Emerging treatment technologies for water contamination
Wastewater treatment has come a long way as filtration systems have become more and more advanced. However, water contamination is still much too common, as heavy metals, bacteria and other pollutants often find their way into groundwater.
In fact, the EPA estimates that thousands of miles of rivers and hundreds of thousands of acres of lake water are contaminated because of industrial wastewater. As such, even though industrial wastewater filtration is more advanced than ever, it is essential that we continue developing new technologies to further refine the treatment processes.
Major advancements are being made every day and several emerging water treatment technologies could have major implications. From membrane filtration systems and nanotechnology to advanced oxidation processes, this article will review some of these new technologies, how they work, and why continued innovation is essential.
Membrane filtration systems
New types of advanced membrane filtration systems are at the forefront of emerging treatment technologies to combat water contamination. There are two specific types of membrane filtration systems that could be the future of membrane filtration technology — low-pressure and high-pressure membrane filtration systems.
Low-pressure membrane filtration
While low-pressure membrane filtration has been around for more than four decades, only now is it being utilized in wastewater treatment plants. It has several advantages over traditional wastewater filtration, including:
- Chemical reduction
- Energy reduction
- Less waste stream
- More opportunities for automation
- A reduction in pathogen and disinfection byproducts
The downside of low-pressure membrane filtration is that they are extremely porous and cannot remove dissolved natural organic matter. As such, it must be coupled with other filtration systems.
High-pressure membrane filtration
High-pressure membrane filtration, which includes nanofiltration and reverse osmosis membranes, is the second key type of emerging membrane system. High-pressure membrane filters work great with low-pressure ones, because they do a great job of removing organic contaminants. In fact, high-pressure membrane filtration can remove up to 90% of natural organic matter.
Photocatalytic oxidation
While traditional ultraviolet light remains the most popular type of light technology in water treatment, photocatalytic wastewater treatment may give it a run for its money. Photocatalytic oxidation is an advanced form of UV water treatment that uses light to eliminate and remove harmful contaminants in wastewater.
It does this changing the radicals and chemical composition of the contaminants in question. It is a very versatile and comprehensive type of emerging water treatment, as it can remove organic contaminants, inorganic contaminants, chemicals and microorganisms, such as viruses, bacteria and more.
Photocatalytic oxidation has the added benefits of being extremely energy efficient, making it good for environmental protection. It is also a very simple system that is easy to implement while being very cost-efficient, because oxygen is the oxidization agent used.
Implementing nanotechnology
Nanotechnology has been a hot talking point in the science and water treatment industries for decades. However, massive strides have been made in recent years in regard to implementing nanotechnology in water treatment processes.
Essentially, nanotechnology in water filtration and treatment is when you use tiny particles or tubules to remove impurities from wastewater and drinking water at the molecular level. There are several different types of nanotechnology being used in drinking water treatment, including:
- Nanometals — Highly effective at removing heavy metals, such as arsenic and mercury.
- Nanoadsorbents — Great for removing heavy metals, organics, volatile organic compounds and bacteria
- Nanomembranes — There are several different types of nanomembrane filtration systems that could be implemented with traditional cartridge and industrial filter bags, as well as reverse osmosis.
- Photocatalysts — Photocatalysts refers to using UV light in conjunction with nanotechnology.
Each type of nanotechnology has a different process for breaking down and removing emerging contaminants in wastewater. They also specialize in removing different types of contaminants, which means you may need to implement multiple types of nanotechnology.
Advanced oxidation processes
Advanced oxidation processes (AOP) is where different chemicals are used as oxidizing agents to break down and remove wastewater contaminants. Here's a quick rundown of how AOP works.
- The oxidizing agents get added to wastewater.
- The oxidizing agents attach themselves to free radicals and pollutants in the water.
- The oxidizing agents then break the pollutants and contaminants down into compounds that are less hazardous and more biodegradable.
- It is then easier to remove the pollutants with other forms of membrane filtration and biological treatment.
Hydrogen peroxide is one of the more commonly used oxidizing agents in advanced oxidation processes. It, along with ozone, are highly effective at breaking down complex pollutants, thereby increasing the removal efficiencies of other filtration systems down the line.
Biological treatment
Thus far, we have explored mostly physical and chemical water treatment technologies. If you want an alternative to these options, biological treatment is the way to go. Biological treatment is a versatile way to treat contaminated groundwater and wastewater. It is also one of the only ways to remove biodegradable organic matter from water.
Removing biodegradable organic matter (BOM) has become increasingly important. It is becoming more and more common in wastewater, and biological treatment is the best way to reduce the concentrated solution of BOM. It is often used in conjunction with ozonation, and typically comes immediately after it.
Biological treatment works by using special filters to collect biofilm as water passes through them. The biofilm then turns into sludge, bacteria and other contaminants, which must then be treated and disposed of. Biological filtration is quickly becoming one of the most popular ways to reduce water contamination.
Zero liquid discharge technology
One of the biggest issues that stems from the treatment processes of wastewater is that it creates significant waste. Zero Liquid Discharge Technology (ZLD) was created to eliminate this very problem.
It is a strategic wastewater treatment method that uses advanced oxidation processes, such as hydrogen peroxide and ozone, to treat water. ZLD then recycles and reuses the wastewater, ensuring there is no waste. This results in an affordable, energy-efficient and eco-friendly form of water treatment.
Conclusion
There are numerous emerging technologies to deal with the high levels of water contamination. This is essential, as traditional means simply are not getting the job done at the necessary level.
However, while advancements in treatment technologies are great, it is up to professionals in the wastewater industry to implement these changes. This requires careful review and creating a plan to effectively implement the right water treatment systems for your needs.
