Page 563 - Industrial Wastewater Treatment, Recycling and Reuse

Industrial Wastewater Treatment, Recycling, and Reuse—Past, Present and Future 533

Nanotechnology is expected to play crucial role in wastewater treatment.
There has been a lot of research on using nano-deposition or nano-coating
in photocatalytic degradation. Nano-materials are also expected to play an
important role in the modification of existing adsorbents and catalysts used in
wastewater treatment processes.
In the future, there will be an increased demand for newer materials,
methods, and sensors that can be used online for accurate and reliable efflu-
ent characterization, along with process control, to eliminate fluctuations in
effluent quality and character. Such sensors can track quality and variations
through the measurement of physical, chemical, or biological parameters.
This kind of measurement can be quite complicated, requiring various
devices for variety of parameters and pollutants. Also, the measurement sys-
tem needs to be developed at an affordable cost. Apart from conventional
measurements, such as pH, dissolved oxygen, and COD, real time measure-
ment and process control measures are required for solids, ammonia, nitrates,
phosphates, microorganisms, pathogens, and toxins in wastewaters. Wireless
sensors, which are mainly battery driven, can provide new opportunities for
cheap and easy installations without wiring, and several such sensors can
improve plant performance. A number of constraints, such as number
and nature of sensors, energy, memory, computational speed, communica-
tions bandwidth, and software development, need to be resolved for the
effective use of wireless sensor networks in wastewater treatment, recycling,
and reuse. Novel network protocols are likely to be invented in the future to
address key requirements in wireless communication and to overcome dif-
ficulties posed by actual implementation of wastewater treatment processes.
Satellite based monitoring systems are also likely to gain prominence in
this regard.
Industrial wastewater reduction can be effectively explored using a
systematic water networks design based on water pinch analysis, which
can minimize fresh water use and wastewater generation for any plant
(see methods discussed by Shenoy, 2012). A suitable parameter or pare-
meters, such as COD or total solids, can be chosen for analysis, with the
objective of minimizing water consumption and wastewater generation.
The water pinch analysis can significantly reduce the operating cost by engi-
neering appropriate modifications. Over time, mathematical and computa-
tional tools improve on the existing knowledgebase, and these tools can
substantially aid the water pinch analysis, which becomes complicated when
multiple parameters are considered. Advanced tools, such as CFD, can help
to intensify desired processes and reduce the spatial footprint of the water