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1.
J Biol Chem ; : 107393, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38777143

RESUMEN

Protein Tyrosine Phosphatase Non-receptor type 22 (PTPN22) is encoded by a major autoimmunity gene and is a known inhibitor of T cell receptor (TCR) signaling and drug target for cancer immunotherapy. However, little is known about PTPN22 post-translational regulation. Here we characterize a phosphorylation site at Ser325 situated C-terminal to the catalytic domain of PTPN22, and its roles in altering protein function. In human T cells, Ser325 is phosphorylated by Glycogen Synthase Kinase-3 (GSK3) following TCR stimulation, which promotes its TCR-inhibitory activity. Signaling through the major TCR-dependent pathway under PTPN22 control was enhanced by CRISPR/Cas9 mediated suppression of Ser325 phosphorylation and inhibited by mimicking it via glutamic acid substitution. Global phospho-mass spectrometry showed Ser325 phosphorylation state alters downstream transcriptional activity through enrichment of Swi3p, Rsc8p and Moira (SWIRM) domain binding proteins, and next-generation sequencing (NGS) revealed it differentially regulates the expression of chemokines and T cell activation pathways. Moreover, in vitro kinetic data suggest the modulation of activity depends on a cellular context. Finally, we begin to address the structural and mechanistic basis for the influence of Ser325 phosphorylation on the protein's properties by Deuterium Exchange Mass Spectrometry (DX/MS) and Nuclear Magnetic Resonance (NMR) spectroscopy. In conclusion, this study explores the function of a novel phosphorylation site of PTPN22 that is involved in complex regulation of TCR signaling and provides details that might inform the future development of allosteric modulators of PTPN22. Significance statement The tyrosine phosphatase PTPN22 serves as a negative regulator in T cells, and its phosphorylation is a major regulatory process for controlling its function. Here, we uncovered a novel phosphorylation site at Ser325 on PTPN22 that allosterically regulates its activity leading to impaired TCR-dependent pathways. Biophysical methods identify multiple regions affected upon Ser325 phosphorylation, which can be the basis for future mechanistic studies of PTPN22 activators or inhibitors.

2.
Nutr Health ; : 2601060241256201, 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38778709

RESUMEN

Aim: Few health checkup studies have reported lifestyle habits and examination results before and during the COVID-19 pandemic. We compared lifestyle habits and examination results surveyed before and during the COVID-19 pandemic. Methods: Five hundred and ten and 396 participants attended the health checkup in 2019 and 2022, respectively. The median age of females was 65 in 2019 and 2022, and that of males was 68 in 2019 and 69 in 2022. We investigated dietary and exercise habits, alcohol consumption, sleeping situation, and examination results, including body mass index (BMI), smell function, and blood examination results before and during the COVID-19 pandemic in a rural area in Japan. Results: An ordinal logistic regression analysis revealed that the intake frequency of vegetables and marine products was significantly less in 2022 than in 2019 after adjusting age and sex; green leafy vegetables (p = .016), fish (p = .002), and other marine products, including squid, shrimp, crabs, and octopus (p = .008). Alcohol consumption amount increased significantly in 2022 than in 2019 in men who drank beer (p = .007) and chuhai (p = .040). Albumin, hematocrit, cholesterols, and uric acid decreased, but serum calcium increased significantly in 2022 than in 2019 after adjusting age and sex. BMI and hemoglobin A1c were not significantly different between 2019 and 2022. A decrease in subjective smell feeling and smell test results was associated with decreased intake frequency of vegetables. Conclusion: Both dietary habits and blood examination results changed significantly during the COVID-19 pandemic in a rural area in Japan.

3.
Acta Otolaryngol ; 144(2): 107-111, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38534204

RESUMEN

BACKGROUND: Posterior expansion of the utricular endolymphatic space (ES) is a finding occasionally observed, and often occurs in bilateral ears. The clinical significance of posterior expansion of the utricular ES is not clear. OBJECTIVES: To investigate the clinical significance of posterior expansion of the utricular ES detected on magnetic resonance imaging (MRI). MATERIALS AND METHODS: Among 957 patients who underwent contrast-enhanced MRI to investigate the presence of endolymphatic hydrops (EH), clinical findings in cases with posterior expansion of the utricular ES were evaluated and the significance of their existence is considered. RESULTS: Posterior expansion of the utricular ES was detected in 30 ears from 20 cases (7 males, 13 females; mean age 48.7 years). The ears with posterior expansion had a significantly lower incidence of vestibular EH than those without, and this tendency was more prominent in cases in bilateral ears. Some cases with posterior expansion had vestibular symptoms and were diagnosed with Ménière's disease, although EH was not detected in their vestibules. CONCLUSION AND SIGNIFICANCE: Posterior expansion of the utricular ES was associated with Ménière's disease without vestibular EH. Posterior expansion of the utricular ES might not be associated with the formation of EH but may occur independently.


