This specialist in envelope and stationery manufacturing has two gluing machines that have to be cleaned and rinsed several times a day. The wastewater generated contains not only glue residues but also dampening agent residues and inks.

Initially, as there was no wastewater treatment plant, our client stored its cleaning water to be evacuated by an external service provider. These evacuations represent significant costs.

Our Client’s objective is to equip itself with a treatment station for a discharge of treated water to the sewer in full compliance.

Our Client, concerned about the environmental impacts generated by its envelope production activities, wishes to reduce contaminants and heavy metal concentrations to a minimum. NISKAE engineers, specialists in industrial water treatment, start several tests and analysis with the samples taken in order to elaborate a coagulant-flocculant formulation specific to the nature of the effluents encountered.

Before treatment, the washing and cleaning water was white, opaque, loaded with glue and ink residues, with a high concentration of iron (1.04mg/L) and a high level of COD at 10,900 mg/L. Our flocculation treatment with a minimum dosage of 1.5 g/L allows the separation of glue and ink residues from the clear water. After this separation, they are filtered and dehydrated through a big-bag filter. The iron concentration was reduced to 0.1 g/L after treatment, which is an abatement of almost 1 g/L. The COD level was reduced to 2600 mg/L, this value remains slightly higher than the target value of 2000mg/L for the discharge to the sewer. The integration of an activated carbon filter in addition to and at the outlet of our flocculation reactor ensures compliance of the discharge by adsorption of the excess COD.

Throughout the process, NISKAE ensures that the pH value is maintained to optimize the coagulation and flocculation reaction.

Once the tests and analyses were completed, we were able to install a SW500 microstation, providing treatment batches of 500L. The proposed installation is automatic and is equipped with all the safety devices required for a safe industrial operation.

The proposed SW500 microstation is composed as follows:

• 2 collecting and pumping stations located at the two existing washing points;
• 1 pneumatic wastewater pump to transfer the wastewater from the storage tank to the treatment reactor;
• 1 wastewater storage tank, with a capacity of 5000L, equipped with a range of filters and an agitator to ensure the homogenization of the water and avoid any settling phenomenon;
• 1 water treatment reactor SW500 with a capacity of 500L, including a programmable PLC, allows to execute the physico-chemical phenomenon of wastewater in less than 15 minutes;
• 1 set of two BIGBAG mobile filtration boxes for sludge conditioning and dehydration;
• 1 water meter at the plant outlet will allow the continuous measurement of the discharge flow. The data will be downloadable from the station’s automatic control system.

A cost-effective wastewater treatment solution has been implemented at our customer’s site. Due to the use of a customized reagent and the installation of a microstation, our Client no longer has to use the services of an external service provider. The complementarity of the microstation and the NISKAE products allowed the reduction of the environmental impacts and a return on investment in less than two years.