RESUMO
In dynamic membrane bioreactors (DMBRs), a dynamic membrane (DM) forms on a support material to act as the separation membrane for solids and liquids. In this study, batch filtration tests were carried out in a DMBR using nylon mesh (25⯵m) as support material to filtrate sludge suspensions of variable properties from three different sources to evaluate the effects on the short-term DM formation process (within 240â¯min). Furthermore, the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory was applied to analyze the sludge adhesion and cohesion behaviors on the mesh surface to predict quantitative parameters of the short-term DM formation process (including initial formation and maturation stage). The filtration results showed that the order of the initial DM formation time (permeate turbidity <1â¯NTU as an indicator) was as follows: sludge with poor settleability and dewaterabilityâ¯<â¯normal sludgeâ¯<â¯sludge with poor flocculability. Moreover, normal sludge (regarding settleability, dewaterability, flocculability, and extracellular polymeric substance) showed a more acceptable DM formation performance (short DM formation time, low permeate turbidity, and high permeate flux) than sludge with poor settleability, dewaterability and flocculability. The influence of sludge properties on the initial DM formation time corroborates the prediction of sludge adhesion behaviors by XDLVO theory. Additionally, the XDLVO calculation results showed that acid-based interaction, energy barrier, and secondary energy minimum were important determinants of the sludge adhesion and cohesion behaviors. Therefore, short-term DM formation process may be enhanced to achieve stable long-term DMBR operation through positive modification of the sludge properties.
Assuntos
Reatores Biológicos , Membranas Artificiais , Esgotos , Reatores Biológicos/microbiologia , Estudos de Viabilidade , Filtração , Nylons/química , Esgotos/microbiologia , Termodinâmica , Fatores de TempoRESUMO
The effects of powdered activated carbon (PAC) addition on sludge morphological, aggregative and microbial properties in a dynamic membrane bioreactor (DMBR) were investigated to explore the enhancement mechanism of pollutants removal and filtration performance. Sludge properties were analyzed through various analytical measurements. The results showed that the improved sludge aggregation ability and the evolution of microbial communities affected sludge morphology in PAC-DMBR, as evidenced by the formation of large, regularly shaped and strengthened sludge flocs. The modifications of sludge characteristics promoted the formation process and filtration flux of the dynamic membrane (DM) layer. Additionally, PAC addition did not exert very significant influence on the propagation of eukaryotes (protists and metazoans) and microbial metabolic activity. High-throughput pyrosequencing results indicated that adding PAC improved the bacterial diversity in activated sludge, as PAC addition brought about additional microenvironment in the form of biological PAC (BPAC), which promoted the enrichment of Acinetobacter (13.9%), Comamonas (2.9%), Flavobacterium (0.31%) and Pseudomonas (0.62%), all contributing to sludge flocs formation and several (such as Acinetobacter) capable of biodegrading relatively complex organics. Therefore, PAC addition could favorably modify sludge properties from various aspects and thus enhance the DMBR performance.
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Reatores Biológicos , Eliminação de Resíduos Líquidos/métodos , Bactérias , Biodegradação Ambiental , Carvão Vegetal , Filtração/métodos , Membranas Artificiais , Esgotos/microbiologia , Águas ResiduáriasRESUMO
INTRODUCTION: The mortality of Parkinson's disease (PD) and its associated risk factors among clinically definite PD patients in China has been rarely investigated. Our study aimed to identify the mortality rates and predictors of death in PD patients in China. METHODS: 157 consecutive, clinically definite PD patients from the urban area of Shanghai were recruited from a central hospital based movement disorder clinic in 2006. All patients were regularly followed up at the clinic until December 31, 2011, or death. Mortality and associations with baseline demographics, health and medical factors were then determined within the cohort. RESULTS: After 5 years, 11(7%) patients had died. The standardised mortality ratio was 0.62 (95% CI 0.32 to 1.07, P=0.104). The main causes of death were pneumonia (54.5%, 6/11) and digestive disorders (18.2%, 2/11), respectively. Age at onset, independent living, the mini mental state examination score, the Parkinson's disease sleep scale score and the Epworth sleepiness scale score at baseline were statistically significantly different between the survival group and the deceased group (P<0.05). Across all participants, risk factors for death included low mini mental state examination score, and high Epworth sleepiness scale score according to a binary variable logistic regression analysis. CONCLUSIONS: This study confirms the similar survival of patients with PD to the control population up to a follow-up of 5 years. Interventions tailored to potential risk factors associated with death may offer further benefits.
