Search results for " tractament"
showing 10 items of 65 documents
A semi-industrial scale AnMBR for municipal wastewater treatment at ambient temperature: performance of the biological process
2022
A semi-industrial scale AnMBR plant was operated for more than 600 days to evaluate the long-term operation of this technology at ambient temperature (ranging from 10 to 27 ºC), variable hydraulic retention times (HRT) (from 25 to 41 h) and influent loads (mostly between 15 and 45 kg COD·d−1). The plant was fed with sulfate-rich high-loaded municipal wastewater from the pre-treatment of a full-scale WWTP. The results showed promising AnMBR performance as the core technology for wastewater treatment, obtaining an average 87.2 ± 6.1 % COD removal during long-term operation, with 40 % of the data over 90%. Five periods were considered to evaluate the effect of HRT, influent characteristics, CO…
Sewage sludge management for phosphorus recovery as struvite in EBPR wastewater treatment plants
2008
The influence of separate and mixed thickening of primary and secondary sludge on struvite recovery was studied. Phosphorus precipitation in the digester was reduced from 13.7 g of phosphorus per kg of treated sludge in the separate thickening experiment to 5.9 in the mixed thickening experiment. This lessening of the uncontrolled precipitation means a reduction of the operational problems and enhances the phosphorus availability for its later crystallization. High phosphorus precipitation and recovery efficiencies were achieved in both crystallization experiments. However, mixed thickening configuration showed a lower percentage of phosphorus precipitated as struvite due to the presence of…
Optimisation of sludge line management to enhance phosphorus recovery in WWTP
2008
The management of the sludge treatment line can be optimized to reduce uncontrolled phosphorus precipitation in the anaerobic digester and to enhance phosphorus recovery in WWTP. In this paper, four operational strategies, which are based on the handling of the prefermented primary sludge and the secondary sludge from an EBPR process, have been tested in a pilot plant. The separated or mixed sludge thickening, the use of a stirred contact tank and the elutriation of the thickened sludge are the main strategies studied. Both the reduction of phosphorus precipitation in the digester and the supernatant suitability for a struvite crystallization process were assessed in each configuration. The…
Cicatrices hipertróficas y queloideas: unificación de criterios e implementación de conocimientos
2019
El proceso de cicatrización del organismo tiende a la reparación del tejido dañado, pero dicho proceso puede alterarse por distintas circunstancias. Por ello se pueden producir una cicatrización: normal, excesiva o insuficiente. El objetivo de este estudio es elaborar una infografía, para ayudar al profesional sanitario a realizar un diagnóstico diferencial entre las cicatrices hipertróficas y queloideas, y exponer las diferentes opciones de prevención y tratamientos más habituales. Material y método: Se realizó una revisión bibliográfica sobre el tema. Resultados: Se han seleccionado un total de 26 artículos, que nos han permitido realizar una infografía, estructurada en tres apartados: 1)…
Back Pain: Pathophysiology, Diagnosis, and Treatment
2023
Although back pain is one of the most common medical conditions [1], with a reported general population prevalence close to 50% along their lifetime in a long-term British survey [2], it does not attract the interest it should from the general population [3], political powers [4,5] and scientific community [6]. Patients keep coming to our offices for a surgical solution to their back pain, hoping that a miraculous operation will solve all their problems [3,7]. Yet, the surgical procedure sometimes does not solve the problem, and it can be the cause of a new nightmare in one third of patients [8,9]. A Japanese study found that 95% of their patients had persistent back pain after surgery at t…
Hepatitis C Crónica y usuarios con un historial de inyección de drogas en España: evaluación de la población, retos para un tratamiento efectivo.
2017
La hepatitis C cronica (HCC) es una enfermedad de desigualdad que afecta desproporcionadamente a las personas desatendidas por la salud publica. Personas con antecedentes de uso de opioides o uso de drogas por via parenteral (UDVP) se enfrentan a desigualdad y estigma. Un historia previa de inyeccion de drogas es un comportamiento que incrementa el riesgo de contraer el VHC. Hay una gran incidencia de HCC entre las personas se inyectan drogas. Hay mas de 300,000 personas en Espana que actualmente se inyectan drogas o tienen antecedentes. Hay 150,000 personas en Espana con un historial trastorno de uso de opioides y la mayoria son UDVP o ex UDVP. Aproximadamente 80,000 personas usan los serv…
A Semi-Industrial Anmbr Plant for Urban Wastewater Treatment at Ambient Temperature: Analysis of the Filtration Process, Energy Balance and Quantific…
2022
A semi-industrial scale AnMBR urban wastewater treatment plant was operated for 580 days at ambient temperature (ranging from 10-30 ○C) to assess its long-term filtration performance, energy balance and GHG emissions. The applied 20ºC-standardized transmembrane flux (J20) was varied between 15 and 25 LMH and the specific gas demand per m2 of membrane (SGDm) was modified between 0.10 to 0.40 Nm3·m-2·h-1 (corresponding to a specific gas demand per permeate volume (SGDP) between 10 to 20 Nm3·m-3). The filtration strategy allowed successful long-term operations without any chemical cleaning requirements and little fouling for 233 days. The plant operated as a net energy producer for more than 5…
Optimising an outdoor membrane photobioreactor for tertiary sewage treatment
2019
[EN] The operation of an outdoor membrane photobioreactor plant which treated the effluent of an anaerobic membrane bioreactor was optimised. Biomass retention times of 4.5, 6, and 9 days were tested. At a biomass retention time of 4.5 days, maximum nitrogen recovery rate:light irradiance ratios, photosynthetic efficiencies and carbon biofixations of 51.7¿±¿14.3¿mg¿N·mol¿1, 4.4¿±¿1.6% and 0.50¿±¿0.05¿kg CO2·m3influent, respectively, were attained. Minimum membrane fouling rates were achieved when operating at the shortest biomass retention time because of the lower solid concentration and the negligible amount of cyanobacteria and protozoa. Hydraulic retention times of 3.5, 2, and 1.5 days …
Improving membrane photobioreactor performance by reducing light path: operating conditions and key performance indicators
2020
[EN] Microalgae cultivation has been receiving increasing interest in wastewater remediation due to their ability to assimilate nutrients present in wastewater streams. In this respect, cultivating microalgae in membrane photobioreactors (MPBRs) allows decoupling the solid retention time (SRT) from the hydraulic retention time (HRT), which enables to increase the nutrient load to the photobioreactors (PBRs) while avoiding the wash out of the microalgae biomass. The reduction of the PBR light path from 25 to 10 cm increased the nitrogen and phosphorus recovery rates, microalgae biomass productivity and photosynthetic efficiency by 150, 103, 194 and 67%, respectively.The areal biomass product…
Production of microalgal external organic matter in a Chlorella-dominated culture: influence of temperature and stress factors
2020
[EN] Although microalgae are recognised to release external organic matter (EOM), little is known about this phenomenon in microalgae cultivation systems, especially on a large scale. A study on the effect of microalgae-stressing factors such as temperature, nutrient limitation and ammonium oxidising bacteria (AOB) competition in EOM production by microalgae was carried out. The results showed non-statistically significant differences in EOM production at constant temperatures of 25, 30 and 35 degrees C. However, when the temperature was raised from 25 to 35 degrees C for 4 h a day, polysaccharide production increased significantly, indicating microalgae stress. Nutrient limitation also see…