Chinese scientists have developed an innovative desalination technology that uses rice straw and sunlight for clean water production.
Solar steam generation is considered to be a promising strategy for purification of wastewater and seawater. Scientists from the Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences have developed a solar steam-generation device from wasted rice straw.
The device is composed of a photothermal membrane and water pumps. The leaves of rice straw are carbonized and composited with bacterial cellulose to function as a photothermal membrane and the lower culms of straw are designed as water pumps.
The rice straw-derived solar still achieves a daily clean water yield of 6.4 to 7.9 kg per square meter on sunny days and 4.6 to 5.6 kg on cloudy days. The water yielded reached safe drinking water standards with over 99.9% of saline ions removed.
Besides seawater desalination, the device can also be used for extracting clean water from various water-bearing areas such as tidal flats, wetlands and marshes.
The research was published in the journal ACS Applied Materials and Interfaces.