干旱区生态环境知识资源中心

Aquifer storage and recovery (ASR) is an effective method of recharging reclaimed or surplus surface water into confined, or semi-confined permeable formations for later extraction as needed. A key factor in the long-term viability of ASR is the extent of mineral interaction between two dissimilar water types, their recoverable fractions and consequent impact on water quality and aquifer stability. An ASR well study was undertaken in the semi-arid region of northern India to assess the technical viability, environmental sustainability and commercial/economic feasibility of the ASR system in a generic sense. About 2000 m(3) of canal water was injected in each recharge cycle aquifer and 100% of the mixture was extracted during each recovery cycle of the experiment. The study revealed that groundwater quality of the recovered water was better than that of the native water and recovery percentage of recharged water (EC <= 2 dS m(-1)) increased from 47% to 74% in successive recovery cycles. The potassium concentration in the recovered water was greater than that of the injected water as a result of potassium release from clay minerals in the aquifer. Borate was also released from the aquifer due the tourmaline dissolution and desorption from clay minerals under lower pH conditions caused by surface water injection.