Maite Pijuan

Maite Pijuan
ICRA Catalan Institute for Water Research | ICRA · Technologies and Evaluation Area

PhD Environmental Engineering

About

94
Publications
13,485
Reads
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3,617
Citations
Additional affiliations
July 2010 - April 2017
ICRA Catalan Institute for Water Research
Position
  • Researcher

Publications

Publications (94)
Article
Full-text available
Microbial communities are responsible for biological wastewater treatment, but our knowledge of their diversity and function is still poor. Here, we sequence more than 5 million high-quality, full-length 16S rRNA gene sequences from 740 wastewater treatment plants (WWTPs) across the world and use the sequences to construct the ‘MiDAS 4’ database. M...
Article
Full-text available
Ammonia recovery from centrate of an anaerobic digester was investigated using an onsite bipolar-electrodialysis (BP-ED) pilot scale plant coupled to two liquid/liquid membrane contactor (LLMC) modules. To investigate the process performance and robustness, the pilot plant was operated at varying current densities, load ratio (current to nitrogen l...
Article
In the present paper, the mesophilic (35 °C) and thermophilic (55 °C) biomethanization of poultry and cattle manures were investigated using biochemical methane potential (BMP) tests. Specific methane production (SMP), 24 pharmaceutical compounds (PhACs), and five antibiotic resistance genes (ARGs) (blaKPC, ermB, qnrS, sul1 and tetW) together with...
Article
Full-text available
Nitrous oxide (N2O) is a greenhouse gas (GHG) emitted during biological nitrogen removal from wastewater treatment plants (WWTPs). Some modelling tools have been proposed to predict N2O emissions during the design and operation of WWTPs. In this study, the novel ASM2d-N2O model, which accounts for the production of N2O in nutrient removal WWTPs, wa...
Chapter
Wastewater treatment relies on the concerted activity of a diverse set of microbial populations which depending on the conditions, can produce harmful greenhouse gases such as carbon dioxide, methane, and nitrous oxide. Furthermore, conventional wastewater treatment produces high quantities of waste sludge that requires post-treatment, thus increas...
Article
The anaerobic treatment of municipal wastewater (WW) results in low biogas production due to its relatively low concentration of organic matter. To overcome this problem, this paper assesses the potential of combining forward osmosis (FO), as a pre-treatment to concentrate real municipal WW with anaerobic digestion (AD), with the aim of enhancing m...
Article
Full-text available
Methane is the final product of the anaerobic decomposition of organic matter. The conversion of organic matter to methane (methanogenesis) as a mechanism for energy conservation is exclusively attributed to the archaeal domain. Methane is oxidized by methanotrophic microorganisms using oxygen or alternative terminal electron acceptors. Aerobic met...
Article
Full-text available
Methane is the final product of the anaerobic decomposition of organic matter. The conversion of organic matter to methane (methanogenesis) as a mechanism for energy conservation is exclusively attributed to the archaeal domain. Methane is oxidized by methanotrophic microorganisms using oxygen or alternative terminal electron acceptors. Aerobic met...
Article
One of the major challenges in existing WasteWater Treatment Plants (WWTPs) is to comply with the increasingly stringent nutrient discharge limits established by the competent authorities to enhance en- vironmental protection, while keeping operation costs as low as possible. This paper describes the re- sults obtained from upgrading a full-scale W...
Article
The effect of COD addition into an anammox reactor was assessed during short and long term exposure. The short term exposure was assessed via batch tests and lasted 48 h. Results indicated the presence of a very active denitrifying community able to consume COD using nitrate and nitrite as electron acceptors. However, the presence of COD did not re...
Article
Secondary sludge pre-treatment with free nitrous acid (FNA) has been proven to enhance methane production during anaerobic digestion. However, it is still unclear if the same enhancement can be achieved only using nitrite, without sludge acidification. In this paper, secondary sludge was pre-treated during 5 h with nitrite within the range of 50–25...
Article
A laboratory scale anaerobic membrane bioreactor was operated for 11 months treating synthetic wastewater that mimicked the concentrate from a forward osmosis process treating municipal wastewater with 80% water recovery. The effect of temperature variation on reactor performance was assessed. The reactor operated during 4 months at 34 °C and then...
Article
Despite the number of studies that have investigated the fate of endocrine disrupting compounds (EDCs), to date results are still contradictory and more research is required to evaluate the contribution of the microbial communities present in different engineered treatment systems. Thus, autotrophic and heterotrophic types of biomass were here comp...
