SUSTAINABILITY IN TREATED SEWAGE EFFLUENT (TSE) MANAGEMENT: EVALUATING STABILITY, STORAGE AND POLISHING STRATEGIES OF ALTERNATIVE WATER SOURCES IN EDUCATION CITY

Abstract

Alternative water sources have become an essential sustainable solution for global water scarcity challenges, particularly in arid regions. Treated sewage effluent (TSE) has emerged as a viable source for non-potable applications. In Qatar, TSE has been used primarily for irrigation, so ensuring its chemical, microbial and physical stability is crucial for safe and effective reuse. This study examines the impact of intermittent storage and seasonal changes on the TSE quality. It also evaluates the feasibility of incorporating a polishing stage using reverse osmosis (RO) and close circuit reverse osmosis (CCRO) through WAVE by DuPont simulation tool. Key water quality parameters were monitored over 10 months using the inlet and outlet of the storage tank located at the female housing at Qatar Foundation Education City. These parameters included total organic carbon (TOC), dissolved organic carbon (DOC), ion concentrations, microbial regrowth indicators (ATP and flow cytometry), and suspended solids. Results show that turbidity and suspended solids levels were the main concerns when comparing the collected parameters to the irrigation reuse standards. Microbial analysis also raised concern due to the high regrowth potential that can cause biofilm formation and pathogen persistence. This confirmed the need for a polishing step to minimise any possible side effects to the irrigation process. While both RO and CCRO were effective for purifying the water, their high energy requirements and operational costs made them an impractical choice for irrigation reuse. So, other filtration and disinfection methods can provide a more cost effective solution, such as ultrafiltration (UF), chlorination or UV. The results of this study offered a practical recommendation to optimise the TSE storage and treatment, contributing not only to Education City’s case but also to the overall sustainable water reuse in water-scarce regions. By enhancing the water quality using effective and cost efficient solutions, this research contributed to efforts to improve water sustainability practices.

Date of Award	2025
Original language	American English
Awarding Institution	HBKU College of Science and Engineering