Hydro Geek Volume 1 Issue 1

Hydro-GEEK Issue 1 Vol 1
A series of graphical monologue on hydrology,
hydro power, hydraulics and water quality issues
Founding Editor : Dr.Mrinmoy Majumder
Blog : https://hydroideas.blogspot.com/
Six types of filters mostly
used in purifying water for
city dwellers

Content
• 1) Six types of filters mostly used in purifying water for city dwellers
• 2) Five most common contaminants in rural water and how to remove them?
• 3) How to identify the filter for purifying raw water?
• 4) Tutorial: Analytical Hierarchy Process
• 5) Tutorial: Analytical Network Process
• 6) Smart Use of Water and Energy in Domestic Households
• 7) Tools: Simple Decision Maker by AHP
• 8) Recent Jobs in Water Quality Engineering

Six filters used in purifying
water for city dwellers

Different Types of Filters
• Broadly filters can be classified into six types :
• Physical Filters : “filtering by gravity”
• Ion Exchange : “filtering by exchanging bad ions with good ions”
• Activated Carbon : “filtering by trapping impurities within pores of carbon material”
• Reverse Osmosis : “filtering by reversing the process of osmosis thus separating
the impurities and water by semipermeable membrane”
• Distillation : “filtering by boiling”
• UV Light : “filtering by lights of ultra-violet frequency”
• A brief description, strength and weakness of the filters are explained in the next slides.

PHYSICAL
FILTERS AND ION
EXCHANGE
FILTERS

ACTIVATED
CARBON
REVERSE
OSMOSIS

ACTIVATED
CARBON AND
REVERSE
OSMOSIS
FILTERS

Water Pollutants in Urban Areas
• Sediment, nutrients, oxygen-demanding substances, road salts, heavy metals,
petroleum hydrocarbons, pathogenic bacteria, and viruses.
• Suspended sediments constitute the largest mass of pollutant loadings to
receiving waters from urban areas
• Emerging Organic Compounds : Hormones, antibiotics, surfactants, endocrine
disruptors, human and veterinary pharmaceuticals, X-ray contrast media,
pesticides and metabolites, disinfection-by-products, algal toxins and taste-
and-odour compounds(Pal et.al.,2014)

Some tips and tricks while buying water filters
• In urban areas generally water is supplied from surface or waste water treatment
plants. At the treatment plant the suspended sediments are already reduced by
different high end filtration procedures. The toxic chemicals and other harmful
infectious compounds were removed at the treatment plant by chlorination
process and then after disinfection the water is supplied to the consumers.
• Thus first of all the supplied water will have high concentration of Chlorine due to
the conduction of chlorination at the treatment plant for disinfecting the treated
water before supplying.
• Water may also get contaminated with organic compounds like micro-bacterium
(thus increasing the Biological Oxygen Demand(BOD)) or by the presence of
inorganic pollutants like microplastics (that will aggravate the Chemical Oxygen
Demand(COD)) in the pipelines through which water is supplied to your
household. There is also a high chance of heavy metal presence.
• There is also a probability of high concentration of Calcium and Magnesium ions
(which is responsible for hardness) in the treated water if required treatment for
reducing hardness is not available in the treatment plants.

• For such cases a four stage filter will be required having one activated carbon
to remove the chlorine and other organic pollutants followed by ion exchange
to remove the hardness.
• At the third stage a reverse osmosis filter can be used to reduce the
concentration of inorganic pollutants including heavy metals.
• In the last stage a UV light can be utilized to remove the remaining
concentration of organic pollutants which will mainly consist of micro-
organisms.
• However such configuration will attract high amount of operation as well as
maintenance cost. That means such filter configurations will not be
economically viable for middle income group of consumers.

