Cost-efficient management of coastal aquifers via recharge with treated wastewater and desalination of brackish groundwater: general framework

Abstract

. (2010) Cost-efficient management of coastal aquifers via recharge with treated wastewater and desalination of brackish groundwater: general framework. Hydrol. Sci. J. 55(7),1217-1233.Abstract Semi-arid coastal zones often suffer water-stress, as water demand is high and markedly seasonal, due to agriculture and tourism. Driven by scarcity of surface water, the communities in semi-arid coastal regions turn to aquifers as prime water source; but intensive exploitation of coastal aquifers causes seawater intrusion, which degrades the quality of groundwater. The cost-efficient and sustainable development of coastal aquifers can be achieved through a holistic management scheme which combines two non-traditional water sources: (a) saltwater, to be treated to the desired quality, and (b) wastewater, to be re-claimed to augment aquifer recharge for control of seawater intrusion, and also to meet certain demands. This management scheme is based on the idea that it is costadvantageous to: (i) desalt brackish groundwater, instead of seawater, as the former requires far less energy, and (ii) to re-use wastewater at only the differential cost to any treatment already practiced. In this paper, we present the general framework of the proposed management scheme, and a decision aid tool (DAT) which has been developed to assist decision makers to explore the scheme's decision space. The DAT uses cost as optimization criterion to screen various management scenarios, via modelling of the dynamic natural-engineered system behaviour, and identifies those cost-efficient ones that meet the water demand and achieve aquifer protection.Key words aquifer; brackish groundwater; coastal; cost; decision aid; desalination; optimization; recharge; sea intrusion; sustainable; water management; wastewater Gestion économe des aquifères côtiers via la recharge d'eaux usées traitées et la désalinisation d'eaux souterraines saumâtres: cadre général Résumé Les zones côtières semi-arides souffrent fréquemment de stress hydrique, dans la mesure où la demande en eau est élevée et particulièrement saisonnière, en lien avec l'agriculture et le tourisme. Poussées par la rareté des eaux de surface, les communautés des régions côtières semi-arides considèrent les aquifères comme étant les principales ressources en eau; mais une exploitation intensive des aquifères côtiers engendre des intrusions marines qui dégradent la qualité des eaux souterraines. Le développement économe et durable des aquifères côtiers peut être conduit grâce à un schéma de gestion holistique qui combine deux ressources non conventionnelles: (a) les eaux salées, à traiter pour atteindre la qualité escomptée, et (b) les eaux usées à traiter pour augmenter la recharge des aquifères et ainsi contrôler les intrusions marines et satisfaire certaines demandes. Ce schéma de gestion est basé sur l'idée qu'il est économiquement avantageux de: (i) désaler les eaux souterraines saumâtres, plutôt que les eaux marines, puisque cela nécessite bien moins d'énergie, et (ii) réutiliser les eaux usées u...

The benefits of hybridising electrodialysis with reverse osmosis

“…A friction factor correlation, such as that obtained by Kuroda et al [28] for spacer A in their analysis, f = 9.6Re −1/2 , (G. 4) allows the computation of p pump . Given the parameters of Table B.2, the power associated with drawing current at 350 ppm TDS is over 620 times that associated with viscous dissipation.…”

“…A higher recovery ratio allows the following benefits: a reduction in the size of the desalination plant intake; a reduction in the volume of brine produced, which requires disposal to the sea, surface waters or confined aquifers below the aquifer from which water is withdrawn [5]; and a reduction in the rate of aquifer recharge required, which might be done continuously with treated waste water [4] or periodically with water sourced from another location during periods of low demand [6]. Conversely, a higher recovery ratio results in the production of higher salinity brine, which, depending upon the degree of dispersion and/or dilution employed at the point of disposal, can have adverse effects on plant and animal life [7].…”

“…The supply of freshwater and mitigation of seawater intrusion with brackish desalination and secondary recharge. Based on an aquifer management system proposed by Koussis et al [4].…”

Cost-efficient management of coastal aquifers via recharge with treated wastewater and desalination of brackish groundwater: application to the Akrotiri basin and aquifer, Cyprus

“…1), is suitable for field-testing the proposed management concept for the following reasons: (a) it serves as a source for drinking and irrigation water; (b) the geology is well-known; (c) the salinity in the coastal wells is high (!2000 ppm TDS), yet reversible in a few years under conditions of natural recharge and reduced pumping; and (d) effluents of the wastewater treatment plant (WWTP) of Lemessos can be used to recharge the aquifer, along with surplus water from the surface reservoirs. In the following, we investigate the implications of applying the methodology detailed in Koussis et al (2010) to this water supply problem.…”

“…In this work we investigate the application of the general methodology for an intensive yet sustainable development of coastal aquifers described in Koussis et al (2010) to the management of the Akrotiri aquifer, Cyprus. The Akrotiri aquifer is located in the southernmost peninsula of Cyprus, west of the city of Limassol (Lemessos; Fig.…”