Page 63 - Industrial Wastewater Treatment, Recycling and Reuse

46 Industrial Wastewater Treatment, Recycling, and Reuse

Hybrid separations and technologies are required mainly for the
following:
– To increase process efficiency along with cost effectiveness
– To comply with stringent pollution control norms
– To take advantage of various new developments in the separations area
including new devices/processes.
Inviewofthediscussionasaboveonvariousseparationprocesses,thefollowing
hybrid processes can be envisaged in combination with individual processes:
• Coagulation +
– Newer formulations combining inorganic and organic coagulants for
improved performance
– Process integration with other technologies such as coagulation
+cavitation¼cavigulation
– Hybrid technologies here can substantially improve the secondary
treatment step
• Adsorption/Ion Exchange +
– Newer materials/nanomaterials coupled with other separation pro-
cesses for final polishing to meet statutory requirements
– Hybrid technologies here can substantially improve the tertiary/
polishing treatment step
• Membrane +
– Advanced materials/membranes including high temperature ceramic
membranes
– Can be combined effectively with most other physico-chemical
methods of separation
– Hybrid technologies here are being increasingly used in biological
effluent treatment, for example, MBR, MMBR, EMBR
• Cavitation +
– New devices for improved performance
– Can be combined with many processes such as coagulation, oxidation,
and others
– Hybrid technologies here can be applied in both secondary and ter-
tiary treatment steps
• Biological +
– The efficiency of the biological oxidation techniques is often ham-
pered by the presence of bio-refractory materials, whereas AOPs
promise degradation of almost all the contaminants
– A hybrid method of AOPs to reduce the toxicity of the effluent up to
a desired level followed by biological oxidation is needed for the
future!