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Doença de Parkinson/mortalidade , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Causas de Morte , China/epidemiologia , Estudos de Coortes , Doenças do Sistema Digestório/etiologia , Doenças do Sistema Digestório/mortalidade , Feminino , Seguimentos , Nível de Saúde , Humanos , Vida Independente , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Pneumonia/etiologia , Pneumonia/mortalidade , Fatores de Risco , Sono , Fatores Socioeconômicos , Análise de Sobrevida , População UrbanaRESUMO
Enhanced methane production and sustainable reduction of pollutants from anaerobic digestate are crucial for swine wastewater treatment. In this study, anaerobic dynamic membrane bioreactor (AnDMBR) was introduced to enhance methane production, then microalgae were cultivated on the digestate for nutrients recovery and lipid production. Results showed that pollutants can be effectively removed under various hydraulic retention time (HRT) conditions during long-term operation. Methanogenesis was enhanced with the reduction of HRT from 20 days to 10 days (0.23 L-CH4/g-CODremoved), but inhibited by shortening HRT to 5 days (0.09 L-CH4/g-CODremoved). Ammonia and phosphate in the digestate were effectively removed after microalgae cultivation. In addition, the highest microalgal biomass and lipid productivity (1.7 g/L and 17.5 mg/(L·d), respectively) were obtained using digestate ratio of 20 %, while microalgal growth was seriously restricted at high digestate content (>50 %). This work provides a prospective pathway for pollutants control and energy production from swine wastewater through integrating of AnDMBR technology with microalgae cultivation.
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Microalgas , Águas Residuárias , Animais , Suínos , Microalgas/metabolismo , Anaerobiose , Estudos de Viabilidade , Estudos Prospectivos , Biocombustíveis , Metano/metabolismo , Biomassa , LipídeosRESUMO
Caproic acid (CA) production from food waste (FW) is a promising way for waste recycling, while the fermentation processes need further exploration. In this study, FW acidogenic fermentation under different pH (uncontrolled, 4, 5, 6) using indigenous microbiota was investigated. Result showed that substrate hydrolysis, carbohydrate degradation and acidogenesis increased with the increase of pH. Although various microbial communities were observed in FW, lactic acid bacteria (Lactobacillus and Limosilactobacillus) were enriched at pH lower than 6, resulting in lactic acid accumulation. CA (88.24 mM) was produced at pH 6 accounting for 31.23% of the total product carbon. The enriched lactic acid bacteria were directionally replaced by chain elongators (Caproicibacter, Clostridium_sensu_stricto, unclassified_Ruminococcaceae) at pH 6, and carbohydrates in FW were firstly transformed into lactic acid, then to butyrate and CA through lactate-based chain elongation processes. This work provided a novel CA fermentation pathway and further enriched the FW valorization.
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Lactobacillales , Microbiota , Eliminação de Resíduos , Alimentos , Ácido LácticoRESUMO
The formation of anammox-hydroxyapatite (HAP) coupled granules has been shown to be an approach to efficient nitrogen removal and phosphorus recovery in the anammox EGSB reactor. However, the granulation cycle mechanism of anammox-HAP coupled granules for sustainable regeneration and growth is still not well understood. In this study, the microstructure, chemical composition and microbial structure of a total of six different-sized granules, from 0.25 mm to 2.8 mm, was determined. An SEM-EDS analysis indicated that the small granules (<0.5 mm) were composed of poly-pellet clusters with anammox biofilms attached to the HAP cores, and the large granules (>0.5 mm) consisted of a three-layer structure: a surface anammox biofilm layer, a middle connection layer, and a HAP mineral inner core. The analysis of elemental composition and microbial structure suggested homogenous granular characteristics regardless of granule size. The dominant microorganisms were anammox bacteria of Candidatus Kuenenia stuttgartiensis and heterotrophic denitrifying bacteria. Based on these results, a granulation cycle mechanism for anammox-HAP coupled granules was proposed for the first time. The growth of the small granules with the simultaneous enlargement of anammox biofilms and HAP cores results in the formation of large granules. Large granules regenerate new small granules in a two-step procedure. The first step is the separation of embryo HAP crystals from the mother core via heterogeneous growth, and the second step is the separation of the biofilms due to biodegradation and shear stress.
