Aging of wastewater treatment plants (WWTPs) reduces their efficiency
and their treated effluent quality while it increases standards of safety,
health and environmental protection to preserve our quality of life.
Therefore, upgrading and optimization out of date WWTPs is essential to
meet new standards within an economically responsible and
environmentally sustainable framework. This paper reviews the most
common wastewater treatment processes and their constrains that could
need for upgrading. Also, it establishes procedures for optimizing and
upgrading existing WWTPS including systematic approaches to find out
the capacity and performance of existing processes, to determine the
places of constrains, to put alternatives for overcoming limitations and
evaluating different alternatives and to select the most suitable and costeffective
for different kinds of processes. WWTPs in Alexandria and
Damietta governorates, Egypt, have been studied for upgrading the
existing situation and increase their treatment capabilities.