Estela Tapia-Venegas's research while affiliated with Playa Ancha University and other places

Publications (20)

Chapter
This book chapter aims to address the microbial diversity associated with implementation prospects of nonconventional technologies for nitrogen removal in wastewater treatment plants. Special focus will be placed on the environmental advantages offered by these processes in contrast to conventional ones as heterotrophic denitrification and anammox....
Article
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One of the bottlenecks of the hydrogen production by dark fermentation is the low yields obtained because of the homoacetogenesis persistence, a metabolic pathway where H2 and CO2 are consumed to produce acetate. The central reactions of H2 production and homoacetogenesis are catalyzed by enzyme hydrogenase and the formyltetrahydrofolate synthetase...
Article
The oxidation-reduction potential (ORP) is an important factor in H2 production via dark fermentation however its effect over microbial diversity in an acidogenic sludge has not, been well studied. This work studies the effect of ORP controlled by hydrogen peroxide and potassium ferricyanide on continuous hydrogen production and microbial diversity...
Article
Full-text available
Hydrogen (H2) production by dark fermentation can be performed from a wide variety of microbial inoculum sources, which are generally pre-treated to eliminate the activity of H2-consuming species and/or enrich the microbial community with H2-producing bacteria. This paper aims to study the impact of the microbial inoculum source on pre-treatment be...
Article
H2 production by dark fermentation using mixed cultures has been studied intensively during the last two decades, and its feasibility has been demonstrated. Different substrates, operational conditions, and reactor technologies have been widely studied and there is a general agreement that the use of non-sterile fermentable substrates is required t...
Article
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Fermentative hydrogen production requires a continuous products-removal and effective upgrading steps to improve its general performance. Therefore, implementation of new technologies capable of achieving both requirements is essential. We present the operationalbehavior of a new process concept based on integration of membranes for gas separation...
Article
Hydrogen production by dark fermentation is an emerging technology of increasing interest due to its renewable feature. Recent scientific advances have well investigated the operational conditions to produce hydrogen through the valorization of several wastes or wastewaters. However, the development of standardized protocols to accurately assess th...
Article
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Glycerol is a highly available by-product generated in the biodiesel industry. It can be converted into higher value products such as hydrogen using biological processes. The aim of this study was to optimize a continuous dark fermenter producing hydrogen from glycerol, by using micro-aerobic conditions to promote facultative anaerobes. For that, h...
Article
Full-text available
Hydrogen is a promising alternative of clean energy carrier which can be biologically produced from glycerol-rich waste an abundant and economic source of substrate. However, continuous hydrogen-producing systems still need to be improved and in particular by manipulating the only few available operating conditions. The aim of this study was to inv...
Article
One of the most important biotechnological challenges is to develop environment friendly technologies to produce new sources of energy. Microbial production of biohydrogen through dark fermentation, by conversion of residual biomass, is an attractive solution for short-term development of bioH2 producing processes. Efficient biohydrogen production...
Chapter
Effluents coming from anaerobic digesters are characterized by a COD/N ratio between 2 and 10, high ammonia NH4⁺ concentrations about 500 mg/L and a temperature range of 25-35°C. To remove nitrogen from these effluents biological processes as the autotrophic denitrification with sulfur compounds, hydrogen or methane can be applied. The main goal of...
Book
Effluents coming from anaerobic digesters are characterized by a COD/N ratio between 2 and 10, high ammonia NH4+ concentrations about 500 mg/L and a temperature range of 25-35 degrees C. To remove nitrogen from these effluents biological processes as the autotrophic denitrification with sulfur compounds, hydrogen or methane can be applied. The main...
Article
Full-text available
To provide new insight into the dark fermentation process, a multi-lateral study was performed to study the microbiology of 20 different lab-scale bioreactors operated in four different countries (Brazil, Chile, Mexico, and Uruguay). Samples (29) were collected from bioreactors with different configurations, operation conditions, and performances....
Article
Full-text available
Currently, the use of alternative renewable energies is broadly supported in many countries, some of which are seriously evaluating the possibility of using hydrogen as an alternative fuel in their power systems. Hydrogen production by biological processes, such as dark fermentation, is a very promising alternative. However, this process has only b...
Article
Full-text available
Hydrogen is a promising alternative as an energetic carrier and its production by dark fermentation from wastewater has been recently proposed, with special attention to crude glycerol as potential substrate. In this study, two different feeding strategies were evaluated for replacing the glucose substrate by glycerol substrate: a one-step strategy...
Article
Full-text available
Hydrogen production by dark fermentation is one promising technology. However, there are challenges in improving the performance and efficiency of the process. The important factors that must be considered to obtain a suitable process are the source of the inoculum and its pre-treatment, types of substrates, the reactor configurations and the hydro...
Article
The ability of (dimethyl siloxane) (PDMS) and SAPO 34 membrane modules to separate a H2/CO2 gas mixture was investigated in a continuous permeation system in order to decide if they were suitable to be coupled to a biological hydrogen production process. Permeation studies were carried out at relatively low feed pressures ranging from 110 to 180 kP...
Article
The objective of this study was to evaluate the production of hydrogen in a two-stage CSTR system – both reactors having the same volume – and compare its performance with a conventional one-stage process. The lab-scale two-stage and one-stage systems were operated at five pHs and five hydraulic retention time (HRTs). The maximum volumetric hydroge...