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Reatores Biológicos , Durapatita , Oxidação Anaeróbia da Amônia , Nitrogênio , FósforoRESUMO
A gravity-driven dynamic membrane bioreactors (DMBR) with GAC addition (G-DMBR) was operated under constant pressure filtration mode (using 20 cm water head) for real domestic wastewater treatment. During the stable operation period, the treatment performance, DM filtration behavior and mechanism as well as microbial properties were studied and compared with a control DMBR (C-DMBR). Both DMBRs showed stable removal of chemical oxygen demand (COD) and ammonia (NH4+-N) with average removal rates over 88% and 98%, respectively. GAC addition effectively enhanced dynamic membrane (DM) permeability with a stable flux of 17 to 65 L/m2h, which was approximately four times higher than that in the C-DMBR without GAC addition. Filtration resistance analysis indicated the DM formation can be divided to three stages: the formation of the initial DM layer, the development of mature DM layer and dynamic equilibrium stage of the DM layer. Filtration model analysis illustrated that added GAC could be the skeleton of the DM, resulting in a more porous and incompressible DM layer. Additionally, microbial community analysis revealed that in the G-DMBR several fouling-causing phyla including Proteobacteria reduced while other phyla preferring attached growth such as Bacteroidetes and Gemmatimonadetes increased. Thus, adding GAC to the DMBR can be an effective strategy for achieving stable and high-flux operation by modifying DM properties and regulating DM formation process and structure.
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Microbiota , Purificação da Água , Reatores Biológicos , Carvão Vegetal , Filtração/métodos , Membranas Artificiais , Águas Residuárias/química , Purificação da Água/métodosRESUMO
BACKGROUND: The association between sarcopenia and mild cognitive impairment (MCI) among elderly adults in China remains unclear. The present study aimed to examine the association based on a nationally representative large-scale survey. METHODS: The study used two waves of data from China Health and Retirement Longitudinal Study (CHARLS) in 2015 and 2018. All subjects met the inclusion criteria were classified based on Asia Working Group for Sarcopenia 2019 criteria. Aging-associated cognitive decline is used to define MCI, and cognitive function is measured based on four dimensions: orientation, computation, memory, and drawing. OLS and logistic regression model were conducted to analyse the cross-sectional association between sarcopenia and different cognitive functions. Logistic regression model was conducted to analyse the longitudinal association between sarcopenia and MCI. RESULTS: Totally, 5715 participants aged over 60 years (43.8% women; mean age 67.3 ± 6.0 years) were enrolled in a cross-sectional association study in 2015, and further 2982 elderly adults were followed up in 2018. During the period, sarcopenia and possible sarcopenia increased from 8.5% to 29.6%. Scores of cognitive and four dimensions (orientation, computation, memory, and drawing) exhibited a decreasing trend from non-sarcopenia to sarcopenia (P < 0.001). In the fully adjusted OLS regression model, scores of four dimensions were lower in possible sarcopenia and sarcopenia groups when compared with the non-sarcopenia group (P < 0.05) respectively. The incidence of MCI was 10.1%, 16.5%, and 24.2% for non-sarcopenia, possible sarcopenia, and sarcopenia groups from 2015 to 2018, with a significantly statistical difference (P < 0.001). Logistic regression model revealed an odds ratio of 1.43 [95% confidence interval (CI): 1.06-1.91, P = 0.017] for the possible sarcopenia group and 1.72 (95% CI: 1.04-2.85, P = 0.035) for sarcopenia group when compared with the non-sarcopenia group. CONCLUSIONS: Sarcopenia is associated with worse cognitive impairment, which provided new evidence for a strong association that warrants further research into mechanistic insights.
