Resultados de investigación

Sample preparation for the analysis of organic micropollutants in wastewater samples is commonly carried out by solid-phase extraction (SPE) procedures, which involve different manual laboratory operations. This conventional approach requires several hours of counter labour and entail the use of a lot of disposable material, and the subsequent contaminated non-recyclable plastic-residue production. In contrast, by coupling and automatizing the pre-treatment to the instrumental analysis most of that burden erases, sample size gets miniaturized and, thus, storage becomes freed-up. Even lab counters get cleared off from sample pre-treatment apparatus. However, method performance could get alter as a trade-off. This paper presents the results from a study in which methodology, including SPE online-coupled to UHPLC-MS/MS chromatography, was developed for multi-residue (58) determination of veterinary and pharmaceutical drugs in urban and piggery wastewater (influent and effluent to wastewater treatment plants (WWTPs)). Similarly, the direct injection (DI) of large volumes (hundreds of µL) of same matrix samples into the chromatographic system was optimized too. The performance of both automated methods was statistically compared with the classical off-line SPE. As dealing with trace analysis, suitable injection volumes for the alternative approaches were selected on the premise of low limits of quantification (MLQs). Under the selected conditions, validation parameters such as linearity range, method quantification limits, peak shape and carry over were determined. Usually more than 50 % of the analytes showed MLQs below 50 ng/L, for all matrices and methodologies, especially for DI. Real wastewater samples from a local urban WWTP and farm were analysed with all three tested methodologies. Determined concentrations and removal rates were statistically compared and turned out being quite similar. However, analysis under offline SPE and DI approaches provided a larger amount of information as they reached lower MLQs. Offline-SPE provided the worst precision among all., Instituto de Procesos Sostenibles, Departamento de Ingeniería Química y Tecnología del Medio Ambiente, Departamento de Química Analítica, Ministerio de Ciencia, Innovación y Universidades, EU Feder Programme, Consejeria de Educacion Junta de Castilla y Leon

The treatment of pig manure is a major environmental issue, and photobioreactors containing consortia of microalgae and bacteria have proven to be a promising and sustainable treatment alternative. This work studies the effect of Cu, Zn and As, three toxic elements frequently present in piggery wastewater, on the performance and microbiome of photobioreactors. After dopage with Zn (100 mg/L), Cu (100 mg/L), and As (500 µg/L), the high biomass uptake of Zn (69–81%) and Cu (81–83%) decreased the carbon removal in the photobioreactors, inhibited the growth of Chlorella sp., and affected heterotrophic bacterial populations. The biomass As uptake result was low (19%) and actually promoted microalgae growth. The presence of Cu and As decreased nitrogen removal, reducing the abundance of denitrifying bacterial populations. The results showed that metal(loid)s significantly affected 24 bacterial genera and that they did not recover after exposure. Therefore, this study makes an important contribution on the impact of the presence of metal(loid)s in piggery wastewater that compromises the overall performance of PBRs, and so, the environmental and health impact of treated effluents., Instituto de Procesos Sostenibles, Departamento de Ingeniería Química y Tecnología del Medio Ambiente, Ministerio de Ciencia, Innovación y Universidades, Consejeria de Educacion Junta de Castilla y Leon, EU Feder Programme, National Research and Development Agency (ANID) of Chile

Scenedesmus almeriensis microalgae–bacteria consortia were evaluated for the removal of a mixture of tetracycline (TET), ciprofloxacin (CIP), and sulfadiazine (SDZ) from the real liquid fraction of pig slurry in a pilot scale photobioreactor. After 15 days of operation, the reactor was spiked with a mixture of /L of each antibiotic. The experiment ran for 20 additional days. From the liquid phase, antibiotic removal were 77 ± 5 %, 90 ± 14 %, and 60 ± 27 % for TET, CIP, and SDZ, respectively. The antibiotics found in the solid phase were 979 ± 382 ng/g for TET and 192 ± 69 ng/g for SDZ; CIP was not detected in the biomass. The parameters analyzed before and after antibiotic addition showed that the antibiotics did not have a negative effect on the reactor biomass. The removal efficiencies of the analyzed parameters were 64.6 ± 0.6 % for TOC, 56.9 ± 0.6 % for IC, 63.9 ± 0.6 % for TN, 88.6 ± 0.9 % for N-NH4+, 64.9 ± 0.6 % for N-NO3-, and 30.1 ± 0.3 % for P-PO4 3- . This study demonstrated the good performance of microalgae-based technology for swine manure wastewater treatment, not only in terms of organic matter and nutrient removal, but also regarding the removal of antibiotics. The mass balance analysis of the entire process is presented. Additionally, the present study is a validation of previous laboratory scale batch studies operating in a quasi-continuous mode on veterinary antibiotics (VA) removal efficiencies and kinetics., Instituto de Procesos Sostenibles, Departamento de Ingeniería Química y Tecnología del Medio Ambiente, Departamento de Química Analítica, Ministerio de Ciencia, Innovación y Universidades, Consejeria de Educacion Junta de Castilla y Leon, EU Feder Programme

