Ms. Hafsa Mahmood1, Dr. Olfa Mahjoub2, Ms. Amel Jemai el Nasri3, Dr. Hiroshan Hettiarachchi4, Dr. Serena Caucci4, Mr. Fritz Kalwa M.Sc.5, Prof. Dr. Rudolf Liedl6
1. UNU Institute for Integrated Management of Material Fluxes, Technical University Dresden (TUD), IHE Delft Institute of Water Education
2. Institution of Agricultural Research and Higher Education (IRESA)
3. National Research Institute for Rural Engineering, Water and Forestry (INRGREF)
4. Waste Management Unit, UNU Institute for Integrated Management of Material Fluxes and of Resources
5. Technical University Dresden (TUD)
6. Groundwater Management Institute, Technical University Dresden (TUD)
Managed aquifer recharge (MAR) is considered a promising technique for increasing groundwater recharge. However, the extent of its effectiveness in replenishing deteriorated groundwater and associated risks need to be studied and assessed. These risks include the occurrence and spread of emerging pollutants (EP) in groundwater associated with the application of surface spreading infiltration using treated wastewater (TWW). Thus, EP present and future trend distribution in Korba aquifer, Tunisia, was investigated along with the effectiveness of managed aquifer recharge in the replenishment of groundwater resource. EP analysis was performed using advanced analytical techniques for enrichment as solid-phase extraction and reversed-phase hydrophilic interaction liquid chromatography coupled with mass spectrometry for targeted analysis. In order to understand the role of managed aquifer recharge in groundwater replenishment, a groundwater flow model was developed. Based on the detected EP, trend originating from the MAR site, conservative solute transport model was set to carry out a qualitative plume analysis for current and future scenario (the year 2100) using Modular Transport, 3-Dimensional, Multi-Species model (MT3DMS) after adequate groundwater flow modelling and climate data downscaling. Groundwater flow modelling results showed depression in the central Korba region with the lowest head of -7 m. MAR was seen to have a minor impact on the groundwater heads as it is 0.4% of the total recharge, playing its role in reducing saltwater intrusion in the region. According to analytical results, MAR is a primary source of EP in Korba aquifer. Only carbamazepine and sulfamethoxazole were present near the MAR site, whereas the rest of the targeted compounds, as atenolol, caffeine and roxithromycin were not detected. Accordingly, conservative solute transport model set for carbamazepine as a tracer of EP showed travelling of plume towards the depression region. Future scenario (2100 year) prediction displayed the growth of depression area (with a minimum hydraulic head of -11 m) and the contaminant plume spread along with the saltwater intrusion. These circumstances are evidence for the governmental organizations to take preventive measures that involves MAR application on a larger scale with a safe water source which contributes to reducing salinization and EP contamination in groundwater. Regulations of MAR are highly recommended for this purpose.