In the heart of Germany, the local branch of a pharmaceutical multinational company produces an anaesthetic containing 2,6-Diisopropilphenol (Active Ingredient A), and an antiviral (Active Ingredient B) made up of sodium chloride, citric acid and sodium acid phosphate.
Traces of these products are present in the wastewater coming from the cleaning process of the production equipment.
The mixture of both the streams to be treated has a significant content in suspended solids, ammonia, heavy metals and chlorides, a COD higher than 100,000 mg/l and an acid pH.
The Solution Provided
The evaporator at the heart of the water treatment system chosen by the client is an EVALED™ PC R500v3. The unit is classified as a heat pump, scraped, vacuum evaporator and is designed to produce about 500 liters of distillate a day.
The parts of the evaporator in contact with the wastewater are made of SAF2507, a type of Super Duplex Stainless Steel which withstood the corrosive effects of chemical compounds concentrated by the continuous water evaporation. The working temperature is around 35°C and the pressure in the boiling chamber is around 5kPa.
Both the streams are sent to a settling tank for equalisation. The mixture is then pumped to a pH correction tank where a certain quantity of caustic soda is dosed in order to increase the pH to 10, as analysis showed that a higher pH improves the separation performance of the evaporator.
Results & Benefits
- The distillation yield of the installed equipment has shown a consistent performance of 92%.
- This means that only 8% of the wastewater volume is sent to disposal, compared with 100% before the installation of the evaporator.
- The full analysis of the distillate is shown in the following Table. Complying with local environmental regulations, the distillate now can be discharged to sewer.