Hey Readers,
We have a lot of innovations this week, so stay the course for a longer read this week.
Waste to methane and clean water!
We have talked in the past about the growing movement to recycle water. The plan has always faltered due to the mental block about the ‘cleanliness’ of this recycled water and also that the economics of cleaning the water didn’t make sense. Innovators have sought to tackle the cost at a later date, arguing economies of scale and have instead focused on educating their fellow citizens about the ‘cleanliness’ of recycled water. This latest innovation from the utility provider in Orange County, CA, aims to squarely tackle the cost factor by generating electricity from the wastewater to power the operations and then some.
How? - The process involves, wastewater sludge being heated to 700 degrees, at which point the water is distilled from the sludge. The resulting dried out biofuel is burned to run turbines which in turn produce electricity. The process will convert 5 wet tons of sewage into 1 dry ton of biofuel and about 1000 gallons of water daily. The water can later be recycled and purified for a variety of uses, while the biofuel runs the turbine, which in turn would create between 500 kilowatts and 1 megawatt of energy (1MW can run between 400 and 1,000 homes).
Double winner - Extracting cellulose from Agri-waste to make membranes and stop pollution
Anyone watching the news the last few years would know that North India sees huge amount of smog and pollution caused in a large part by burning of crop remains at the end of a harvest season. Now a team of researchers from multiple universities in India have come together and devised a technique to purify air and water through food waste and crop remains.
How? - They extract cellulose from food waste and rice straw in an eco-friendly and single-step process (that is in the process of being patented). This cellulose is then coated with copper oxide and other nanomaterials and converted into a film, which can be used to filter air or water, depending on the need.
Rice husk to activated carbon for filtration
Staying with crop remains, a company in the Midwest has shown that the waste from rice production has other adjacent uses. Rather than extract cellulose, this group gathers the rice hulls (the 20% of the weight of a rice harvest which has to be removed before the rice is eaten) and turns it into water-filtrating activated carbon. These rice hulls have the added bonus of being high in silica, which not only pulls organic contaminants from the water but pulls metals too. How? - Rice hulls are put into a rotary kiln and roasted at 400 degrees Celsius for about 8 minutes. This chars them well enough to make them activated carbon.
AOP for the win! (3rd week in a row)
For a third week in a row, we have found out something about a stand-alone Advanced Oxidation Process (AOP) treatment. This time the AOP process is being used to completely reuse dye wastewater from the textile industry, eliminating its toxicity and making it nearly zero liquid discharge (ZLD). This one is developed by researchers from Indian Institute of Technology (IIT) Kanpur along with Malaviya National Institute of Technology, Jaipur and MBM College Jodhpur.
Without getting into the weeds, the proposed treatment process consists of the primary AOP dosing step followed by the sand filtration step, another AOP and subsequent carbon filtration. While targeting a ZLD water management system, it is being utilized currently for complete reuse of industrial dye wastewater for domestic and industrial usage at a rate of 10 kilo liters/day.
Sorry, we couldn’t help ourselves! This San Diego-based company has an acronym’d process that transforms brackish water and acidic mine drainage into valuable fertilizers and clean drinking water by using ‘environmentally responsible’ processes. They say that their patented method involving ion exchange processes, recovers water and converts the brine to potassium nitrate and ammonium sulfate fertilizers. The sale of these fertilizers allows the KNeW process to sell water at competitive rates and offset treatment costs.
As the schematic above shows, the brackish water from rivers or underground aquifers is filtered to remove coarse particles, after which it is pumped through an ion exchange battery to remove all the dissolved ions. This process removes the substance most damaging to the earth’s crust—sodium. The residual nitrates are then recycled or treated to create useful products for agricultural, chemical and other industries.
Saving water at the Urinals and eliminating the Odor
Fun fact we learned this week - stand up urinals found in most public restrooms, use up to 5 liters of water per flush. Enter this innovator from India who has devised an add-on device to urinals which is placed on the drains of urinals. It allows urine to pass through it swiftly, and a flap placed within it opens up when the liquid passes. It closes once the flow stops. The device itself is made from an antibacterial material, which has a nanocoating. This coating prevents bacteria cultivation and the formation of foul-odor ammonia.
They go on to say that 800 devices have been deployed across India, and that they have helped to save 167,900 liters of water per urinal. Which is a total of 190 million liters of potable water every year.
In Other News
On to the news section, where we have a fair bit to cover.
First, new research from the University of Saskatchewan shows that the estimated volume of ancient, salty groundwater stored deep within Earth's crust is the largest reservoir of water on land, measuring 44 million cubic kilometers and surpassing the volume of Earth's ice sheets!!
But Before you get your hopes up, the authors say that while vast, this deep groundwater will not solve the world's water shortages. Nor is it feasible to rely on desalinating this brine and using it as a source of water for drinking or irrigation.
In some much needed good news, the remediation efforts for PFAS contamination in an old well in New Hampshire has worked with the toxins now down to non-detectable levels. How did they do it? Well, they built a new treatment facility utilizing resin and granular activated carbon filters, known as GAC, removing twenty-four different PFAS compounds from the well.
In associated news, the EPA has finally released guidelines for PFAS limits across the country. Finally! Better late than never, right?
The decades long release of treated radioactive water into the oceans from the erstwhile Fukushima disaster in Japan is still going to happen. Since they have no way to store the water and not have it seep into the groundwater they are choosing to treat and dissipate it into the oceans. No one is quite sure what that will do.
Newly appointed NY governor Kathy Hochul has approved more than $53 million to help nine municipalities finance their drinking water and wastewater projects. While a good start, its a long way to go still with the crumbling infrastructure all around.
Wings4Water anyone? The town of Lee’s Summit, MO is holding a chicken wings tasting contest to raise money for clean water. How? - Well, 35 teams shared their wings with townsfolk, if they want to vote for a particular wing, they donate money to that team via credit card or online with their phones. The team with the most money raised at the end is the winner and 100% of the money is donated to relief efforts. This happened last week, so let’s see how it turned out!
Lastly we wanted to close with a great read from the BBC. It talks about how they have used ecology and the humble Oyster to rebuild a sea wall barrier and protect villages in Bangladesh. Do give it a read!
That is it for this week folks,
‘Til next Friday, Peace