In this study, pilot-scale hybrid constructed wetlands (CWs) and multistage horizontal subsurface flow CWs (HF CWs) have been studied and compared for the treatment of raw urban wastewater. In the hybrid CWs, the first stage was a mulch-based horizontal subsurface flow CW and the second stage was a vertical subsurface flow CW (VF CW). The VF CWs were used to determine if sand could improve the performance of the hybrid CW with respect to the mulch. In the multistage HFs, mulch, gravel and sand were used as substrates. The effect of water height (HF10: 10 cm vs. HF40: 40 cm) and surface loading rate (SLR: 12 vs. 24 g Chemical Oxygen Demand (COD)/m²d) has been studied. The results show that the use of sand in the vertical flow stage of the hybrid CW did not improve the average performance. Additionally, the sand became clogged, while the mulch did not. The effect of water height on average pollutant removal was not determined but HF10 performed better regarding compliance with legal regulations. With a SLR of 12 g COD/m²d, removals of HF10 were: 79% for COD, 75% for NH₄⁺-N, 53% for dissolved molybdate-reactive phosphate-P (DRP), 99% for turbidity and 99.998% for E. coli and total coliforms. When SLR was doubled, removals decreased for NH₄⁺-N: 49%, DRP: −20%, E coli and total coliforms: 99.5–99.9%, but not for COD (85%) and turbidity (99%). Considering the obtained results and the simplicity of the construction and operation of HFs, HF10 would be the most suitable choice for the treatment of raw urban wastewater without clogging problems.

In this study, the effects of plants on the performance and bacterial community structure of palm mulch-based vertical flow constructed wetlands was studied. The wetlands were built in August 2013; one of them was planted with Canna indica and Xanthosoma sp., and the other one was not planted and used as a control. The experimental period started in September 2014 and finished in June 2015. The influent was domestic wastewater, and the average hydraulic surface loading was 208 L/m²d, and those of COD, BOD, and TSS were 77, 57, and 19 g/m²d, respectively. Although the bed without plants initially performed better, the first symptoms of clogging appeared in December 2014, and then, its performance started to fail. Afterwards, the wetland with plants provided better removals. The terminal restriction fragment length polymorphism (T-RFLP) analysis of Enterococci and Escherichia coli in the effluents suggests that a reduction in their biodiversity was caused by the presence of the plants. Thus, it can be concluded that the plants helped achieve better removals, delay clogging, and reduce Enterococci and E. coli biodiversity in the effluents.

In this study, we designed and validated in silico and experimentally a rapid, sensitive, and specific multiplex RT qPCR for the detection and quantification of faecal indicator bacteria (FIB) used as microbiological references in marine bathing water regulations (Escherichia coli and intestinal enterococci). The 16S rRNA gene was used to quantify group-specific enterococci and Escherichia/Shigella and species-specific such as Enterococcus faecalis and E. faecium. Additionally, a ybbW gene encoding allantoin transporter protein was used to detect E. coli. An assessment of marine coastal systems (i.e., marine water and sediment) revealed that intestinal enterococci were the predominant group compared to Escherichia/Shigella. The low contribution of E. faecalis to the intestinal enterococci group was reported. As E. faecalis and E. faecium were reported at low concentrations, it is assumed that other enterococci of faecal origin are contributing to the high gene copy number of this group-specific enterococci. Moreover, low 16S rRNA gene copy numbers with respect to E. faecalis and E. faecium were reported in seawater compared to marine sediment. We conclude that marine sediments can affect the quantification of FIBs included in bathing water regulations. Valuing the quality of the marine coastal system through sediment monitoring is recommended.

At present, higher education demands innovation processes that facilitate the improvement of student learning. We present the design and development of a cooperative learning experience in the superior institution in a subject of the Degree in Chemical Engineering developed during three academic years. The level of satisfaction of the students was assessed by means of a questionnaire according to the Likert scale, which was approached with respect to three dimensions (methodology, competences and experiences) and their corresponding subdimensions (activities developed, class dynamics, role of the teacher, relation tasks and time, autonomy of the students, protagonists of the formation and differences between the received methodologies). The results show that student satisfaction in relation to cooperative learning lies in the distribution of tasks and the ability to work actively.

The aim of this work was molecular identification of bacteria associated with marine sand at the drift line, where most plastic debris is deposited, and evaluation of the alteration of plastic polymers by them. Bacterial communities growing on plastic polymer surfaces may differentially cause surface alteration through exopolysaccharide production. This alteration can be analyzed by changes in spectra regions of colonized polymers compared to uncolonized polymers using Fourier Transform Infrared Spectroscopy (FTIR). In this study, bacteria located in sand at the drift line above sea water, where microplastics are most abundant, were isolated and identified through 16S rRNA. Six of the identified species produced exopolysaccharides, namely Bacillus thuringiensis, B. cereus, Bacillus sp. Proteus penneri, Alcaligenes faecalis and Myroides gitamensis. These bacteria species were inoculated into plates, each containing two frequently reported types of polymers at the drift line. Specifically, the two types of plastic polymers used were polypropylene and polystyrene spheres in whole and mechanically crushed states. Differences in bacterial growth were reported as inferred from weight increase of polypropylene and polystyrene spheres after 1-year long culture. Results also showed that Alcaligenes faecalis, Bacillus cereus and Proteus penneri colonized polypropylene spheres and modified spectra regions of FTIR. It is concluded that bacteria located in sand can be considered plastic-altering bacteria as changes in FTIR-spectra of polymers can be related to bioalteration.

In this work, metabolite profiling of seeds and antioxidant analysis of fragments of two marine seagrasses, Posidonia oceanica and Cymodocea nodosa, were carried out to identify metabolite signature involved in seed viability and to evaluate the potential of fragments as a source of bioactive compounds. Using HILIC/QTOF-MS, UHPLC-MS and spectrophotometric analysis, seed metabolites and polyphenols and antioxidant activities, such as those of radical scavenging (RSA), reduction (FRAP, CUPRAC) and complexation (CCA), of rhizome fragments were evaluated. Metabolite comparison between seeds revealed differences across development stages (germinated and non-germinated) and seed types (dormant and non-dormant), providing insights into metabolic activity potentially associated with germination processes and seed viability. Furthermore, polyphenol analysis showed the highest content of caffeic acid in mature leaves (17.00 ± 0.02 μg g⁻¹ dw for P. oceanica and 98.00 ± 0.03 μg g⁻¹ dw for C. nodosa). Total phenolic content was correlated with flavonoids and with reduction and complexation activities. The combination of radical scavenging activity and t_1/2 was higher in P. oceanica than C. nodosa and also surpassed the commercial synthetic antioxidant BHA. We conclude P. oceanica and C. nodosa exhibit distinct seed metabolite profiles related to germination and type of seeds, and that fragments are rich in antioxidants, with potential as sustainable sources of bioactive compounds.