Garcia, M.; Gutierrez, R.; Uggetti, E.; Matamoros Mercadal, Víctor; Garcia, J.; Ferrer, I. Biosystems engineering Vol. 166, p. 138-149 DOI: 10.1016/j.biosystemseng.2017.11.016 Data de publicació: 2018-02 Article en revista
Diffuse pollution in rural areas due to agricultural runoff is a widespread and difficult problem to address due to the large areas affected. Drainage channels receive polluted water, but its introduction into conventional treatment network is often unfeasible. Within this context, microalgae-based treatment systems could be used as alternative treatment plants. A new design of semi-closed (hybrid) tubular horizontal photobioreactor (HTH-PBR) with low energy requirements has been evaluated for microalgae cultivation at full-scale (8.5 m3), using agricultural runoff as feedstock. This novel system was tested in batch and continuous mode over 4 and 135 d. Considering a full-scale application in an agricultural context, a batch test was carried out to evaluate the performance of the system. An increase of 22% in the biomass concentration in 4 d was registered, and all nutrients were consumed during the first two days. In the continuous experiment carried out over winter (December–April), productivity was between 2 and 14 g g [TSS] m-3 d, but values up to 76.4 g [TSS] m-3 d were reached at the end of the study in spring, despite the low nutrients concentration in the feedstock. Elimination of emerging contaminants was also evaluated, obtaining the highest removals for the synthetic musk fragrances tonalide and galaxolide (73% and 68%), and the anti-inflammatory drug diclofenac (61%).
Mamo, J.; Garcia, M.; Stefani, M.; Rodriguez, S.; Barceló, D.; Monclus, H.; Rodríguez-Roda, I.; Comas, J. Chemical engineering journal Vol. 331, p. 450-461 DOI: 10.1016/j.cej.2017.08.050 Data de publicació: 2018-01 Article en revista
The removal of pharmaceuticals (PhACs) present in urban wastewater by membrane bioreactors (MBRs) followed by reverse osmosis (RO) or nanofiltration (NF) membranes has been frequently addressed in the literature. However, data regarding the removal of their main human metabolites and transformation products (TPs) is still scarce. In this study, the presence of 13 PhACs and 20 of their metabolites and TPs was monitored during 2 consecutive years in the different treatment steps of urban raw wastewater (sewer, primary treatment, MBR and RO/NF). Rejection of the selected contaminants when using low pressure NF membranes (NF-90) or RO membranes (ESPA 2) after the MBR step was also investigated. The analgesic acetaminophen, which was found at the highest concentrations in the sewer and influent samples (18–74 µg L-1) over the two experimental periods, was fully eliminated during MBR treatment. Those PhACs that were only partially removed after the MBR, were almost completely removed (>99%) by the RO membrane working under different process conditions. At a similar average permeate fluxes (18 L m-2 h-1), the NF membrane showed high removal efficiencies (>90%) for all of the PhACs and their metabolites, though lower than those achieved by the RO membrane. When the flux of the NF90 membrane was increased to 30 L m-2 h-1 (while still operating at a feed pressure lower than the RO membrane at 18 L m-2 h-1) the performance of the membrane increased, achieving 98% rejection of PhACs.
The potential ecotoxicological effects of mixtures of contaminants in the aquatic environment are generating a global concern. Benthic invertebrates, such as the crustacean Gammarus fossarum, are key in the functioning of aquatic ecosystems, and are frequently used as sentinel species of water quality status. The aim of this work was to study the effects of a mixture of the most frequently detected surfactants in the bioconcentration kinetics of two pharmaceuticals in G. fossarum, evaluating their potential enhancing or suppressing effects. Laboratory exposure experiments for both pharmaceuticals and surfactants (concentration ratio 1:25) were set up for two individual compounds, the anxiolytic oxazepam and the antibiotic sulfamethoxazole. Gammarid samples were processed using microQuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction. Pharmaceuticals concentration in the organisms was followed-up by means of nanoliquid chromatography coupled to tandem mass spectrometry (nanoLC-MS/MS). Results indicated a similar mode of action of the surfactants in the bioconcentration kinetics of both drugs, decreasing the accumulation rate in the organism. Oxazepam showed a higher accumulation potential than sulfamethoxazole in all cases. Depuration experiments for oxazepam also demonstrated the high depurative capacity of gammarids, eliminating > 50% of the concentration of oxazepam in < 6 h.