Assuntos
Disfunção Cognitiva , Sarcopenia , Idoso , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Estudos Transversais , Estudos Longitudinais , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/complicações , China/epidemiologiaRESUMO
The anaerobic membrane bioreactor (AnMBR) has gained huge attention as a municipal wastewater (MWW) treatment process that combined high organics removal, a low sludge yield and bioenergy recovery. In this study, a 20 L AnMBR was set up and operated steadily for 70 days in temperate conditions with an HRT of 6 h and a flux of 12 LMH for the treatment of real MWW, focusing on the behavior of the major elements (C, N, P and S) from an elemental balance perspective. The results showed that the AnMBR achieved more than 85 % COD removal, a low sludge yield (0.081 gVSS/gCODremoved) and high methane production (0.31 L-CH4/gCODremoved) close to the theoretical value. The elemental flow analysis revealed that the AnMBR converted 77 % of the influent COD to methane (57 % gaseous and 20 % dissolved) and 6 % of the COD for sludge production. In addition, the AnMBR converted 34 % of the total carbon to energy-generated carbon, and only 3 % was in the form of CO2 in the biogas for further upgradation, which was in line with the concept of carbon neutrality. Since little nitrogen or phosphorus were removed, the permeate was nutrient-rich and further treatment to recover the nutrients would be required. This study illustrates the superior performance of the AnMBR for MWW treatment with a microscopic view of elemental behavior and provides a reference for implementing the mainstream AnMBR process in carbon-neutral wastewater treatment plants.
Assuntos
Esgotos , Purificação da Água , Águas Residuárias , Eliminação de Resíduos Líquidos/métodos , Anaerobiose , Biocombustíveis , Carbono , Dióxido de Carbono , Membranas Artificiais , Reatores Biológicos , Purificação da Água/métodos , Metano , Fósforo , NitrogênioRESUMO
The seasonal and annual energy efficiency of mainstream anaerobic membrane bioreactor (AnMBR) was first assessed in an onsite pilot plant (15 m3/d) and then estimated in a scaled-up plant (10,000 m3/d) in temperate climates (15-25 °C). It was found that the annual net electricity demand was 0.100 and 0.090 kWh/m3, and the annual net energy (electricity + heat) demand was -0.158 and -0.309 kWh/m3 under the dissolved methane recovery condition and the non-recovery condition, respectively, demonstrated that the application of mainstream AnMBR in temperate climates is electricity saving and energy positive. The energy efficiency of the AnMBR decreased with temperature drop due to the reduction of methane production, and the increase in biogas sparging to mitigate membrane fouling. Since approximately 26.7%-39.7% of input COD remained in sludge, attention should be paid to recovering this potential energy to improve the overall energy performance of the mainstream AnMBR plants in future.
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Eliminação de Resíduos Líquidos , Águas Residuárias , Anaerobiose , Reatores Biológicos , Conservação de Recursos Energéticos , Membranas Artificiais , Metano , Estações do Ano , Esgotos , Águas Residuárias/análiseRESUMO
Sustainable urban development is threatened by an impending energy crisis and large amounts of organic wastes generated from the municipal sector among others. Conventional waste management methods involve greenhouse gas (GHG) emission and limited resource recovery, thus necessitating advanced techniques to convert such wastes into bioenergy, bio-fertilizers and valuable-added products. Research and application experiences from different scale applications indicate that the anaerobic membrane bioreactor (AnMBR) process is a kind of high-rate anaerobic digester for urban organic wastes valorization including food waste and waste sludge, while the research status is still insufficiently summarized. Through compiling recent achievements and literature, this review will focus on the following aspects, including AnMBR treatment performance and membrane fouling, technical limitations, energy balance and techno-economic assessment as well as future perspectives. AnMBR can enhance organic wastes treatment via complete retention of functional microbes and suspended solids, and timely separation of products and potential inhibitory substances, thus improving digestion efficiency in terms of increased organics degradation rates, biogas production and process robustness at a low footprint. When handling high-solid organic wastes, membrane fouling and mass transfer issues can be the challenges limiting AnMBR applications to a wet-type digestion, thus countermeasures are required to pursue extended implementations. A conceptual framework is proposed by taking various organic wastes disposal and final productions (permeate, biogas and biosolids) utilization into consideration, which will contribute to the development of AnMBR-based waste-to-resource facilities towards sustainable waste management and more economic-environmental benefits output.