The mechanisms involved in the removal of a mixture of four veterinary antibiotics (VA) – tetracycline (TTC), ciprofloxacin (CPF), sulfadiazine (SDZ) and sulfamethoxazole (SMX) – in synthetic wastewater using microalgae–bacteria consortia (MBC) dominated by Scenedesmus almeriensis was studied at different initial concentrations of 1000, 500, 100 and 20 g/L per antibiotic. Ultra-high performance liquid chromatography and tandem mass spectrometry (UHPLC-MS/MS) were used to determine the removal of the VA for each mechanism. For a hydraulic retention time of 4 days, the overall removal of antibiotics by the MBC was 99.9% for TTC, 78.0% for CPF, 52.6% for SDZ and 5.0% for SMX. A pseudo-first order irreversible model was applied to best fit the experimental data. The degradation constant rates were 0.136 h−1 for TTC, 0.012 h−1 for CPF, 0.010 h−1 for SDZ and 0.0007 h−1 for SMX. Under all the evaluated conditions, CPF and TTC exhibited the highest removal efficiency. Biosorption was the main mechanism for all four antibiotics, followed by biodegradation in the cases of TTC and SDZ. CPF did not show removal via biodegradation. SMX did not show removal via hydrolysis or photolysis. This study (i) integrates and evaluates individually the mechanisms involved in VA removal using an MBC; (ii) determines an overall removal rate constant for a wide array of TTC, CPF, SDZ and SMX concentrations; and (iii) demonstrates the high removal capacity and potential use of microalgae as an ecofriendly wastewater treatment process., Instituto de Procesos Sostenibles, Departamento de Ingeniería Química y Tecnología del Medio Ambiente, Departamento de Química Analítica, Ministerio de Ciencia, Innovación y Universidades, Consejeria de Educacion Junta de Castilla y Leon, EU Feder Programme, Generalitat Valenciana, Spain

The removal of a mixture of four veterinary antibiotics (VA) – tetracycline (TET), ciprofloxacin (CIP), sulfadiazine (SDZ) and sulfamethoxazole (SMX) – via photo-degradation (UVC) and photocatalysis with TiO2 (UVC/TiO2) was investigated in a batch reactor under different initial concentrations (20, 100, 500 and 1000 μg/L per antibiotic). Ultra-high performance liquid chromatography coupled to a mass spectrometry (UHPLC-MS/MS) was used to determine the removal of these veterinary antibiotics. The removal of all antibiotics via photolysis was around 98–99% after 100 h for TET, 122 h for CIP, 212 h for SDZ and 240 h for SMX. Nevertheless, the removal of all antibiotics via photocatalysis was around 99–100% after 4.2 h for TET, 3.5 h for CIP, 7.1 h for SDZ and 16.5 h for SMX. The photolysis for the four veterinary antibiotics followed a first-order irreversible kinetic model. The photocatalysis of TET, CIP and SDZ followed a Langmuir-Hinshelwood kinetic model, and adsorption was considered the limiting step. SMX followed a first-order irreversible kinetic model. The photolytic degradation rate constant (k1) was 0.00073 min−1 for TET, 0.00055 min−1 for CIP, 0.00031 min−1 for SDZ and 0.00027 min−1 for SMX. While for photocatalysis k1 was 0.0044 min−1 for SMX; kL-H was 0.0284 min−1 for TET, 0.0379 min−1 for CIP and 0.0141 min−1 for SDZ. The VA degradation was enhanced by the use of a catalyst. Additionally, electrical energy per order (EEO) was assessed to estimate the electrical energy efficiency of each process. EEO values for photolysis were 339.06 kWh/m3/order for TET, 449.84 kWh/m3/order for CIP, 795.31 kWh/m3/order for SDZ and 897.71 kWh/m3/order for SMX. On the other hand, EEO values for photocatalysis were 14.96 kWh/m3/order for TET, 12.07 kWh/m3/order for CIP, 20.39 kWh/m3/order for SDZ and 62.10 kWh/m3/order for SMX. The energy consumption for photocatalysis was considerably lower than for photolysis. This study determined an overall degradation rate constant for a wide range of TET, CIP, SDZ and SMX concentrations. Furthermore, when working with a pH of 8 (a typical pH from wastewater from livestock farms) and a VA mixture whose concentrations resemble the characteristics of real water samples, that photolysis and photocatalysis are potential processes for wastewater treatment with low energy consumption., Instituto de Procesos Sostenibles, Departamento de Ingeniería Química y Tecnología del Medio Ambiente, Departamento de Química Analítica, Ministerio de Ciencia, Innovación y Universidades MICIU/AEI/ 10.13039/501100011033, Consejería de Educación de la Junta de Castilla y León, EU Feder Programme

