Research School for Socio-Economic and
Natural Sciences of the Environment
Research School for Socio-Economic and
Natural Sciences of the Environment
Agenda

Ahmed Ragab Abdelrady Mahmoud

Date: 10 November 2020
Location: TU Delft, Auditorium, Mekelweg 5: the ’Senaatszaal’

Dissertation title: 

Effectiveness of Bank Filtration for water supply in Arid Climate: A case study in Egypt

Group: IHE Delft, Water Supply
Promotor: Prof.dr. Maria D. Kennedy
Co-promotor: Dr. Saroj Sharma

Abstract:

Bank filtration (BF) has shown its efficacy in the elimination of chemical pollutants and the supply of potable water to humid countries. Howver, its effectivness in arid environments is still needed to be investigated. This research was conducted to facilitate the transferability of this technique to arid climatic nations. The work was subdivided into two phases. Firstly, batch and column laboratory-scale studies were performed to determine the effect of environmental variables on chemical pollutant removal (organic matter, microorganics, and heavy metals). Furthermore, a further set of experiments were conducted under anaerobic conditions to assess the mobilization of iron, manganese and arsenic during the BF. Secondly, a framework of three steps was followed to examine the effectiveness of BF in arid environment (Aswan, Egypt). Based on the results, the research proposed several guidelines for the efficient application of BF, including: (1) BF is an effective technique for removing biodegradable matter (>80%) during the infiltration process at high temperature; however, humic compounds are anticipated to be enriched, and therefore post-treatment may be needed. (ii) The high humic content of infiltrating water reduces the removal efficiencies of heavy metals and promotes the releasing of metal(loids) into the infiltrating water, rendering it more feasible to install BF wells within the surface water system with low organic content. (iii) moderate-hydrophobic organic micropollutants (roughly -2.5>logS>-4) are the most persistent compounds and a long infiltration time (>30 days) is required to eliminate such compounds. (iv) BF design parameters (e.g., number of wells) should be configured to minimize the share of polluted groundwater in the overall pumped water, the consequences of dropping the surface water level could be overcome by continuing long-term operation of the wells. Overall, BF is a promising technique to be implemented in arid environments. However, other issues still need to be addressed, such as high clogging development process.