Chinese scientists have created a cheap and super-efficient sea water desalination solution that runs on solar energy.

The desalination system employs a Titanium-containing Layer that absorbs solar energy. The solar absorber consists of a unique paper on which they deposit the Titanium-containing layer which uses foam to float on the sea.

The Titanium layer heats rapidly when exposed to sunlight. It is this heat that vaporizes water. Sealing the unit within a transparent container with a slopy roof made of quartz allows the vapor to condense and the fresh water is collected.

Lead author Chao Chang explains that TiNO is already proven to be effective: “In the solar energy field, TiNO is a common commercial solar-absorbing coating, widely used in solar hot water systems and in photovoltaic units.  It has a high solar absorption rate and a low thermal emittance and can effectively convert solar energy into thermal energy.”

Together, the scientists came up with an innovative way to deposit the TiNO using the magnetron sputtering technique.

The team worked with airlaid paper – a porous paper that supplies the contraption with seawater. It functions like a wicker.

They assembled three parts to create the evaporation unit: the airlaid paper at the very bottom, a thermal insulator, and the TiNO paper at the very top. Airlaid paper is a component of disposable diapers and is built from wood fibres.

The insulation is made using polyethylene foam and contains many pores filled with air that give the unit the buoyancy it needs to float on seawater. This keeps heat loss at a minimum.

“The porous airlaid paper used as the substrate for the TiNO solar absorber can be reused and recycled more than 30 times,” explained Chang.

The researchers wanted to minimize any negative impact of salt precipitation on the device’s efficiency. But they observed that there was no layer of salt on the TiNO surface even after a long while.

This might mean that the paper wicks are porous enough to keep salt from depositing on the TiNO, and that all the salt in the seawater goes back to the main reservoir of water.

Normal seawater is highly saline, at 75,000mg per liter. This is vastly different from normal drinking water whose salinity is only 200mg per liter.  After going through the desalination unit, seawater goes all the way down to 2mg per liter of salt.

The Chinese team of researchers puts together a winning combination of affordability, high efficiency, and hygiene to create desalination that could help make fresh water available to people who face scarcity of water.

A Florida-based team of scientists suggested harnessing geothermal energy to desalinate water without using carbon fuels.

Researchers have created a new way to check soil moisture with a normal digital camera and a synthetic neural network.

The United Nations predicts that by 2050 some parts of the world will not have the fresh water they need to sustain agriculture. This means that we urgently need to adopt more efficient methods of soil irrigation to alleviate the coming crisis.

According to the researchers from the University of South Australia, the techniques currently in use for detecting soil moisture are contributing to the problem.

The sensors they bury in the soil are affected by salts and this calls for specially designed hardware to facilitate the connections.

At the same time, the thermal imaging cameras necessary for the operations cost too much and are sensitive to too much clouds, sunlight, and fog.

“The system we trialed is simple, robust and affordable, making it promising technology to support precision agriculture,” explained researcher Dr Ali Al-Naji referring to his newly innovated solution based on machine learning. “It is based on a standard video camera which analyses the differences in soil color to determine moisture content. We tested it at different distances, times and illumination levels, and the system was very accurate.”

They connect the camera to an artificial neural network that is already trained to identify a range of moisture levels under a variety of sky conditions.

They can train the monitoring system on the network to precisely identify soil conditions regardless of the location. This makes it a customizable solution that each user can adapt to their climatic conditions and make it as accurate as possible.

“Once the network has been trained it should be possible to achieve controlled irrigation by maintaining the appearance of the soil at the desired state,” Professor Javaan Chahl added. “Now that we know the monitoring method is accurate, we are planning to design a cost-effective smart-irrigation system based on our algorithm using a microcontroller, USB camera and water pump that can work with different types of soils.

“This system holds promise as a tool for improved irrigation technologies in agriculture in terms of cost, availability and accuracy under changing climatic conditions.”

For the most part, concrete is the stuff that man-made structures are made of. Cement is an essential ingredient in the making of concrete, but most people have no idea that 8% of the carbon dioxide we produce globally is in the production of cement.

Cement manufacturing generates massive amounts of carbon dioxide. It is such a massive carbon dioxide producer that this one industry produces more carbon dioxide than all other countries except for the US and China.

Global cement production is expected to grow from the present four billion tons a year to five billion tons a year within the coming three decades, according to Watchdog Chatham House.

Cement factory emissions mostly come from fossil fuels burned to produce heat to facilitate cement formation. This includes the chemical processes that convert limestone to clinker within kilns, after which the kiln is ground and combined with other ingredients that form cement.

The construction industry resists change.  Safety concerns, issues of reliability are not necessarily always compatible with reducing the carbon footprint of the industry.

The Global Cement and Concrete Association in 2018 launched a set of Sustainability Guidelines for the industry that sets standards for key measurements like emissions and water usage with a view to improve transparency and encourage improvement.

At the same time, experts are pursuing lower-carbon processes for manufacturing cement. A New Jersey startup for example is working on a chemical process that reduces the carbon dioxide produced in cement manufacturing by 30%.

Solidia which is based in Piscataway, N.J., uses a larger quantity of clay and less limestone than the typical cement making process. The company also uses less heat, which reduces its reliance on carbon fuel.

Another startup, CarbonCure based in Dartmouth, Nova Scotia, harnesses carbon dioxide from other chemical processes using a process of mineralization. It turns a potential by product from a hazard.

A Montreal company CarbiCrete has opted to create concrete without any cement at all. They use steel slag, a steel manufacturing by product to replace cement.

Norwegian cement producer Norcem wants to create the first zero-emissions cement manufacturing plant in the world. Norcem is currently using alternative fuels harnessed from industrial waste and now wants to invest in carbon capture as well as storage methods that completely eliminate emissions.

Researchers are also researching with bacteria that absorb atmospheric carbon dioxide in concrete formulations and thus create a better and more environmentally friendly concrete.

Multiple startups including N.C.s BioMason are experimenting with ‘live’ building materials. BioMason works with bacteria and aggregate particles to grow bricks a lot like cement.

Researchers based at the University of Colorado Boulder have published their research with cyanobacteria, micro-organisms which they use to build a concrete alternative.

By inoculating a scaffold of sand and hydrogel with bacteria, they created brocks that are capable of healing cracks.

Even though these replacement concrete bricks cannot replace the many uses of concrete, they can be used in place of concrete for things like facades, pavers, and other structures that don’t bear heavy loads.