Biological wastewater treatment is a process where bacteria break down the organic substances in wastewater. Wastewater typically contains food particles, toilet paper, solids, and even pharmaceuticals, pathogens, toxins like cleaning products, and heavy metals.
All of these have to be cleaned from the wastewater before it is clean enough to be released to nearby lakes, rivers, or ponds. It’s an essential part of any wastewater treatment program. Whether you own a wastewater treatment plant or have a plant or industrial facility that produces a lot of wastewater each day, you need a biological treatment system that helps clean wastewater.
How Does Biological Wastewater Treatment Work?
The wastewater that comes into a treatment plant is contaminated with many things. You have urine, feces, water from showers, dishwashers, washing machines, and baths. Water coming in from a sewer may have wastewater from factories, car washes, industrial laundromats, and public toilets. It has to be cleaned properly before it is released back into your community’s lakes, rivers, ponds, etc.
To do this, water flows or is pumped into a septage acceptance plant and goes through screens into clarifying tanks where solids sink to the bottom and are removed using pumps. Floating items like fats, oils, and grease float to the surface and are removed. Trash rakes work with the screens to clear out larger items like plastics, rags, and flushable wipes, which really should never be flushed as they do not break down as you’d expect.
While you may have removed a lot of material and sludge from the wastewater, there are still many contaminants in the wastewater. It will go into an aeration tank where it is pumped full of small oxygen bubbles. This oxygen is important as it’s part of a biological aerobic treatment process.
With this, oxygen feeds the bacteria, which gets them energized to start feeding on the pollutants. That breaks down pollutants and converts them into phosphate, nitrate, and carbon dioxide. The wastewater settles again, and any remaining sludge is removed. This process continues with bacteria helping remove pollutants
Aerobic treatments are faster than the anaerobic process that skips the use of oxygen. With this process, biogas is produced, which can affect the environment. Because of this, aeration is often preferred as it’s fast, efficient, and effective.
If you need a cost-effective option for biological treatment using aeration, a Sequencing Batch Reactor has a small footprint and can be expanded if that’s needed in the future. It has a continuous feed system that repeats the aeration, settling, and decanting phases in a reactor basin. It’s a five-phase operation:
- Mix Fill – The valve opens to allow raw wastewater into the tank as the mixer turns on, but aeration is turned off.
- React Fill – Aeration turns on and off as phosphorus, nitrogen, Chemical Oxygen Demand (COD), and Biological Oxygen Demand (BOD), are processed or treated.
- React – The valve allowing raw wastewater into the tank shuts off the flow. Aeration and mixing continue to completely treat the wastewater for the final stages before release.
- Settle – Aeration and mixing stop to allow any solids to sink to the bottom or rise to the top.
- Sludge Removal – Sludge and scum are removed from the system and the clear water is released or decanted.
What Are Biological Wastewater Treatment’s Benefits?
Biological wastewater treatment is an essential part of a wastewater treatment plant. It’s what keeps pollution out of rivers, lakes, and oceans. It also helps conserve water in some regions as treated water goes into tanks where it’s drawn into the water treatment facility for additional disinfection to make it safe for the community members to drink, cook with, and shower in.
Facilities that use a lot of water can also benefit from biological wastewater treatment processes. If you own a facility like a meat processing plant, the strain you put on a local wastewater treatment district is tremendous. You can improve your company’s reputation by taking extra steps to lower the strain you’re putting on your district’s facilities.
With industrial wastewater facilities that handle biological treatments before releasing your wastewater to the sewers, you help out. You lower the work required to treat the wastewater you’re releasing, which reduces your district’s operating costs.
Wastewater treatment districts that use biological treatment processes find it easier to comply with federal and state regulations. Businesses that pre-treat wastewater help keep districts in compliance.
People also benefit. With an increased number of industrial wastewater facilities at different factories and plants, it creates jobs for people in your community.
It creates cleaner water that’s going into lakes, rivers, and oceans. If you live in an area where you spend time in the water, you want the assurance that you’re swimming or boating in clean water and not being exposed to contaminants. You don’t want to eat fish that are a potential health risk because they’ve ingested too many pharmaceuticals or toxins.
Studies have found that fish that are exposed to water with high levels of birth control medications are impacted. They don’t lay as many eggs, which can deplete the availability of seafood. Biological wastewater treatment is an important step in protecting waterways.
What Types of Biological Wastewater Treatment Systems Are Popular Today?
As mentioned earlier, aerobic is quicker as you add oxygen into the process. But, anaerobic is best when you want to convert your organic materials into methane, carbon dioxide, and biomass. A third option, Anoxic, requires the use of nitrates, nitrites, selenite, or sulfate to feed the bacteria.
Activated sludge is the most commonly used biological wastewater treatment method and it’s been around for over a century. It’s an aerobic wastewater treatment technology. It’s going to be the first choice in many districts.
Ultimately, the decision is yours, but it’s a conversation you should have with an expert in wastewater treatment. You need to make sure whatever changes you make remain in compliance with federal and state regulations.
If your wastewater treatment facility isn’t using biological wastewater treatment processes, it’s time. Lakeside Equipment can help guide you into the best processes to add to your current system. Our wastewater experts advise you on the cost of biological wastewater treatment to ensure any additions fit your district’s budget. We’ll help you make sure you are following regulatory requirements.
Lakeside Equipment has been helping clean water around the world for close to a century. Our team has the solutions you need at a budget you can afford. Reach us online or by phone to talk about your facility’s needs and what improvements will help make wastewater treatment processes efficient and effective.