Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
Math Biosci Eng ; 19(5): 4368-4395, 2022 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-35430819

RESUMO

The development of China's manufacturing industry is still facing the challenge of regional imbalance. To solve the problem of development imbalance, it is necessary to realize regional development. First, we must analyze the development characteristics of different regions. To this end, we consider the requirements of the new development era and design an evaluation index system for the high-quality development level of the manufacturing industry from the dimensions of innovation, green, and efficiency. Then construct a novel hybrid model which combines the grey incidence clustering model and AP algorithm for panel data in this paper. According to the statistical data from 2014 to 2018, we find out the high-quality development of China's manufacturing industry is characterized by obvious regional differences, different development stages and different constraints.


Assuntos
Indústrias , Indústria Manufatureira , China , Análise por Conglomerados
2.
BMC Infect Dis ; 21(1): 1118, 2021 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-34715793

RESUMO

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) has become a major public health problem in China, with mounting evidence suggesting that recent transmission accounts for the majority of MDR-TB. Here we aimed to reveal the transmission pattern of an MDR-TB outbreak in the Jing'an District of Shanghai between 2010 and 2015. METHODS: We used whole-genome sequencing (WGS) to conduct genomic clustering analysis along with field epidemiological investigation to determine the transmission pattern and drug resistance profile of a cluster with ten MDR-TB patients in combining field epidemiological investigation. RESULTS: The ten MDR-TB patients with genotypically clustered Beijing lineage strains lived in a densely populated, old alley with direct or indirect contact history. The analysis of genomic data showed that the genetic distances of the ten strains (excluding drug-resistant mutations) were 0-20 single nucleotide polymorphisms (SNPs), with an average distance of 9 SNPs, suggesting that the ten MDR-TB patients were infected and developed the onset of illness by the recent transmission of M. tuberculosis. The genetic analysis confirmed definite epidemiological links between the clustered cases. CONCLUSIONS: The integration of the genotyping tool in routine tuberculosis surveillance can play a substantial role in the detection of MDR-TB transmission events. The leverage of genomic analysis in combination with the epidemiological investigation could further elucidate transmission patterns. Whole-genome sequencing could be integrated into intensive case-finding strategies to identify missed cases of MDR-TB and strengthen efforts to interrupt transmission.


Assuntos
Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose , Antituberculosos/uso terapêutico , China/epidemiologia , Farmacorresistência Bacteriana Múltipla/genética , Genótipo , Humanos , Epidemiologia Molecular , Mycobacterium tuberculosis/genética , Tuberculose/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia
3.
Zhongguo Dang Dai Er Ke Za Zhi ; 23(9): 877-881, 2021.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-34535200

RESUMO

OBJECTIVES: To study the efficacy of Huaiqihuang granules as adjuvant therapy for bronchial asthma in children. METHODS: A multicenter, prospective, and registered real-world study was performed for the children, aged 2-5 years, who had a confirmed diagnosis of bronchial asthma in the outpatient service of 21 hospitals in China. Among these children, the children treated with medications for long-term asthma control (inhaled corticosteroid and/or leukotriene receptor antagonist) without Huaiqihuang granules were enrolled as the control treatment group, and those treated with medications for long-term asthma control combined with Huaiqihuang granules were enrolled as the combined treatment group. The medical data of all children were collected. Outpatient or telephone follow-up was performed at weeks 4, 8, 12, 20, 28, and 36 after treatment, including asthma attacks and rhinitis symptoms. A statistical analysis was performed for the changes in these indices. RESULTS: There was no significant difference in the frequency of asthma attacks or rhinitis attacks between the two groups before treatment (P>0.05). After treatment, the combined treatment group had significantly lower frequencies of asthma attacks, severe asthma attacks, and rhinitis attacks compared with the control treatment group (P<0.05). There was no signification difference in the incidence rate of adverse reactions between the two groups (P=0.667). CONCLUSIONS: Huaiqihuang granules in addition to medications for long-term asthma control can alleviate the symptoms of bronchial asthma and rhinitis and improve the level of asthma control in children with bronchial asthma, with good safety and little adverse effect. Citation.