Article
Temperature has a known effect on ammonia oxidizing bacteria (AOB) activities, reducing its ammonia oxidizing rate (AOR) when temperature is lowered. However, little is known concerning its effect on N2O and NO emissions which are produced during ammonia oxidation having a greenhouse effect. To study this, an AOB enriched partial nitrification sequ...
Article
Denitrifying enhanced biological phosphorus removal (EBPR) systems can be an efficient means of removing phosphate (P) and nitrate (NO3-) with low carbon source and oxygen requirements. Tetrasphaera is one of the most abundant polyphosphate accumulating organisms present in EBPR systems, but their capacity to achieve denitrifying EBPR has not previ...
Article
The effectiveness of the Free Nitrous Acid (FNA) sludge treatment was tested in the range from 0 to 3.0 mg NHNO2/L with acidified and neutral pH. 4 h pre-treatment times were used and the specific methane production (SMP) investigated. Results show that between 50 and 100 mg/L of N-NO2 −/L disappeared during the FNA pretreatment, reducing its effec...
Article
In the past few years, anaerobic ammonium oxidation-based processes have attracted a lot of attention for their implementation at the mainstream line of wastewater treatment plants, due to the possibility of leading to energy autarky if combined with anaerobic digestion. However, little is known about the potential degradation of micropollutants by...
Article
Wastewater transport along sewers favors the colonization of inner pipe surfaces by wastewater-derived microorganisms that grow forming biofilms. These biofilms are composed of rich and diverse microbial communities that are continuously exposed to antibiotic residues and antibiotic resistant bacteria (ARB) from urban wastewater. Sewer biofilms thu...
Article
This study aims at investigating the relationship between the nitric oxide (NO) and nitrous oxide (N2O) production rates with the ammonia oxidation rate (AORsp) in an enriched AOB culture. Different concentrations of ammonia were applied in a sequential batch reactor (SBR) performing partial nitritation in order to determine the effect of AORsp on...
Article
Antibiotics such as sulfamethoxazole (SFX) are environmentally hazardous after being released into the aquatic environment and challenges remain in the development of engineered prevention strategies. In this work, a mathematical model was developed to describe and evaluate cometabolic biotransformation of SFX and its transformation products (TPs)...
Article
Recent studies have shown the effectiveness of Free Nitrous Acid (FNA) pre-treatment in enhancing sludge biodegradability and improving its methane production potential. FNA is regarded as an environmental friendly pre-treatment which can be easily applied when a source of nitrite is present in wastewater treatment plants. However, when nitrite is...
Conference Paper
The project C-FOOT-CTRL develops a standalone software tool composed by different modules. An on-line data module is in charge of communicating to different on-line data providers and sending these data to the Database module. Model predictions based on on-line input data and mechanistic models including N2O emission calculation will provide on-lin...
Conference Paper
Temperature is a very important parameter during nitritation, having a direct effect on ammonia oxidation rate (AOR) and enzymatic activities which relate to both N2O and NO emission. This study aims at investigating the effect of temperature on AOR, N2O and NO production in an enriched ammonia oxidizing bacteria (AOB) sequencing batch reactor (SBR...
Conference Paper
Nitrous oxide (N2O) is a greenhouse gas with a significant global warming potential. A dynamic model was developed to estimate the N2O production and emission in a full-scale sequencing batch reactor (SBR) municipal wastewater treatment plant (WWTP). Based on the Activated Sludge Model 1 (ASM1), the model considered all known biological and abiotic...
Article
The ef­fec­tive­ness of low free ni­trous acid (FNA) pre-treat­ment times (PTs) (<8 h) on waste ac­ti­vated sludge (WAS) is not known. This study ex­plores the ef­fec­tive­ness of four dif­fer­ent FNA con­cen­tra­tions (0, 2.49, 3.55 and 4.62 mg N-HNO2/L) and three low PTs (2, 5 and 8 h) on WAS char­ac­ter­is­tics and methane gen­er­a­tion. In­crea...
Article
The present study was undertaken to investigate the effect of different free nitrous acid (FNA) concentrations at low pre-treatment times (PTs) (1, 2 and 5 h) and without pH control with mild agitation on primary sludge (PS) biodegradability and methane production (MP). Increasing PTs resulted in an increase in the solubility of the organic matter...
