes, had a higher proportion of deterministic phylogenetic turnover (88.89%) than other sites, as well as a wider ecological niche and a tighter network structure. Further, as the difference in TN increased, the main assembly processes in surface sediments changed from stochastic to deterministic. However, the majority of phyla from the lake edge showed a greater correlation with excessive nutrients, and the selection of the community by excessive nutrients was more obvious at the edge of the lake. In addition, our results demonstrated that the stability of the bacterial community in macrophyte-free areas is greater than in macrophyte-dominated areas, while an excessively high deterministic process ratio and nutrient (TN and OM) concentration significantly reduced bacterial community stability at macrophyte-dominated areas. Taken together, these results provide a better understanding of the effects of excessive nutrients derived from macrophytes on bacterial community patterns, and highlight the importance of avoiding the accumulation of TN and OM in macrophyte-dominated areas to enhance the sustainability of the ecosystem after restoration of lakes with macrophytes.


Assuntos
Lagos , Microbiota , Ecossistema , Sedimentos Geológicos/microbiologia , RNA Ribossômico 16S/genética , Filogenia , Nitrogênio , Bactérias/genética , Nutrientes , China , Fósforo
17.
J Environ Manage ; 325(Pt B): 116559, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36283170

RESUMO

Effective integrated watershed management requires models that can characterize the sources and transport processes of pollutants at the watershed with multiple landscape patterns. However, few studies have investigated the influence of landscape spatial configuration on pollutant transport processes. In this study, the SPARROW_TN and SPARROW_TP models were constructed by combining direct pollution source data and landscape pattern data to investigate the source composition and nutrient transport processes and to reveal the influence of landscape patterns on nutrient transport in the urbanized Beiyun River Watershed. The introduction of landscape metrics significantly improved the simulation results of both models, with R2 increasing from 0.89 to 0.85 to 0.93 and 0.91, respectively. Spatial variations existed in TN and TP loads and yields, as well as the source compositions. Pollution hotspots were effectively identified. Source apportionment showed that for the entire watershed, TN came from atmospheric nitrogen deposition (35.25%), untreated sewage (28.23%), agricultural sources (22.60%), and treated sewage (13.92%). In comparison, TP came from untreated sewage (44.94%), agricultural sources (40.22%), and treated sewage (11.51%). In addition, the largest patch index of grassland correlated positively with both TN and TP, whereas the largest shape index of buildup land and interspersion and juxtaposition index of forest were negatively correlated with TN and TP, respectively. The results of this study will provide insight into effective nutrient control measures that consider spatially varying nutrient sources and associated nutrient transport processes.


Assuntos
Monitoramento Ambiental , Poluentes Químicos da Água , Fósforo/análise , Poluentes Químicos da Água/análise , Esgotos , Rios , Nitrogênio/análise , Nutrientes , China
18.
J Environ Manage ; 325(Pt B): 116556, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36283173

RESUMO

There have been numerous summaries of the runoff purification characteristics of bioretention cells in warm climates. However, little has been done on the effects of freeze-thaw cycles (FTCs) that frequently occur in cold regions on bioretention cell performance. Three experimental columns were constructed to simulate the operation of the bioretention cell under the FTCs. The effects of FTCs on the nutrient removal efficiency of different filling bioretention cells were analyzed. The results showed that the ammonia nitrogen (NH4+-N) concentration in the effluent of the wood chip bioretention cell under the T3 conditions (WBCF) (2.35 mg/L) was significantly higher than that of the wood chip bioretention cell operating at room temperature (WBCR) (0.62 mg/L). The effluent NH4+-N concentration of aluminum sludge bioretention cell (ABCF) (0.096 mg/L) under the FTCs was lower than that of WBCF (0.91 mg/L). Under the T3 condition, the effluent nitrate nitrogen (NO3--N) and total nitrogen (TN) concentrations of WBCF (5.33 mg/L and 8.86 mg/L) were higher than those of WBCR (5 mg/L and 6.11 mg/L) at room temperature. Under FTCs conditions, both WBCF and ABCF had high NO3--N removal efficiency (up to 85.87% and 24.75%) at the initial stage of thawing of the filler, and the efficiency gradually decreased with the thawing of the filler. With the increase of FTCs, the NO3--N removal efficiency of WBCF gradually decreased (always higher than 13.6%), while the removal efficiency of ABCF fluctuated wildly (the removal efficiency was primarily negative). The total phosphorus (TP) concentration in the effluent of WBCF (0.11 mg/L) under the T3 conditions was lower than that of WBCR (0.02 mg/L) at room temperature, and the TP concentration of ABCF (0.021 mg/L) in the effluent under the FTCs was slightly lower than that of WBCF (0.031 mg/L). The FTCs have a more significant impact on removing nitrogen pollutants in runoff, but have little effect on phosphorus. Compared with aluminum sludge, wood chips are more suitable for efficient removal of nitrogen pollutants in runoff under the FTCs. The experimental conclusions can provide a reference for the construction of bioretention cells in cold regions.


Assuntos
Poluentes Ambientais , Chuva , Alumínio , Esgotos , Fósforo , Nitrogênio/análise , Nutrientes
19.
J Environ Manage ; 325(Pt A): 116520, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36306650

RESUMO

The performance of a mixotrophic photoelectroactive biofilm reactor (MPBR) was improved in order to achieve enhanced simultaneous removal of multiple aqueous pollutants and the production of valuable biomass. The MPBR was optimized by integrating the regulation of light intensity (3000, 8000 and 23000 lux) and microbial extracellular electron extraction (using an electrode at -0.3, 0 and 0.3 V). Results showed that the MPBR operated at a high light intensity (23000 lux) with a potential of -0.3 V (Coulomb efficiency (CE) of 9.65%) achieved maximum pollutant removal efficiencies, effectively removing 65% NH4+-N, 95% PO43--P and 52% sulfadiazine (SDZ) within 72 h, exhibiting an increase by 30%, 56% and 26% compared to an MPBR operated at the same light intensity but without an externally applied potential. The use of an electrode with an applied potential of -0.3V was most suitable for the extraction of photosynthetic electrons from the photoelectroactive biofilm, in which Rhodocyclaceae was highly enriched, effectively alleviating photoinhibition and thereby enhancing N, P assimilation and SDZ degradation under high light conditions. A maximum lipid content of 409.28 mg/g was obtained under low light intensity (3000 lux) conditions with an applied potential of 0.3 V (CE 9.08%), while a maximum protein content of 362.29 mg/g was obtained at a low light intensity (3000 lux) and 0 V (CE 10.71%). The selective enrichment of Chlorobium and the subsequent enhanced conversion of excess available carbon under low light and positive potential stimulation conditions, were responsible for the enhanced accumulation of proteins and lipids in biomass.


Assuntos
Antibacterianos , Elétrons , Biofilmes , Biomassa , Nutrientes , Sulfadiazina , Águas Residuárias , Reatores Biológicos
20.
J Environ Manage ; 325(Pt A): 116548, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36308786

RESUMO

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


Assuntos
Fertilizantes , Esgotos , Estruvita/química , Esgotos/química , Ácido Edético , Fósforo/química , Nutrientes , Fosfatos
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