Assuntos
Asma , Medicamentos de Ervas Chinesas , Asma/tratamento farmacológico , Criança , Medicamentos de Ervas Chinesas/uso terapêutico , Humanos , Estudos Prospectivos , Qualidade de Vida
5.
Sci Total Environ ; 726: 138221, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32320868

RESUMO

Struvite precipitation may become ineffective in removing phosphorus due to the low concentration of phosphate in the liquid. In this study, electrolysis with a magnesium anode was applied to recovering phosphorus and ammonia as struvite from wastewater. A novel electrodialysis process (ED) with a magnesium anode was developed, and its feasibility to treat synthetic wastewater with low phosphate concentration was demonstrated in a pilot-scale experimental system. To achieve high phosphate removal efficiency in the product stream, the optimal initial pH and flow rate were found to be 8.8 and 200 L h-1, respectively, for the ED system at a constant current of 0.1 A. The pilot-scale ED system under the consecutive batch mode removed 65% phosphate from the synthetic wastewater containning 10 mg L-1P, and the phosphate concentration in the product stream was kept at 30 mg L-1 after 280 min. The running cost of the ED system was estimated to be $31.27 kg-1 P for synthetic wastewater with 10 mg L-1 P, mainly resulting from the cost of the loss of the magnesium anode. The precipitates generated from the product stream were confirmed as struvite by XRD analysis.

6.
Int J Nurs Knowl ; 31(3): 173-179, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31697041

RESUMO

OBJECTIVE: To evaluate the reliability, validity, responsiveness, importance, and application level of the Core Nursing Outcomes Evaluation System for inpatients with stroke. METHODS: The reliability, validity, responsiveness, importance, and application level were evaluated by expert scoring, clinical measurement, and questionnaire survey. RESULTS: The scale-level content validity index (S-CVI) and item-level content validity index (I-CVI) were >0.8. The scoring of intraclass coefficient of all indicators was >0.600 (p < .001). There were significant differences in the total scores among patients with different severities (p < .001). Compared with total scores at admission, the total scores at discharge were significantly improved (p < .01). The importance and application level scores of all indexes are >4.5 points. CONCLUSION: The system has higher reliability, validity, responsiveness, and importance, but the application of each dimension is disproportionate. Stroke is an acute cerebrovascular disease characterized by cerebral ischemia and hemorrhagic injury. Epidemiological findings revealed that stroke is the second leading cause of death and the leading cause of disability in the world (Feigin et al., 2014). Epidemiological survey of 600,000 people in China showed that the prevalence of stroke has been increasing over the past 30 years (Sun & Wang, 2018). At present, stroke has become the first cause of death among Chinese residents (Wang, 2018; Zhou et al., 2016). In surviving patients with stroke, more than 60% of patients had different degrees of neurological dysfunction (Wang, Liu, Yang, Peng, & Wang, 2018), about 40% of them had severe disabilities (You & Wu, 2016). About 60% of first onset stroke patients were associated with higher risk of recurrence (Wang et al., 2018). With increasing age, the global burden of stroke is becoming heavier and heavier (Johnston, Mendis & Mathers, 2009). In 2015, the cost of stroke treatment in China reached about 29.2 billion RMB, bringing heavy economic burden to families as well as society (Ma, 2018). From the above data, we deduced that stroke has characteristics of high prevalence rate, high disability rate, high mortality rate, and high recurrence rate. It is one of the important causes of death and disability, seriously threatening human health and has become an important public health problem faced by Chinese society currently.