Article
Full-text available
Free nitrous acid (FNA) has been shown to enhance the biodegradability of waste activated sludge (WAS) but its effectiveness on the pre-treatment of mixed sludge is not known. This study explores the effectiveness of four different FNA concentrations (0, 2.49, 3.55, 4.62 mg N-HNO2/L) and three exposure times (2, 5, 9 h) lower than the ones reported...
Article
This study aims at investigating the denitrification kinetics in two separate enriched cultures of denitrifying polyphosphate accumulating organisms (dPAO) and denitrifying glycogen accumulating organisms (dGAO) and compare their N2O accumulation potential under different conditions. Two sequencing batch reactors were inoculated to develop dPAO and...
Article
Bioproduction of hydrogen sulfide (H2S) and methane (CH4) under anaerobic conditions in sewer pipes causes detrimental effects on both sewer facilities and surrounding environment. Among the strategies used to mitigate the production of both compounds, the addition of nitrite (NO2(-)) has shown a greater long-term inhibitory effect compared with ot...
Article
Clark-Type nitrous oxide (N2O) sensors are routinely used to measure dissolved N2O concentrations in wastewater treatment plants (WWTPs), but have never before been applied to assess gas-phase N2O emissions in full-scale WWTPs. In this study, a full-scale N2O gas sensor was tested and validated for online gas measurements, and assessed with respect...
Article
The occurrence of the widely-used antibiotic sulfamethoxazole (SFX) in wastewaters and surface waters has been reported in a large number of studies. However, the results obtained up-to-date have pointed out disparities in its removal. This manuscript explores the enhanced biodegradation potential of an enriched culture of Ammonia Oxidizing Bacteri...
Article
The effect of nitrite on N2O and NO emission was assessed in a nitrifying lab-scale reactor fed with low strength ammonium wastewater. The effect of nitrite pulse additions (5-50mg NO2--NL-1) and of step-wisely increasing nitrite concentrations (0-150mg NO2--NL-1) was studied. For the pulse addition experiments, N2O and NO emissions increased upon...
Article
Coexistence of sulfate-reducing bacteria (SRB) and methanogenic archaea (MA) in anaerobic biofilms developed in sewer inner pipe surfaces favours the accumulation of sulfide (H2S) and methane (CH4) as metabolic end products, causing severe impacts on sewerage systems. In this study we investigated the time-course of H2S and CH4 production and emiss...
Article
A continuous, on-line quantification of the nitrous oxide (N2O) emissions from a full-scale sequencing batch reactor (SBR) placed in a municipal wastewater treatment plant (WWTP) was performed in this study. In general, N2O emissions from the biological wastewater treatment system were 97.1 ± 6.9 g N2O–N/Kg consumed or 6.8% of the influent load. In...
Article
Nitrate (NO) is commonly dosed in sewer systems to reduce sulfide (H2S) and methane (CH4) produced in anaerobic rising main pipes. However, anoxic conditions along the whole rising pipes are difficult and costly to maintain since nitrate is added at the upstream sections of the sewer. In this study we tested the effects of the Downstream Nitrate Do...
Article
Full-text available
Outlining integrative solutions for humans and ecosystems In relation to other areas of the world, the Mediterranean region is one of the most vulnerable to global changes, as well as to potential alterations in water availability. Dryland regions are particularly water-thirsty, and overpressures on water resources are the rule of thumb. The conjoi...
Article
The competition for electrons has been recently demonstrated to affect the reduction rates of the nitrogen oxides in a methanol enriched denitrifying community. The aim of this study was to test if electron competition also occurred when other substrates were used for denitrification and if that could have an effect on the potential nitrous oxide (...
Article
Clark-type nitrous oxide (N2O) microelectrodes are commonly used for measuring dissolved N2O levels, but have not previously been tested for gas-phase applications, where the N2O emitted from wastewater systems can be directly quantified. In this study, N2O microelectrodes were tested and validated for online gas measurements, and assessed with res...
Article
Nitrous oxide (N2O) emissions from nitritation reactors receiving real anaerobic sludge digestion liquor have been reported to be substantially higher than those from reactors receiving synthetic digestion liquor. This study aims to identify the causes for the difference, and to develop strategies to reduce N2O emissions from reactors treating real...
Article
Nitrous oxide (N2O) and methane emissions were monitored in a continuous granular airlift nitritation reactor from ammonium-rich wastewater (reject wastewater). N2O emissions were found to be dependent on dissolved oxygen (DO) concentration in the range of 1-4.5 mg O2/L, increasing within this range when reducing the DO values. At higher DO concent...