Citations

... Another approach is to improve the mass transfer conditions either through headspace recirculation (Buitron et al., 2019) or through increasing stirring velocity in a continuous reactor (Palomo-Briones et al., 2019). In general, it is difficult to control the homoacetogenic activity since sometimes homoacetogens can also produce H 2 , being the same microorganisms, which due to the prevailing conditions can shift their metabolism from H 2 production towards homoacetogenesis (Fuentes et al., 2021). These microorganisms are in general resistant in heat treatments, or extreme pH values (Buitron et al., 2019). ...
... For instance, the addition of 0.5 g/L L-cysteine accelerated the startup process of expanded granular sludge bed reactors and increased the hydrogen production rate and yield by 23.7 % and 20.6 %, respectively (Guo et al., 2013). Controlling the redox potential (ORP) with chemicals or electrodes has also been demonstrated to be effective in improving the production of reduced products (i.e., ethanol and hydrogen) in dark fermentation (Moscoviz et al., 2016;Vesga-Baron et al., 2021). ...
... Acid and alkali-treated inoculum showed over 65% CHP compared to control experiments (p-value < 0.05). Heat-shock treatment has been regarded as an effective inoculum pretreatment strategy to selectively enrich sporulating H 2 producing bacteria for higher CHP and HY (Toledo-Alarcón et al., 2020;Wang & Wan, 2008;Yin et al., 2014). In sharp contrast, this study showed that inoculum treated with 'acid' and 'alkali' had higher CHP, HY, and HPR compared to heattreated inoculum as reported in other literature (Goud et al., 2017). ...
... High HLa concentration (up to 4800 g-HLa L − 1 ; Fig. 3b), low and highly unstable volumetric hydrogen production rate (569 ± 214 mL-H 2 L − 1 d − 1 ; Fig. 2c) and hydrogen yield (2.87 ± 0.72 mmol-H 2 g-CH − 1 ; Fig. 2d) were observed in this period. The responses are frequently reported as a consequence of the predominance of LAB in dark fermentation systems (Castelló et al., 2020;Elbeshbishy et al., 2017;Fuess et al., 2019;García-Depraect et al., 2021). Once the OLR was constant and microbial growth occurred, the sOLR reached the upper limit of the optimal range (6 g-COD g-VSS 3.4 ± 1.1 3.5 ± 0.6 2.6 ± 0.8 5.3 ± 4.1 4.9 ± 2 13.1 ± 2,9 ---HY (mmol-H 2 g-COD conv. ) ...
... The fermentation system consists of two membranes (M1 and M2), the former integrated to a continuous stirred tank reactor (CSTR) once the hydrogen production of the mixed culture reached a steady state and the latter achieving a high hydrogen composition. The operation of the reactor resulted in a decreased partial pressure (55.5-49 kPa) which lead to a 16.3% increase in HY [155]. A 1.0 L anaerobic dynamic membrane bioreactor (AnDMBR) constructed of monofilament woven meshes made of polyamide/nylon submerged inside a cross-flow module was used to study the effects on biohydrogen production, by Saleem et al. [75]. ...
... The equipment was set to a temperature of 37 C, an initial pH of 7.5, and shaking of 120 rpm (1 min ON, 3 min OFF from the motor controller). A blank essay in duplicate was prepared without substrate to estimate the endogenous hydrogen production from inoculum [42]. After set-up, the bottles were purged with N 2 gas to ensure an anaerobic environment. ...
... The substrate to inoculum ratio (S/X) is used to determine the required amount of inoculum to add for a given biomass quantity in batch tests. The literature mentions S/X or F/M (food to microorganism ratio) in batch test from 1 to 20 (on VS basis) depending on the authors (Cappai et al., 2018;Favaro et al., 2013;Paillet et al., 2019). Only few studies reported that the substrate to inoculum ratio (S/X) could significantly impact the hydrogen yield (Cappai et al., 2018;Stanislaus et al., 2018). ...
... Y. . This process is reported to be influenced by fermentation time (Chen et al., 2014), temperature (Hossain et al., 2017;Alberti et al., 2017), pH (Azhar et al., 2017;Silva-Illanes et al., 2017) and inoculum loading (Azhar et al., 2017;Alberti et al., 2017). The optimum conditions for glucose fermentation using S. cerevisiae to obtain maximum ethanol production were at 25°C to 40°C (Tofighi et al., 2014;Ünal et al., 2020), pH 5 (Mishra et al., 2016), and inoculum loading of 1 × 10 8 cells/mL for 48 hours (Nuanpeng et al., 2018). ...
... Concerning hypothesis 2: This would agree with the observation that the amendment with OM shifts the ratio compared to the ratio in the unamended 4°C incubations. The most likely inorganic electron donor in our incubation would be hydrogen that would be released as the product of primary or secondary fermentations (e.g., Cabrol et al. 2017). Though hydrogen could play a role in our system, we do not expect it to account for an up to fivefold stimulation, as observed in some of our samples. ...
... The results at phylum level showed that the bacterial communities were dominated by Firmicutes, while Proteobacteria, Actinobacteriota, Thermotogota, Synergistota were less abundant but present in all samples (Fig. 3). This result was expected because the Firmicutes phylum usually prevails in acidogenic reactors [55]. The Proteobacteria phylum, which was observed mainly in samples from runs 1, 2 and 9 (Fig. 3), is another important phylum found in anaerobic reactors [56,57]. ...