Ivet Ferrer | Universitat Politecnica de Catalunya (original) (raw)

Papers by Ivet Ferrer

Research paper thumbnail of The use of magnetic iron oxide based nanoparticles to improve microalgae harvesting in real wastewater

Research paper thumbnail of Selenium recovery from wastewater by the green microalgae Chlorella vulgaris and Scenedesmus sp

Science of The Total Environment

Research paper thumbnail of Assessment of Selenium and Zinc Enriched Sludge and Duckweed as Slow-Release Micronutrient Biofertilizers for Phaseolus Vulgaris Growth

Research paper thumbnail of Valorization of selenium-enriched sludge and duckweed generated from wastewater as micronutrient biofertilizer

Chemosphere, 2021

Selenium (Se) is an essential trace element for humans and animals with a narrow window between d... more Selenium (Se) is an essential trace element for humans and animals with a narrow window between deficiency and toxicity levels. Application of conventional chemical Se fertilizers to increase the Se content of crops in Se deficient areas could result in environmental contamination due to the fast leaching of inorganic Se. Slow-release Se-enriched biofertilizers produced from wastewater treatment may therefore be beneficial. In this study, the potential of Se-enriched biomaterials (sludge and duckweed) as slow-release Se biofertilizers was evaluated through pot experiments with and without planted green beans (Phaseolus vulgaris). The Se concentration in the bean tissues was 1.1-3.1 times higher when soils were amended with Se-enriched sludge as compared to Se-enriched duckweed. The results proved that the Se released from Se-enriched biomaterials was efficiently transformed to health-beneficial selenoamino acids (e.g., Se-methionine, 76-89%) after being taken up by beans. The Se-enriched sludge, containing mainly elemental Se, is considered as the preferred slow-release Se biofertilizer and an effective Se source to produce Se-enriched crops for Se-deficient populations, as shown by the higher Se bioavailability and lower organic carbon content. This study could offer a theoretical reference to choose an environmental-friendly and sustainable alternative to conventional mineral Se fertilizers for biofortification, avoiding the problem of Se losses by leaching from chemical Se fertilizers while recovering resources from wastewater. This could contribute to the driver for a future circular economy.

Research paper thumbnail of The use of solar pre-treatment as a strategy to improve the anaerobic biodegradability of microalgal biomass in co-digestion with sewage

Chemosphere, 2022

Sustainable sewage treatment plants (STPs) have been intensively investigated in search for low-c... more Sustainable sewage treatment plants (STPs) have been intensively investigated in search for low-cost, environmental-friendly options. Anaerobic-aerobic treatment solutions, as upflow anaerobic sludge blanket (UASB) reactors followed by high rate algal ponds (HRAP) have already proved to be efficient for pollutants and micropollutants removal, as well as for energy recovery from the co-digestion of raw sewage and microalgal biomass. Since microalgae cells have complex structures that make them resistant to anaerobic digestion, pre-treatment techniques may be applied to improve microalgal biomass solubilisation and methane yield. Among the thermal pre-treatments, the use of solar energy for biomass solubilisation has yet to be investigated. Therefore, this study aimed at evaluating the performance of a solar thermal microalgal biomass pre-treatment prior to the anaerobic co-digestion with raw sewage, comparing a UASB reactor feed only raw sewage and other UASB reactor feed with raw sewage and pre-treated microalgal biomass. The results showed that, the solar pre-treatment step reached an organic matter solubilisation of 32% (COD). Furthermore, the methane yield was increased by 45% (from 81 to 117 NL CH4 kg-1 COD), after the anaerobic co-digestion with pre-treated microalgae as compared to the mono-digestion of raw sewage, indicating significant difference between the evaluated UASB reactors. The energy assessment showed a positive energy balance, as the total energy produced was twice the energy consumed in the system.

