Weighing environmental advantages and disadvantages of advanced wastewater treatment of micro-pollutants using environmental life cycle assessment.
Much research and development effort is directed towards advances in municipal wastewater treatment aiming at reducing the effluent content of micro-pollutants and pathogens. The objective is to further reduce the eco-toxicity, hormone effects and pathogenic effects of the effluent. Such further polishing of the effluent, however, involves an environmental trade-off: the reduction in eco-toxicity, hormone effects, etc. will happen at the expense of increased resource- and energy consumption. Obviously, at some point of further advances, there must be an 'environmental break-even'. This trade-off was investigated using Life Cycle Assessment (LCA) methodology and based on a literature review of advanced treatment performance. The LCA evaluation comprised sand filtration, ozonation and MBRs and assessed the effect of extending existing tertiary treatment with these technologies on a variety of micro-pollutants being: heavy metals (Cd, Pb, Ni), endocrine disruptors (E2 and EE2), PAH, DEHP, and detergents (LAS & NPE). It was found, in some of the studied scenarios, that more environmental impact may be induced than removed by the advanced treatment. The study showed that for the 3 technologies, sand filtration has the best balance between prevented and induced impacts, and sand filtration proved to have a net environmental benefit under the assumptions used in the study. But the outcome of the study suggests that this is not always the case for ozonation and MBR.
Wenzel
H
H
University of Southern Denmark, DK-5230, Odense, Denmark. henrik.wenzel@kbm.sdu.dk
Larsen
H F
HF
Clauson-Kaas
J
J
Høibye
L
L
Jacobsen
B N
BN
D003247:Conservation of Natural Resources; D003657:Decision Making; D017753:Ecosystem; D019216:Metals, Heavy / Q000032:analysis; D018570:Risk Assessment; D014865:Waste Disposal, Fluid / Q000379:methods*; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods*
D019216:Metals, Heavy; D014874:Water Pollutants, Chemical