Article
Full-text available
To better understand granule growth and breakage processes in aerobic granular sludge systems, the particle size of aerobic granules was tracked over 50 days of wastewater treatment within four sequencing batch reactors fed with abattoir wastewater. These experiments tested a novel hypothesis stating that granules equilibrate to a certain stable gr...
Article
The processes of nitritation and full nitrification of synthetic reject wastewater were compared in terms of N2O and NO emissions. Two lab-scale sequencing batch reactors (SBR1 and SBR2) were enriched with Nitrosomonas (ammonia-oxidizing bacteria) and Nitrobacter (nitrite-oxidizing bacteria), as shown by fluorescence in situ hybridization (FISH) an...
Article
A sequencing batch reactor (SBR) was enriched with ammonia oxidizing bacteria (AOB) in order to treat synthetic reject wastewater (1 g [Formula: see text] ). Partial nitrification was successfully achieved at a [Formula: see text] to [Formula: see text] conversion rate of 98%. The emission dynamics of nitrous oxide (N2O) and nitric oxide (NO) were...
Article
The processes of nitritation and full nitrification were compared in terms of N2O and NO emissions. Two lab-scale sequencing batch reactors (SBR1 and SBR2) were enriched with Nitrosomonas (ammonia-oxidizing bacteria) and Nitrobacter (nitrite-oxidizing bacteria). Stable conversion of ammonium to nitrite and nitrite to nitrate was achieved in SBR1 an...
Article
Endogenous processes such as biomass decay and intracellular polymers degradation of polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) were investigated. Cultures enriched in Accumulibacter (a well known PAO) or Competibacter (a well known GAO) were subjected to 21 and 26days of alternating anaerobic/aerobic con...
Article
This study presents a novel strategy based on free nitrous acid (FNA) treatment to improve the biodegradability of secondary sludge. Several experiments were conducted to demonstrate the biocidal effect of FNA on activated sludge. The viable fraction as well as the biological activity of the biomass decreased significantly after 8-48 h treatment wi...
Article
Full-text available
Aerobic granulation is a novel and promising technology for wastewater treatment. However, long start-up periods required for the development of granules from floccular sludge, and the loss of biomass in this period leading to poor nutrient removal performance are key challenges. In a recent study the addition of crushed granules to a floccular slu...
Article
This study focuses on the enhancement of aerobic granulation and biological nutrient removal maintenance treating domestic wastewater. Two sequencing batch reactors (SBRs) were inoculated with either only floccular sludge (100%-floc SBR) or supplemented with 10% crushed granules (90%-floc SBR). Granules developed in both reactors. The 100%-floc SBR...
Article
One of the main challenging issues for the aerobic granular sludge technology is the long startup time when dealing with real wastewaters. This study presents a novel strategy to reduce the time required for granulation while ensuring a high level of nutrient removal. This new approach consists of seeding the reactor with a mixture of crushed aerob...
Article
A gel-forming exopolysaccharide was previously shown to play an important structural role in aerobic granules treating nutrient-rich industrial wastewater. To identify whether this exopolysaccharide performs a similar role in other granular biomass and if conditions favouring its production can be more precisely elucidated, extracellular polymeric...
Article
Free Nitrous Acid (FNA), rather than nitrite, has recently been suggested to be the true inhibitor on the aerobic P–uptake of polyphosphate accumulating organisms (PAOs). Also, it has been demonstrated to have a stronger inhibitory effect on the aerobic PAO processes than on the aerobic metabolism of glycogen accumulating organisms (GAOs), competit...
Article
Enhanced biological phosphorus removal (EBPR) normally occurs together with nitrogen removal in wastewater treatment plants (WWTPs). In recent years, efforts have been devoted to remove nitrogen via the nitrite pathway (oxidation of ammonia to nitrite and reduction of nitrite to nitrogen gas without going through nitrate), reducing the requirement...
Article
In full-scale wastewater treatment systems, phosphorus removal typically occurs together with nitrogen removal. Nitrite, an intermediate of both the nitrification and denitrification processes, can accumulate in the reactor. The inhibitory effect of nitrite/free nitrous acid (FNA) on the aerobic metabolism of poly-phosphate accumulating organisms (...
