Publications by authors named "Edgar Martin Hernandez"

Despite advances in anaerobic digestion (AD), full-scale implementation faces significant challenges, particularly during the start-up phase, where inoculum selection is crucial. This study examines the impact of inoculum choice on the operational and economic performance of thermophilic digesters during the start-up phase. Methanogenic reactors R3 and R4 were inoculated with digested sludge (DiS) and diluted sewage sludge (DSS), respectively, and fed with hydrolyzed source-sorted organic fraction of municipal solid waste (SS-OFMSW) and thickened sewage sludge, which were processed in R1 and R2, serving as acidogenic reactors.

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Article Synopsis
  • The study explores two nutrient recovery processes from urine: a centralized method using thermal NH stripping, Na-chabazite adsorption, and struvite precipitation, and a decentralized method that combines Na-chabazite and biochar adsorption, followed by urea hydrolysis.
  • It evaluates the technical and financial aspects of both methods over a 30-year period, revealing that the decentralized approach achieves higher nutrient recovery rates and has lower initial investment costs, leading to better profits and a break-even point by year 21.
  • Additionally, both methods could help mitigate contaminant load in wastewater treatment and promote sustainable nutrient recycling, with potential economic benefits from increased urine flow and biochar prices.
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The application of sewage sludge to agricultural land is facing increasing restrictions due to concerns about various micropollutants, including polycyclic aromatic hydrocarbons (PAHs), dioxins and furans (PCDD/Fs), polychlorinated biphenyls (PCBs), per- and poly-fluoroalkyl substances (PFAS), and heavy metals (HMs). As an alternative approach to manage this residue, the use of pyrolysis, a process that transforms sludge into biochar, a carbon-rich solid material, is being explored. Despite the potential benefits of pyrolysis, there is limited data on its effectiveness in removing micropollutants and the potential presence of harmful elements in the resulting biochar.

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Biochar obtained from sewage sludge serves as a valuable soil amendment in agriculture, enhancing soil properties by increasing the nutrient content, cation exchange capacity, water retention, and oxygen transmission. However, its utilisation is hampered by the presence of micropollutants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and volatile organic compounds (VOCs). Previous studies indicate that the type and amount of micropollutants can be significantly adjusted by selecting the right process parameters.

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Article Synopsis
  • * The study conducts a techno-economic assessment of various nitrogen recovery techniques from livestock waste, analyzing efficiency, costs, and environmental impacts.
  • * Results indicate that the transmembrane chemisorption process is the cheapest option for nitrogen recovery, costing between 3.4-10.4 USD per kilogram, while the economic losses from uncontrolled nitrogen release are much higher, making nitrogen recycling a beneficial solution.
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Modeling and optimization are essential tasks that arise in the analysis and design of supply chains (SCs). SC models are essential for understanding emergent behavior such as transactions between participants, inherent value of products exchanged, as well as impact of externalities (e.g.

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Livestock operations have been highly intensified over the last decades, resulting in the advent of large concentrated animal feeding operations (CAFOs). Intensification decreases production costs but also leads to substantial environmental impacts. Specifically, nutrient runoff from livestock waste results in eutrophication, harmful algal blooms, and hypoxia.

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Nutrient pollution of waterbodies is a major worldwide water quality problem. Excessive use and discharge of nutrients can lead to eutrophication and algal blooms in fresh and marine waters, resulting in environmental problems associated with hypoxia, public health issues related to the release of toxins and freshwater scarcity. A promising option to address this problem is the recovery of nutrient releases prior to being discharged into the environment.

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Nutrient pollution is one of the major worldwide water quality problems, resulting in environmental and public health issues. Agricultural activities are the main source of nutrient release emissions, and the livestock industry has been proven to be directly related to the presence of high concentrations of phosphorus in the soil, which potentially can reach waterbodies by runoff. To mitigate the phosphorus pollution of aquatic systems, the implementation of nutrient recovery processes allows the capture of phosphorus, preventing its release into the environment.

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