Borja Valverde Pérez | Technical University of Denmark (DTU) (original) (raw)

Papers by Borja Valverde Pérez

Resources, Conservation and Recycling

Renewable and Sustainable Energy Reviews

 Users may download and print one copy of any publication from the public portal for the purpose... more  Users may download and print one copy of any publication from the public portal for the purpose of private study or research.  You may not further distribute the material or use it for any profit-making activity or commercial gain  You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

In a novel approach, we use life cycle assessment (LCA) to support early stage research and devel... more In a novel approach, we use life cycle assessment (LCA) to support early stage research and development of a biochemical system for wastewater resource recovery (TRENS system, (12). To this end, we combined the use of conventional activated sludge models (ASM-2d, (8); ASM-A, (12)) with environmental assessment models (EASETECH, (2)). The chosen scenario in the LCA study considers TRENS as a side-stream process implemented in a full-scale wastewater treatment plant (WWTP) in Copenhagen, Denmark. TRENS reduces global warming up to 15% and marine eutrophication impacts up to 9% compared to conventional treatment. This is due to the TRENS system’s lower greenhouse gas emissions, as well as nutrient recovery. The key environmental concerns obtained through the LCA are linked to increased human toxicity impacts from the chosen end use of TRENS products. The toxicity impacts are from heavy metals release associated with land application of recovered wastewater nutrients. Our study provided...

The Indian Wells Valley Water District (IWVWD) is situated just east of the southern Sierra Nevad... more The Indian Wells Valley Water District (IWVWD) is situated just east of the southern Sierra Nevada and relies exclusively on groundwater for all water supply needs. Groundwater levels have been steadily declining since at least the 1950s and the area is now categorized as one of 21 "Critically Overdrafted Basins" within the state of California. The Indian Wells Valley groundwater basin (IWV) is located at the southeastern corner of the Sierra Nevada Range in the northern portion of the Mojave Desert. This province is characterized by numerous northwest trending faults, dominated by alluvial sediments and playas. The basin water demand is approaching 31mio m 3 /yr with an annual sustainable yield estimated at 9m m3/yr, meaning that there will be significant effort required to bring the basin into balance as required under the Sustainable Groundwater Management Act (SGMA). To meet SGMA mandates, local agencies have found that desalination of brackish groundwater can potentially be affordable and is an attractive component in reaching sustainability. A unique part of the desalination plan is the fact that the two private companies, Coso Geothermal and Searles Valley Minerals can make use of the brine and the fact that the groundwater is brackish and not saline sea water makes desalination economical feasible. An important part in the desalination study has been to locate brackish water as a resource for desalination. Even though the groundwater basin has undergone numerous investigations over the years we have found that there is a need for further investigations and a compilation of all the data as basis for the development of a Hydrogeological Conceptual Model (HCM).

Nitrous oxide (N2O) is a strong greenhouse gas (GHG) and ozone depleter, with a warming potential... more Nitrous oxide (N2O) is a strong greenhouse gas (GHG) and ozone depleter, with a warming potential 300 times higher than carbon dioxide (CO2). 1.2% of the total antrophopogenic N2O emissions are believed to originate from the wastewater treatment (WWT) sector. Conventional biological nutrient removal processes relying on nitrification and denitrification are known to produce N2O. A one year long-term study of N2O production and emissions was performed at Lynetten, Denmark’s largest WWTP. Nitrification and denitrification takes place by alternating process conditions as well as influent and effluent flows in 20 pairs of interconnected and surface aerated reactors. The long-term data revealed that the N2O emissions contribute to as much as 30% of the total CO2 footprint from the WWTP. High ammonium concentrations and long aeration phases lead to high N2O production and emissions rates. Nitrification phases were identified to produce and emit most of the N2O. High production and emissio...

In the later years, significant focus has been placed on spin-outs and commercialization of resea... more In the later years, significant focus has been placed on spin-outs and commercialization of research from the universities. Working in this tension field between high-level research and commercialization can be difficult and to be successful many barriers at the universities and in the commercial world has to be crossed, while balancing expectations from both worlds. Our background is a large research group working with geophysical methods for high-resolution characterization of the shallow subsurface where most of the human activities take place. Like CRT scanners provide insight into the hidden parts of the human body in the medical world we provide electromagnetic scans of the hidden underground. This information is used in different areas like farming, construction, water exploration etc. We are in many ways very successful and run a research group of about 20 people all driven by various sources of external funding. In this presentation, we discuss barriers between the research...

