Environmental Improvement of Alexandria’s Wastewater Treatment Plants Using Life Cycle Assessment Approach

Improving the treatment efficiency of a primary wastewater treatment plant(WWTP),in Alexandria,
Egypt,was studied.In order to improve the treatment efficiency of the plant, different improving
scenarios were proposed and evaluated. The improvement scenarios are: scenario 1,use of
engineered wetland instead of the current treatment system, scenario 2, use of the engineered
wetland as a secondary treatment after the existing treatment system and scenario 3,replace the
existing treatment system with a secondary WWTP. The scope of this study is to environmentally
assess the existing primary WWTP, in addition to assess the possibility of using the engineered
wetland for improving the primary WWTP. To evaluate the performance of each treatment system,
Life Cycle Assessment (LCA) approach was applied.

Based on the results, the main improvement achieved in all the scenarios is in the category of
eutrophication and acidification, as the three scenarios have higher removal efficiency for the
nutrients than the current system. Unlike the total reduction in the environmental impact, scenario 3
gave the highest reduction in the category of eutrophication and acidification (25%) followed by
scenario 2 (24%) and the lowest reduction achieved by scenario 1 (13%). The analysis revealed that
the use of combined system from natural and traditional systems (scenario 2) is the best scenario.
However, scenario3 achieved a very close result.