Waste water treatment units

Treatment of washing water from an ink and toner cartridge recycling process

A player in the global compatible printing consumables market consults the NISKAE’S team to find a solution for the treatment of its washing water polluted with ink pigments. To do so, our Customer decided to adopt the fully automated SW500 water treatment unit corresponding to specific requirements. It can treat a volume of wastewater of 2,500 L to 3,000 L each day, with a minimal treatment time of around 10 to 15 minutes.

A large volume of wastewater containing ink pigments and heavy metals must be treated

When dismantling ink cartridges and toners, a cleaning phase is necessary to remove residue. Cleaning is carried out using an aqueous solution mixing cleaning product and reverse osmosis water. These water cleaning phases generate a daily volume of wastewater of around 3m3. This wastewater mainly contains ink pigments, heavy metals and has a Chemical Oxygen Demand - COD higher than required for a discharge in accordance with the wastewater treatment plant.

Since it does not have a wastewater treatment unit, our Customer must store its cleaning water before being removed for disposal by an external service provider, on a regular basis. Such storage without prior treatment presents a significant environmental risk. This involves the development of a retention storage area and incurs substantial costs for disposal and reprocessing by an external service provider.

Determined to reduce its expenses and limit its environmental impact, our Client decides to call on NISKAE for a water treatment micro-station suitable for industrial use. The objective of our Client is to treat the cleaning water for discharge to the wastewater treatment plant in accordance with the regulations in force.

Preliminary analyzes in order to obtain the best formulation of coagulant-flocculant specific to our Customer’s needs

Coagulation-Flocculation for ink and toner cartridge washing water
Coagulation-Flocculation for ink and toner cartridge washing water

A first representative sample of the washing water was analyzed in the laboratory by our NISKAE experts. Following analyzes and several coagulation and flocculation tests, our laboratory is developing a specific formulation for a powdery product with a low impact on the pH value.

The treatment process consists of a prior dilution at the rate of one volume of wastewater and one volume of city water. Dilution is in this case necessary to reduce the water load and ensure good expansion of the coagulated and flocculated particles. The dosage of the coagulant-flocculant reagent is 2.0 g/L to ensure the separation and clarification of the water. The copper and iron contents are lowered to values below the regulatory thresholds. The initial appearance of the wash waters is black. Once the bespoke reagent is added, the filtrate is clean and clear with a slight lingering tint. For this, NISKAE will add an activated carbon filter at the outlet of its treatment reactor. At the same time, the value of the Chemical Oxygen Demand will also be improved.

NISKAE offers the installation of a SW500 micro-station suitable for their industrial use

Thanks to its laboratory analyzes and considering the type of effluents and the volumes generated daily, the NISKAE team proposes the installation of a SW500 cleaning water treatment plant. This VSAT operates automatically and can treat a volume of wastewater of 2,500 to 3,000 L per 8-hour workstation. The time to complete a treatment batch is of the order of 10 to 15 minutes and does not require the permanent presence of an operator.

The proposed installation is composed as follows:

  • 2 200 L wastewater collection tanks;
  • 1 wastewater tank with a capacity of 2000 L. This tank is equipped with a pneumatic pump and an agitator to limit the settling phenomenon and ensure proper homogenization of the water before treatment. The level control is ensured by an ultrasonic sensor;
  • 1 SW500 SMAX water treatment reactor with automatic operation including a powder doser. The station is controlled using a touch screen on the front of the electrical control panel;
  • 2 BIGBAG filtration boxes ensure the storage and dehydration of the sludge resulting from the treatment by flocculation;
  • 1 Activated carbon filter with a capacity of 1000 L secures the discharge to the pipeline and absorbs the coloring and smoothes the COD value.

A reliable solution meeting economic and environmental needs

The NISKAE water treatment station, autonomous and reliable, allows us to meet our Customer’s request. The treatment of cleaning water from recycling ink and toner cartridges can now be done with an innovative and environmentally friendly NISKAE micro-station. By drastically reducing the storage and transport of wastewater, significant savings are made. This investment is just as beneficial for the company as it is for the environment.

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