Ultra-Efficient Saline Soil Remediation with Passive Multistage Solar Distiller via Water Recycling

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Saline land poses a threat to food security and ecological balance.
• Current solar evaporation methods for soil remediation face challenges in efficiency and water consumption.

Purpose of the Study:

• To develop an ultra-efficient passive multistage solar distiller for saline soil desalination.
• To address limitations of existing solar evaporators, focusing on efficiency and water conservation.

Main Methods:

• A 7-stage solar distiller integrating latent heat recovery, water recycling, and edge salt rejection was designed and tested.
• Performance was evaluated under one-sun irradiation (1 kW m⁻²), measuring water yield and solar-steam efficiency.
• The system's effectiveness in reducing soil salinity over time was assessed.

Main Results:

• The distiller achieved a water yield of 3.0 kg m⁻² h⁻¹ and a solar-steam efficiency of 200%.
• Soil salinity decreased from 22.5 to 2.33 g kg⁻¹ within 12 days, with a water consumption of 40.1 kg m⁻².
• Successful large-scale outdoor desalination demonstrated the system's practical applicability.

Conclusions:

• The passive multistage solar distiller offers a highly efficient and water-conserving method for saline soil remediation.
• This technology holds significant potential for promoting green land management and sustainable agriculture globally.