• A cheaper alternative can be a three stage filter having a physical filter in the
first part to remove the suspended solids which will include most of the
inorganic pollutants.
• The second stage can include activated carbon which can adsorb most of the
organic pollutants including chlorine and lastly an ion exchange filter which will
remove the hardness of water.
• Such arrangement will be cheaper but the quality of the treated water will not
be as good as from the earlier configuration of filters.
• But you can avoid the additional requirement of electricity consumption and
waste water removal produced at the end of RO process

• If you stay in a location where the water is heavy (i.e.presence of Calcium or Magnesium
ions) then go for a filter configuration with activated carbon filter in the first stage, ion
exchange in the second and physical filter in the last stage.
• This configuration will remove most of the hardness of water during the medium stage and
the salt which will be produced by the medium stage as a by-product of ion exchange filter,
can be removed by the physical filter at the last stage.
• Off course if you have high budget then you can go for ion exchange at first stage followed
by reverse osmosis(RO) filter in the second stage and Ultraviolet(UV) light in the last
stage. In this type of configurations, the ion exchange will remove hardness of the water
and then the reverse osmosis filter will remove the sodium as well as other inorganic
contaminants like sodium, chloride, copper, chromium, and lead; may reduce arsenic,
fluoride, radium, sulphate, calcium, magnesium, potassium, nitrate, and phosphorous etc.
also (Centers for Disease Control and Prevention,2015).
• Lastly, the UV light will kill the micro-bacteriums which can seep through the semi-
permeable membrane of the RO filter.

Five most common
contaminants in rural water
and how to remove them?

Contaminants in Rural Water
• In rural areas, sources of diffuse water pollution include: run-off from
agricultural land containing substances including pest control products, animal
medicines, slurry, sewage sludge and manure. run-off and leaching from
contaminated land. silt and dust from mining, quarrying, construction and
demolition.
• “….much of the pollution originates from animal wastes and commercial
fertilisers. To a lesser extent, groundwater contamination also occurs in this
sector as a result of inadequate percolation at septic tanks and from leaching
of water soluble plant nutrients from the soil.”…. (Department of the
Environment, Community and Local Government.Ireland,2020)
• Infectious diseases caused by bacteria like E Coli and parasites like
Cryptosporidium are the most significant health risk indicators associated with
contaminated drinking water mainly found in rural water.

Tips and Tricks
• In rural areas as described earlier (slide 25) water is generally collected from
surface water sources like lakes, ponds or rivers and there will be high chance of
contamination by both organic and inorganic pollutants which can be present in the
fertilizers and pesticides used in the agricultural fields for cultivation.
• In some location where ground water is extracted and used, probability of
concentration of heavy metals will be more compared to the water collected from
surface water sources.
• As the soil in the agricultural fields are loosely bound, soil particles can be carried
away by the surface runoff after a spell of rainfall which will also contaminate the
surface water source by increasing the Total Suspended Solids in the water body.
• Rural Water may also contain hardness.

• In such areas activated carbon followed by ion exchange and if you have high
budget for procuring filters, then you can use RO at the last stage. Activate
Carbon filter will remove the suspended soil particles, Volatile Organic
Compounds(VOC), herbicides, pesticides, chlorines and some other inorganic
chemicals. In a study conducted by Abdulrazak et.al.(2016) activated carbon
filter was found to be able to remove heavy metals like Cadmium, Copper,
Nickel, and Lead from waste water.
• The remaining inorganic pollutants like sulphates and nitrates which was
dissolved due to the contamination from fertilizers and pesticides including
hardness of the water can be removed by the ion exchange filter.

• RO filter will remove the remaining micro-organisms as both activated carbon
and ion-exchange filter can not remove micro-organic pollutants.
• However if you want to reduce your electricity consumption and avoid using
additional infrastructure for managing the waste water which is produced as a
by-product at the end of RO process then RO stage can be replaced by UV
lights which consume less electricity and also does not require any additional
waste water management procedure.
• On the other hand UV lights can remove the remaining amount of
microorganic pollutants after filtration by the ion exchange filter.

