Wastewater treatment plants fill many roles. The water that’s treated and released to bodies of water must be treated in a way that protects fish, shellfish, and other wildlife. If it goes back into the drinking water supply, it must be safely treated before the public consumes it. It also has to protect the general public who swim in water coming from treatment plants.
The EPA sets water quality standards for all wastewater treatment plants to meet. If a facility fails to do this, it can lead to fines and negative press. For this reason, experts in wastewater continue to look for ways to improve wastewater treatment. With more than 30 billion gallons of water treated every day, things still can slip through the cracks. Here are some recent discoveries that can help return cleaner water to the environment.
When ground, the shells of crabs, lobster, and shrimp create a fibrous substance that binds to things. It’s touted as helping with wound care as it causes the blood to clot. It’s also studied as a means for lowering cholesterol levels in the blood. People with high blood pressure use it as a salt substitute.
The company Tidal Vision is researching the use of chitosan to create a liquid solution that removes metals like iron and copper from stormwater runoff and wastewater. It reduces the amount of waste going into landfills, and it can reduce costs as this is a substance that is thrown away by seafood manufacturers and restaurants every day.
Researchers are studying beneficial magnetic nanosponges in water treatment, especially when treating wastewater in agricultural settings. Microscopic holes allow molecules to travel through the sponge-like structures at record speeds. Not only is this helping with efficient water treatment, but it’s also aiding with the capture of fuel from the wastewater treatment process.
In the study, a 75% mixture of magnetic nanosponges excelled at removing contaminants in the sedimentation tanks and farm pits where the tests were run. Nanosponges speed up that reaction time by 6x, allowing optimal water treatment. This improves efficiency and is more cost-effective than current wastewater filtration steps.
Until now, sponges haven’t had the ideal pore sizes for the split of hydrogen and oxygen, which impacts how well plants can convert the CO2 into fuel that can be used for things like heating a facility. With the use of nanosponges, the optimal pore sizes aid the division, so the structures prove beneficial both at cleaning wastewater and converting the gases to usable fuel.
Stop and think about the results of wastewater treatment, and we’re not talking about the cleaned water that can return to public water supplies or bodies of water. Plants create greenhouse gases, such as methane. Methane is often burned to heat or power plants, but that produces carbon dioxide that’s released into the environment. Carbon dioxide may not smell like methane, but it’s still harmful to the environment.
Researchers in Arizona have been studying the benefits of using microalgae to process these greenhouse gases. The microalgae are in ponds and feed on methane and carbon dioxide that results from wastewater treatment.
As the algae feed on the gases, methane is captured as a more valuable form of biomethane for power and heat. The carbon dioxide is fully ingested and helps the algae multiply. The excess algae are rich in omega-3 fatty acids beneficial in food products for both animals and humans.
One area that has been researched for several decades is microbial ecosystems. There are thousands of microbes, and newer discoveries improve water treatment steps. While aeration is one of the most common steps in wastewater, it also uses a lot of energy. As much as 80% of a plant’s operating costs are linked to aeration.
Microbial ecosystems help by eliminating some of the chemical additives and excessive use of aeration. Lowering chemical additives helps lower the amount of nitrogen and phosphorus in wastewater sludge.
In the 1990s, researchers discovered anaerobic ammonium oxidation bacteria (anammox) could convert ammonia in waste and farm runoff to nitrogen gas. While some aeration was still required, the amount was far lower.
The microbes took up space, but that issue was resolved by introducing granular pellets that required 25% less space and helped lower operating costs by as much as 30%. A Dutch town became the first to embrace the microbe pellets for both industrial and residential wastewater, and it was successful in both areas.
Research on microbial ecosystems didn’t stop with that project. A Danish university uncovered a new type of ammonia oxidation bacteria known as comammox in 2015. Comammox was a massive discovery as they could process the ammonia without requiring any oxygen. However, testing is still ongoing to see if they can eliminate the need for aeration in wastewater treatment facilities.
A California company specializing in oxygenation is rapidly expanding the use of equipment that creates nanobubbles to aid in water treatment. Moleaer is investing $9 million to work with universities across the country to study all of the benefits and uses of nanobubbles in food manufacturing, wastewater treatment, and agriculture.
While aeration is a critical step in wastewater treatment, most mixers stir and aerate with the bubble sizes you’d expect in water. Nanobubbles are tiny. They’re so little, you cannot see them. In fact, nanobubbles are reportedly more than 2,000 times smaller than a grain of salt. Due to their size, they remain in the water for longer, increasing the amount of oxygen within the water.
A professor at UCLA reported that nanobubbles could transfer oxygen at rates of 85%, which is far greater than the typical average of 2%. When this technology is used, it can reduce the need for chemicals in wastewater treatment and reduce operating budgets.
Polyhydroxyalkanoates (PHAs) are a polymer that bacteria can produce when they digest sewage. This is an important study as PHA can be converted into biodegradable plastic. A plant in the Netherlands is currently researching the use of bacteria to create PHA bioplastic that can be used in manufacturing in areas where a water-resistant, flame-retardant biodegradable composite is needed, such as construction materials.
Researchers at the National University of Singapore came across a new strain of bacteria that proved effective at removing nitrogen and phosphorus from raw sewage. The microbe named Thauera sp. strain SND5 was found in a wastewater treatment plant, but it behaved differently, catching Associate Professor He Jianzhong’s attention.
Bacteria are already used in wastewater treatment to purify the water, but most can handle one compound. SND5 was the first bacteria he’d seen that was able to multitask. Because this bacterium can take care of both nitrogen and phosphorus simultaneously, it has the potential of being more effective at a lower cost.
Research is ongoing, and discoveries occur each year. What can wastewater treatment plants do in the meantime? One of the best steps to take is to do a walkthrough of your plant’s equipment to explore the equipment’s age, how often it breaks down or requires maintenance, and what’s driving your plant’s utility costs up.
When you sit down and look at every aspect of your wastewater treatment plant’s operating costs, successes, and failures, it helps you realize where there is room for improvement. That’s when you talk to an expert in wastewater treatment plant equipment and design.
Lakeside Equipment’s experts help you find ways to improve performance, lower costs, and enhance efficiency. Call us to schedule a consultation.