A Sequencing Batch Reactor (SBR) with activated sludge was operated with synthetic wastewater containing ibuprofen (IBU) to investigate the biomass stress-responses under long-term IBU exposure. There were 3 different phases: phase I as the control without IBU for 56 days, phase II (40 days), and phase III (60 days) containing IBU at 10 and 5 mg L − 1 each. The overall performance of the SBR as well as the extracellular polymeric substances (EPS) in terms of polysaccharides, proteins, and humic acid substances were estimated. Morphological parameters of microbial aggregates in the presence of IBU (phase II and phase III) were assessed by quantitative image analysis (QIA). Removal efficiencies of chemical oxygen demand (COD) and ammonium (NH 4 + ) were significantly reduced by IBU. Loosely bound EPS (LB-EPS) decreased during phase II and phase III, and tightly bound EPS (TB-EPS) was slightly higher in phase II than phase I. TB-EPS proteins were greater in phase II, perhaps to protect microbial cells from IBU exposure. These findings provided insight into both activated sludge stress-responses and EPS composition under long-term IBU exposure. Spearman correlation showed that EPS and morphological parameters significantly affected sludge settleability and flocculation. QIA also proved to be a powerful technique in investigating dysfunctions in activated sludge under IBU exposure.
Non-acclimated aerobic granules can treat fish canning wastewater with variable composition. • Carbon and nitrogen loads were the main disturbance factors. • Main microbial community changes occurred during higher organic load period. • Bacterial groups associated to EPS production, carbon and nutrients removal were resilient. • Microbiome diversity and adaptation supported AGS long-term stability.
The purpose of the present study was to develop an optimal freezing method for cryopreservation of human donor corneas for transplantation. Three groups of ten human donor corneas each were cryopreserved using cooling rates of 0.5 degree C/ min, 1 degree C/min and 9 degrees C/min. The freezing medium contained 10% fetal calf serum and 7% dimethylsulphoxide. Ten additional human donor corneas were used as controls. Endothelial cell survival after complete thawing was assessed by calculating the mean endothelial cell density and percentage of non-viable endothelial cells from vital staining and scanning electron micrographs. Significant differences in endothelial cell survival between all groups were detected by analysis of variance (p < 0.001), but paired contrast found no real differences between corneas frozen at 0.5 degree C/min or 1 degree C/min. Nevertheless, 60% of the corneas cryopreserved at 1 degree C/min but only 10% of those cryopreserved at 0.5 degree C/min fulfilled both requirements to be considered suitable for transplantation (endothelial cell density > 2000 cells/mm2 and less than 10% dead cells). None of the corneas frozen at 9 degrees C/min fulfilled these requirements. Mean endothelial cell density of corneas frozen at 1 degree C/min was 2084 cells/mm2 (range 2020 to 2630 cells/mm2). Except for isolated corneas frozen at 0.5 degree C/min, only corneas cryopreserved at a cooling rate of 1 degree C/min achieved satisfactory endothelial cell survival for their use in transplantation. However the significant interindividual variability among corneas frozen at 1 degree C/min (ANOVA: p < 0.001) prevents prediction of the condition of the cornea after the complete cryopreservation process. Until this high variability can be drastically reduced, systematic corneal cryopreservation in eye banking remains unattainable.
This study presents an experiential process and a market-oriented approach for realizing cities’ energy transition through smart solutions. The aim of this study is twofold: (a) present a process for defining a repository of innovative solutions that can be applied at building, district, or city level, for two European Union cities, Evora and Alkmaar, and support the deployment of positive energy districts enabling a sustainable energy transition, and (b) understand in a systematic way the attributes of value offered by energy-related smart city solutions, in order to facilitate the development of sustainable value propositions that can successfully address city needs. The repository is assessed against four elements of value, which include social impact, life-changing, emotional, and functional attributes, according to the value pyramid of Maslow. Results show that the value attributes of quality, motivation, integration, cost reduction, information, and organization are highly relevant to the proposed smart solutions. The results presented in this study are useful for city planners, decision-makers, public bodies, citizens, and businesses interested in designing their energy transition strategy and defining novel technologies that promote urban energy sustainability.
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