Controlled methane production from wastewater containing oil with double climate benefits
| Reference number | |
| Coordinator | Högskolan i Borås - Akademin för Textil Teknik och Ekonomi |
| Funding from Vinnova | SEK 2 626 878 |
| Project duration | November 2015 - November 2017 |
| Status | Completed |
Purpose and goal
The aim was to develop a controlled process for anaerobic biological treatment of water contaminated with mineral oil, while producing biogas. The work focused on gaining more knowledge of the spontaneous process started in the storage tank and on evaluation of sludge and substrates. Three different process solutions were developed and tested in lab scale, and a process for combining water treatment with biogas production has been developed. How a full-scale process might look like can now be communicated to interested stake holders.
Expected results and effects
Purification of oil contaminated water with an Anaerobic Moving Bed Biofilm Reactor (AnMBBR) could be performed at higher load (1.1 vs 0.4 kg tCOD/m3/day) and shorter retention time (25 days vs 104 days) than the process today going on in C1. AnoxKaldnes biofilm-based ARCH AnMBBR at 37 ° C was able to handle the highest OLR with a corresponding COD reduction of up to 70% and methane production of around 180 Nml/ gCOD/day. The benefits of the developed process are better treatment of oil-contaminated water, and at the same time the renewable energy is produced and utilized in the form of biogas.
Planned approach and implementation
The project was conducted in collaboration between University of Borås, Veolia Water Technologies AnoxKaldnes AB and Stena recycling AB. The process in C1 showed about 60% COD reduction at about 100 days residence time. The sludge in C1 is not unique. The BMP tests showed that other types of sludge can reduce the COD in as much or better than the sludge in C1. Three different process setups were tested in lab scale for 300 days; one Anaerobic Moving Bed Biofilm Reactors (AnMBBR), at 37 °C and one at 50 °C, and a contact reactor at 50 °C. AnoxKaldnes biofilm-based ARCH AnMBBR at 37 °C performed best.