Page 89 - Industrial Wastewater Treatment, Recycling and Reuse

64 Industrial Wastewater Treatment, Recycling, and Reuse

Figure 1.20 Wastewater treatment processes: technology maturity analysis.

Although there has not been much progress in developing new separa-
tion processes, a lot of new process schemes are being developed through
modification of existing methods and intelligent combinations of different
separation methods or reaction and separation methods. These newer sep-
aration processes combine or redefine finer aspects of existing methods, for
example, distillation, extraction, ion exchange, adsorption, membrane sep-
aration, cavitation, and biological processes. Figure 1.20 qualitatively pre-
sents the status of different technologies where the use of the technology
is plotted against its technological maturity. It can be seen that processes such
as adsorption and biological processes have securely established themselves in
terms of commercial use and are also technologically mature, indicating their
wide acceptability in the industry. Processes such as membrane separation,
oxidation, and coagulation are considered technologically mature to a lesser
extent and require further development in terms of materials for increasing
their use in the industry. Ion exchange and extraction have less use in
wastewater treatment, mainly because of their fundamental limitations. Inter-
estingly, cavitation and hybrid separations, although sufficiently technologi-
cally mature, find less applicability in the industry. The plausible reason for
this is the lack of awareness and adequate knowledge on design and application
of such systems. Broadly, one needs to evolve the following options for
accomplishing enhanced water treatment technologies:
1. Development of new adsorbent materials having high selectivity,
improved stability, and with more favorable geometries and better
kinetics with substantially reduced cost.