Halophyte inspired solar-driven salt extractor for saline soil remediating

Saline soil remediating is crucial to enhance arable land and address the global food crisis. One of the great challenges is to develop low-cost and effective technology to directly extract salt from saline soil. Herein, we designed a biomimetic solar-driven salt extractor to extract the salt from saline soil with the fact that the salt will migrate along with water flow during evaporation process. A salt-resistant polyacrylic acid sodium hydrogel was used as the evaporator to ensure prolonged stable operation and salt was enriched in a cotton fabric beneath the evaporator. In one desalination cycle of 10 days under one solar irradiation, the soil salinity was reduced from 27 g kg −1 to 1.4 g kg −1 , thereby meeting the requirements for normal agricultural crops. Under outdoor conditions, similar salt extraction process could be reduced to 7 days with a desalination efficiency of 95.2 %, and the desalted soil could be used to plant ryegrass. We envisioned that such a high-efficiency solar-driven salt extraction strategy could have great potential application in saline land remediation.