Asunto(s)
Hidropesía Endolinfática , Imagen por Resonancia Magnética , Enfermedad de Meniere , Sáculo y Utrículo , Humanos , Femenino , Masculino , Persona de Mediana Edad , Adulto , Enfermedad de Meniere/diagnóstico por imagen , Hidropesía Endolinfática/diagnóstico por imagen , Sáculo y Utrículo/diagnóstico por imagen , Anciano , Adulto Joven , Estudios Retrospectivos , Relevancia Clínica
4.
Laryngoscope Investig Otolaryngol ; 9(1): e1210, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38362179

RESUMEN

Objective: The pathophysiology and symptoms underlying Meniere's disease (MD) manifest as endolymphatic hydrops (EH), potentially impacting acoustic power absorbance in vestibular EH. The longitudinal effects of middle ear pressure therapy (MEPT) and conservative therapies for EH by magnetic resonance imaging (MRI) and on acoustic power absorbance on wideband acoustic immittance (WAI) were evaluated, and their changes were compared with clinical symptoms. Methods: Eleven patients with definite MD or delayed endolymphatic hydrops (DEH), resistant to conservative therapies and who continued MEPT for 1 year, were included. Vertigo scores, hearing levels, acoustic power absorbance on WAI, and degrees of EH on 3-T MRI were evaluated and compared before and after the treatments. Results: One year after the start of MEPT, all cases showed symptomatic improvement in vertigo score; however, the degrees of EH showed no improvements except in one case. In the affected ears with EH, their absorbances on WAI improved, particularly at 1580-1905 or 2400-2953 Hz (p < .05). Conclusion: Alleviation of vestibular symptoms with the therapy of MD was not necessarily associated with improved EH. Vestibular symptoms could be related to the change in the impedance of inner ear pressure, which was proven by the normalization of acoustic power absorbance. Assessments of acoustic power absorbance may provide useful information for physiological conditions and causative factors of vertigo in ears with EH. Level of evidence: 4.

5.
Otol Neurotol ; 44(8): e560-e565, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37525397

RESUMEN

OBJECTIVE: To evaluate the listening conditions of bilateral cochlear implant (CI) users in their daily living environment. STUDY DESIGN: Retrospective study. SETTING: University hospital. PATIENTS: Thirty-one adult CI users 16 years or older; 18 underwent sequential surgery, and 13 underwent simultaneous surgery. Inclusion criteria included the availability of CI data logging features and a minimum duration of binaural use of 6 months. INTERVENTION: Retrospective analysis of data obtained from the automatic scene classifier data logging system. MAIN OUTCOME MEASURE: Comparison of data logging and maximum speech discrimination scores of the two surgery groups (sequential vs. simultaneous) to investigate the potential influence of these factors on the listening conditions of CI users. RESULTS: The maximum speech discrimination score of the second CI in the sequential group was significantly worse than that of any other CI in the sequential and simultaneous CI groups. Additionally, the longer the interval between surgeries, the more significant the difference in "time on air" between the first and the second CIs. The second CI in sequential CI surgery had a shorter "time on air" than the first or the bilateral simultaneous CIs; the second CI was also used more frequently in noisy and speech with background noise environments. CONCLUSIONS: A second CI may be more frequently used in challenging listening environments because of its binaural auditory effect, despite its lower speech discrimination performance. The timing of sequential implantation and the potential impact of binaural hearing should be considered when developing rehabilitation strategies for individuals with bilateral CIs.