Research paper thumbnail of Co-digestion strategies to enhance microalgae anaerobic digestion: A review

Renewable and Sustainable Energy Reviews, 2019

Research paper thumbnail of Benefits and risks of agricultural reuse of digestates from plastic tubular digesters in Colombia

Waste Management, 2021

The aim of this study is to characterize the digestates from three plastic tubular digesters impl... more The aim of this study is to characterize the digestates from three plastic tubular digesters implemented in Colombia fed with: i) cattle manure; ii) cattle manure mixed with cheese whey; iii) pig manure. All the digesters worked under psychrophilic conditions. Physico-chemical characteristics, heavy metals, pathogens, and agronomic quality were investigated. All the digestates were characterized by physico-chemical characteristics and nutrients concentration suitable for their reuse as biofertilizer. However, these digestates may only partially replace a mineral fertilizer due to the high nutrients dilution. Heavy metals were under the detection limit of the analytical method (Pb, Hg, Ni, Mo, Cd, Chromium VI) or present at low concentration (Cu, Zn, As, Se) in all the digestates. Biodegradable organic matter and pathogens (coliform, helminths and Salmonella spp.) analysis proved that all the digestates should be post-treated before soil application in order to prevent environmental and health risks, and also to reduce residual phytotoxicity effects. The digestate from pig manure had a higher nutrient percentage (0.2, 0.6 and 0.05 % w/w of total N, P2O5 and K2O, respectively), but also higher residual phytotoxicity than the other digestates. Co-digestion seemed not to significantly improve the digestate fertilizing potential. Finally, further studies should address how to improve fertilizing potential of digestates from plastic tubular digesters, avoiding environmental and health risks.

Research paper thumbnail of Exploration of Se-rich bioproducts generated from (waste)water as fertilizers

Research paper thumbnail of Production of selenium-enriched microalgae as potential feed supplement in high-rate algae ponds treating domestic wastewater

Bioresource Technology, 2021

This study assessed the selenium (Se) removal efficiency of two pilot-scale high-rate algae ponds... more This study assessed the selenium (Se) removal efficiency of two pilot-scale high-rate algae ponds (HRAPs) treating domestic wastewater and investigated the production of Se-enriched microalgae as potential feed supplement. The HRAP-Se had an average Se, NH4+-N, total phosphorus and COD removal efficiency of, respectively, 43%, 93%, 77%, and 70%. Inorganic Se taken up by the microalgae was mainly (91%) transformed to selenoamino acids, and 49-63% of Se in the Se-enriched microalgae was bioaccessible for animals. The crude protein content (48%) of the microalgae was higher than that of soybeans, whereas the essential amino acid content was comparable. Selenium may induce the production of the polyunsaturated fatty acids omega-3 and omega-6 in microalgae. Overall, the production of Se-enriched microalgae in HRAPs may offer a promising alternative for upgrading low-value resources into high-value feed supplements, supporting the drive to a circular economy.

Research paper thumbnail of Life cycle assessment of drinking water: Comparing conventional water treatment, reverse osmosis and mineral water in glass and plastic bottles

Journal of Cleaner Production, 2016

Research paper thumbnail of Artículo original de investigación Treatment of piggery wastewater in experimental high rate algal ponds

The objective of this work was to evaluate the efficiency of high rate algal ponds (HRAP) for the... more The objective of this work was to evaluate the efficiency of high rate algal ponds (HRAP) for the treatment of piggery wastewater pretreated with an electroflocculation system. Experiments were conducted in two experimental raceway ponds with a surface area of 1.54 m 2 and a water depth of 0.26 m. The efficiency of both ponds was compared as a function of the surface organic loading rate and ammonia loading rate. Pretreated piggery wastewater had average COD and ammonia concentrations of 3000 mgO2/L and 790 mgNH4 + -N/L, respectively. The COD removal was 90 % with an organic loading equal to or below 20 g O2/m 2 d. The ammonia removal was 90 % with an ammonia load of 2.5 gNH4 + N/m 2 d, however it decreased throughout the experiments when ammonia accumulated in the mixed liquor. Simultaneous COD and ammonia removal was limited by ammonia removal. From a mass balance it was determined that the main pathway for ammonia removal was nitrification.