Assuntos
Pacientes Internados , Avaliação de Resultados em Cuidados de Saúde , Acidente Vascular Cerebral/enfermagem , Adulto , Humanos , Reprodutibilidade dos Testes , Adulto Jovem
7.
Artigo em Inglês | MEDLINE | ID: mdl-29035679

RESUMO

To identify the performance of step-fed submerged membrane sequencing batch reactor (SMSBR) treating swine biogas digestion slurry and to explore the correlation between microbial metabolites and membrane fouling within this novel reactor, a lab-scale step-fed SMSBR was operated under nitrogen loading rate of 0.026, 0.052 and 0.062 g NH4+-N (gVSS·d)-1. Results show that the total removal efficiencies for NH4+-N, total nitrogen and chemical oxygen demand in the reactor (>94%, >89% and >97%, respectively) were high during the whole experiment. However, the cycle removal efficiency of NH4+-N decreased significantly when the nitrogen loading rate was increased to 0.062 g NH4+-N (gVSS·d)-1. The total removal efficiency of total phosphorus in the step-fed SMSBR was generally higher than 75%, though large fluctuations were observed during the experiments. In addition, the concentrations of microbial metabolites, i.e., soluble microbial products (SMP) and extracellular polymeric substances (EPS) from activated sludge increased as nitrogen loading rate increased, both showing quadratic equation correlations with viscosity of the mixed liquid in the step-fed SMSBR (both R2 > 0.90). EPS content was higher than SMP content, while protein (PN) was detected as the main component in both SMP and EPS. EPS PN was found to be well correlated with transmembrane pressure, membrane flux and the total membrane fouling resistance. Furthermore, the three-dimensional excitation-emission matrix fluorescence spectroscopy results suggested the tryptophan-like protein as one of the main contributors to the membrane fouling. Overall, this study showed that the step-fed SMSBR could be used to treat swine digestion slurry at nitrogen loading rate of 0.052 g NH4+-N (gVSS·d)-1, and the control strategy of membrane fouling should be developed based on reducing the tryptophan-like PN in EPS.


Assuntos
Incrustação Biológica , Reatores Biológicos , Esgotos/química , Purificação da Água/métodos , Animais , Análise da Demanda Biológica de Oxigênio , Fazendas , Membranas Artificiais , Consórcios Microbianos/fisiologia , Nitrogênio/metabolismo , Polímeros/metabolismo , Suínos , Triptofano/metabolismo , Viscosidade
8.
Sci Rep ; 7(1): 6279, 2017 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-28740247

RESUMO

Foodborne disease outbreak caused by food microbiological contamination is a serious public health problem. Slightly acidic electrolyzed water (SAEW), a new ultra-high effect and wide-spectrum disinfectant that is colourless, odourless, and harmless to humans and the environment, is directly used on food surfaces in Japan and America. However, the underlying inactivation mechanism remains unknown. In this study, biochemical and cellular changes were observed to investigate the bactericidal mechanism of SAEW against Escherichia coli (E. coli). The results indicated that SAEW with a pH of 6.40, an oxidation-reduction potential (ORP) of 910 mV, an available chlorine concentration (ACC) of 60 mg/L, and a volume ratio of 20:1, produced the most effective sterilization action. A fluorescence-based live-dead assay was further used to demonstrate the sterilized effect and the cell esterase activity damage caused by SAEW. During the observation period, within 10 min, the cell morphology changed, which was characterized by cell expansion, cell elongation and increased membrane permeability. Meanwhile, reactive oxygen substances (ROS) were released in the bacterial cells. E. coli inactivation and apoptosis induced by SAEW were observed. Our findings illustrate that the bactericidal effects of SAEW against E. coli occurred through cellular and biochemical mechanisms of cell necrosis and apoptosis.


Assuntos
Ácidos/farmacologia , Desinfecção/métodos , Eletrólise/métodos , Escherichia coli/efeitos dos fármacos , Peróxido de Hidrogênio/química , Cloro/metabolismo , Concentração de Íons de Hidrogênio
9.
AMB Express ; 7(1): 113, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28582972

