I am a student of chemical engineering.I decided to share this presentation which I was prepared for my elective course to be beneficial for you.

1. DEPARTMENT OF CHEMICAL ENGINEERING
EGE UNIVERSITY
ChE 457 INDUSTRIAL WASTEWATER TECHNOLOGY

2. WHAT IS WASTEWATER?
Water containing wastes from residental, commercial
and industrial processes which need to be treated
before discharge to a nearby receiving body of water.

3. Figure 1. Source of wastewater

4. INDUSTRIAL WASTEWATER
 Until the mid 18th century,
water pollution was
essentially limited to small,
localized areas.
 Then came the Industrial
Revolution, the development
of the internal combustion
engine, and the petroleum-
fuelled explosion of the
chemical industry. With the
rapid development of various
industries, a huge amount of
fresh water is used as a raw
material, as a means of
production (process water),
and for cooling purposes.

5. Many kinds of raw material, intermediate products and
wastes are brought into the water when water passes
through the industrial process.
So in fact the wastewater is an "essential by-product” of
modern industry, and it plays a major role as a pollution
sources in the pollution of water environment.

6. SOURCES OF INDUSTRIAL WASTEWATER
 Iron and steel industry
 Mines and quarries
 Mining processing chemicals
 Food industry
 Pulp and paper industry
 Complex organic chemicals
industry
 Nuclear industry
 Water treatment

7. WHAT IS DESALINATION?
Basically, it is the process of removing salts from
water in order to produce water suitable for various
applications.
It extracts mineral components from saline water.

8. WHY IS DESALINATION IMPORTANT?
 High salt wastewater refers to the total salt (NaCl content meter) for at
least 1% of the wastewater, the wastewater in addition to containing a
large number of high concentration of organic matter, also contains a
large number of inorganic salts, such as Cl-, Na-, Ca2+ and SO4 2 -
 High salt waste water containing high concentrations of organic
matter and nutrients in the aquatic environment caused tremendous
pressure, speeded up the process of eutrophication of lakes and rivers.
 High salt wastewater often contains high concentration of organic
pollutants, direct emissions causing serious pollution and damage to
the environment. Such as high salt wastewater flow into the soil
system, can make the soil organisms, plants died of dehydration,
caused the collapse of the soil ecological system.

9. INDUSTRIES GENERATING SALINE EFFLUENTS
Salt is known to reduce the water activity and therefore constitutes a
microbiological agent of stability.
Food-processing industry
The agro-food sectors requiring the highest amounts of salt are:
 meat canning,
 pickled vegetables,
 dairy products
 the fish processing

10. In the pickled vegetables industry,
 The main source of saline pollution is
related to the use of brine for canning and
pickling.
 Consequently, the brine losses and rejections
pollute the wash water.
In the fish processing industry,
 The sources of pollution are initially related
to the unloading of fish accompanied by
seawater.
 The fisheries then generate wastewater rich
in proteinic nitrogen, organic matter and
salts.

11. Leather Industry
 The tanning process, which turns raw hides and skins into finished
leather products, is a lengthy process that involves several steps,
many of which requiring the addition of salt.
 This process is almost wholly a wet process that generates very large
amounts of wastewater.
 Certain streams are hypersaline, such as the pickling and the
chromium tanning effluents or the soak liquor generated by the
soaking of hides and skins that can contain as much as 80 g l-1 of
NaCl.

12. Petroleum Industry
 Crude oil is a complex mixture that contains mainly aliphatic,
alicyclic and aromatic hydrocarbons.
 The refining process requires de-emulsifiers and the waste
water(called production water) resulting from the decantation of the
oil–water emulsion presents a broad range of salinity, from fresh
water up to three times the salinity of seawater and beyond.

13. INDUSTRIAL APPLICATIONS OF DESALINATED WASTEWATER
Industrial applications require specific quality parameters that can be
achieved only by using desalination techniques. Examples of the
industrial applications are:
 Power generation industry
 Glass manufacturing industry
 Electronics industry
 Cooling systems
 Textile industry
 Construction industry
 Metal manufacturing industry
 Pulp and paper industry

14. Figure 2. Different types of desalination processes

15. There are three basic categories of water purification
technologies that are used for desalination:
 Membrane technologies
 Distillation processes (thermal technologies)
 Chemical approaches
Some water purification plants use a combination of these
technologies.
*Membrane technologies are the most common technology of
desalination in the world, while thermal technologies are not
widely used.
*Chemical approaches include processes such as ion exchange,
which is considered impractical for treating waters with high levels
of dissolved solids.

17. In general, membrane treatment processes use either pressure-
driven or electrical-driven technologies.
 Pressure-driven membrane technologies include reverse osmosis
(RO), nanofiltration (NF), ultrafiltration, and microfiltration
*Reverse osmosis, and to some extent nanofiltration processes, are
considered effective in salt removal.
 Electrical-driven membrane technologies that are effective with salt
removal include electrodialysis (ED) and electrodialysis reversal
(EDR).

18. REVERSE OSMOSIS
 RO is a process in which
water is separated from
dissolved salts in solutions
by filtering through a
semipermeable membrane at
a pressure greater than the
osmotic pressure caused by
the dissolved salts in the
wastewater.
Figure 3. Reverse Osmosis vs. Osmosis

19.  It is the most efficient and most commonly used process in
desalination, allowing the removal of monovalent ions such as NaCl.
 RO has the advantage of removing dissolved organics that are less
selectively removed by other demineralisation techniques.
 The primary limitations of RO are its high cost and the limited
operating experience in the treatment of domestic and industrial
wastewater.