10th International Conference on Biofilm Reactors, 9th - 12th May 2017, University College Dublin... more 10th International Conference on Biofilm Reactors, 9th - 12th May 2017, University College Dublin, Ireland

General information Publication status: Published Organisations: Water Technologies, Department o... more General information Publication status: Published Organisations: Water Technologies, Department of Environmental Engineering, Residual Resource Engineering, Technical University of Denmark, Sharif University of Technology, Shahid Beheshti University of Medical Sciences Contributors: Ghofrani Isfahani, P., Valverde Pérez, B., Alvarado-Morales, M., Mohammadifar, M. A., Vossoughi, M., Angelidaki, I. Number of pages: 1 Publication date: 2018

Sustainability, 2018

Algal cultivation has been proposed as a means to produce biofuels. However, the sustainability o... more Algal cultivation has been proposed as a means to produce biofuels. However, the sustainability of algal biorefineries is compromised if microalgae are not cultivated on used water resources. Pending on the end product to be accumulated in algal biomass (e.g., lipids or pigments), cultivation conditions should be optimized. Nevertheless, online monitoring tools used in algal reactors are limited and mostly tested in systems using synthetic media. In this work we present a UV-Vis sensor, conventionally used to monitor municipal wastewater treatment plants, as a means to monitor algal cultivation. Different models have been successfully applied to estimate nitrate, total biomass and pigment concentration using the spectra collected by the sensor.

and it is a condition of accessing publications that users recognise and abide by the legal requi... more and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

Recent research focuses on the development of cost-effective ways to recover nutrients, energy an... more Recent research focuses on the development of cost-effective ways to recover nutrients, energy and fresh water from wastewater. Microalgal photobioreactors (PBRs) coupled with wastewater treatment processes offer an opportunity for efficient resource recovery. Several models with different complexities have been developed to simulate microalgal growth. However, none of these models can effectively describe all the relevant processes when microalgal growth is coupled to nutrient removal and recovery from wastewaters. We present a novel consensus model (ASM-A) developed in the activated sludge modelling (ASM) framework to predict photoautotrophic growth, nutrient uptake and storage, as well as heterotrophic microalgal growth, and decay of mixed green microalgae. A two-step model evaluation was carried out using independent data obtained in a 24-L sequenced batch PBR. Three hypothesis were answered comprising (I) Does culture history or substrate availability influence parameter values...

resources DTU Orbit (31/12/2018) Modelling of green microalgal growth and algal storage processes... more resources DTU Orbit (31/12/2018) Modelling of green microalgal growth and algal storage processes using wastewater resources Recent research focuses on the recovery of nutrients, water and energy from wastewater. Microalgal cultivation on wastewater resources is considered as a more sustainable means to produce fertilizers or biofuels. Innovative systems that incorporate microalgal cultivation into conventional wastewater processes have been developed. The effective design, optimisation and control of these systems require modelling tools that can readily extend existing benchmark models with new sub-models. Several process models have been developed to simulate algal growth. Some models include only one variable, e.g., light, whereas others include multiple variables, such as pH, nitrogen, phosphorus and organic carbon. This chapter aims to collect and describe green microalgal process models that can be used in wastewater resource recovery systems together with their limitations. ...

Two of the key questions regarding secondary settling are (a) Does a process model exist for whic... more Two of the key questions regarding secondary settling are (a) Does a process model exist for which all hindered and compression settling velocity parameters can be estimated using experimental data?; (b) What is the minimum data that need be inferred, from a settling sensor setup to identify process models?” This international research effort aimed to address these questions by carrying out a comprehensive practical identifiability assessment of constitutive functions for hindered and compression settling velocity using laboratory-scale measurements and one-dimensional (1-D) simulation models. For model validation, the triangulation technique was used, including independent laboratoryand full-scale measurements as well as 1-D and computational fluid dynamics (CFD) simulation models.

Resources, Conservation and Recycling

Renewable and Sustainable Energy Reviews

Sustainability, 2018