RESUMO

The interactions between environmental factors and bacterial community shift in solid-phase denitrification are crucial for optimum operation of a reactor and to achieve maximum treatment efficiency. In this study, Illumina high-throughput sequencing was applied to reveal the effects of different operational conditions on bacterial community distribution of three continuous operated poly(butylene succinate) biological denitrification reactors used for recirculating aquaculture system (RAS) wastewater treatment. The results indicated that salinity decreased OTU numbers and diversity while dissolved oxygen (DO) had no obvious influence on OTU numbers. Significant microbial community composition differences were observed among and between three denitrification reactors under varied operation conditions. This result was also demonstrated by cluster analysis (CA) and detrended correspondence analysis (DCA). Hierarchical clustering and redundancy analysis (RDA) was performed to test the relationship between environmental factors and bacterial community compositions and result indicated that salinity, DO and hydraulic retention time (HRT) were the three key factors in microbial community formation. Besides, Simplicispira was detected under all operational conditions, which worth drawing more attention for nitrate removal. Moreover, the abundance of nosZ gene and 16S rRNA were analyzed by real-time PCR, which suggested that salinity decreased the proportion of denitrifiers among whole bacterial community while DO had little influence on marine reactors. This study provides an overview of microbial community shift dynamics in solid-phase denitrification reactors when operation parameters changed and proved the feasibility to apply interval aeration for denitrification process based on microbial level, which may shed light on improving the performance of RAS treatment units.

10.
Bioresour Technol ; 216: 1004-13, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27343453

RESUMO

In this study, an airlift inner-loop sequencing batch reactor using poly(butylene succinate) as the biofilm carrier and carbon source was operated under an alternant aerobic/anoxic strategy for nitrogen removal in recirculating aquaculture system. The average TAN and nitrate removal rates of 47.35±15.62gNH4-Nm(-3)d(-1) and 0.64±0.14kgNO3-Nm(-3)d(-1) were achieved with no obvious nitrite accumulation (0.70±0.76mg/L) and the dissolved organic carbon in effluents was maintained at 148.38±39.06mg/L. Besides, the activities of dissimilatory nitrate reduction to ammonium and sulfate reduction activities were successfully inhibited. The proteome KEGG analysis illustrated that ammonia might be removed through heterotrophic nitrification, while the activities of nitrate and nitrite reductases were enhanced through aeration treatment. The microbial community analysis revealed that denitrifiers of Azoarcus and Simplicispira occupied the dominate abundance which accounted for the high nitrate removal performance. Overall, this study broadened our understanding of simultaneous nitrification and denitrification using biodegradable material as biofilm carrier.


Assuntos
Amônia , Biofilmes , Reatores Biológicos , Butileno Glicóis/química , Nitratos , Polímeros/química , Amônia/análise , Amônia/química , Amônia/isolamento & purificação , Amônia/metabolismo , Desnitrificação , Nitratos/análise , Nitratos/química , Nitratos/isolamento & purificação , Nitratos/metabolismo , Nitrificação
11.
Ying Yong Sheng Tai Xue Bao ; 25(10): 3056-66, 2014 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-25796919

RESUMO

With the advent of the post-genomic era, metaproteomics is gradually emerging as a new tool that has been successfully applied in life sciences and pharmacology, and has become one of the most popular methods in many research fields. Although application of metaproteomics in studying wastewater biotreatment is still in its infancy, its strong potential that contributes to basic research has already been well noticed. This paper reviewed the recent research advances in using metaproteomics to biotreatment wastewater. It also reviewed and summarized the research strategies and application of metaproteomics, such as the identification of functional proteins or enzymes, understanding of the mechanisms of pollutant biodegradation, deduction of key metabolic pathways, and investigation of microbial ecosystems within different sludge of microbial habitats.


Assuntos
Proteômica , Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Ecossistema , Redes e Vias Metabólicas , Proteínas , Esgotos/microbiologia , Águas Residuárias
12.
Pediatr Emerg Care ; 28(9): 921-3, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22940894

RESUMO

Flow cytometry was used to analyze the changes in lymphocyte subsets in the youngest child with avian influenza in China. During the early stage, the absolute CD3 count was 62.9% (lower limit of normal), the CD8 count was 32.5% (slightly higher than normal), and the CD4 count was 28.6% (lower than normal). The CD4/CD8 ratio was also decreased (0.88). The natural killer (CD3CD1656) cell count was 4.9% (lower than normal). During the convalescent stage, the CD4 count and the CD4/CD8 ratio returned to normal. The CD3CD1656 count increased from its value at the early stage of the disease.