Research paper thumbnail of Use of full-scale hybrid horizontal tubular photobioreactors to process agricultural runoff

Biosystems Engineering, 2018

Research paper thumbnail of Microalgae recycling improves biomass recovery from wastewater treatment high rate algal ponds

Research paper thumbnail of Recent Achievements in the Production of Biogas from Microalgae

Waste and Biomass Valorization, 2016

Research paper thumbnail of Evaluación energética de la digestión anaerobia termofílica con pre-tratamiento térmico de los fangos a 70 ºC

Research paper thumbnail of Optimization of the hydrolytic-acidogenic anaerobic digestion stage (55 °C) of sewage sludge: Influence of pH and solid content

Research paper thumbnail of Properties of biosolids from sludge treatment wetlands for land application

Research paper thumbnail of Long term operation of a thermophilic anaerobic reactor: Process stability and efficiency at decreasing sludge retention time

Bioresource Technology, 2010

Research paper thumbnail of Increasing biogas production by thermal (70°C) sludge pre-treatment prior to thermophilic anaerobic digestion

Biochemical Engineering Journal, 2008

Research paper thumbnail of Enhancement of thermophilic anaerobic sludge digestion by 70 C pre-treatment: energy considerations

ABSTRACT The objective of this work was to investigate the effect of a low temperature pre-treatm... more ABSTRACT The objective of this work was to investigate the effect of a low temperature pre-treatment (70°C) on the thermophilic anaerobic digestion of sewage sludge. Experimental results were used for the calculation of theoretical energy balances of full-scale digesterswith and without pre-treatment step. The 70°C sludge pre-treatment increased sludge solubilization by 10 times and enhanced volatile fatty acids generation. Biogas production increased up to 30-40% and methane content in biogas from 64 to 68-70%. Theoretical calculations showed that additional surplus energy production would be expected by incorporating a 70°C pre-treatment step to a thermophilic reactor.

Research paper thumbnail of The use of magnetic iron oxide based nanoparticles to improve microalgae harvesting in real wastewater

Research paper thumbnail of Selenium recovery from wastewater by the green microalgae Chlorella vulgaris and Scenedesmus sp

Science of The Total Environment

Research paper thumbnail of Assessment of Selenium and Zinc Enriched Sludge and Duckweed as Slow-Release Micronutrient Biofertilizers for Phaseolus Vulgaris Growth

Research paper thumbnail of Valorization of selenium-enriched sludge and duckweed generated from wastewater as micronutrient biofertilizer

Chemosphere, 2021

Selenium (Se) is an essential trace element for humans and animals with a narrow window between d... more Selenium (Se) is an essential trace element for humans and animals with a narrow window between deficiency and toxicity levels. Application of conventional chemical Se fertilizers to increase the Se content of crops in Se deficient areas could result in environmental contamination due to the fast leaching of inorganic Se. Slow-release Se-enriched biofertilizers produced from wastewater treatment may therefore be beneficial. In this study, the potential of Se-enriched biomaterials (sludge and duckweed) as slow-release Se biofertilizers was evaluated through pot experiments with and without planted green beans (Phaseolus vulgaris). The Se concentration in the bean tissues was 1.1-3.1 times higher when soils were amended with Se-enriched sludge as compared to Se-enriched duckweed. The results proved that the Se released from Se-enriched biomaterials was efficiently transformed to health-beneficial selenoamino acids (e.g., Se-methionine, 76-89%) after being taken up by beans. The Se-enriched sludge, containing mainly elemental Se, is considered as the preferred slow-release Se biofertilizer and an effective Se source to produce Se-enriched crops for Se-deficient populations, as shown by the higher Se bioavailability and lower organic carbon content. This study could offer a theoretical reference to choose an environmental-friendly and sustainable alternative to conventional mineral Se fertilizers for biofortification, avoiding the problem of Se losses by leaching from chemical Se fertilizers while recovering resources from wastewater. This could contribute to the driver for a future circular economy.