Article
Nuclear magnetic resonance (NMR) techniques were used to elucidate the structure of an exopolysaccharide material previously revealed to be important in formation of aerobic granules. The 1D NMR spectral data acquired showed that this gel-forming polysaccharide was a major component of granular EPS, while 1D and 2D NMR spectra showed it consisted o...
Article
The application of aerobic sludge granules in wastewater treatment could increase the intensity of wastewater treatment processes because of their greater density and size relative to conventional sludge flocs. It has been suggested that granules are distinguished from flocs by gel forming exopolysaccharides. In this study, evidence is presented li...
Article
Full-text available
Glycolysis has been generally accepted to be the source of reducing power used for the synthesis of polyhydroxyalkanoates (PHAs) in the anaerobic metabolism of polyphosphate accumulating organisms (PAOs). However, the tricarboxylic acid cycle (TCA) has also been suggested to contribute to the generation of reducing equivalents, creating some contro...
Article
A sequencing batch reactor (SBR) was used for the treatment of abattoir wastewater to produce effluent with desirable nitrogen and phosphorus levels for irrigation. The SBR cycle consisted of an anaerobic phase with wastewater feeding, a relatively short aerobic period (allowing full ammonium oxidation), a second anoxic period with feeding, followe...
Article
Nitrite/Free Nitrous Acid (FNA) has previously been shown to inhibit aerobic and anoxic phosphate uptake by polyphosphate accumulating organisms (PAOs). The inhibitory effect of FNA on the aerobic metabolism of Glycogen Accumulating Organisms (GAOs) is investigated. A culture highly enriched (92+/-3%) in Candidatus Competibacter phosphatis (hereaft...
Article
Nitrogen removal through the nitrite pathway has been successfully achieved using on-line aeration length control. However, it takes a long time period to get steady performance when using on-line control as the sole strategy. On the other hand, salt inhibition has also been used to achieve the nitrite pathway, with potentially adverse effects on t...
Article
The effect of long term anaerobic and intermittent anaerobic/aerobic starvation on the structure and activity of aerobic granules was studied. Aerobic granular sludge treating abattoir wastewater and achieving high levels of nutrient removal was subjected to 4–5 week starvation under anaerobic and intermittent anaerobic/aerobic conditions. Microsco...
Article
The sol-gel transition of extracellular polymeric substances (EPS) derived from sludge flocs and granules is investigated in order to explain basic differences between the two aggregates. A reversible, pH dependent sol-gel transition was observed at pH 9.0-12.0 in EPS extracted from granules. At pH <9 granule EPS existed as a strong gel, indicating...
Article
Aerobic sludge granules are larger, denser microbial aggregates than activated sludge flocs with a smoother and more regular surface, which facilitates greater wastewater treatment intensity. Factors important in their growth are still poorly understood, which is an impediment to the construction and operation of full-scale aerobic sludge granule p...
Article
For decades, glycolysis has been generally accepted to supply the reducing power for the anaerobic conversion of volatile fatty acids (VFAs) to polyhydroxyalkanoates (PHAs) by polyphosphate accumulating organisms (PAOs). However, the importance of the tricarboxylic acid (TCA) cycle has also been raised since 1980s. The aim of this study is to demon...
Article
Polyhydroxyalkanoate (PHA) is a biodegradable plastic synthesised by bacteria as energy and carbon storage material. PHA production is mostly based on pure cultures operated under sterile conditions, which increase the costs of this biopolymer. The use of inexpensive mixed culture biomass, such as activated sludge, to produce biodegradable plastics...
Article
Nitrite has generally been recognized as an inhibitor of N2O reduction during denitrification. This inhibitory effect is investigated under various pH conditions using a denitrifying-enhanced biological phosphorus removal (EBPR) sludge. The degree of inhibition was observed to correlate much more strongly with the free nitrous acid (FNA) concentrat...
Article
A novel 2-sludge 3-stage process using a combination of granular sludge and biofilm was developed to achieve biological removal of nitrogen and phosphorus from nutrient-rich wastewater. The system consists of a granular sequencing batch reactor (SBR) working under alternating anaerobic/anoxic conditions supplemented with a short aerobic phase and a...
Article
Polyphosphate (poly-P) is known to be a key compound in the metabolism of polyphosphate-accumulating organisms (PAOs). In this study, a sludge highly enriched (80%) in Candidatus Accumulibacter phosphatis (hereafter referred to as Accumulibacter), a widely known PAO, was used to study the ability of these microorganisms to utilize acetate anaerobic...