Asunto(s)
Implantación Coclear , Implantes Cocleares , Percepción del Habla , Adulto , Humanos , Estudios Retrospectivos , Percepción Auditiva , Audición
6.
Audiol Res ; 13(4): 563-572, 2023 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-37622925

RESUMEN

Clinical findings on cartilage conduction hearing aids (CCHAs) have gradually become clear; however, few reports include a large number of cases. This study included 91 ears from 69 patients who underwent CCHA fitting in our hospital. Their ears were divided into six groups (i.e., bilateral aural atresia or severe canal stenosis, unilateral aural atresia or severe canal stenosis, chronic otitis media or chronic otitis externa with otorrhea, sensorineural hearing loss, mixed hearing loss, and conductive hearing loss) according to their clinical diagnosis and type of hearing loss. Most clinical diagnoses were aural atresia or meatal stenosis (bilateral, 21.8%; unilateral, 39.6%). The purchase rate of CCHAs was higher in the closed-ear group (bilateral, 77.3%; unilateral, 62.5%). In the bilateral closed-ear group, air conduction thresholds at 1000, 2000, and 4000 Hz and aided thresholds with CCHAs at 4000 Hz were significantly lower in the purchase group than the non-purchase group. No significant difference was observed between the purchase and non-purchase groups in the unilateral closed-ear group. In the bilateral closed-ear group, air conduction thresholds and aided thresholds were associated with the purchase rate of CCHAs. In the unilateral closed-ear group, factors other than hearing might have affected the purchase rate of CCHAs.

8.
Nagoya J Med Sci ; 85(2): 375-379, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37346840

RESUMEN

The potential mechanism of augmented response on cervical vestibular evoked myogenic potential (cVEMP) testing and its decrease following treatment in a patient with Meniere's disease (MD) are discussed. Changes of static posturography and cVEMP testing before and after a glycerol drip in a 69-year-old man with unilateral MD, in which significant endolymphatic hydrops (EH) was confirmed on magnetic resonance imaging (MRI) on the diseased side, were evaluated. Values of total locus lengths, areas of postural sway, and their Romberg ratios were decreased after the glycerol drip. On cVEMP testing, the diseased ear demonstrated a 375% larger amplitude than the contralateral ear before treatment, but both ears showed almost the same responses after treatment. An augmented response on cVEMP testing and a decrease following treatment for MD reflect the diversity of clinical findings in MD. Responses on cVEMP testing may relate not only to the degree of EH, but also be due to abnormal acoustic energy absorbance transmitted into the saccule.


Asunto(s)
Hidropesía Endolinfática , Enfermedad de Meniere , Potenciales Vestibulares Miogénicos Evocados , Masculino , Humanos , Anciano , Enfermedad de Meniere/diagnóstico , Potenciales Vestibulares Miogénicos Evocados/fisiología , Glicerol , Hidropesía Endolinfática/diagnóstico , Imagen por Resonancia Magnética/métodos
9.
Front Neurol ; 14: 1193104, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37153681

RESUMEN

Objective: To summarize the pathophysiological analysis of idiopathic sudden sensorineural hearing loss (ISSNHL) by magnetic resonance imaging (MRI), focusing on the findings of high signal or endolymphatic hydrops (EH) in the inner ear. Methods: We summarize the published studies of our research group regarding the pathophysiological analysis of ISSNHL on MRI and review related clinical articles that have reported significantly high signal or the existence of EH in ears with ISSNHL. Results: Pre-contrast high signal on MRI may indicate minor hemorrhage or increased permeability of surrounding vessels to the perilymph, whereas post-contrast high signal indicates breakdown of the blood-labyrinth barrier, in which irreversible changes would lead to poor prognosis. In some cases of ISSNHL, primary EH could be pre-existing and may be a risk factor for the onset of ISSNHL. Conclusion: Analysis of ISSNHL by cutting-edge MRI evaluation could provide useful information for elucidating its pathophysiology and for predicting prognosis in this disease.

10.
Acta Otolaryngol ; 143(2): 163-169, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36855795

RESUMEN

BACKGROUND: Listening difficulties (LiD) present difficulties in listening and paying attention to spoken information despite normal pure tone audiometry. Endolymphatic hydrops (EH) is a common inner ear condition associated with Ménière's disease but may also be present in the asymptomatic ear. OBJECTIVES: Using magnetic resonance imaging, we investigated EH in patients with LiD and assessed whether the severity of EH was related to the results of auditory processing tests (APTs). MATERIALS AND METHODS: 111 patients with no abnormalities on pure tone audiometry, but displaying difficulties in listening, underwent evaluation through APTs and questionnaires. Upon obtaining informed consent, the inner ears of 20 consenting patients were evaluated utilizing a 3-Tesla magnetic resonance imaging. RESULTS: A higher percentage of patients diagnosed with LiD by APTs had significant EH in the cochlea and vestibule than in previously reported control cases. The percentage of correct answers in the speech-in-noise test was significantly lower in patients with than in those without significant EH. CONCLUSION AND SIGNIFICANCE: In this study, significant EH of the cochlea was associated with poor listening to noise. The presence of EH affects the functioning of the auditory processing system, even in ears that test normally on standard audiometric tests.