Research paper thumbnail of The use of solar pre-treatment as a strategy to improve the anaerobic biodegradability of microalgal biomass in co-digestion with sewage

Chemosphere, 2022

Sustainable sewage treatment plants (STPs) have been intensively investigated in search for low-c... more Sustainable sewage treatment plants (STPs) have been intensively investigated in search for low-cost, environmental-friendly options. Anaerobic-aerobic treatment solutions, as upflow anaerobic sludge blanket (UASB) reactors followed by high rate algal ponds (HRAP) have already proved to be efficient for pollutants and micropollutants removal, as well as for energy recovery from the co-digestion of raw sewage and microalgal biomass. Since microalgae cells have complex structures that make them resistant to anaerobic digestion, pre-treatment techniques may be applied to improve microalgal biomass solubilisation and methane yield. Among the thermal pre-treatments, the use of solar energy for biomass solubilisation has yet to be investigated. Therefore, this study aimed at evaluating the performance of a solar thermal microalgal biomass pre-treatment prior to the anaerobic co-digestion with raw sewage, comparing a UASB reactor feed only raw sewage and other UASB reactor feed with raw sewage and pre-treated microalgal biomass. The results showed that, the solar pre-treatment step reached an organic matter solubilisation of 32% (COD). Furthermore, the methane yield was increased by 45% (from 81 to 117 NL CH4 kg-1 COD), after the anaerobic co-digestion with pre-treated microalgae as compared to the mono-digestion of raw sewage, indicating significant difference between the evaluated UASB reactors. The energy assessment showed a positive energy balance, as the total energy produced was twice the energy consumed in the system.

Research paper thumbnail of Co-digestion strategies to enhance microalgae anaerobic digestion: A review

Renewable and Sustainable Energy Reviews, 2019

Research paper thumbnail of Benefits and risks of agricultural reuse of digestates from plastic tubular digesters in Colombia

Waste Management, 2021

The aim of this study is to characterize the digestates from three plastic tubular digesters impl... more The aim of this study is to characterize the digestates from three plastic tubular digesters implemented in Colombia fed with: i) cattle manure; ii) cattle manure mixed with cheese whey; iii) pig manure. All the digesters worked under psychrophilic conditions. Physico-chemical characteristics, heavy metals, pathogens, and agronomic quality were investigated. All the digestates were characterized by physico-chemical characteristics and nutrients concentration suitable for their reuse as biofertilizer. However, these digestates may only partially replace a mineral fertilizer due to the high nutrients dilution. Heavy metals were under the detection limit of the analytical method (Pb, Hg, Ni, Mo, Cd, Chromium VI) or present at low concentration (Cu, Zn, As, Se) in all the digestates. Biodegradable organic matter and pathogens (coliform, helminths and Salmonella spp.) analysis proved that all the digestates should be post-treated before soil application in order to prevent environmental and health risks, and also to reduce residual phytotoxicity effects. The digestate from pig manure had a higher nutrient percentage (0.2, 0.6 and 0.05 % w/w of total N, P2O5 and K2O, respectively), but also higher residual phytotoxicity than the other digestates. Co-digestion seemed not to significantly improve the digestate fertilizing potential. Finally, further studies should address how to improve fertilizing potential of digestates from plastic tubular digesters, avoiding environmental and health risks.

