Ecoteam has created Zero Liquid Discharge systems on wastewater from processes of:
Aeronautic
Automotive
Mechanics (Oily emulsion)
Plating
Non-destrucive processes
Nodic oxidation
Coating
Electrolitic zink plating
“Zero Liquid Discharge”(ZLD) identifies industrial wastewater treatment plants which have no external discharge on the surface or into sewers, but only occasional disposals by lorry.
ZLD is a treatment philosophy originating from a deep knowledge of the production cycle and allows the “complete” recovery of otherwise wasted water, through several steps of treatment.
The main steps leading to the recovery of solutions or rinse water are:
1) Optimization of the prodcution cycle
2) Recovery of exhausted solutions
3) Effluents treatment
4) Concentration by evaporation
The physical law that "nothing is created and nothing is destroyed, but all is transformed" is the basic principle upon which a ZLD treatment works.
More in detail, the above concept can be explained throught the following steps:
1 - Reducing the amount of discharged pollutants from the production cycle to the treatment plant brings a consistent reduction of the sludge and concentrated salts produced at the end of the line.
This can be done by:
§Limiting the drag-out
§Keeping the chemical solutions under control
§Using specific treatment units which extend the chemical solutions lifetime.
2 - Use purification systems of the solutions, whose purpose is to remove specific pollutants that generate pollution.
Some examples are: Systems of oil removal from solutions of degreasing Systems of removal of specific pollutants from heavy metals Specific removal systems
3 - Specific wastewater treatment which allows the waste reuse in production processes.
4 - The concentration by evaporation's technology allows to concentrate solutions up to a density very close to the crystallization's one (Density> 1.2 kg / liter).
ZLD treatment plants produce:
- A slurry (Sludge), mainly made of metal hydroxides, which has a dry matter content of not less than 25%
- Liquid concentrates of dissolved salts or even crystals
This liquid mainly consists in inorganic compounds such as:
• Chlorides
• Sulfates
• Nitrates
• Fluorides
• Sodium
• Potassium
Both these wastes should be disposed of through authorized centers.
Further treatments of the concentrated liquids by evaporation will lead to the formation of a crystalline solid waste, to be properly disposed of either.
Crystallization occurs in a separate dedicated evaporator.
Of course not all solutions will lead to crystallized solids: for certain liquids, such as organic solutions, heavily concentrated may only be obtained, never leading to solid matter, unless using enormous amounts of heat.
On the contrary, if the original liquid is predominantly made of an inorganic nature, crystallization is feasible.
SPECIFIC APPLICATION
ECOZLD-ZN - Zero liquid Discharge in electrolitic Zinc Plating
ECOZLD-ZN
ECOZLD-AL - Zero liquid Discharge in Aluminium Coating pretreatment
ECOZLD-AL
ECOZLD-CRH - Zero liquid Discharge in Hard Chrome plating
M.V.R. Evaporator 
Crystalization unit