Asunto(s)
Hidropesía Endolinfática , Vestíbulo del Laberinto , Humanos , Hidropesía Endolinfática/complicaciones , Hidropesía Endolinfática/diagnóstico por imagen , Vestíbulo del Laberinto/patología , Audiometría de Tonos Puros , Percepción Auditiva , Audición , Imagen por Resonancia Magnética/métodos
11.
Laryngoscope Investig Otolaryngol ; 8(1): 262-268, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36846415

RESUMEN

Objective: The increased endolymph volume affects a shift in the organ of Corti and basilar membrane in ears with endolymphatic hydrops (EH), which might affect distortion-product otoacoustic emissions (DPOAE) by altering the operating point of the outer hair cells. We investigated how changes in DPOAE are related to the distribution site of EH. Study Design: Prospective study. Methods: Among 403 patients with hearing or vestibular symptoms who underwent contrast-enhanced magnetic resonance imaging (MRI) for the diagnosis of EH and subsequent DPOAE testing, subjects whose hearing levels on pure tone audiometry were ≤35 dB at all frequencies were included in this study. In patients with EH on MRI, the presence and amplitude of DPOAE were evaluated between groups with hearing levels of ≤25 dB at all frequencies versus hearing levels of >25 dB at one or more frequencies. Results: There were no differences in the distribution of EH between groups. The amplitude of DPOAE had no clear correlation with the presence of EH. However, in both groups, there was a significantly higher probability of the presence of a DPOAE response from 1001 to 6006 Hz in cases with EH in the cochlea. Conclusion: Among patients whose hearing levels were ≤35 dB at all frequencies, better responses on DPOAE testing were found in subjects with EH in the cochlea. Alteration of DPOAEs in the early stages of hearing impairment could indicate morphological changes in the inner ear with altered basilar membrane compliance due to EH. Level of Evidence: 4.

12.
Auris Nasus Larynx ; 50(2): 299-304, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35058072

RESUMEN

Otitis media with antineutrophil cytoplasmic antibody-associated vasculitis (OMAAV) has been proposed as a new type of otitis media. The hearing loss caused by OMAAV can be expected to improve with early detection and intervention, but if it continues to worsen and leads to deafness, it is challenging to recover the patient's hearing. When bilateral deafness occurs, cochlear implant (CI) surgery is the only way to improve hearing. Here, Case 1 showed unilateral cochlear calcification, and Case 2 showed bilateral cochlear calcification. In Case 1, CI surgery was performed on the ear lacking calcification, and in Case 2 it was performed on the ear with milder calcification. In Case 2, granulation was present from the tympanic space to the mastoid, the round window was closed, and the basal turn of the cochlea was narrowed. Such calcification of the cochlea caused by OMAAV has not been reported so far. It is essential to detect these changes by computed tomography scans at an early stage and to perform CI surgery at an appropriate time, because hearing improvements are not expected in patients who become deaf because of OMAAV.


Asunto(s)
Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos , Oído Interno , Pérdida Auditiva , Otitis Media , Humanos , Anticuerpos Anticitoplasma de Neutrófilos , Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos/complicaciones , Vasculitis Asociada a Anticuerpos Citoplasmáticos Antineutrófilos/diagnóstico , Otitis Media/complicaciones , Pérdida Auditiva/etiología
13.
Nagoya J Med Sci ; 84(4): 900-905, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36544607

RESUMEN

Primary laryngeal cryptococcosis is an extremely rare infection and presents with non-specific symptoms such as hoarseness or sore throat, resulting in delayed diagnosis. Here, we report the patient of a 56-year-old female patient with primary laryngeal cryptococcosis, who was being treated with oral and inhaled steroids for rheumatoid arthritis and bronchial asthma. The patient suffered from prolonged hoarseness and sore throat, and endoscopic biopsy was performed several times under local anesthesia, demonstrating only inflammatory cell infiltration. Considering the possibility of laryngeal malignancy, a third biopsy was performed by endoscopic laryngomicrosurgery under general anesthesia. Intraoperative frozen section revealed non-neoplastic laryngeal mucosa with erosion and severe inflammatory cell infiltration. However, we could not confirm the definite diagnosis of the lesion in the intraoperative consultation. Postoperative histopathological examination revealed a small number of yeast-type fungi and a definitive diagnosis was established by special stains including Alcian blue stain. Finally, the patient was diagnosed as primary laryngeal cryptococcosis. Daily oral administration of fluconazole (400 mg/day) was performed for 6 months according to the treatment protocol for pulmonary cryptococcosis. The symptoms gradually improved, and endoscopy revealed no recurrence 6 months post-treatment. Clinicians should consider the possibility of laryngeal cryptococcosis when severe inflammation is found in the larynx and discuss the disease history and pathological results with pathologists more closely.