Despite the interest in the utilization of photobioreactors as an alternative wastewater treatment, the research about posterior recovery and valorization of nutrients accumulated in the biomass is still limited. This work compared several hydrolysis methods for the recovery of proteins and carbohydrates from the biomass grown in a photobioreactor treating swine wastewater. Ultrasound-assisted and microwave-assisted enzymatic hydrolysis at mild conditions and chemical methods at different temperatures (40, 60, 120ºC) were applied to the microalgae and bacteria biomass. Alkaline hydrolysis provided the greatest peptide recoveries, increasing with temperature up to a maximum of 81%, but with very small peptide sizes in all temperature range. Acid hydrolysis provided the highest carbohydrate recoveries (60.7% at 120ºC) but degraded proteins, even at mild temperatures. Protein degradation did not vary with temperature in each chemical hydrolysis, obtaining similar peptide sizes in all temperatures, while carbohydrate losses were higher at lower temperatures. Ultrasound-assisted enzymatic extraction recovered 43.6% of the initial proteins as large peptides (up to 135 kDa) with the highest peptide purity (46.7%). Microwave-assistance increased the carbohydrate solubilization of enzymatic hydrolysis, achieving yields of 73% of xylose, but with significant losses., Instituto de Procesos Sostenibles, Departamento de Ingeniería Química y Tecnología del Medio Ambiente, Ministerio de Ciencia, Innovación y Universidades, Consejeria de Educacion Junta de Castilla y Leon

The intensification of livestock activities lead to an increase in waste generation with high content of nutrients, as is the case of piggery wastewater. However, this type of residue can be used as culture media for algae cultivation in thin-layer cascade photobioreactors to reduce its environment impact and produce a valorizable algal biomass. Biostimulants were produced by enzymatic hydrolysis and ultrasonication of microalgal biomass, using membranes (Scenario 1) or centrifugation (Scenario 2) as harvesting methods. The co-production of biopesticides by solvent extraction was also evaluated using membranes (Scenario 3) or centrifugation (Scenario 4). The four scenarios were analyzed by a technoeconomic assessment estimating the total annualized equivalent cost and the production cost, i.e., the minimum selling price. Centrifugation provided biostimulants approximately 4 times more concentrated than membranes, but with higher expense due to the cost of the centrifuge (contribution of 62.2 % in scenario 2) and the electricity requirements. The biopesticide production resulted the highest contribution to investment cost in scenarios 3 and 4 (34 % and 43 % respectively). The use of membranes was also more advantageous to produce biopesticides, although it was 5 times more diluted than using centrifuge. The biostimulant production cost was 65.5 €/m3 with membranes and 342.6 €/m3 by centrifugation and the biopesticide production cost was 353.7 €/m3 in scenario 3 and 2,122.1 €/m3 in scenario 4. Comparing the treatment of 1 ha of land, the cost of the biostimulant produced in the four scenarios was lower than the commercial one (48.1 %, 22.1 %, 45.1 % and 24.2 % respectively). Finally, using membranes for biomass harvesting allowed economically viable plants with lower capacity and longer distance for biostimulant distribution (up to 300 km) than centrifuge (188 km). The algal biomass valorization for agricultural products production is an environmentally and economically feasible process with the adequate capacity of the plant and distribution distance., Instituto de Procesos Sostenibles, Departamento de Ingeniería Química. Universidad de Almeria, Departamento de Ingeniería Química y Tecnología del Medio Ambiente, Ministerio de Ciencia, Innovación y Universidades, Consejeria de Educacion Junta de Castilla y Leon

