Technology and quality management: a review of concepts and opportunities in the digital transformation

Purpose - The Digital Transformation brings change to organizations, their processes, and their production systems. Nevertheless, most efforts observed in its context tend to be technology-driven, and it is often argued that Quality Management is inadequately integrated into the discussion. Design/methodology/approach - Surveying the literature, this work reviews, list, and organizes the different technological concepts and integration opportunities that have been explored in the scope of Quality Management in the Digital Transformation. Findings - Findings include the expanded capacity of quality tools and methods for managerial purposes; the reinforced importance of Data Quality; the increased automation and augment resources for Quality control; and the increased process optimization and integration of systems and between organizational areas. Originality/value - It is demonstrated that although scattered in the literature, there are already a number of works exploring the impacts of technology in the management of Quality in the scope of the Digital Transformation. Three main areas for integration arise: (a) Digital Quality Management (application of industry 4.0 technologies to Quality Management itself, its tools, methods, and systems), (b) the management of the Quality of digital products and services, and (c) the management of the Quality of digital product development and production processes.(undefined

Improving polyhydroxyalkanoates production in phototrophic mixed cultures by optimizing accumulator reactor operating conditions

The authors would also like to acknowledge the Fundacao para a Ciencia e a Tecnologia (Portugal) for funding through SFRH/BPD/101642/2014. co-financed by ERDF under PT2020 Partnership Agreement (POCI-01-0145-FEDER-007728).Polyhydroxyalkanoates (PHAs) production with phototrophic mixed cultures (PMCs) has been recently proposed. These cultures can be selected under the permanent presence of carbon and the PHA production can be enhanced in subsequent accumulation steps. To optimize the PHA production in accumulator reactors, this work evaluated the impact of 1) initial acetate concentration, 2) light intensity, 3) removal of residual nitrogen on the culture performance. Results indicate that low acetate concentration (<30 CmM) and specific light intensities around 20 W/gX are optimal operating conditions that lead to high polyhydroxybutyrate (PHB) storage yields (0.83 ± 0.07 Cmol-PHB/Cmol-Acet) and specific PHB production rates of 2.21 ± 0.07 Cmol-PHB/Cmol X d. This rate is three times higher than previously registered in non-optimized accumulation tests and enabled a PHA content increase from 15 to 30% in <4 h. Also, it was shown for the first time, the capability of a PMC to use a real waste, fermented cheese whey, to produce PHA with a hydroxyvalerate (HV) content of 12%. These results confirm that fermented wastes can be used as substrates for PHA production with PMCs and that the energy levels in sunlight that lead to specific light intensities from 10 to 20 W/gX are sufficient to drive phototrophic PHA production processes.authorsversionpublishe

The impact of biomass withdrawal strategy on the biomass selection and polyhydroxyalkanoates accumulation of mixed microbial cultures

UIDP/04378/2020 UIDB/04378/2020 LA/P/0140/2020 SFRH/BD/110673/2015The production of polyhydroxyalkanoates (PHA) by mixed microbial cultures (MMC) has been studied as an alternative to pure cultures in order to reduce the price of PHA through use of open systems and low-cost substrates, such as agro-industrial sub-products. However, the widespread applicability of this process depends on the optimization of operational factors impacting PHA productivity. This study addresses the impact of biomass withdrawal strategy on the performance of MMC selection reactors and consequently on biomass productivity and global PHA productivity. Two selection reactors were operated in parallel under similar conditions, except for the timing of biomass withdrawal, at the end of the famine phase (Reactor 1, R1) versus at the end of the feast phase (Reactor 2, R2) at an organic loading rate of 100 Cmmol.L−1.d−1 and solids retention time of 4 days. The biomass selected in both conditions had similar PHA storing capacity as shown by the similar yields of PHA per substrate obtained in the accumulation assays; however, R1 reached a higher biomass productivity (about 4-fold higher than R2). This study demonstrated that removing the excess biomass at the end of the famine phase resulted in a much higher global PHA productivity and that the key parameter affecting the global PHA productivity of the 2-stage system was the volumetric biomass productivity. Results obtained provide important insight into how MMC systems can be best operated to maximize PHA productivity.publishersversionpublishe

Impact of CO2 concentration and light exposure on process performance

Funding Information: This research was financed by national funds from FCT-Fundação para a Ciência e a Tecnologia , I.P., in the scope of the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy—i4HB. Publisher Copyright: © 2023 The AuthorsThe utilization of non-aerated microalgae-bacterial consortia for phototrophic biological nutrient removal (photo-BNR) has emerged as an alternative to conventional wastewater treatment. Photo-BNR systems are operated under transient illumination, with alternating dark-anaerobic, light-aerobic and dark-anoxic conditions. A deep understanding of the impact of operational parameters on the microbial consortium and respective nutrient removal efficiency in photo-BNR systems is required. The present study evaluates, for the first time, the long-term operation (260 days) of a photo-BNR system, fed with a COD:N:P mass ratio of 7.5:1:1, to understand its operational limitations. In particular, different CO2 concentrations in the feed (between 22 and 60 mg C/L of Na2CO3) and variations of light exposure (from 2.75 h to 5.25 h per 8 h cycle) were studied to determine their impact on key parameters, like oxygen production and availability of polyhydroxyalkanoates (PHA), on the performance of anoxic denitrification by polyphosphate accumulating organisms. Results indicate that oxygen production was more dependent on the light availability than on the CO2 concentration. Also, under operational conditions with a COD:Na2CO3 ratio of 8.3 mg COD/mg C and an average light availability of 5.4 ± 1.3 W h/g TSS, no internal PHA limitation was observed, and 95 ± 7%, 92 ± 5% and 86 ± 5% of removal efficiency could be achieved for phosphorus, ammonia and total nitrogen, respectively. 81 ± 1.7% of the ammonia was assimilated into the microbial biomass and 19 ± 1.7% was nitrified, showing that biomass assimilation was the main N removal mechanism taking place in the bioreactor. Overall, the photo-BNR system presented a good settling capacity (SVI ∼60 mL/g TSS) and was able to remove 38 ± 3.3 mg P/L and 33 ± 1.7 mg N/L, highlighting its potential for achieving wastewater treatment without the need of aeration.publishersversionpublishe

