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

Abstract

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.