20. Figure 4. Simplified generic sequence of the global treatment chain
of hypersaline wastewater.

21.  Pre-treatment of feedwater is essential in order to protect the RO
membrane, reduce energy costs, and increase salt retention. It
should be free of large particles, organic matter, bacteria, oil and
grease.
 Typical pre-treatment involves multimedia, cartridge, and sand
filtration to remove larger particles, organic matter and other
materials; and adding chemicals to prevent the formation of
precipitates and scaling of the membrane.
 pH adjustment is also needed.
 Certain membrane materials are sensitive to oxidants such as
chlorine; therefore, additional chemicals may be needed in order to
remove the oxidants from the feedwater prior to membrane
treatment.
 Post-treatment of RO permeate may also be needed depending on
the intended use of the product water.

22. o Recovery rate is a major parameter for evaluating membrane
effectiveness.
o Recovery is defined as the volume of freshwater produced as a
percentage of the volume of feedwater processed.
o Typical recovery rates for RO systems can be 30 percent to 80 percent
depending on the quality of feedwater, pressure applied, and other
factors. Reverse osmosis membranes that operate at low pressures but
maintain high recovery rates have been developed.

23. Nanofiltration
 A nanofiltration (NF) membrane
works similar to reverse osmosis
except that with NF, less
pressure is needed (70 and 140
psi) because of larger membrane
pore size (0.05 μm to 0.005 μm).
 Nanofiltration can remove some
total dissolved solids, but is
often used to partially soften
water and is successful at
removing solids, as well as
dissolved organic carbon.
 For low TDS waters, NF may be
used as a standalone treatment
for removing salts.

24.  Electrodialysis (ED) utilizes electromotive force applied to electrodes adjacent to
both sides of a membrane to separate dissolved minerals in water.
 The separation of minerals occurs in individual membrane units called cell pairs.
 A cell pair consists of an anion transfer membrane, a cation transfer membrane,
and two spacers.
 The complete assembly of cell pairs and electrodes is called the membrane stack
(Figure 5).
 The number of cells within a stack varies depending on the system. The spacer
material is important for distributing the water flow evenly across the membrane
surface.
ELECTRODIALYSIS
Figure 5. Electrodialysis Stack

25.  The ED process is effective with salt removal from feedwater
because the cathode attracts the sodium ions and the anode attracts
the chloride ions.
 The required pressure is between 70 and 90 psi.
 In general, ED has a high recovery rate and can remove 75% to
98% of total dissolved solids from feedwater.
Electrodialysis reversal (EDR) is a similar process, except that the
cation and anion reverse to routinely alternate current flow.
EDR has a higher recovery rate (up to 94%) because of the feedwater
circulation within the system and alternating polarity.

26. o ED and EDR can remove or reduce a host of contaminants from
feedwater and the process is not as sensitive to pH or hardness levels in
feedwater.
o The EDR process is adaptable to various operation parameters,
requires little labor, and the maintenance costs are generally low.
o However, when using ED and EDR technologies for desalination,
treatment cost is directly related to the TDS concentration in feedwater.

28. ION EXCHANGE
Ion exchange is a commonly used technique to soften hard water and to
demineralise water.
 Ion exchange resins contain fixed cations or anions capable of reversible
exchange with mobile ions of the opposite signs in the solutions with
which they are brought into contact.
 For salt reduction, both anionic and cationic exchangers must be used.
The wastewater is first passed through a cation exchanger where the
positively charged ions are replaced by hydrogen ions.
 The cation exchanger effluent is then passed over an anionic exchanger
were the anions are replaced by hydroxide ions.
 Thus, salts are replaced by hydrogen and hydroxide ions to form water
molecules. Following this service cycle, the process involves a
regeneration cycle in which the exhausted resin is backwashed to remove
trapped solids.

29. Figure 6. Ion Exchange Resins
 The main problem of applying ion exchangers to wastewater
treatment is a high influent suspended solids concentration that can
plug the resin, causing inefficient operation.
 Another problem is that ion exchangers require costly regenerant and
produce troublesome waste streams.

31.  Solar evaporation is a low-cost technique commonly applied to
concentrate the salts and organic content of saline effluents,
thereby reducing the volume of effluents.
 In the leather industry, the hypersaline soak liquor generated by
the soaking of hides and skins is sometimes segregated from the
other streams because of its high salt content and sent to solar
evaporation pans.
 However, the reuse of the solid salt thus obtained is made
impossible due to its high degree of impurity.

32.  Thermal technologies are based on the concept of using evaporation
and distillation processes.
 Modern thermal-based technologies are mostly developed as dual-
purpose power and water desalination systems.
 These technologies are generally applied to desalination of
seawater.
 Some common processes include multi-stage flush (MSF), which is
widely used in the Middle East, as well as vapor compression (VC)
and some variation of those technologies.

33. REFERENCES
Ya, S. and Xin, Y. (2014). Progress and Prospects of High Salted
Wastewater. Ph.D. Shen Yang Jian Zhu University.
Lefebvre, O. and Moletta, R. (2006). Treatment of organic pollution in
industrial saline wastewater: A literature review. Water Research,
40(20), pp.3671-3682.
Madwar, K. and Tarazi, H. (2003). Desalination techniques for industrial
wastewater reuse. Desalination, 152(1-3), pp.325-332.
Kabeel, A., Hamed, M., Omara, Z. and Sharshir, S. (2013). Water
Desalination Using a Humidification-Dehumidification Technique—A
Detailed Review. Natural Resources, 04(03), pp.286-305.
Younos, T. and Tulou, K. (2009). Overview of Desalination
Techniques. Journal of Contemporary Water Research & Education,
132(1), pp.3-10.