Environmental impact analysis of chemicals and energy consumption in wastewater treatment plants: case study of Oslo, Norway

摘要

Wastewater treatment plants, while performing the important function of treating wastewater tonmeet the prescribed discharge standards, consume energy and a variety of chemicals. This papernanalyses the consumption of energy and chemicals by wastewater treatment plants in Oslo overneight years, and their potential environmental impacts. Global warming and acidification werenthe dominant impacts for chemicals and energy, respectively. Avoided impacts due to usablenby-products – sludge, ammonium nitrate and biogas – play a key role in shrinking thenenvironmental footprint of the wastewater plants. The scope for decreasing this footprint bynstreamlining energy and chemicals consumption is limited, however, considering that over 70%nof the impact is accounted for by the eutrophication potential (thanks to the nitrogen andnphosphorus which is discharged to the sink) of the treated effluent wastewater.