Papers by Tove Wium-Andersen
Alliance for Global Sustainability Bookseries, 2009
ABSTRACT
Alliance for Global Sustainability Bookseries, 2011
Water research, 2008
Hydrogen sulfide oxidation on sewer pipe surfaces was investigated in a pilot scale experimental ... more Hydrogen sulfide oxidation on sewer pipe surfaces was investigated in a pilot scale experimental setup. The experiments were aimed at replicating conditions in a gravity sewer located immediately downstream of a force main where sulfide related concrete corrosion and odor is often observed. During the experiments, hydrogen sulfide gas was injected intermittently into the headspace of partially filled concrete and plastic (PVC and HDPE) sewer pipes in concentrations of approximately 1,000 ppm(v). Between each injection, the hydrogen sulfide concentration was monitored while it decreased because of adsorption and subsequent oxidation on the pipe surfaces. The experiments showed that the rate of hydrogen sulfide oxidation was approximately two orders of magnitude faster on the concrete pipe surfaces than on the plastic pipe surfaces. Removal of the layer of reaction (corrosion) products from the concrete pipes was found to reduce the rate of hydrogen sulfide oxidation significantly. Ho...
Water Environment Research, 2012
Five sorption materials were studied with a focus on polishing pretreated stormwater: crushed lim... more Five sorption materials were studied with a focus on polishing pretreated stormwater: crushed limestone, shell-sand, zeolite, and two granulates of olivine. These materials are commercially available at comparatively low cost and have been subjected to a minimum of modification from their natural states. The sorbents were tested for phosphorus, arsenic, cadmium, chromium, copper, nickel, lead, and zinc at concentration and conditions relevant for typical stormwater. The materials were tested for sorption capacity and kinetics. Desorption was tested under neutral and alkaline conditions and in the presence of chloride. For most sorbent/sorbate combinations, significant sorption occurred within the first minutes of contact between sorbent and sorbate. Treatment to the low microgram per liter range could be achieved by contact times of less than 1 hour. The study indicated that sorption filters can be designed for long life expectancy at comparatively low cost by applying the materials tested. Water Environ. Res., 84, 605 (2012).
Science of The Total Environment, 2008
Hydrogen sulfide absorption and oxidation by corroding concrete surfaces was quantified in a test... more Hydrogen sulfide absorption and oxidation by corroding concrete surfaces was quantified in a test rig consisting of 6 concrete pipes operated under sewer conditions. The test rig was placed in an underground sewer monitoring station with access to fresh wastewater. Hydrogen sulfide gas was injected into the pipe every 2nd hour to peak concentrations around 1000 ppm. After some months of operation, the hydrogen sulfide became rapidly oxidized by the corroding concrete surfaces. At hydrogen sulfide concentrations of 1000 ppm, oxidation rates as high as 1 mg S m(-2) s(-1) were observed. The oxidation process followed simple nth order kinetics with a process order of 0.45-0.75. Extrapolating the results to gravity sewer systems showed that hydrogen sulfide oxidation by corroding concrete is a fast process compared to the release of hydrogen sulfide from the bulk water, resulting in low gas concentrations compared with equilibrium. Balancing hydrogen sulfide release with hydrogen sulfide oxidation at steady state conditions demonstrated that significant corrosion rates--several millimeters of concrete per year--can potentially occur at hydrogen sulfide gas phase concentrations well below 5-10 ppm. The results obtained in the study advances the knowledge on prediction of sewer concrete corrosion and the extent of odor problems.
Ecological Engineering, 2013
A model, targeting eutrophication of stormwater detention ponds was developed and applied to simu... more A model, targeting eutrophication of stormwater detention ponds was developed and applied to simulate pH, dissolved oxygen and the development of algae and plant biomass in two mature planted wetponds for run off control. The model evaluated algal and plant biomass growth into three groups namely; phytoplankton, benthic algae and macrophytes. The study evaluated large data sets from an intensive monitoring campaign of two Danish mature stormwater ponds which were used to calibrate and validate the model. One general calibration covering 6 consecutive months together with two additional short-term calibrations during summer (31 days) and winter (56 days) were carried out applying the data series from one of the ponds. The calibrations showed a good agreement between measured and modeled data for the time spans evaluated. The calibration showed that growth rates for the three groups of primary producers were approximately the same for the two calibrations. The validation for both trends of DO and pH were well simulated, even though pond Aarhus showed a better agreement of the absolute values. The eutrophication model could be successfully calibrated to two stormwater ponds and has the potential of providing a tool for improving the design of stormwater ponds by taking into account the behavior of the plant ecosystem.
Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering, 2012
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Papers by Tove Wium-Andersen