Treatment of vegetation water from oil mills
Customer
The client is an oil mill in Sicily that uses biological processes to treat water.
Objectives
Using the vacuum evaporation process to make the treatment of vegetation water more efficient, in regional and extra-regional mills, both from a practical and economic point of view.
01.
Challenge
Vegetation water produced by olive oil processing is an important source of environmental pollution due to its high COD values, strong acrid odor and dark color.
Spreading on the ground is widespread and the maximum quantities allowed are regulated by law 574/96 and subsequent amendments. However, the ratio between the volume produced and the volume allowed for spreading is very high, difficult to respect and concentrated in a short period of time
The treatment of waste water from oil mills consists of chemical-physical processes (dilution, evaporation, sedimentation, filtration and centrifugation) and biological processes (anaerobic or aerobic digestion, composting, etc.)
The antimicrobial activity due to the presence of phenols in biological processes makes these treatments not very effective, while practical and economic reasons make other treatments not very convenient
02.
Project
Study and analysis of the treatment of vegetation water through vacuum evaporation tests in the field with different pilot plants, conditioning if necessary the incoming sample to be at neutral pH.
03.
Solution
To address the issue of vegetation water management in oil mills, a V-NT 12000 vacuum evaporator was installed, designed to reduce the volume of wastewater up to 15 times and reduce the polluting organic load. The system allows obtaining a clear distillate with significantly reduced COD values, simplifying disposal and improving the sustainability of the process.
Decrease in COD value.
Characteristics of incoming wastewater
Appearance: cloudy
Color: Dark green to brown
PH: between 5 and 6
COD: between 40,000 and 135,000 mg/L O₂
Characteristics of the distillate produced
Appearance: clear
Color: colorless
PH: between 6 and 7
COD: between 500 to 2,000 mg/L O₂
Analysis of the results
The implementation of the V-NT 12000 vacuum evaporator has led to a significant improvement in the management of vegetation water from olive mills, reducing their environmental impact and optimizing the disposal process.
Thanks to vacuum evaporation technology, the vegetation water has been concentrated up to 15 times, drastically reducing the volume of liquid to be managed and facilitating disposal in compliance with environmental regulations.
The treatment allowed to obtain a distillate with significantly improved characteristics compared to the initial effluent. The COD (Chemical Oxygen Demand) was reduced from a value between 40,000 and 135,000 mg/L to 500-2,000 mg/L, reducing the polluting organic load. The pH was stabilized between 6 and 7, making the treated liquid more compatible with any reuse processes. The initial effluent, characterized by a cloudy appearance and dark green/brown color, was transformed into a clear and colorless distillate, a sign of significant removal of pollutants.
The evaporator operates with an energy consumption of approximately 160 Wh/L of condensate produced, ensuring effective treatment with low costs and greater sustainability compared to other disposal solutions.
Savings
Reduction of management costs
Circularity
Reuse of production water
Sustainability
Reducing environmental impact