Water Desalination Challenges and Solutions in Australia: A Report

This report provides a comprehensive analysis of water desalination in Australia, addressing the critical need for sustainable water sources in the face of increasing water scarcity. It begins with an executive summary and an introduction that highlights the importance of water and the growing reliance on desalination technologies. The report then delves into the background of water challenges in Australia, examining the advantages of desalination, with a focus on reverse osmosis (RO) technology. It explores the detailed design of an RO plant, including seawater intake parameters, tank capacity, membrane types, and factors affecting system performance. A significant portion of the report is dedicated to the environmental impact of brine discharge on cuttlefish and other marine life, discussing the effects of increased salinity and proposing mitigation strategies such as diffuser use and wastewater mixing. Finally, the report touches upon plant shutdown procedures and concludes with recommendations for sustainable desalination practices in Australia, emphasizing the need for responsible brine disposal and the protection of aquatic ecosystems. The report is based on the student's assignment for Advanced Water and Wastewater Treatment course.

ADVANCED WATER AND WASTE WATER TREATMENT
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EXECUTIVE SUMMARY
There is rapid industrialization and urbanization in the entire world not Australia alone.
Mechanism that is used to be part of solution to water shortage which emanates from demands as
necessitated by the circumstances has been developed including desalination. According to the
detailed review of the unconventional and connectional water sources in Australia, technology
for desalination, their advantages, and disadvantages as presented in this particular paper, the
country is actually headed to a very pathetic state of fresh water shortage. The situation will
probably turn to be disastrous in case actions are not taken by the relevant authorities on time.
The government and other concerned bodies should, therefore, move so quickly to have the
following recommendation put into practice this particular paper evaluates various aspect of
water desalination in Australia while giving recommendation on the possible mechanisms of
mitigating the impacts of industrial waste like brine on the aquatic life.

Contents
EXECUTIVE SUMMARY.................................................................................................................................2
Introduction.................................................................................................................................................3
Back ground.............................................................................................................................................3
Related issues and Importance of the desalination.................................................................................4
Desalination Plant Design Assessment........................................................................................................5
Detailed Design of RO..................................................................................................................................5
RO Process Design...................................................................................................................................5
Intake of Sea Water Parameters..............................................................................................................6
Capacity of Tank Equalizer...................................................................................................................6
Type of the membrane............................................................................................................................7
Factors affecting system of RO............................................................................................................8
Impacts of brine discharge or disposal on cuttle fish.............................................................................10
Mitigation of the problems related to Brine Disposal............................................................................11
Shut-down plant of a desalination plant................................................................................................11
Conclusion and Recommendation.............................................................................................................13
REFERENCES..............................................................................................................................................14
APPENDIX..................................................................................................................................................16

Introduction
Water is crucial and basic resource that is used for growth as well as survival of life. Actually no
one can live without water. The research work by various scholars has indicated that nearly one
fourth of the world population is already suffering from shortage of fresh water supply. This is
experienced both in terms of quantity and quality. As a result of the increasing population in the
world as well as the expansion of both agricultural and industrial activities, the requirement of
water is expected to increase even further(Dorji et al.2018).
Back ground
Due to the importance of water to human beings, there has been development of different
kinds of the system of water supply. However, it is important to note that all of them have a
common problem. The key challenge being that nearly all of them requires only fresh water. The
research work has indicated that of all the water sources on the earth surface, 97% is sea water
while freshwater accounts for only 2%.The 2% may include the other forms locked as glaciers
and ice caps.
Another important point that is worth consideration is that human activities have
contributed to the pollution of the water sources and as such they cannot be relied on. This

makes it obvious that traditional system of fresh water supply cannot meet the demands. There is
need for development of an alternative option to assist in addressing the problem. Desalination
refers to a technology that involves processes of removal of salt and other minerals from the sea
water in order to produce freshwater. In Australia this particular technology has been developing
very rapidly and has actually become very popular(Haddad et al.2018).
Related issues and Importance of the desalination
The use of desalination technique in Australia has had several advantages to the general
population. Some of these advantages include the following:
Access to the clean water for drinking
The desalination technologies that are used in Australia have led to the accessibility of drinking
water to the general population. The water that has been obtained from the salty regional has
even been used to supplement the other areas with an unreliable fresh water source. It is
important to note once again theta 0ver 70 present of Australia get their clean water through the
process(Gude 2016).
Protection of the habitat
The quality of the desalinated water meets the demands and even sometimes supposes the
other quality standards of water. This basically implies they can assist in offloading the pressure
on other sources of water which are regarded as fresh(Shahzad et al.2017)
Provision of water for agricultural purposes
The program of desalination has not only been used in Australia to provide water for the drinking
or the commonly reefed to as potable water but also water for agricultural use.

Desalination Plant Design Assessment
Flow chart for Treatment Process of Water.
Figure 1: Flow chart of water treatment(Shemer and Semiat 2017)
Detailed Design of RO
RO Process Design
The process of the design is considered to be membrane oriented. The process begins with
the filtration of the water that has particles of larger sizes. The process of the filtration is believed
to be responsible for the improvement of the water quality including odor and taste. The water
pollutants like sulphates, bacteria among others are effectively removed.