Assuntos
Virus da Influenza A Subtipo H5N1/imunologia , Influenza Humana/imunologia , Subpopulações de Linfócitos/imunologia , China , Diagnóstico Diferencial , Feminino , Citometria de Fluxo , Humanos , Lactente , Influenza Humana/diagnóstico , Influenza Humana/terapia
13.
Bioresour Technol ; 116: 386-95, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22537401

RESUMO

Higher contents of NH(4)(+) and SS in wastewater hamper the anaerobic digestion; necessitating its pretreatment to reduce them. This study reveals optimization of struvite/MAP precipitation protocol followed by anaerobic digestion of pretreated swine wastewater for pollutants removal. Levels of different treatments: stirring speeds, 400 and 160 rpm; pH values, 9.0, 9.5, 10.0, 10.5, 11.0 and 11.5; and P:Mg:N ratios, 1:1:1.2, 1:1:1.7, 1:1:2.2, 1:1:2.7, 1:1:4.0 and 1:1:5.0 were evaluated for MAP crystallization. Among various combinations, protocol comprising of initial 10 min stirring at 400 rpm followed by 160 rpm for 30 min, pH 10.0, and P:Mg:N ratio 1:1:1.2 rendered the best removal efficiency for NH(4)(+), PO(4)(3-), COD, TC and TOC. Subsequent anaerobic biodegradation revealed superiority of MAP supernatant over raw swine wastewater for methane yield and NH(4)(+)-N, PO(4)(3-)-P, COD, TC and TOC removals. It suggests that struvite precipitation as pretreatment to anaerobic digestion is highly effective and advantageous in wastewater treatment.


Assuntos
Compostos de Magnésio/química , Fosfatos/química , Sus scrofa , Eliminação de Resíduos Líquidos , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Amônia/análise , Anaerobiose , Animais , Biodegradação Ambiental , Biocombustíveis/análise , Análise da Demanda Biológica de Oxigênio , Carbono/isolamento & purificação , Precipitação Química , Cristalização , Concentração de Íons de Hidrogênio , Magnésio/análise , Metano/análise , Nitrogênio/isolamento & purificação , Compostos Orgânicos/isolamento & purificação , Fosfatos/análise , Fósforo/análise , Compostos de Amônio Quaternário/isolamento & purificação , Solubilidade , Estruvita , Volatilização
14.
Water Environ Res ; 83(7): 643-9, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21790083

RESUMO

Two feeding ratios, 3:1 (RUN I) and 2:1 (RUN II), were experimented to investigate their effect on removal of nitrogen, phosphorus, organic matter, and on the trends of oxidization-reduction potential (ORP) and pH in sequencing batch reactors (SBR) with dual anoxic feedings of swine wastewater. Results showed for both runs, the feeding ratio had a more significant effect on the removal of phosphorus and nitrogen than on COD in the operating cycle. As compared to RUN I, the removal of nitrogen and phosphorus was enhanced in RUN II. In addition, the optimal feeding ratio greater than 1:1 for SBR with dual anoxic feedings can be determined with reference to the decreasing range of ORP following the primary feeding, and the denitrification-associated ORP bending point in the second non-aeration phase.


Assuntos
Agricultura , Reatores Biológicos , Oxigênio/química , Suínos , Eliminação de Resíduos Líquidos/métodos , Anaerobiose , Animais , Concentração de Íons de Hidrogênio , Oxirredução , Fatores de Tempo
15.
Ying Yong Sheng Tai Xue Bao ; 22(2): 537-42, 2011 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-21608272

RESUMO

Methanogens play an important role in global carbon cycle. There exists a range of unknown methanogenic archaea in acidic peat lands, among which, acidophilic methanogens have attracted increasing research interests because of their special metabolic characteristics. To introduce acidophilic methanogens in the anaerobic digestion process of high concentration organic wastes or waste water could essentially overcome the inhibition of acid accumulation on the methanogens and help reduce the operation cost, broadening the industrial application of anaerobic bio-treatment technology. In this paper, we reviewed the recent researches on acidophilic methanogens, with the focus on enrichment and isolation methods, physiological and biochemical characters, metabolic characteristics, and application of molecular biology. The potential applications of acidophilic methanogens in anaerobic digestion process were analyzed and proposed, and the directions for further researches were suggested.


