Optimization of methanol dosage for denitrification in MBR pilot plant

Published: 17 February 2021

In 2020, a large reconstruction project was initiated at Syvab with the purpose to transition into an MBR process configuration. In parallel, a pilot plant with the same setup was built and has now been commissioned. Your task will be to optimize the distribution and dosing points of naturally occurring and external carbon source to maintain good denitrification and minimize methanol consumption.

Application deadline: 2021-03-14

In 2020, a comprehensive project which goes by the name “NKH” (Nya Krav Himmerfjärdsverket) was initiated with the goal to be able to meet new effluent criteria and to expand the treatment capacity. In parallel, a pilot plant with the future process configuration, Membrane BioReactor (MBR), has been constructed and was recently commissioned. In the pilot, the incoming wastewater is step-fed to three consecutive biological treatment cascades. Furthermore, methanol can be added in the anoxic zones to support denitrification. This will be instrumental to meet the future effluent requirements.

The aim of this thesis project is to increase the knowledge regarding how and where carbon source should be distributed to the three cascades in order to a) maintain acceptable denitrification and b) to limit the consumption of fossil methanol. This will be investigated partly by process simulation of different scenarios for step-feeding and through selection of dosing point of methanol. The scenarios will be rendered in collaboration with our R&D partner, IVL Swedish Environmental Research Institute. The most promising scenarios will then be evaluated in practical experiments on site at the pilot plant.

We seek you who are about to finish your master's degree. Through your studies, you should have gained basic knowledge about municipal wastewater treatment and the associated biological processes. You like to solve problems, both theoretical and of a more practical nature. Experience of process simulations and specific knowledge of the MBR process could also be to your advantage in the screening process. The thesis project will mainly be carried out at Himmerfjärdsverket in Grödinge under the supervision of Syvab's process engineers Ross Roberts and Victor Kårelid.


Screening and interviews will be done on an ongoing basis. Send your application to with subject "Exjobb VT2021" and please attach your CV.


Syvab owns and operates Himmerfjärdsverket, which is a modern, high-tech wastewater treatment plant. At Syvab we are responsible for treating the wastewater from our connected municipalities; Botkyrka, Huddinge, Nykvarn, Salem, Södertälje and Stockholm. We work actively to extract utility from our sewers to reduce resource and energy consumption. It is a constant challenge and our ambition is to not only be an early adopter, but also to be a pioneer within our industry.


If you have questions regarding the project, please contact Victor Kårelid at or 073-209 56 21.

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