Abstract
The thesis investigates how anaerobic digestion could be utilized to improve wastewater management,
specifically in regards to future expected regulation on sludge management in Sweden.
Two possible paths of applying anaerobic digestion are investigated. First, the usage of thermophilic anaerobic
digestion of sludge in order to achieve pathogen hygienization. Second, the usage of anaerobic digestion to
treat wastewaters at decreased temperature. The evaluation of each path was made through practical lab
scale experiments. Additionally, the benefits of each path was compared through desk top environmental
impact studies and economic analysis.
The results for the first path showed that thermophilic anaerobic digestion renders high pathogen hygienization
even at relative short exposure times. However no additional beneficial impact on biogas production or the
reduction of organic micropollutants was found. The results for the second path showed that the difficulty of
operating the sensitive anaerobic digestion process at low temperatures can be partly overcome by simple
engineering batch tests. Furthermore, the dissolved methane in the effluent wastewaters can be extracted
using membrane contactors. Finally, the environmental impact assessment showed that increased resource
recovery from wastewater, as well as decreased climate impact, can be achieved by applying anaerobic
digestion on source separated domestic wastewaster.
The economic evaluation of the two paths showed that the implementation of source separation systems is
expensive compared to implementing the needed thermophilic hygienization. However, source separation
systems would greatly boost nutrient recovery from cities to agriculture which complies well with the goals of
the Swedish Environmental Protection Agency.
specifically in regards to future expected regulation on sludge management in Sweden.
Two possible paths of applying anaerobic digestion are investigated. First, the usage of thermophilic anaerobic
digestion of sludge in order to achieve pathogen hygienization. Second, the usage of anaerobic digestion to
treat wastewaters at decreased temperature. The evaluation of each path was made through practical lab
scale experiments. Additionally, the benefits of each path was compared through desk top environmental
impact studies and economic analysis.
The results for the first path showed that thermophilic anaerobic digestion renders high pathogen hygienization
even at relative short exposure times. However no additional beneficial impact on biogas production or the
reduction of organic micropollutants was found. The results for the second path showed that the difficulty of
operating the sensitive anaerobic digestion process at low temperatures can be partly overcome by simple
engineering batch tests. Furthermore, the dissolved methane in the effluent wastewaters can be extracted
using membrane contactors. Finally, the environmental impact assessment showed that increased resource
recovery from wastewater, as well as decreased climate impact, can be achieved by applying anaerobic
digestion on source separated domestic wastewaster.
The economic evaluation of the two paths showed that the implementation of source separation systems is
expensive compared to implementing the needed thermophilic hygienization. However, source separation
systems would greatly boost nutrient recovery from cities to agriculture which complies well with the goals of
the Swedish Environmental Protection Agency.
| Original language | English |
|---|---|
| Qualification | Doctor |
| Awarding Institution | |
| Supervisors/Advisors |
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| Award date | 2017 Mar 31 |
| Publisher | |
| ISBN (Print) | 978-91-7422-503-7 |
| ISBN (electronic) | 978-91-7422-504-4 |
| Publication status | Published - 2017 Mar 31 |
Bibliographical note
Defence detailsDate: 2017-03-31
Time: 09:00
Place: lecture hall KC:B, at Kemicentrum, Naturvetarvägen 14, Lund University, Faculty of Engineering LTH, Lund
External reviewer
Name: Zeeman, Grietje
Title: Professor
Affiliation: Wageningen University, the Netherlands
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Subject classification (UKÄ)
- Water Treatment
