Industrial evaporation ponds are surely an inexpensive way to reduce industrial pollution and they have versatile use too. The ponds can be used in different kinds of industries like desalination plants, power plants, oil, gas, lithium industries, etc. However, these ponds require a massive amount of land sometimes covering a large area. The wastewater in the ponds is left to be evaporated naturally and after the process, the solid waste can be easily removed.
But fortunately, scientists have found an efficient way to reduce the amount of land used for industrial evaporation ponds. Reportedly, scientists of Berkeley developed a solar umbrella to help out with the process.
Scientists have developed a prototype that has shown a success rate of more than 100% tan that of the usual industrial ponds. Akanksha Menon and Ravi Prasher, scientists at Berkeley reportedly led the study which has been published in the Nature Sustainability journal.
Looking for a solution
Usually, the industries often adopt the policy of "zero liquid discharge" to maximize the water recovery from the wastewater. The common industrial wastewater ponds absorb solar energy to evaporate the water and leave only solid waste.
However, these ponds are dangerous for the birds as they sometimes mistake them for natural wetlands. Furthermore, high concentrations of elements can harm the birds greatly.
Therefore, scientists were trying to come up with an effective way to deal with this. Some even advised to use floating sunlight-absorbing structures to maximize the evaporation. But, those structures started to get clogged with the wastes and failed to separate them from water. Instead of absorbing the sunlight, they started to reflect it.
How the solar umbrella works
The researchers at the Berkeley lab involved themselves deeply to find a proper solution. Akanksha Menon, a researcher says:
We realized if you look at the properties of water, it has very strong absorption in the mid-infrared wavelength range. If you shine mid-infrared light on water, it’ll absorb it so strongly it retains all of that heat in a very thin layer.
Keeping that into mind, they came up with the idea of a device that works like a "radiation transformer". This device reportedly takes energy from sunlight in the range of 400 to 1,500 nanometers and converts it to 3,000 nanometers or greater. This means it works within the mid-infrared range properly.
This method is more efficient and can evaporate more water than before. They are hopeful to increase the evaporation of water by 160% with this thermal technique.
The newly introduced solar umbrella is basically a photo-thermal device. It is a flat sheet that selectively absorbs solar energy on one side and emits mid-infrared energy on the other hand. This can sit on the water like an umbrella increasing the evaporation process.
In lab scientist Ravi Prasher's words:
If you’re going to do large-scale desalination, one of the biggest challenges is how to come up with scalable technologies. This is potentially a highly scalable zero-liquid discharge technology, which doesn’t require any energy because it’s based on solar energy.
Places, where these industrial ponds are common can benefit from this device. China, Australia, Europe, the Middle East, and parts of the United States have much-industrialized area than the rest of the world. They can easily use the device to get rid of the wastes naturally adapting this faster way.