Your Road Map for Success

Six Types of Wastewater

Often when speaking with a customer or prospect they will comment, “This is the most unique and difficult wastewater you will ever see,” and they are absolutely correct. Remember their system or possibly a similar system may be the only applications they’ve seen. As a Wastewater Professional we have the opportunity to see and treat a vast plethora of treatment plants and types of water.

There may be different names for equipment, types of contaminants or different industries but these are the ONLY six types of wastewater you may encounter:

Dissolved Material is any detected contaminant able to pass through a 0.45 micron filter paper. Dissolved heavy metals are a prime example.

Colloidal Suspension are finely dispersed solids incapable of settling out quickly. An example of this is river water. Although these fine particles will settle out eventually, the customer’s systems typically will not have the needed residence time.

Oily Wastewater (oil in water) is much like Colloidal Suspension, where oily wastewater will not separate on its own. Finely dispersed oil droplets are emulsified in the water. This emulsion is often caused by a surfactant preventing the oil particles from coalescing and in turn remain emulsified. Typically, colloidal solids are also present in oil waste water.

Suspended Solids are larger particles which will settle out quickly. The speed by which they settle will often need to be improved for plant operation.

Sludge occurs when a Colloidal Suspension and/or a suspension is treated. These solids are known as sludge and settle out in a system.

Oily Emulsion (water in oil) is when oily wastewater (oil in water) is treated and it creates a more concentrated waste known as an Oily Emulsion or a water in oil emulsion.

Before testing can begin you must know exactly what is important to the customer.


Do you know what is important to your customer?

Once you understand this, the Application Road Map provides a logical, systematic approach to solving your customer’s jar testing problems.

For a liquid solids separation program to be effective, a dissolved solid must be made insoluble to be extracted. This can be accomplished through various processes including precipitation, biological removal or complexing. Knowing what contaminant needs to be removed will determine the process required for removal.

Example: A customer needs to reduce soluble copper. By researching on the internet you will find that pH adjustment for hydroxide precipitation, sulfide precipitation and heavy metal precipitants are possible treatment schemes. These processes will make the copper insoluble and place you on the insoluble side of the Application Road Map.

What are you trying to remove from your wastewater?