The Ultimate Guide To Good Wastewater Odor Control: Part One
Odor control is essential to a happy, healthy public. Nobody likes to be reminded of untreated waste in the form of a bad smell, especially if the odors start to creep into our neighborhoods and homes. Once it does, it can be a smelly nightmare to get rid of.
When it comes to treating wastewater, odor control is a significant point of focus for local and federal governments. Collection and treatment sites alike have to deal with the problem of unfortunate odors building up and impacting public health. Left untreated it can have a significant impact on things like local property value, consistent illnesses, and other unpleasantries we'd all rather avoid.
The problem is that these bad odors can be caused by a variety of sources, and those sources can’t necessarily be targeted by one single treatment. Or if they can, it's bound to cost a lot of money. But as a primary concern and a major nuisance, there is a lot of pressure to resolve these odor issues quickly and affordably. So how are we to manage the odors effectively, but also without taking too long or ramping up costs too much?
Wastewater treatment has become more important than ever before as populations and cities have grown rapidly. Additional pressure on collection and treatment centers means we're constantly working to keep head above water and maintain the right levels.
This type of pressure has also sparked multiple approaches to odor control that all have their own advantages and disadvantages. We’ll cover these in detail below:
Why Wastewater Odor Control Is Essential
Any time you have a location where wastewater is either being collected, moved, or treated, annoying odors can start to build up in the area. The worst culprit, however, typically tends to be where collection initially takes place.
Usually, odors come from bacteria that are in a septic condition, meaning they have gotten limited oxygen supply (a state known as anaerobic). With no way to properly respirate, the odors take over, causing a disgusting and distinct rotten egg smell. So the bacteria in the collection system quickly make themselves known to the general surrounding area and public.
Similar odor issues can take place in biosolid processing facilities. There can be a lot of changes in biosolids over the course of the wastewater treatment process, especially during dewatering and thermal increases. Here, the odors that are being released have a mainly chemical source, including strong-smelling compounds like ammonia, hydrogen sulfide, and mercaptans.
This is where new odor control treatment technologies come in. The majority of these solutions fall into one of two categories, namely vapor-phase or liquid-phase. In part one of this guide, we'll be focusing on the vapor-phase technologies used to banish bad odors, including what makes them good and not-so-good.
Understanding Vapor-Phase For Odor Control
Vapor-phase technologies mostly target wastewater odor control problems through special ventilation procedures. Using specific air treatments, the vapor-phase ventilation system maintains a negative air pressure which stops bad odors from emerging through accessible areas. They can only make their way through the system, be cleaned and deodorized before being released.
This means that vapor-phase solutions are especially good for escaping, airborne biogases and odors that start to linger. The odors can only follow the ventilation system, which leads it directly to filtration and other treatments before they are released in a new harmless form.
With the vapor-phase approaches to biogas treatment, contaminant levels can be drastically reduced to fall within safety restrictions and guidelines. This is especially important to treatment facilities that make use of anaerobic sludge for fuel due to concerns regarding emissions. There are stringent emissions requirements for plants that levels have to fall within in order to avoid penalties and fines.
Now that we understand the basics and the demand, let’s break down some of the most common vapor-phase solutions in further detail.
Approach #1: Wet Air Scrubbing
One of the most prominent vapor-phase treatments for odor control is wet air scrubbing. This relatively flexible solution can be used to treat a variety of water-soluble compounds, working especially well against ammonia and other nitrogen-based chemical build-ups.
Using the wet air scrubbing tool, contaminants are turned from a gas into a liquid chemical solution which can be further injected with treatments based on the contaminants that are present.
The biggest benefit of this system is how reliable it is, as well as how customizable it is based on the chemicals used and the treatments needed. The downside is that maintenance and the cost of chemicals can be quite high, especially in a multi-stage scrubbing system.
If you consider how often this type of treatment takes place, it's easy to see how the cost of chemicals can quickly outweigh the benefits that this approach can bring.
Let's look at another example of vapor-phase treatment for odor control.
Approach #2: Liquid Redox Technology
Liquid redox technology isn't necessarily new, but it has not been used as prominently as some of the other solutions in this article for the purpose of odor control. This is because liquid redox-based options are considered to be more complicated and costly to implement.
This approach works by integrating chelated metals that are dissolved in a liquid solution. The process causes hydrogen sulfide to be removed via a gas stream and then to be converted into a solid compound - sulfur. It's essentially a natural chemical reaction that has been fast-tracked. The solution's metal ions can also introduce oxygen into the process which can further aid with reducing bad odors.
The disadvantages are worth noting as they can impact the decision to make use of liquid redox solutions in treatment plants. When it comes to odor control, this option can have some limitations, especially if compared to something like wet scrubbing. The liquid redox equipment and supplies come at a higher cost that can be difficult to maintain over the long term due to issues like erosion and more.
Still, there are some places where the use of liquid redox is essential. In biogas treatment facilities, for example, the use of this approach can actually lead to lower costs over time due to how heavily other vapor-phase solutions rely on chemicals to defeat bad odors. Over time, the cost of these supplies can be so substantial that it's actually more affordable to invest in liquid redox options and to use them only when necessary instead of continuously.
Approach #3: Biofiltration
Biofiltration is a highly lauded technology for its ability to treat multiple water-soluble contaminants. When a biofilter is introduced, odors are transformed from a vapor state into a liquid state which has other purposes.
Once liquified, the mixture is biodegradable and can be used in fertilizers and compost heaps for a variety of soil-improving advantages.
With that being said, biofilters are only suitable for removing specific contaminants, specifically hydrogen sulfide and other organic sulfides. It's less effective at reducing the presence of ammonia and other nitrogen-based contaminants, which means it might need to be used in conjunction with another type of treatment.
It's also important to note that the biofiltration process needs to be monitored carefully. The biological bacteria populations that exist in the biofiltration process are vulnerable to significant changes. If the concentration levels or conditions change too much, bad odors may recur until the balance is restored.
Approach #4: The In-Pipe Solution
In-Pipe likes to take an innovative approach to issues like odor control. For example, In-Pipe Technology now offers the IPT-AOP-16 Advanced Oxidation Process System for Lift Stations that requires no chemicals, needs only a small footprint, and uses minimal resources like electricity. That already makes it more affordable long-term. But how does it work?
The IPT-AOP-16 is essentially a chemical-free scrubber system that connects to existing lift station vents to oxidize hydrogen sulfide outside of the lift station environment. This means that odors are scrubbed before emission to ambient air and to prevent corrosion of the existing infrastructure.
Individual IPTC(OH-) scrubber units can be installed in parallel, enabling a scalable and flexible treatment solution. It also works for industrial applications and the power use is a dream.
The IPTC(OH-) requires only 120V power and can be installed in a small space, typically less than 25% of the footprint of currently-popular biological scrubber devices and with 50% of the power requirements. The photocatalytic cells in the chemical-free scrubber produce a continuous supply of powerful hydroxyl radical oxidizing agents to neutralize hydrogen sulfide (H2S) and other bad odors.
In short, if you're tired of breaking the bank just for better odor control: don't. Try our unique and customizable solution and see the pressure taken off your yearly operational budget. It's fast and easy to implement but offers a lifetime of better choices and fresher air. Visit https://www.in-pipe.com/lift-station-odor-control to get started today!
Remember to stay tuned for part two of this guide where we discuss liquid-phase treatment options for odor control.