Assuntos
Archaea/metabolismo , Metano/metabolismo , Methanosarcinaceae/metabolismo , Eliminação de Resíduos/métodos , Anaerobiose , Biodegradação Ambiental , Methanosarcinaceae/classificação , Methanosarcinaceae/genética
16.
Artigo em Inglês | MEDLINE | ID: mdl-21409696

RESUMO

With the rapid development of swine production in China, odor pollution associated with piggery facilities has become an increasing environmental concern. N-butyric acid (n-BA) is one of the key odor compounds selected to represent volatile fatty acids (VFAs) found in piggery facilities. In this study, two biofilters (BFs) packed with compost (BFC) or sludge (BFS) and two biotrickling filters (BTFs) packed with pall rings (BTFP) or multidimensional hollow balls (BTFM), respectively, were compared with regard to their performances in the removal of n-BA. The non-biological removal capacities of packing material of the bioreactors on a per unit volume basis were BFS>BFC>BTFM>BTFP. Maximum biological removal capacities per unit volume of packing material of the bioreactors all exceeded 9.1 kg/m(3)·d and in the order of BFC>BTFM>BFS>BTFP. Kinetic analysis as well as overall evaluation by radar graphs showed that the BTFs achieved superior removal rates to the BFs in the order of BTFM>BTFP>BFC>BFS. The biotrickling filter packed with multidimensional hollow balls could be an effective technology for VFAs removal. Results from this research provide economical and effective alternatives for odor control in piggery facilities.


Assuntos
Poluição do Ar/prevenção & controle , Ácido Butírico/análise , Filtração/métodos , Esterco/análise , Odorantes/prevenção & controle , Eliminação de Resíduos/métodos , Agricultura , Animais , Biodegradação Ambiental , Reatores Biológicos , China , Filtração/instrumentação , Eliminação de Resíduos/instrumentação , Solo/química , Sus scrofa
17.
Bioresour Technol ; 102(2): 710-5, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20971638

RESUMO

To achieve an appropriate mixture of ammonium and nitrite for anaerobic ammonium oxidation (ANAMMOX), 50% partial nitritation was optimized in a fixed bed biofilm reactor treating synthetic wastewater. Results suggested that 50% partial nitritation could be achieved by stepwise increases of influent NH4+-N at pH of 7.8±0.2, temperature of 30±1°C and dissolved oxygen (DO) of 0.5-0.8 mg l(-1). Hydraulic retention time (HRT) and influent alkalinity did significantly affect partial nitritation. At HRT 12 h, 50% partial nitritation could be kept stable, regardless of influent NH4+-N variation, by controlling the influent HCO3-/NH4+ molar ratio at 1:1. The fluorescent in situ hybridization (FISH) results indicated the abundance of evolution of ammonia-oxidizing bacteria (AOB) and the nitrite-oxidizing bacteria (NOB) coincided well with the performance of partial nitritation. Furthermore, the AOB were highly affiliated with Nitrosomonas spp. and Nitrosospira spp. dominated (64.1%) in the biofilm with a compact structure during the stable 50% partial nitritation period.


Assuntos
Biofilmes , Reatores Biológicos/microbiologia , Nitrificação/fisiologia , Purificação da Água/instrumentação , Purificação da Água/métodos , Álcalis , Bactérias/metabolismo , Bactérias/ultraestrutura , Biodegradação Ambiental , Hibridização in Situ Fluorescente , Microscopia Eletrônica de Varredura , Nitrogênio/análise , Compostos de Amônio Quaternário/isolamento & purificação , Fatores de Tempo
18.
Ying Yong Sheng Tai Xue Bao ; 21(1): 247-54, 2010 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-20387451

RESUMO

Composting is an effective way to realize livestock manure treatment and recycling. However, the nitrogen loss during manure composting is relatively serious. Studies on this nitrogen loss and its control could provide theoretic basis and practical reference for efficient nitrogen loss control. This paper described the nitrogen transformation and the main nitrogen loss ways during the composting, and summarized the main factors (including raw material characteristics, environment factors, and technological conditions) affecting the nitrogen loss in the composting. In addition, the research progress in the nitrogen loss control, including adjusting carbon and nitrogen metabolism, changing nitrogen form, adding ammonia adsorbent, and controlling pile aeration and temperature, was reviewed, and the prospects for future research were presented.


