Differences Between Surfactants, Enzymes and Bacteria

In the wastewater industry you hear a lot of talk about surfactants, enzymes and bacteria as it relates to how to effectively treat wastewater , but what do they do, what role do they play and what problems can they create?

How Do Surfactants Work?

Surfactants are responsible for the ability of cleaning solutions to lift, dirt, grease, grime and oily stains from surfaces and prevents those particles from re-depositing back on the surface they came from. Dish washing liquids/ detergents are good examples of products with surfactants along with many types of tool cleaning solvents that remove oil and grease from tools and machine parts, not to mention basic fabric stain removers use surfactants as well.

So if surfactants provide so many uses, why do wastewater treatment plants hate them and try to limit their usage? Surfactants can cause problems in wastewater treatment facilities due to the excessive foaming they can create. These systems can experience foaming in their basins to the extent that the foam overflows and spills out into other areas creating messes and interfering with the treatment process. Surfactants can also interfere with microbial process of waste degredation. Surfactants that are easily biodegraded can act as a food source for bacteria causing them to leave the oil and grease behind. Additionally, they can reduce the flocculation properties of the bacteria resulting in poor settling, resulting in reduced system efficiency. It for these reason many municipalities and industrial waste treatment plants keep a close eye on the level of surfactants entering their plants and encourage people to limit their usage.

How Do Enzymes Work?

Enzymes are another popular ingredient used in cleaning agents, fabric care products and wastewater treatment products. Enzymes are biocatalysts produced by living micro-organisms used to speed up various biological processes. In terms of cleaning and actual commercial usage, enzymes are collected and concentrated from these micro-organisms and added to cleaning solutions. They work by solubilizing large organic deposits, stains and particles so they can be easily removed by mechanical action like scrubbing and rinsing with water.

If enzymes can liquefy waste, why would wastewater treatment professionals not prefer to use them? The reason is, enzymes are only a partial solution and if not used correctly can cause more problems. Enzymes can liquefy fats, oils and greases and other organic wastes in wastewater, allowing it to flow with water, however at this point all that is happening is the waste is just being passed from one place to the next, where eventually it will just coagulate and create clogs further down the treatment line. Additionally, waste in a treatment plant is complex and there really are not that many commercially available enzyme products that can address this diversity of waste. Sure enzymes work great for stain removal and general household cleaning, but the real solution in a wastewater treatment has to be bioagmentation. Bioagmentation is the use of additional beneficial bacteria to assist or aid indigenous species to treat waste in water or soil.

How does Bacteria Work?

As stated above, enzymes are produced by microorganisms, these microorganisms are called bacteria. Most people don't realize that not all bacteria is bad, in fact beneficial bacteria are like natures garbage disposal...they can aggressively devour and clean up organic waste.

Depending on the makeup of the waste to be cleaned up, bacteria can produce the necessary enzymes to effectively liquefy the waste to help remove it. The next step is what separates the bacteria solution vs an enzyme solution. Bacteria will take the waste that has been liquefied by the enzymes and digest it, converting it into carbon dioxide and water. This 2nd step is key to bioremediating a spill or wastewater, as it is the step that actually removes the waste from the environment. Furthermore, bacteria are renewable meaning they will multiply provided they have a food source and a fair amount of oxygen. Enzymes on their own are not renewable and have to be constantly added. As long as bacteria are present, enzymes will be produced. Another advantage of bacteria is that they can produce a wide array of enzymes based on the situation at hand. In the commercial world there are only a few varieties of enzymes available commercially and these cannot compete with a diverse profile of thriving micro-organisms.

It is rare that you will find a wastewater treatment professional who will recommend enzyme treatment over bacteria. The cost savings benefits are apparent due to the renewable nature of the bacteria, plus the diverse enzyme portfolio they create if far superior to any commercially available alternative and finally, bacteria treatment can have lasting effects further downstream past the application point and can relieve FOG congestion on other plumbing and sewer lines.

In conclusion, surfactants, enzymes and bacteria all have their place in the residential and commercial world and all play valuable roles in keeping homes, businesses and industries clean. However, when it comes to the task of cleaning up wastewater and reducing costs and expenses associated with wastewater treatment, bacteria is the clear cut choice.