Research paper thumbnail of Exploration of Se-rich bioproducts generated from (waste)water as fertilizers

Research paper thumbnail of Production of selenium-enriched microalgae as potential feed supplement in high-rate algae ponds treating domestic wastewater

Bioresource Technology, 2021

This study assessed the selenium (Se) removal efficiency of two pilot-scale high-rate algae ponds... more This study assessed the selenium (Se) removal efficiency of two pilot-scale high-rate algae ponds (HRAPs) treating domestic wastewater and investigated the production of Se-enriched microalgae as potential feed supplement. The HRAP-Se had an average Se, NH4+-N, total phosphorus and COD removal efficiency of, respectively, 43%, 93%, 77%, and 70%. Inorganic Se taken up by the microalgae was mainly (91%) transformed to selenoamino acids, and 49-63% of Se in the Se-enriched microalgae was bioaccessible for animals. The crude protein content (48%) of the microalgae was higher than that of soybeans, whereas the essential amino acid content was comparable. Selenium may induce the production of the polyunsaturated fatty acids omega-3 and omega-6 in microalgae. Overall, the production of Se-enriched microalgae in HRAPs may offer a promising alternative for upgrading low-value resources into high-value feed supplements, supporting the drive to a circular economy.

Research paper thumbnail of Life cycle assessment of drinking water: Comparing conventional water treatment, reverse osmosis and mineral water in glass and plastic bottles

Journal of Cleaner Production, 2016

Research paper thumbnail of Artículo original de investigación Treatment of piggery wastewater in experimental high rate algal ponds

The objective of this work was to evaluate the efficiency of high rate algal ponds (HRAP) for the... more The objective of this work was to evaluate the efficiency of high rate algal ponds (HRAP) for the treatment of piggery wastewater pretreated with an electroflocculation system. Experiments were conducted in two experimental raceway ponds with a surface area of 1.54 m 2 and a water depth of 0.26 m. The efficiency of both ponds was compared as a function of the surface organic loading rate and ammonia loading rate. Pretreated piggery wastewater had average COD and ammonia concentrations of 3000 mgO2/L and 790 mgNH4 + -N/L, respectively. The COD removal was 90 % with an organic loading equal to or below 20 g O2/m 2 d. The ammonia removal was 90 % with an ammonia load of 2.5 gNH4 + N/m 2 d, however it decreased throughout the experiments when ammonia accumulated in the mixed liquor. Simultaneous COD and ammonia removal was limited by ammonia removal. From a mass balance it was determined that the main pathway for ammonia removal was nitrification.

Research paper thumbnail of Use of full-scale hybrid horizontal tubular photobioreactors to process agricultural runoff

Biosystems Engineering, 2018

Research paper thumbnail of Microalgae recycling improves biomass recovery from wastewater treatment high rate algal ponds

Research paper thumbnail of Recent Achievements in the Production of Biogas from Microalgae

Waste and Biomass Valorization, 2016

Research paper thumbnail of Evaluación energética de la digestión anaerobia termofílica con pre-tratamiento térmico de los fangos a 70 ºC

Research paper thumbnail of Optimization of the hydrolytic-acidogenic anaerobic digestion stage (55 °C) of sewage sludge: Influence of pH and solid content

Research paper thumbnail of Properties of biosolids from sludge treatment wetlands for land application

Research paper thumbnail of Long term operation of a thermophilic anaerobic reactor: Process stability and efficiency at decreasing sludge retention time

Bioresource Technology, 2010

Research paper thumbnail of Increasing biogas production by thermal (70°C) sludge pre-treatment prior to thermophilic anaerobic digestion

Biochemical Engineering Journal, 2008

Research paper thumbnail of Enhancement of thermophilic anaerobic sludge digestion by 70 C pre-treatment: energy considerations

ABSTRACT The objective of this work was to investigate the effect of a low temperature pre-treatm... more ABSTRACT The objective of this work was to investigate the effect of a low temperature pre-treatment (70°C) on the thermophilic anaerobic digestion of sewage sludge. Experimental results were used for the calculation of theoretical energy balances of full-scale digesterswith and without pre-treatment step. The 70°C sludge pre-treatment increased sludge solubilization by 10 times and enhanced volatile fatty acids generation. Biogas production increased up to 30-40% and methane content in biogas from 64 to 68-70%. Theoretical calculations showed that additional surplus energy production would be expected by incorporating a 70°C pre-treatment step to a thermophilic reactor.