Assuntos
Fertilizantes , Gado , Esterco , Nitrogênio/análise , Eliminação de Resíduos/métodos , Animais , Nitrogênio/química , Aves Domésticas
19.
Chemosphere ; 78(9): 1177-81, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20060567

RESUMO

Composting is an effective methodology for the treatment of organic waste like pig manure (PM) before land application. However, nitrogen loss through NH(3) volatilization during the thermophilic phase is one of the major disadvantages of composting. The presence of Cu and Zn in compost arising from pig feed additives is also an issue. In this study the effects of bamboo charcoal (BC) and bamboo vinegar (BV) added to composting piles on nitrogen conservation and immobility of Cu and Zn during PM composting was investigated. Total Kjeldahl nitrogen (TKN) loss and mobility of Cu and Zn decreased with increased BC addition. TKN loss and mobility of Cu and Zn in the treatment with 9% BC at the end of composting significantly decreased by 65%, 35% and 39% respectively, as compared to the control. Addition of BV further decreased TKN loss. After composting, TKN loss in the treatment with 3% BC+0.4% BV was 23% lower than that in the treatment with 9% BC. The final results indicated that by adding BC or BC+BV into PM composting is an effective method to reduce TKN loss and control the mobility of Cu and Zn.


Assuntos
Ácido Acético/química , Bambusa/química , Carvão Vegetal/química , Esterco/microbiologia , Metais Pesados/metabolismo , Nitrogênio/metabolismo , Animais , Cobre , Concentração de Íons de Hidrogênio , Metais Pesados/química , Nitrogênio/química , Solo , Suínos , Temperatura
20.
Biomed Environ Sci ; 22(3): 201-9, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19725462

RESUMO

OBJECTIVE: To investigate the struvite precipitation under constant and non-constant pH conditions and to test a stainless steel device under different operating regimes to maximize the recovery of struvite. METHODS: The molar ratio of NH4+: Mg2+: PO4(3-) was adjusted to 1: 1.2: 1.2 and pH was elevated to 9.0. The absorbance measurement was used to trace the process of struvite crystallization. Wastewater and precipitate analysis was done by standard analytical methods. RESULTS: The pH constant experiment reported a significantly higher struvite precipitation (24.6 +/- 0.86 g) than the non-constant pH experiment (19.8 +/- 1.86 g). The SAR ranged from 5.6 to 8.2 g m(-2) h(-1) to 3.6-4.8 g m(-2) h(-1) in pH constant and non-constant experiments, respectively. The highest struvite deposit on the device was found in regime 3 followed by in regimes 2 and 4. The highest PO4(3-) (97.2%) and NH4+ (71%) removal was reported in the R1 regime. None of the influent Cu2+ or Zn2+ was precipitated on the device. CONCLUSION: A higher struvite yield is evident in pH constant experiments. Moreover, the stainless steel device facilitates the isolation of heavy metal free pure (around 96%) struvite from swine waste biogas digester effluent contaminated with cu2+ and Zn2+ and the highest yield is attainable with the device operating at 50 rpm with agitation by a magnetic stirrer.


Assuntos
Reatores Biológicos , Compostos de Magnésio/química , Esterco , Fosfatos/química , Suínos , Eliminação de Resíduos Líquidos/instrumentação , Animais , Precipitação Química , Concentração de Íons de Hidrogênio , Aço Inoxidável , Estruvita , Fatores de Tempo , Eliminação de Resíduos Líquidos/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...