Evaporation is among the most energy intensive methods to treat wastewater. For this reason it is not typically the first choice or the best option for handling most waste streams. While recycling is the optimal solution, there are circumstances under which no treatment method will do the trick of returning the water to its original quality. For example, if there is a diversity of contaminants it may require too large an assembly of treatment stages to remove them all. Occasionally the contamination is just too heavy for other treatment methods to be feasible and so evaporation becomes the solution.
When can you evaporate?
By nature evaporation is somewhat of a catch-all treatment method under the conditions that:
- The waste stream contains no ignitable components. The threshold of ignitability, referred to as the flash point, is critical to prevent malfunctions and even explosions in the system.
- VOC’s are not present in high quantities. Volatile organic compounds can cause harm to the environment and to human health. Wastewater high in VOC’s should not be evaporated.
If the wastewater is deemed suitable the system may be coupled with pretreatment to improve system efficiency or simply to regulate the pH of the effluent vapor. Typically the evaporator can function as the sole necessary piece of equipment.
If you can’t remove the waste from wastewater, remove the water.
An evaporator uses heat to reduce the volume of wastewater by 90 to 95 percent. The effluent wastewater, highly concentrated with contaminants, is much easier to dispose of than the original volume. In some cases it can even be captured as a solid and disposed of by landfill. The most common evaporator design can be described as a hot plate. Similar to boiling a pot of water on the stove, heat is introduced from the bottom of the system. The main issue with this method is that not all of the heat makes it from the source to the water.
The innovators at Watermaze have developed a new technology employing a submerged flame to bring the heat exchange efficiency to 100%. The design allows for the greatest possible fuel efficiency at a small footprint and with minimal maintenance.
Contact an expert at HPI Processes for great deals on Watermaze products or for any of your wastewater handling inquiries.