Waste water treatment units

A manufacturer of technical fibers contacts NISKAE for the treatment of its washing water from it coating process

An industrial group specialized in composite materials and technical textiles contacts NISKAE to treat its wastewater. With a strategy oriented towards innovation and research of new technologies, the group engages with academic and technical partners around the world. The company has four industrial sites on four continents and offers expertise in various sectors such as aeronautics, energy, construction and automotive.

A coating step generating washing water

The manufacture of technical fibers requires a coating step. The coating consists in applying a resin forming a plastic layer on the textile after drying. The coating is composed of a mixture of several binders adapted to the desired visual and tactile qualities. Additives such as softeners, fixers, thickeners or pigments are also added to the coating process. These are substances that we find in the washing water during the cleaning of the coating process.

A significant problem: a COD level higher than the required limit

Physico-chemical treatment of water with a high COD level

Our customer washes its coating machines several times a day, generating a daily wastewater volume of approximately 15,000 liters of wastewater containing mainly varnish residues, TSS, BOD and COD. Within the framework of its operating permit, our customer must treat its wastewater with the main criterion of correction: the COD (Chemical Oxygen Demand). The level of COD must be lower than 800 mg/L. In order to secure this discharge, NISKAE proposes a coagulation-flocculation process.

The NISKAE team carried out a complete study for the different effluents of the workshop generated by the three main stages of the process. For this purpose, several samples were taken and tested in our laboratory following several protocols of dosage and adjustment of parameters such as temperature, pH or conductivity

The physico-chemical treatment solution proposed for the global discharge of the industrial site requires the dosage of 2 g/L of a unique coagulant-flocculant product allowing the lowering of the COD, the reduction of heavy metals and the clarification of the washing water. The COD level was lowered to 142 mg/L and will allow our Client to ensure compliance with the discharge parameters at all times. This result has been achieved by the fact that the COD reductions obtained on the different samples are from 30 to 50%.

As for heavy metals, the specific formulation developed by the NISKAE laboratory allowed to reduce iron concentrations from 0.27 mg/L to 0.02 mg/L and zinc from 0.10 mg/L to 0.03 mg/L.

A solution that allows water to be discharged in compliance with regulations

NISKAE has been able to meet the needs of its industrial Client by developing an adapted and specific reagent allowing a discharge of water directly into the pipeline while respecting the regulations in force. The conformity of the discharge and the stability of the treatment will allow our Customer to avoid from now on the constraints of exploitation and the financial costs related to the exceeding of the limit values.

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