What Makes a Waste Stream a Good Fit for Evaporation?
Evaporation is exceptionally broad in the waste streams it can handle, but there are a few primary factors that determine suitability and guide equipment selection. Here is how to think through each one:
Water Content: 70% or Greater
The fundamental requirement for evaporation is that the waste stream is predominantly water. If your waste stream is 70% to 99% water by volume, it is almost certainly a strong candidate. Streams with lower water content may still be candidates in specific configurations, but the economics become less favorable as water content decreases.
pH: Manageable Range, With Solutions for Extremes
ENCON evaporators in standard materials of construction handle a wide range of pH. Moderately acidic and moderately alkaline streams are routinely processed without modification.
- Highly acidic waste streams (low pH) or streams combining low pH with high chloride content may require elementary pH adjustment before evaporation, or construction in more corrosion-resistant alloys.
- Streams with a pH below 2 are classified as hazardous by RCRA (corrosive characteristic) and require pH adjustment to at least 6–7 before processing.
- Streams with a pH above 12.5 are similarly classified as hazardous by RCRA and require neutralization.
In most cases, simple pH adjustment is a straightforward and inexpensive pretreatment step. ENCON also offers pH adjustment systems as part of a complete wastewater management solution.
Solids Concentration
Most ENCON evaporators can accommodate a range of solids concentrations. For waste streams with very high solids loading - including sludges and viscous liquids - the ENCON Drum Evaporators and slurry dryers are designed to handle it. Their indirect heating design means the heating elements never contact the wastewater, preventing fouling and scaling that would affect other evaporator types.
Flash Point and Volatile Organics
Waste streams containing significant concentrations of volatile organic compounds (VOCs) or flammable solvents require special consideration. If a stream contains flammable components, evaporation equipment must be appropriate for the hazard classification. ENCON's engineering team will review your waste stream composition as part of the free analysis to determine appropriate design parameters.
Scale-Forming Constituents
Some waste streams contain constituents - calcium, magnesium, silica, sulfate - that precipitate as scale on heated surfaces. ENCON engineers for scale formation in system design, selecting appropriate operating temperatures, materials, and cleaning procedures based on the expected concentrate chemistry. ENCON also offers anti-scalent chemistry for the waste streams that require it.
What Waste Streams Has ENCON Successfully Processed?
ENCON has 3,000+ installations processing a wide variety of industrial waste streams, including:
|
Industry / Application |
Typical Waste Stream |
|
Metal finishing & plating |
Rinse water with metals, pH-adjusted |
|
Landfill operations |
Leachate - high organics, metals, variable pH |
|
Compressed air systems |
Compressor condensate with trace oils |
|
Reverse osmosis systems |
RO reject / concentrate |
|
Ion exchange systems |
Regenerate waste - high salts |
|
Parts washing |
Detergent / degreaser wash water |
|
Food & beverage |
Process water, CIP rinse water |
|
Pharmaceutical |
Aqueous process effluent |
|
Chemical processing |
Aqueous chemical waste streams |
What If I'm Not Sure Whether My Waste Stream Qualifies?
ENCON offers free waste stream analysis for prospective customers. You provide a 2-liter sample of your wastewater and some basic information - composition, volume, current disposal method, and treatment goals - and ENCON's applications team evaluates suitability, recommends appropriate technology, specifies materials of construction, and provides guidance on operating procedures. This analysis carries no obligation.