12
C. Gutiérrez-Bouzán et al.
inside the desired range for the EC-UV system. As long as the effluent does not
reach this condition, the effluent can be discarded through a by-pass section.
This is intended to reduce the electrodes damage.
2. Tank filling: Depending on the effluent volume to be treated, the system is suitable to work with one or more recirculation tanks. The tanks can be filled sequentially with effluent flowing through the electrochemical cell, so the decolouration
process will start immediately from the first moment the water enters into the
tank.
3. Tank recirculating: All the system tanks should be filled at this stage; the oxidation should be taking place in all of them; however, the desired decolouration could have not been achieved. Therefore, a recirculation (for a predefined
amount of time) of effluent for each tank, sequentially, though the electrochemical cells can add oxidation agents when required to speed up the decolouration
process. While one is recirculating, the other two will be stored. According to
the laboratory tests, the storage with stirring and UV lamp irradiation increases
the efficiency of the process and reduces the electrical costs. It also achieves the
removal of undesirable residual compounds. This recirculating process could be
carried out with each tank until the colour sensor indicates that it is decolourised
to the pre-defined value.
4. Preparation for reuse: When the colour sensor detects that the effluent is into
the specified range, the effluent reconstitution can take place in this tank. While
this process takes place, the other tanks can be recirculating.
5. Water flush: Once the effluent if decolourised and/or ready to be reused
(depending on the predefined target), it would be pumped to the output tank.
The tank that is empty would be filled to continue the process.
Of course, all these steps must be supported by the appropriate sensors, actuators
and electronic control. One of the advantages of the system is that it is suitable to
work with predefined recipes based on the characteristics of the effluent (higher or
lower conductivity, colour load, etc.). The right design of valves and sensors also
allows to implement auxiliary processes like cell cleaning to maximise electrode life,
etc.
Joining the maximum system functionality and adaptability to different effluents can generate a moderately complex industrial engineering design, as depicted
in patent and Fig. 7, although its industrial implementation is clean, compact and
provides an immediate impact in the competitiveness of the dyeing mill when applied.
7 Results of EC-UV Treatment
As indicated in the previous sections, the EC-UV system can operate in two ways:
1. decolourisation mode.
2. decolourisation + reuse mode.
C. Gutiérrez-Bouzán et al.
inside the desired range for the EC-UV system. As long as the effluent does not
reach this condition, the effluent can be discarded through a by-pass section.
This is intended to reduce the electrodes damage.
2. Tank filling: Depending on the effluent volume to be treated, the system is suitable to work with one or more recirculation tanks. The tanks can be filled sequentially with effluent flowing through the electrochemical cell, so the decolouration
process will start immediately from the first moment the water enters into the
tank.
3. Tank recirculating: All the system tanks should be filled at this stage; the oxidation should be taking place in all of them; however, the desired decolouration could have not been achieved. Therefore, a recirculation (for a predefined
amount of time) of effluent for each tank, sequentially, though the electrochemical cells can add oxidation agents when required to speed up the decolouration
process. While one is recirculating, the other two will be stored. According to
the laboratory tests, the storage with stirring and UV lamp irradiation increases
the efficiency of the process and reduces the electrical costs. It also achieves the
removal of undesirable residual compounds. This recirculating process could be
carried out with each tank until the colour sensor indicates that it is decolourised
to the pre-defined value.
4. Preparation for reuse: When the colour sensor detects that the effluent is into
the specified range, the effluent reconstitution can take place in this tank. While
this process takes place, the other tanks can be recirculating.
5. Water flush: Once the effluent if decolourised and/or ready to be reused
(depending on the predefined target), it would be pumped to the output tank.
The tank that is empty would be filled to continue the process.
Of course, all these steps must be supported by the appropriate sensors, actuators
and electronic control. One of the advantages of the system is that it is suitable to
work with predefined recipes based on the characteristics of the effluent (higher or
lower conductivity, colour load, etc.). The right design of valves and sensors also
allows to implement auxiliary processes like cell cleaning to maximise electrode life,
etc.
Joining the maximum system functionality and adaptability to different effluents can generate a moderately complex industrial engineering design, as depicted
in patent and Fig. 7, although its industrial implementation is clean, compact and
provides an immediate impact in the competitiveness of the dyeing mill when applied.
7 Results of EC-UV Treatment
As indicated in the previous sections, the EC-UV system can operate in two ways:
1. decolourisation mode.
2. decolourisation + reuse mode.