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Eliminação de Resíduos , Eliminação de Resíduos Líquidos , Anaerobiose , Reatores Biológicos , Alimentos , Metano , Esgotos , Eliminação de Resíduos Líquidos/métodos , Águas ResiduáriasRESUMO
Up-concentration of municipal wastewater using physico-chemical methods can effectively enrich organic matter, facilitating subsequent anaerobic digestion of up-concentrated wastewater for enhanced methanogenesis at reduced energy consumption. An anaerobic dynamic membrane bioreactor (AnDMBR) assisted with biogas-sparging was developed to treat up-concentrated municipal wastewater, focusing on the effects of operating temperature and hydraulic retention time (HRT) as well as COD mass balance and energy balance. The COD removal stabilized at about 98 % over the experimental period, while gaseous and dissolved methane contributed 43-49 % and 2-3 % to the influent COD reducing greenhouse gas emissions. The formed dynamic membrane exists mainly as a heterogeneous cake layer with a uneven distribution feature, ensuring the stable effluent quality. Without adopting any physico-chemical cleaning, the transmembrane pressure (TMP) maintained at a low range (2.7 to 14.67 kPa) with the average TMP increasing rate of 0.089 kPa/d showing a long-term low-fouling operation. Increasing the concentration ratio, the methane production rate decreased from 0.18 to 0.15 L CH4/gCOD likely due to the accumulation of particulate organics. Microbial community analysis indicated the predominant methanogenic pathway shifted from hydrogenotrophic to acetoclastic methanogenesis in response to the temperature change. Net energy balance (0.003-0.600 kWh/m3) can be achieved only under room temperature (25 °C) rather than mesophilic conditions (36 °C).
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Águas Residuárias , Purificação da Água , Anaerobiose , Reatores Biológicos , Membranas Artificiais , Metano/análise , Esgotos , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/análiseRESUMO
The present study introduced a new method for enhanced biomethane production and pollution control of swine wastewater (SW) using anaerobic membrane bioreactor (AnMBR). Results confirmed 35 °C as the optimum temperature for enhanced anaerobic digestion which resulted in relatively higher methane production rate and potential. In AnMBR system, robust pollutants removal and conversion rate were achieved under various hydraulic retention time (HRT) ranging from 20 to 10 days, while the highest methane yield (0.24 L/g-CODremoved) and microbial activity (6.65 mg-COD/g-VSS·h) were recorded at HRT of 15 days. Reduction of HRT to 10 days resulted in serious membrane fouling due to accumulation of extracellularpolymericsubstances(EPS) and cake layer on the membrane. However, cake layer as the dominant membrane foulant could be effectively removed through periodic physical backwash to recover the membrane permeability. Overall, the suggested AnMBR is a promising technology to enhance SW treatment and energy recovery.
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Gado , Purificação da Água , Anaerobiose , Animais , Reatores Biológicos , Membranas Artificiais , Metano , Suínos , Eliminação de Resíduos Líquidos , Águas ResiduáriasRESUMO
In this study, data-driven deep learning methods were applied in order to model and predict the treatment of real municipal wastewater using anaerobic membrane bioreactors (AnMBRs). Based on the one-year operating data of two AnMBRs, six parameters related to the experimental conditions (temperature of reactor, temperature of environment, temperature of influent, influent pH, influent COD, and flux) and eight parameters for wastewater treatment evaluation (effluent pH, effluent COD, COD removal efficiency, biogas composition (CH4, N2, and CO2), biogas production rate, and oxidation-reduction potential) were selected to establish the data sets. Three deep learning network structures were proposed to analyze and reproduce the relationship between the input parameters and output evaluation parameters. The statistical analysis showed that deep learning closely agrees with the AnMBR experimental results. The prediction accuracy rate of the proposed densely connected convolutional network (DenseNet) can reach up to 97.44%, and the single calculation time can be reduced to within 1 s, suggesting the high performance of AnMBR treatment prediction with deep learning methods.
