이스라엘 벤구리온대학 연구진에 따르면 해안 대수층에서 염분지하수를 활용하는 방안은  멤브레인 오염 및 전처리 비용의 감소 등의 장점을 가져 해수 역삼투 담수화보다 나은 대안이 될 수 있다.

 

이번 연구는 국제적 환경 전문지인 「환경과학과 기술(Environmental Science & Technology)」에 게재되었으며 벤구리온대학의 물 연구를 위한 주크버크 기관(Zuckerberg Institute for Water Research)  및 지질환경과학부(Department of Geological and Environmental Sciences), 이스라엘 지질조사부(Israel Geological Survey) 등에서 수행되었다. 연구에서 수직정(vertical wells)은 염분지하수에서 샘플을 채취하기 위해 사용되었다.

 

 

 

Saline groundwater from coastal aquifers is a better alternative water source than seawater for reverse osmosis (RO) desalination due to reduced membrane fouling and pre-treatment costs, researchers at Ben-Gurion University of the Negev (BGU) have found.

 

The study was published in Environmental Science & Technology and conducted by Researchers at the BGU Zuckerberg Institute for Water Research, the BGU Department of Geological and Environmental Sciences and the Israel Geological Survey.

 

In the study, vertical wells were used to take samples from the saline groundwater. All the wells were a maximum of 300 feet (100 meters) from the shoreline. Researchers said that other saline groundwater benefits include consistent annual water temperatures, and lower levels of dissolved oxygen, silt density and phytoplankton. It also decreases the cost of desalination, researchers said.

 

“Decision-makers in both California and Israel can use this research to seriously consider saline groundwater as a realistic alternative when planning future large-scale seawater desalination facilities,” explained Dr. Roni Kasher, a senior lecturer in the BGU Zuckerberg Institute’s Department of Desalination and Water Treatment. “In Israel, seawater desalination accounts for 60% of the total freshwater supply, so these findings are significant.”

 

BGU researcher Shaked Stein said: “Saline groundwater results from seawater intrusion into coastal aquifers, shifting the fresh-saline water interface upward and landward, and replaces fresh groundwater with saline groundwater. The RO process in coastal aquifers will be helpful in restraining seawater intrusion.

 

"The study showed that aquifer filtration increases the feed water quality and reduces the need for extensive pre-treatment processes. RO desalination with saline groundwater as feed water is also more efficient, with higher freshwater recoveries, less chemical use and maintenance, and therefore less overall operational costs."

 

Due to seasonal seawater characteristic fluctuations, Stein specifically recommended using saline groundwater in the summertime rather than seawater since the research identified higher membrane fouling in summer. “Salt rejection decreases in elevated temperatures due to changes in membrane permeability and mass transfer.”

 

Saline Groundwater from Coastal Aquifers as a Source for Desalination research received support from the Water Authority of Israel.

 

[출처 = Water World / 2016년 3월 9일]