Cargo aircraft landing gear washing water

Our Client realizes weekly maintenance of cargo planes, which includes the washing of the landing gear. The wastewater mainly contains grease but also waste residues of heavy metals such as iron and cadmium. Several tests made in our laboratory have made it possible to develop a coagulant-flocculant reagent capable of ensuring the compliance of the discharges for disposal to the wastewater treatment plant.


Thousands of liters of wastewater are generated by washing operations

A leading multinational air cargo company has a fleet of several dozen cargo aircraft requiring annual or even multi-year maintenance. The maintenance of the aircraft consists in the cleaning of the cabin liners and landing gear. These washing operations generate several thousands of liters of wastewater daily, mainly containing oils, greases, suspended matter and residues of heavy metals such as iron, zinc or cadmium from the braking systems.

A tailor-made formulation to reduce high concentrations of heavy metals

Concerned about its environmental impact, our Client decided to call upon NISKAE to obtain an efficient solution for the treatment of its washing water. Our Customer provided the NISKAE laboratory with samples of the wastewater generated by the washing operations.

The analysis of the water revealed a high concentration of iron of 4.95 mg/L and zinc of 1.42 mg/L. The presence of cadmium of 0.17 mg/L will also have to be lowered. After several series of laboratory tests, a precise and unique reagent powder was developed with a dosage of 2.5 g/L. By adding this coagulant-flocculant reagent, the analysis of the treated water reveals a lowered iron concentration of 0.41 mg/L, a zinc concentration of cadmium lower than 0.01 mg/L. The sludge generated by the treatment is non-sticky and well dehydratable.

The powdery product elaborated by NISKAE also allows to stabilize the neutrality of the pH value of the effluent. The main objective of our customer is to find an efficient solution for the treatment and the discharge of its washing water.

An environmentally responsible investment

This goal was achieved by developing a custom-made NISKAE coagulant-flocculant. The amount of heavy metals has been greatly reduced and the pH-value has been stabilized. Our customer will now be able to reduce its exposure to environmental risk, significantly reduce its storage and external disposal costs and directly discharge the treated water in a compliant manner to the airport’s wastewater treatment plant.