**Pilot equipment**

Nanofiltration experiments were carried out with the separation unit illustrated in **Figure 9**. On an industrial scale, this unit is multiplied according to needs.

*Treatment of Wastewater by Nanofiltration DOI: http://dx.doi.org/10.5772/intechopen.94329*

CA is the cartridge filter with activated carbon and 25 μm of wound cartridge filter. S is the safety valve (14 bars). B1 is the feed tank (100 L). B2 is the permeate tank (20 L). C2 is the nanofiltration membrane. FI1 is the upstream flow meter (100–1000 l/h). FI2 is the downstream flow meter of retentive. FI3 is the downstream flow meter of permeate. PI1 & PI2 are the manometers at upstream and downstream of module (0–16 bars). PI3 & PI4 are the monitoring manometers of filters state (0–2.5 bars). LSL1 is the low level sensor (pump safety). CE1 is the sensor of permeate conductivity measuring. Y is the emptying, CIT1 to the electrical display cabinet. V1–5, 7, 10, 11, 14–16, 19 & 22 are the pressure regulation valves for nanofiltration process. P is the multistage centrifugal pump (high pressure).

#### **5.1 Materials**

Analyzes of water are carried out on turbidimeter, pH meter, conductimeter, atomic absorption spectrophotometer, UV–visible, apparatus for measuring DBO5 and DCO, and ICP-MS.