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Aprendizado Profundo , Águas Residuárias , Anaerobiose , Reatores Biológicos , Membranas Artificiais , Eliminação de Resíduos LíquidosRESUMO
A 5,000-L anaerobic membrane bioreactor (AnMBR) fed with actual municipal wastewater was employed to study the impact of temperature drops on methanogenic performance and membrane fouling. With temperature dropped from 25 °C to 15 °C, the methane yield decreased from 0.244 to 0.205 NL-CH4/g-CODremoval and the dissolved methane increased from 29% to 43%, resulted in the methanogenic performance reduced by 25%. The membrane rejection offset the deteriorated anaerobic digestion at low temperatures and ensured the stable COD removal efficiency of 84.5%-90.0%. The synergistic effects of the increased microbial products and viscosity and the residual inorganic foulants aggravated the membrane fouling at lower temperatures. As the organic fouling was easily removed by NaClO, the inorganics related to the elements of S, Ca and Fe were the stubborn membrane foulants and required the enhanced acid membrane cleaning. These findings obtained under the quasi-practical condition are expected to promote the practical applications of mainstream AnMBR.
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Eliminação de Resíduos Líquidos , Águas Residuárias , Anaerobiose , Reatores Biológicos , Membranas Artificiais , Metano , TemperaturaRESUMO
This study aimed to reveal the membrane fouling mechanisms during anaerobic membrane bioreactor (AnMBR) operation for swine wastewater treatment under different organic loading rates (OLR). Results showed that AnMBR could achieve high pollutant removal (71.9-83.6 %) and energy recovery (0.18-0.23 L-CH4/g-COD) at an OLR range of 0.25-0.5 g-COD/g-VSS.d, realizing energy production. However, higher OLR would aggravate the membrane fouling due to accumulation of fine sludge particles, organic foulants, and extracellular polymeric substances (EPS) on cake layer. Based on the high-throughput sequencing, microbial communities significantly changed and fouling-causing bacteria (e.g. Pseudomonas, Methanosarcina and Methanothrix) enriched in the cake layer at higher OLR conditions, leading to lower membrane permeability. Backwash can effectively remove the cake layer from the membrane surface and recover membrane permeability. The present study provides important information about membrane fouling and microbial information that could have significant impact on large-scale AnMBR application.
Assuntos
Microbiota , Águas Residuárias , Anaerobiose , Animais , Reatores Biológicos , Membranas Artificiais , Esgotos , Suínos , Eliminação de Resíduos LíquidosRESUMO
Partial nitritation-anammox (PN/A) is a promising deammonification process to develop energy-neutral wastewater treatment plants. However, the mainstream application of PN/A still faces the challenges of low nitrogen concentration and low temperatures, and has not been studied under a realistic condition of large-scale reactor (kiloliter level), real municipal wastewater (MWW) and seasonal temperatures. In this research, a pilot-scale one-stage PN/A, with integrated fixed-film activated sludge (IFAS) configuration, was operated to treat the real MWW pretreated by anaerobic membrane bioreactor. The removal efficiency of total nitrogen (TN) was 79.4%, 75.7% and 65.9% at 25, 20 and 15°C, corresponding to the effluent TN of 7.3, 9.7 and 12.0 mg/L, respectively. The suppression of ammonium-oxidizing bacteria (AOB) and anammox bacteria (AnAOB) occurred at lower temperatures, and the significant decrease in AOB treatment capacity was the reason for the poorer nitrogen removal at 15°C. Biomass retention and microbial segregation were successfully achieved. Specifically, Candidatus_Brocadia and Candidatus_Kuenenia were main AnAOB genera and mainly enriched on carriers, Nitrosomonas and uncultured f_Chitinophagaceae were main AOB genera and mainly distributed in suspended sludge and retained by sedimentation tank. Moreover, nitrite-oxidizing bacteria (NOB) were sufficiently suppressed by intermittent aeration and low dissolved oxygen, the presence of heterotrophic bacteria upgraded the PN/A to a simultaneous partial nitritation, anammox, denitrification, and COD oxidation (SNADCO) system, which improved the overall removal of TN and COD. The results of this investigation clearly evidence the strong feasibility of PN/A as a mainstream nitrogen removal process in temperate climates.