Asunto(s)
Criptococosis , Neoplasias Laríngeas , Laringe , Faringitis , Femenino , Humanos , Persona de Mediana Edad , Neoplasias Laríngeas/diagnóstico , Neoplasias Laríngeas/cirugía , Ronquera , Laringe/patología , Criptococosis/diagnóstico , Criptococosis/tratamiento farmacológico , Criptococosis/patología
14.
Front Neurol ; 13: 1016577, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36408495

RESUMEN

We evaluated the inner ear distribution of 17O-labeled saline administered to the human tympanic cavity. Magnetic resonance imaging was performed after intratympanic administration in five healthy volunteers and one patient with cochlear endolymphatic hydrops. In all volunteers, 17O-labeled water permeated the cochlear basal turn and vestibule at 30 min and disappeared gradually within 2-4 h. All participants experienced positional vertigo lasting a few hours to a few days. Visualization of 17O-labeled water distribution in the endolymphatic space of the posterior ampulla showed indistinct separation of endolymph and perilymph in the cochlea and most of the vestibule in all participants. Intralabyrinthine distribution of 17O-labeled water differed from that in previous reports of intratympanically administered gadolinium-based contrast agent. 17O-labeled water in the endolymphatic space may cause heavier endolymph and positional vertigo. These results of this study may add new insights for investigating the distribution and the effects of molecules in the inner ear after the intratympanic administration in living humans.

15.
Nagoya J Med Sci ; 84(3): 497-505, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36237884

RESUMEN

We summarize the presence of endolymphatic hydrops (EH) in otological disorders evaluated with magnetic resonance imaging (MRI) of temporal bones, and propose a classification of EH based on its pathological significance. A search of the literature published in English-language journals was performed using electronic databases, especially focusing on EH-related otological disorders. Clinical articles that contained the terms EH and contrast-MRI published from 2007 to the present, with relevant human temporal bone studies, were included. The following three main points are discussed based on the results in the relevant articles: i) otological disorders that present EH, ii) current grading for evaluation of EH on MRI, and iii) a proposed classification of EH based on its pathological significance. MRI evaluation revealed that EH exists extensively not only in ears with typical Meniere's disease (MD), but also in those with various other otological disorders. The etiological classification of EH helps to summarize ideas for determining the pathophysiology of otological disorders, while a therapeutic classification provides clues to their management. MRI evaluations of EH have led to breakthroughs in investigations of EH in otological disorders. Precise grading for evaluation and clarification of EH on MRI based on its pathological significance could provide keys to elucidating the pathophysiology of EH-related otological disorders.


Asunto(s)
Hidropesía Endolinfática , Enfermedad de Meniere , Hidropesía Endolinfática/diagnóstico por imagen , Hidropesía Endolinfática/patología , Humanos , Imagen por Resonancia Magnética/métodos , Enfermedad de Meniere/diagnóstico por imagen , Hueso Temporal/diagnóstico por imagen
16.
Water Res ; 225: 119194, 2022 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-36215833

RESUMEN

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.


Asunto(s)
Compuestos de Amonio , Aguas del Alcantarillado , Aguas Residuales , Nitritos , Biomasa , Temperatura , Oxidación Anaeróbica del Amoníaco , Estaciones del Año , Reactores Biológicos/microbiología , Nitrógeno , Bacterias , Oxidación-Reducción , Oxígeno
17.
Bioresour Technol ; 354: 127167, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35436540

RESUMEN

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.