Intake of Sea Water Parameters
The sea water intake parameters included the following:
Table 1: Intake parameters
Capacity of Tank Equalizer
Table 2: Tank parameters
The capacity of the strainer was assumed to be 25MLD while the MF tankage was assumed to be
of 28m height and diameter 31.6m. The stage of disinfection was found to be crucial for getting
high quality water. The removal of boron at limit of 0.3 mg/L can be optimized by adjusting the
capacity of the strainer to a value more than 25MLD.
Type of the membrane
Despite the existence of several types of the membrane, the study chosen SWC6 membrane. The
selection of the element was guided by the water feeds. The specification of the membrane which
was selected for the study is as follows:

Table 3: Properties of the membrane
Characteristics
The membrane used allowed for the passage of permeate with salt rejection of 100%.The ratio of
the boron rejection was established to be 95%.Also its energy consumption was found to be
extremely low.
Plant Design Parameters
In the study, the followed parameters were assumed to be values effective for running a
desalination plant and give high PH value of desalinated water.
Table 4: Design parameters

Factors affecting system of RO
The performances of the RO system usually rely on the control flow, temperature and water
quality. The above factors affect the recovery percentage. Taking for example 2-3% would mean
variance of temperature which translates to 1 degree Celsius. The biocide of the membrane can
effectively remove chlorine from water to the entire system of the product. The maximum
maintenance as well as cleaning of chemicals that influences the system of RO(Turner et
al.2016).
System of Multi-Stage membrane.
The reverse osmosis system utilizes the multi-way model. This model is connected in parallel
manner. Such connections are very important since through it the purifier can effectively produce
at least 150ML per day. This production rate is equivalent to 150000 cubic meters per day of
permeate. This implies that the number of trains will be large. The process thus balances high
and low pressure during the process of multi way filtration process. The multi-particles are thus
filtered simultaneously with the approximated cost of 50 gpm(Thiruvenkatachari et al.2016).

Figure 2: Multi –stage system.
The study involved there major stages in a single passage. In the first stage the result obtained
was 35% with the flow capacity of 1500 cubic meters. This was due to the fact that it was multi-
stage membrane that advances while increasing the level of purity. The second stage being 65%
was higher than the first stage. The last stage value is estimated to be 70% as the recovery value
within the membrane itself.
Pressure bar of 32.6 was used in the maintenance of all stages with the temperature of 31 degrees
Celsius. Although the existing components utilizes two passes, the study involved the use of
single pass in order to obtained water that had been desalinated. Using two passes could possibly
lead to temperature elevation and such high value of the temperature will affect the desalination
process.
The single pass process utilized over 100 vessels with the first stage taking or using 40 vessels.
The second stage utilized 30 vessels while the last stage also utilized 30 vessels. The value of the
nominal diameter was 6.The removal of salt was thus done 100% by the use of the chemicals of
sulphites and chlorine.

Impacts of brine discharge or disposal on cuttle fish
The research work has indicated that an increase in the concentration of the desalination
brine inhibits success of hatching process. This affects the development and growth as well of
the species of cuttle fish called S. apama especially the embryos. During such studies, the
embryos from the samples that had their values of salinity close those of the natural natures
provided successful rates of hatching. Few of the embryos were able to survive in full growth at
percentage of 45% as salinity.
Complete mortality was realized at salinity value beyond 45%. I n general the research
work has indicated that the ranges in the values of the salinity which extends to the b values of
more than 40% decreases the chances of the survival of S. apama embryos. In fact for every
increase of 1% of the salinity value beyond 40%, there is a decrease of survival chance of the S.
apama embryos by 7%. Despite the fact that physiological uptake of nutrients and oxygen by the
embryos of cuttlefish takes place through the capsule of the eggs by the process of the diffusion
with the egg acting as a protective structure, there has been inference of the osmotic stress as a
probable cause for the development malfunctioning of the embryos of the cephalopod. Salinity
increase results into the limitation of the diffusion which is responsible for the processes of the
embryo diffusion(Zarzo and Prats 2018). This is due to the fact solubility of gases like oxygen
decreases in water that is hypersaline. The osmotic stress demands for a lot energy which can
never be produced to facilitate development of the embryos.
The normal metabolic activities of the embryos of S. apama are affected or inhibited by the
higher salinity of the water bodies in Australia. The research work which has been carried out by
the scholars have indicated that the abiotic factors like salinity which results from the brine
disposal reduces the conditions of the nutrition by the larvae which is under development. This

has been demonstrated by the studies which have focused on the weight as well as length of the
same larvae sample.
Mitigation of the problems related to Brine Disposal
It is a conventional requirement that any industrial establishment protects the environment
on a priority basis. The desalination process however much are very crucial in a dressing the
water shortage in Australia, it should not be done at the expense destruction and elimination of
the aquatic life through irresponsible brine disposal into the water bodies(Christ. In order to
minimize the impacts of the brine disposal or discharge into the water bodies, diffusers can be
used. These components assist in the dilution as we’ll as mixing of the brine to effectively reduce
the brine concentration prior to its discharge into the water body. The systems of the discharge
should be connected to the industrial effluents that are basically composed of water in order to
lower the salinity of the water or the discharge which originates from the desalination plants.
The research work done by various scholars has indicated that when treated waste water is
mixed with the brine water it can lower the chemical quantity in the brine. This will actually be
more eco-friendly. Also the incorporation of the system of zero liquid discharge will be used so
as to enhance evaporation process. The solid residue of salts can be disposed by the use of other
mechanisms that do not pose any form of threat to the water body PH(Shemer and Semiat 2017).
Shut-down plant of a desalination plant
Pre-Communication
There should be adequate strategies by the companies for reaching out all the participants before
the process of the shutdown can be put in place. The management is expected to have a meeting
together with the policy team. During the meeting, the policy team is expected to properly