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Compostos de Amônio , Esgotos , Águas Residuárias , Nitritos , Biomassa , Temperatura , Oxidação Anaeróbia da Amônia , Estações do Ano , Reatores Biológicos/microbiologia , Nitrogênio , Bactérias , Oxirredução , OxigênioRESUMO
China's population has rapidly aged over the recent decades of social and economic development as neurodegenerative disorders have proliferated, especially Alzheimer's disease (AD) and related dementias (ADRD). AD's incidence rate, morbidity, and mortality have steadily increased to make it presently the fifth leading cause of death among urban and rural residents in China and magnify the resulting financial burdens on individuals, families and society. The 'Healthy China Action' plan of 2019-2030 promotes the transition from disease treatment to health maintenance for this expanding population with ADRD. This report describes related epidemiological trends, evaluates the economic burden of the disease, outlines current clinical diagnosis and treatment status and delineates existing available public health resources. More specifically, it examines the public health impact of ADRD, including prevalence, mortality, costs, usage of care, and the overall effect on caregivers and society. In addition, this special report presents technical guidance and supports for the prevention and treatment of AD, provides expertise to guide relevant governmental healthcare policy development and suggests an information platform for international exchange and cooperation.
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To support smart city in terms of municipal waste management and bioenergy recovery, a high-solid anaerobic membrane bioreactor (AnMBR) was developed for sewage sludge (SeS) and food waste (FW) treatment in this study. COD mass balance showed that 54.1%, 66.9%, 73.5%, 91.4% and 93.5% of the COD input was converted into methane at the FW ratio of 0, 25%, 50%, 75% and 100%, respectively. The corresponding net energy balance was 13.6, 14.1, 17.1, 22.9 and 27.4 kJ/g-VS, respectively. An important finding of this investigation was that, for the first time, the relationship between net energy balance and carbon to nitrogen (C/N) ratio was revealed and the established sigmoid-type function was shown to be capable of predicting energy balance at different C/N ratios regardless of the region. The outcomes of this study show the potential of high-solid AnMBRs in SeS and FW treatment for supporting smart cities in the future.
Assuntos
Eliminação de Resíduos , Esgotos , Anaerobiose , Reatores Biológicos , Digestão , Alimentos , Metano , Eliminação de Resíduos LíquidosRESUMO
Domestic wastewater (DWW) can be preconcentrated to facilitate energy recovery via anaerobic digestion (AD), following the concept of "carbon capture-anaerobic conversion-bioenergy utilization." Herein, real DWW and preconcentrated domestic wastewater (PDWW) were both subject to particle size fractionation (0.45-2000 µm). DWW is a type of low-strength wastewater (average COD of 440.26 mg/L), wherein 60% of the COD is attributed to the substances with particle size greater than 0.45 µm. Proteins, polysaccharides, and lipids are the major DWW components. PDWW with a high COD concentration of 2125.89 ± 273.71 mg/L was obtained by the dynamic membrane filtration (DMF) process. PDWW shows larger proportions of settleable and suspended fractions, and accounted for 63.4% and 33.8% of the particle size distribution, and 52.4% and 32.2% of the COD, respectively. The acceptable biomethane potential of 262.52 ± 11.86 mL CH4/g COD of PDWW indicates bioenergy recovery is feasible based on DWW preconcentration and AD.