Asunto(s)
Eliminación de Residuos Líquidos , Aguas Residuales , Anaerobiosis , Reactores Biológicos , Membranas Artificiales , Metano , Temperatura
18.
Bioresour Technol ; 351: 127062, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35351558

RESUMEN

At ambient temperature condition, the one-stage partial nitritation/anammox (PNA) process has been successfully adopted to treat the filtrate from the mainstream anaerobic membrane bioreactor (AnMBR). However, there is no investigation of the performance of this process at low-temperature condition. In this study, the nitrogen removal performance of a pilot-scale PNA reactor at the temperature of 15 °C for treating the filtrate of a mainstream AnMBR was investigated. The nitrogen removal rate of 0.09 kg/m3/d and the nitrogen removal efficiency of 37.6% were achieved. The anammox reaction was the rate-limiting step of the nitrogen removal. Nitrogen removal was attributed in part to denitrification activity. The microbial community analysis confirmed that the main functional bacteria comprised of genus Nitrosomonas and genus Kuenenia. In sum, this research demonstrated the applicability of PNA process for mainstream AnMBR filtrate treatment to some extent and enriched the related knowledge.


Asunto(s)
Compuestos de Amonio , Aguas del Alcantarillado , Oxidación Anaeróbica del Amoníaco , Anaerobiosis , Reactores Biológicos/microbiología , Desnitrificación , Nitrógeno , Oxidación-Reducción , Aguas Residuales
19.
Bioresour Technol ; 349: 126864, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35183723

RESUMEN

A pilot-scale anaerobic membrane bioreactor (AnMBR) integrated with a one-stage partial nitritation-anammox (PN/A) reactor was operated for the treatment of municipal wastewater (MWW) at seasonal temperatures of 15-25 °C. The removal efficiencies of COD and total nitrogen (TN) were always > 90% and > 75% respectively. The methanogenesis and PN/A were identified as the primary removal pathways of COD and TN, respectively, and were suppressed at low temperatures. With the temperature dropped from 25 °C to 20 °C to 15 °C, the methane-accounted COD decreased from 63.1% to 59.6% to 48.4%, and the PN/A-accounted TN decreased from 58.1% to 51.7% to 45.3%. The AnMBR and PN/A mutually complement each other in this combined process, as the AnMBR removed 8.5%-16.1% of TN by sludge entrainment and the PN/A reactor removed 2.6%-3.4% of COD by denitrification and aerobic oxidation. These results highlighted the strong feasibility of applying the AnMBR-PN/A process to the treatment of MWW in temperate climate.


Asunto(s)
Compuestos de Amonio , Aguas Residuales , Compuestos de Amonio/metabolismo , Oxidación Anaeróbica del Amoníaco , Anaerobiosis , Reactores Biológicos , Desnitrificación , Nitrógeno , Oxidación-Reducción , Estaciones del Año , Aguas del Alcantarillado , Temperatura
20.
Sci Total Environ ; 807(Pt 3): 151063, 2022 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-34673073

RESUMEN

Recently, it was reported that for synthetic low-strength wastewater, the excellent nitrogen removal rate (NRR) accompanied with phosphorus removal could be achieved through the partial nitritation/anammox (PNA)-hydroxyapatite (HAP) process. Thus, this research further investigated the performance of the pilot-scale PNA-HAP process treating the effluent of an anaerobic membrane bioreactor (AnMBR) fed with the actual municipal wastewater. The results showed that with the hydraulic retention time of 4.0 h, the influent ammonium concentration ranging from 36.0 to 41.0 mg/L, and the BOD5 ranging from 6.3 to 12.7 mg/L, the average NRR and the nitrogen removal efficiency was 0.13 kg/m3/d and 63.38%, respectively. The specific activity test of sludge confirmed that the PNA process was the main nitrogen metabolism pathway. The effluent nitrate and the BOD5 were almost zero, indicating the existence of denitrification activity in reactor. Given that the oxygenation condition, the heterotrophic organic matter oxidization activity also occurred in reactor. The sludge analysis confirmed the phosphate formation in sludge. Thus, in the reactor, four kinds of biological activities and chemical crystallization occurred harmoniously in sludge. From the mixed liquid volatile suspended solid of 2.4 g/L and the low distribution range of granule size, it was obvious that the sludge had a high dispersity. Based on the well settling ability of sludge during the operation, it was inferred that there was a close bond between biomass and HAP in sludge, which was helpful to enhance the settleability of sludge granule. Besides, the phosphorus-containing sludge was suitable as the fertilizer. In all, this study demonstrated that the PNA-HAP process is an ideal alternative treating the effluent of the AnMBR process in the municipal wastewater treatment.


Asunto(s)
Durapatita , Aguas Residuales , Oxidación Anaeróbica del Amoníaco , Anaerobiosis , Reactores Biológicos
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