Piggery wastewater has become a large source of pollution with high concentrations of nutrients, that must be managed and properly treated to increase its environmental viability. Currently, the use of microalgae for treating this type of wastewater has emerged as a sustainable process with several benefits, including nutrient recovery to produce valuable products such as biostimulants, and CO2 capture from flue gases. However, the biostimulant production from biomass grown on piggery wastewater also has environmental impacts that need to be studied to identify possible hotspots. This work presents the life cycle assessment by IMPACT 2002+ method of the production of microalgae-based biostimulants, comparing two different harvesting technologies (membrane in scenario 1 and centrifuge in scenario 2) and two different technologies for on-site CO2 capture from flue gases (chemical absorption and membrane separation). The use of membranes for harvesting (scenario 1) reduced the environmental impact in all categories (human health, ecosystem quality, climate change, and resources) by 30 % on average, compared to centrifuge (scenario 2). Also, membranes for CO2 capture allowed to decrease environmental impacts by 16 %, with the largest reduction in the resource category (∼33 %). Thus, the process with the best environmental viability was achieved in scenario 1 using membranes for CO2 capture, with a value of 217 kg CO2 eq/FU. In scenario 2 with centrifugation, the high contribution of the cultivation sub-unit in all impacts was highlighted (>75 %), while in scenario 1 the production sub-unit also had moderate contribution in the human health (∼35 %) and climate change (∼30 %) categories due to the lower concentration and high flow rates. These results were obtained under a worst-case situation with pilot scale optimized parameters, with limited data which would have to be further optimized at industrial-scale implementation. The sensitivity analysis showed a little influence of the parameters that contribute the most to the impacts, except for the transportation of the piggery wastewater to the processing plant in scenario 2. Because of the relevant impact of biostimulant transportation in scenario 1, centrifugation becomes more favourable when transportation distance is longer than 321 km., Instituto de Procesos Sostenibles, Departamento de Ingeniería Química y Tecnología del Medio Ambiente, Department of Civil and Environmental Engineering, Politecnico di Milano, Department of Chemistry, Materials and Chemical Engineering, “Giulio Natta”, Politecnico di Milano, Ministerio de Ciencia, Innovación y Universidades, EU Feder Programme, Consejeria de Educacion Junta de Castilla y Leon

Photobioreactors are a promising alternative for piggery wastewater treatment which allows to produce valuable biomass, but the presence of antibiotics or heavy metals in the pig manure can influence the biomass composition and the posterior valorization processes. This study evaluates the effect of these pollutants on mass, composition and hydrolysis yields of the consortia of microalgae and bacteria obtained in a 1280 L photobioreactor treating pig manure. The photobioreactor feed was doped with 1) veterinary antibiotics; 2) copper, zinc, and arsenic; and 3) combination of both pollutants. The pollutants presence decreased the mass of biomass grown in the photobioreactor by up to 35% while glucose content of the biomass by up to 42% and increased protein and xylose by 30% and 16% due to oxidative stress. Likewise, they increased the protein solubilization yield by acid hydrolysis at 120 ºC by 32% while reduced glucose solubilization by 49% after alkaline hydrolysis at 120 ºC. Applying enzymatic hydrolysis and ultrasound assisted enzymatic extractions, glucose and xylose recoveries were drastically reduced in presence of heavy metals (∼100%). Antibiotics increased xylose solubilization by ultrasonication (74%), but also its degradation, decreasing xylose recovery. Thus, the presence of all these pollutants in pig manure affected biomass production and valorization and these results must be considered for biorefinery processes., Instituto de Procesos Sostenibles, Departamento de Ingeniería Química y Tecnología del Medio Ambiente, Departamento de Ingeniería Química. Universidad de Almeria, Ministerio de Ciencia, Innovación y Universidades, Consejeria de Educacion Junta de Castilla y Leon, EU-Next Generation

The performance of a pilot-scale thin-layer cascade photobioreactor, operated in semicontinuous mode, for the removal of veterinary drug residues and other contaminants of emerging concern (CECs) from pig manure has been assessed in six operation stages. Chlorella sp. (70–90%), Scenedesmus sp. (10–25%) and Diatomea (<5%) comprise the microalgae species present during the stages. The global performance to remove the total CEC content in the photobioreactor effluent varied from 62 to 86% on each stage, while an CEC mean amount close to 8% was accumulated in the photobioreactor biomass. A relation with weather conditions was not observed. Elimination ratio was not related to the concentration in the influent which reached up to 8000 ng L−1 for some CECs. As expected, the concentrations of veterinary drugs were higher than those of non-veterinary CECs. The concentrations accumulated in the grown biomass were relative low, lower than 10 ng per fresh g excepting for a few cases. However, statistical data suggested that the linkage of CECs to microalgae biomass boosted their removal from the influent. Furthermore, it was observed that the manure liquid phase contained higher amounts of CECs than the solid phase., Instituto de Procesos Sostenibles, Departamento de Ingeniería Química y Tecnología del Medio Ambiente, Departamento de Química Analítica, Ministerio de Ciencia, Innovación y Universidades, Consejeria de Educacion Junta de Castilla y Leon, EU Feder Programme, EU-Next Generation