Publicação
Developing an ultrasound-based water treatment system
| Resumo: | This dissertation examined the effects of ultrasound in different stages of a Wastewater Treatment Plant (WWTP), focusing on adsorption and oxidation processes. Additionally, it provided guidance for the proper design of an ultrasound-assisted equipment aimed at water treatment. Initially, the physical effects of ultrasound treatment on water were explored. The initial understanding of these phenomena guided the research in two distinct directions. On one hand, the feasibility of combining ultrasound treatment with existing adsorption mechanisms was investigated. On the other hand, the potential of this technology in isolation for wastewater treatment was examined. In the context of wastewater treatment, sensors were developed to monitor acoustic cavitation within the ultrasound equipment. After validating the sizing of this equipment, a study was conducted at a WWTP to evaluate the effectiveness of ultrasound treatment in water contaminated with various pollutants and organisms. The application of ultrasound proved impactful in the initial moments. When applied to ultra-filtered water, ultrasound treatment (Is=20.7 ± 1.6 W·cm−2 ) in the first 18 seconds resulted in a 2.7-fold increase in ORP and a 2.29-fold reduction in pH. The combination of ultrasound treatment with the organic compound ”Nutrimais da Lipor” in adsorption resulted in a Cu removal rate of 82%, surpassing conventional mechanical action by 4.3 times. The removal of CIP was accelerated, reaching the maximum adsorption capacity (70%) in 1 minute, being 1.75 times more effective than the mechanical approach. With the Kaolin adsorbent, both methods showed comparable results after 1 minute. Regarding the treatment of contaminated water at the WWTP, the developed sensors for monitoring acoustic cavitation identified cavitation thresholds and transition zones, confirming the geometric dimensions of the ultrasound chamber. Applying ultrasound treatment with different powers (200 W, 400 W, and 800 W) showed a significant variation in physicochemical parameters in the first 5 minutes, followed by stabilization and return to initial values. COD decreased in the first 2 to 5 minutes, then returned to initial values. These results highlight the potential of ultrasound treatment, especially in the initial stages of application, for accelerating processes and the possibility of integration with other methods. |
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| Autores principais: | Fernandes, José Pedro Oliveira |
| Assunto: | Adsorption Cavitation Piezoelectric Ultrasound Wastewate Adsorção Águas residuais Cavitação Piezoelétrico Ultrassom |
| Ano: | 2023 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | This dissertation examined the effects of ultrasound in different stages of a Wastewater Treatment Plant (WWTP), focusing on adsorption and oxidation processes. Additionally, it provided guidance for the proper design of an ultrasound-assisted equipment aimed at water treatment. Initially, the physical effects of ultrasound treatment on water were explored. The initial understanding of these phenomena guided the research in two distinct directions. On one hand, the feasibility of combining ultrasound treatment with existing adsorption mechanisms was investigated. On the other hand, the potential of this technology in isolation for wastewater treatment was examined. In the context of wastewater treatment, sensors were developed to monitor acoustic cavitation within the ultrasound equipment. After validating the sizing of this equipment, a study was conducted at a WWTP to evaluate the effectiveness of ultrasound treatment in water contaminated with various pollutants and organisms. The application of ultrasound proved impactful in the initial moments. When applied to ultra-filtered water, ultrasound treatment (Is=20.7 ± 1.6 W·cm−2 ) in the first 18 seconds resulted in a 2.7-fold increase in ORP and a 2.29-fold reduction in pH. The combination of ultrasound treatment with the organic compound ”Nutrimais da Lipor” in adsorption resulted in a Cu removal rate of 82%, surpassing conventional mechanical action by 4.3 times. The removal of CIP was accelerated, reaching the maximum adsorption capacity (70%) in 1 minute, being 1.75 times more effective than the mechanical approach. With the Kaolin adsorbent, both methods showed comparable results after 1 minute. Regarding the treatment of contaminated water at the WWTP, the developed sensors for monitoring acoustic cavitation identified cavitation thresholds and transition zones, confirming the geometric dimensions of the ultrasound chamber. Applying ultrasound treatment with different powers (200 W, 400 W, and 800 W) showed a significant variation in physicochemical parameters in the first 5 minutes, followed by stabilization and return to initial values. COD decreased in the first 2 to 5 minutes, then returned to initial values. These results highlight the potential of ultrasound treatment, especially in the initial stages of application, for accelerating processes and the possibility of integration with other methods. |
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