The Master thesis deals with effects of increased wastewater loading on Hjørring Wastewater Treatment
Plant and the interactions between long force mains in the sewer system and wastewater treatment
processes. The goal of the thesis is to investigate both, positive and negative, effects of this increase. The
Master thesis is carried out in several steps. First, the wastewater influent is characterized in terms of
composition and biodegradability. This includes volatile fat acids (VFA) measurements on wastewater
samples, which were done in the laboratory. Furthermore, respirometry experiments were carried
out to measure oxygen uptake rate (OUR). The aim of this is to characterize the wastewater organic
matter composition, that accounts for possible sulfide formation and investigate sulfide abatement
methods. For this case two experimental wastewater treatment reactors were constructed. In addition,
negative impacts of sulfide generation in the sewer system were quantified by placing an odor sensor at
the inlet to the wastewater treatment plant (WWTP) to measure volatilized sulfides. Laboratory data
serves as a basis for setting up models describing wastewater transformations. Models were used to
simulate wastewater transformations with wide array of parameters. Sulfide abatement methods were
implemented into mathematical models to investigate possible sulfide control methods that would be applicable in the site of the thesis. Monte Carlo simulations were carried out to account for uncertainties.
After laboratory experiments, measurement campaign and simulations were completed, results were
discussed in a report and conclusions were drawn. Visual abstract above illustrates workflow throughout
this master thesis.