Evaluation of the effects of low energetic microwave irradiation on anaerobic digestion
| Autor: | Rob Van den Broeck, Lise Appels, Bert Bastiaens, Raf Dewil |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Environmental Engineering
020209 energy Biomass 02 engineering and technology 010501 environmental sciences Management Monitoring Policy and Law Waste Disposal Fluid 01 natural sciences Methane Acetic acid chemistry.chemical_compound Biogas 0202 electrical engineering electronic engineering information engineering Anaerobiosis Microwaves Waste Management and Disposal 0105 earth and related environmental sciences Sewage Waste management Chemistry General Medicine Anaerobic digestion Biofuels Degradation (geology) Anaerobic exercise Microwave Nuclear chemistry |
| Zdroj: | Journal of Environmental Management. 202:69-83 |
| ISSN: | 0301-4797 |
| Popis: | The present study investigates the effects of microwave irradiation on the performance of anaerobic digestion processes. A first set of experiments is performed to distinguish the upper limit of the applied energy levels. Secondly, the effects of these treatments on the performance of the digestion process are evaluated in 3 experimental setups: (i) monitoring the acetic acid degradation, (ii) performing a biological methane potential (BMP) assay and (iii) conducting a specific methanogenic activity (SMA) test. The solubilisation experiment reveals a limited degree of disintegration of anaerobic biomass up to a microwave treatment of 10000 kJ/kg TS. Above this threshold value the soluble COD level started to rise, with up to 350% at 30000 kJ/kg TS regardless of the microwave output power. Because solubilisation of the biomass increases the easily degradable content, this would lead to false observations regarding increased activity. Therefore, solubilisation is minimized by limiting the microwave treatment to a maximum of 6000 kJ/kg TS during the second part of the experiments. Monitoring the degradation of acetic acid after a low intensity microwave treatment, reveals that microwave irradiation shortens the lag phase, e.g., from 21 to 3 h after a microwave treatment of 1000 kJ/kg TS at 100 W. However most treatments also result in a decrease of the maximum degradation and of the degradation rate of acetic acid. BMP assays are performed to evaluate the activity and performance of the entire anaerobic community. Every treatment results in a decreased biogas production potential and decreased biogas production rate. Moreover, each treatment induced an increase of the lag phase. The SMA experiments show no influence of the microwave irradiation in terms of biogas or methane production. |
| Databáze: | OpenAIRE |
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