Observations and Prediction of Recovered Quality of Desalinated Seawater in the Strategic ASR Project in Liwa, Abu Dhabi

Water

Mohamed A. Dawoud¹  Pieter J. Stuyfzand²  Koen G. Zuurbier²  Niels Hartog²  Ebel Smidt³ 

[1] Environment Agency Abu Dhabi, PO Box 45553, Al Mamoura Building (A), Muroor Road, Abu Dhabi, United Arab Emirates;KWR Watercycle Research Institute, 3430 BB Nieuwegein, The Netherlands;Waterfocus, 3981 EB Bunnik, The Netherlands;

关键词: Aquifer Storage and Recovery (ASR);    hydrochemistry;    desalinated seawater;    chromate;    trace elements;    transport modeling;    break-through curve;    Abu Dhabi;    recovery efficiency;   

DOI  :  10.3390/w9030177

来源: DOAJ

【 摘 要 】

To be able to overcome water shortages, Abu Dhabi Emirate started an Aquifer Storage and Recovery (ASR) project with desalinated seawater (DSW) as source water near Liwa. It is the largest DSW-ASR project in the world (stored volume ~10 Mm3/year), and should recover potable water for direct use. DSW is infiltrated into a desert dune sand aquifer using “sand-covered gravel-bed” recharge basins. In this study, we evaluate the hydrogeological and hydrogeochemical stratification of the (sub)oxic target aquifer, and water quality changes of DSW during trial infiltration runs. We predict water quality changes of DSW after 824 d of infiltration, during 90 d of intensive recovery (67% recovered) without storage (scenario A), as well as after 10 years of storage (scenario B, with significant bubble drift). Monitoring of preceding trials revealed a lack of redox reactions; little carbonate dissolution and Ca/Na exchange; much SiO2 dissolution; a strong mobilization of natural AsO43−, B, Ba, F, CrO42−, Mo, Sr and V from the (sub)oxic aquifer; and immobilization of PO4, Al, Cu, Fe and Ni from DSW. The Easy-Leacher model was applied in forward and reverse mode including lateral bubble drift, to predict water quality of the recovered water. We show that hydrogeochemical modeling of a complex ASR-system can be relatively easy and straightforward, if aquifer reactivity is low and redox reactions can be ignored. The pilot observations and modeling results demonstrate that in scenario A recovered water quality still complies with Abu Dhabi’s drinking water standards (even up to 85% recovery). For scenario B, however, the recovery efficiency declines to 60% after which various drinking water standards are exceeded, especially the one for chromium.

【 授权许可】

Unknown