The main objective of this study was to select and grow wastewater-borne cyanobacteria in a closed photobioreactor (PBR) inoculated with a mixed consortium of microalgae. The 30 L PBR was fed with a mixture of urban secondary effluent and digestate, and operated in semi-continuous mode. Based on the nutrients variation of the influent, three different periods were distinguished during one year of operation. Results showed that total inorganic nitrogen (TIN), inorganic phosphorus concentration (PO43 -), phosphorus volumetric load (LV-P) and carbon limited/non-limited conditions leaded to different species composition, nutrients removal and biomass production in the culture. High TIN/PO43 - concentrations in the influent (36 mg N L- 1/3 mg P L- 1), carbon limitation and an average LV-P of 0.35 mg P L- 1d- 1 were negatively related to cyanobacteria dominance and nutrients removal. On the contrary, cyanobacteria predominance over green algae and the highest microbial biomass production (averaging 0.084 g Volatile Suspended Solids (VSS) L- 1d- 1) were reached under TIN/PO43 - concentrations of 21 mg N L- 1/2 mg P L- 1, no carbon limitation and an average LV-P of 0.23 mg P-PO43 - L- 1d- 1. However, although cyanobacteria predominance was also favored with a LV-P 0.15 mg L- 1d- 1, biomass production was negatively affected due to a P limitation in the culture, resulting in a biomass production of 0.0.39 g VSS L- 1d- 1. This study shows that the dominance of cyanobacteria in a microalgal cyanobacterial community in an agitated PBR using wastewater as nutrient source can be obtained and maintained for 234 days. These data can also be applied in future biotechnology applications to optimize and enhance the production of added value products by cyanobacteria in wastewater treatment systems.
“The final publication is available at Springer via http://dx.doi.org/10.1016/j.scitotenv.2017.02.097"
Taking into account the current global water scarcity and the expensive operation and maintenance cost of wastewater treatment, INCOVER concept has been designed to move wastewater treatment from being primarily a sanitation technology towards a bio-product recovery industry and a recycled water supplier. A wastewater specific Decision Support System methodology will be tailored to the INCOVER technologies and provide data and selection criteria for a holistic wastewater management approach.
Three added-value plants treating wastewater from three case-studies (municipalities, farms and food and beverage industries) will be implemented, assessed and optimised concurrently. INCOVER plants will be implemented at demonstration scale in order to achieve Technology Readiness Level(TRL) of 7-8 to ensure straightforward up scaling to 100,000 population equivalents (PE). INCOVER added-value plants will generate benefits from wastewater offering three recovery solutions: 1) Chemical recovery (bio-plastic and organic acids) via algae/bacteria and yeast biotechnology; 2) Near-zero-energy plant providing upgraded bio-methane via pre-treatment and anaerobic co-digestion systems; 3) Bio-production and reclaimed water via adsorption, biotechnology based on wetlands systems and hydrothermal carbonisation. To improve added-value production efficiency, INCOVER solutions will include monitoring and control via optical sensing and soft-sensors.
INCOVER solutions will reduce at least a 50% overall operation and maintenance cost of wastewater treatment through the use of wastewater as a source for energy demand and added-value production to follow UE circular economy strategy. In addition, strategies to facilitate the market uptake of INCOVER innovations will be carried out in order to close the gap between demonstration and end-users.
An estimated turnover of 188 million€ for INCOVER lead-users is expected after the initial exploitation strategy of 5 years implementing 27 INCOVER solutions.