Polyhydroxyalkanoate granules quantification in mixed microbial cultures using image analysis: Sudan Black B versus Nile Blue A staining

Polyhydroxyalkanoates (PHA) can be produced and intracellularly accumulated as inclusions by mixed microbial cultures (MMC) for bioplastic production and in enhanced biological phosphorus removal (EBPR) systems. Classical methods for PHA quantification use a digestion step prior to chromatography analysis, rendering them labor intensive and time-consuming. The present work investigates the use of two quantitative image analysis (QIA) procedures specifically developed for PHA inclusions identification and quantification. MMC obtained from an EBPR system were visualized by bright-field and fluorescence microscopy for PHA inclusions detection, upon Sudan Black B (SBB) and Nile Blue A (NBA) staining, respectively. The captured color images were processed by QIA techniques and the image analysis data were further treated using multivariate statistical analysis. Partial least squares (PLS) regression coefficients of 0.90 and 0.86 were obtained between QIA parameters and PHA concentrations using SBB and NBA, respectively. It was found that both staining procedures might be seen as alternative methodologies to classical PHA determination.The authors thank the Fundacao para a Ciencia e a Tecnologia (FCT) Strategic Project PEst-OE/EQB/LA0023/2013 and the Project "BioEnv - Biotechnology and Bioengineering for a sustainable world", REF. NORTE-07-0124-FEDER-000048, co-funded by the Programa Operacional Regional do Norte (ON.2 - O Novo Norte), QREN, FEDER. The authors also acknowledge the financial support to Daniela P. Mesquita through the postdoctoral grant (SFRH/BPD/82558/2011) and the project PTDC/EBB-EBI/103147/2008 provided by FCT

Dynamics of Microbial Communities in Phototrophic Polyhydroxyalkanoate Accumulating Cultures

DFA/BD/8201/2020 UIDP/04378/2020 UIDB/04378/2020 LA/P/0140/2020Phototrophic mixed cultures (PMC) are versatile systems which can be applied for waste streams, valorisation and production of added-value compounds, such as polyhydroxyalkanoates (PHA). This work evaluates the influence of different operational conditions on the bacterial communities reported in PMC systems with PHA production capabilities. Eleven PMCs, fed either with acetate or fermented wastewater, and selected under either feast and famine (FF) or permanent feast (PF) regimes, were evaluated. Overall, results identified Chromatiaceae members as the main phototrophic PHA producers, along with Rhodopseudomonas, Rhodobacter and Rhizobium. The findings show that Chromatiaceae were favoured under operating conditions with high carbon concentrations, and particularly under the PF regime. In FF systems fed with fermented wastewater, the results indicate that increasing the organic loading rate enriches for Rhodopseudomonas, Rhizobium and Hyphomicrobiaceae, which together with Rhodobacter and Chromatiaceae, were likely responsible for PHA storage. In addition, high-sugar feedstock impairs PHA production under PF conditions (fermentative bacteria dominance), which does not occur under FF. This characterization of the communities responsible for PHA accumulation helps to define improved operational strategies for PHA production with PMC.publishersversionpublishe

Polyphosphates and poly-β-hydroxybutyrate granules identification through quantitative image analysis in enhanced biological phosphorus removal systems

Enhanced biological phosphorus removal (EBPR) is a widely implemented technique for having the potential to cheaply and reliably remove phosphate from wastewater treatment processes, than traditional chemical methods. EBPR is performed by operating the system sequentially with anaerobic and aerobic conditions. Several studies were already performed ranging from different strategies for the competition between polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) to modeling both types of bacterial activities. Until now, slight attention has been given to the development of newer, faster, simpler, and better suited monitoring techniques for this type of system. This work is focused on the development of image analysis techniques for polyphosphates and poly-β-hydroxybutyrate granules in EBPR systems since off-line analyses are labor intensive and not able to be performed in full-scale plants. A lab-scale sequencing batch reactor fed with synthetic wastewater containing volatile fatty acids (VFAs) and orthophosphate was used. The reactor had a working volume of 4 L and was operated with a cycle time of 6 h consisting of 2 h anaerobic, 3 h aerobic, 50 min settling and decanting, and 5 min anaerobic idle periods. In each cycle, 2 L of synthetic wastewater was fed to the reactor in the first 5 min of the anaerobic period, resulting in a hydraulic retention time (HRT) of 12 h. The pH was controlled during both the anaerobic and aerobic periods around 7, and the temperature was controlled at 30 ºC in order to provide selective advantages to GAOs over PAOs. The ratio between chemical oxygen demand (COD) and P in the feed was kept at 10 (gCOD/g P). Biomass samples were collected at the end of the anaerobic and aerobic phases and fixed with phosphate buffer saline solution (PBS) and ethanol. Two fluorescence staining methods were used: (1) DAPI for poly-P identification; and (2) nile blue for poly-β-hydroxybutyrate granules. So far, promising results were achieved regarding the type of images achieved by these fluorescence staining methods and the image analysis procedures still under development