ppt on advanced technology in sewage treatment nutrient remov
al

Advanced nutrient removal processes, while improving the water quality of the receiving water body, can also produce indirect environmental and health impacts associated with increases in usage of energy, chemicals, and other material resources. The present study evaluated three levels of treatment for nutrient removal (N and P) using 27 representative treatment process configurations. Impacts were assessed across multiple environmental and health impacts using life-cycle assessment (LCA) following the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) impact-assessment method. Results show that advanced technologies that achieve high-level nutrient removal significantly decreased local eutrophication potential, while chemicals and electricity use for these advanced treatments, particularly multistage enhanced tertiary processes and reverse osmosis, simultaneously increased eutrophication indirectly and contributed to other potential environmental and health impacts including human and ecotoxicity, global warming potential, ozone depletion, and acidification. Average eutrophication potential can be reduced by about 70% when Level 2 (TN = 3 mg/L; TP = 0.1 mg/L) treatments are employed instead of Level 1 (TN = 8 mg/L; TP = 1 mg/L), but the implementation of more advanced tertiary processes for Level 3 (TN = 1 mg/L; TP = 0.01 mg/L) treatment may only lead to an additional 15% net reduction in life-cycle eutrophication potential.
The purpose of this report is to give an overview of different methods for phosphorus
removal from municipal wastewater. Focus is given to chemical precipitation and
enhanced biological phosphorus removal although also other methods are discussed,
namely, local treatment methods and ecological and natural treatment systems.
The basic removal mechanisms, process schemes and treatment results are
described. In the report, a historical background is also given of phosphorus removal
methods and trends in research and process design. Important factors for process
design is hereby also treatment requirements for other components in the
wastewater and interactions with sludge handling. The need for better evaluation
methods of different phosphorus removal processes is pointed out.
Phosphorus may become a limiting substance in the future and phosphorus leakage
from deposits may be a diffusive phosphorus source. This has led to an increased
interest in phosphorus recovery and reuse. Three main routes are briefly discussed:
Improvement of the quality of the sludge from the treatment plants, production of
different products from the sludge, and source separation of human wastes from grey
water.