References
• Abdulrazak, Sani, K. Hussaini, and H. M. Sani. "Evaluation of removal efficiency of
heavy metals by low-cost activated carbon prepared from African palm fruit." Applied
Water Science 7, no. 6 (2017): 3151-3155.
• Centers for Disease Control and Prevention. "A Guide to Drinking Water Treatment
Technologies for Household Use." (2015).
• Department of the Environment, Community and Local Government,2020,Urban
and Rural Water Pollution, Retrieved from http://www.askaboutireland.ie/enfo/irelands-
environment/water/water-pollution/urban-and-rural-water-pol/
• Pal, Amrita, Yiliang He, Martin Jekel, Martin Reinhard, and Karina Yew-Hoong Gin.
"Emerging contaminants of public health significance as water quality indicator
compounds in the urban water cycle." Environment international 71 (2014): 46-62.

How to identify the best filter for purifying
raw water?

Common
Impurities
and how to
remove it
from water ?

How to select the best water filter ?
• Step 1 : Go to https://tinyurl.com/y4g2slld. This is the link to a “Simple Decision
Maker by AHP” Webware which will help to select the best filter(to be more
precise : filter configurations) with the help of some criteria and following the
most famous decision making method : Analytical Hierarchy Process(AHP). For
more details about AHP go to :
https://learnmetaheuristics.blogspot.com/2019/06/simple-decision-making-tool-following.html
• Step 2 : Select the set of criteria based on which you will identify the best filter
among the available options (Go to Slide No.10).
• Step 3 : For example, let four different types of filter configurations are
available for procurement. The table in the next slide depicts the cost of
purchase, type of filter, number of stages, maintenance cost and frequency and
contaminant removal efficiency of the available filter configurations.

Name of Filter
Configurations*
Cost of
procurement
(INR)
Type of filter Number of
Stages
Cost of
Maintenance
(INR/six month)
Frequency of
Maintenance(pe
r year)
Contaminant
Removal
Efficiency (%)
Filter A 2500 Activated Carbon 2 100 3 55
Filter B 3500 Activated Carbon
+ UV Light
2 125 2 65
Filter C 7500 Activated Carbon
+ Ion Exchange
+ UV Light
4 250 2 75
Filter D 15000 Activated Carbon
+ Reverse
Osmosis + UV
Light
5 500 1 85
*Number of different types of filters are arranged to create one filter configuration which is sold to consumers. Normally a filter
configuration have more than one stage(Stage means one type of filter). In this example only those configurations which have minimum
2 stages are considered. Same type of filter can also be used in more than one stage.
Note : This example is for demonstration purpose only.

Now try to rank the filter configurations based on its characteristics represented by the selected criteria. It is better
to represent Type of filter and number of stages by a single criteria :Number of Stages(as it depend on both type
and number of stages) and Cost and frequency of maintenance as : Cost of Maintenance(cost will depend on cost
per maintenance as well as number of times maintenance is required per year).
Name of Filter
Configurations*
Cost of
procurement
(INR) /Rank
Number of Stages /Rank Cost of Maintenance /Rank Contaminant
Removal Efficiency
(%) /Rank
Filter A 2500/ 01 Activated Carbon 2 / 03 100 3 / 02 55 / 04
Filter B 3500 / 02 Activated Carbon +
UV Light
2 / 03 125 2 / 01 65 / 03
Filter C 7500 / 03 Activated Carbon +
Ion Exchange + UV
Light
4 / 02 250 2 / 03 75 / 02
Filter D 15000 / 04 Activated Carbon +
Reverse Osmosis +
UV Light
5 / 01 500 1 / 03 85 / 01

How the filter configurations were ranked ?
• For Cost of Procurement and Cost of Maintenance, more the cost less will be
preference to buy as all the consumers tries to look for cheaper alternatives
having low cost and requirement of maintenance. That is why while ranking the
filter configuration with respect to the cost of procurement and maintenance more
the cost of the configuration less rank was awarded. The configurations were
sorted in such a manner that the costliest configuration received the worst rank or
preference.
• For Number of Stages criteria, as more the number of stages more contaminant
can be removed. That is why more the number of stagers higher rank of
preference was awarded to the configuration
• For Contaminant Removal Efficiency, more the removal efficiency of the
configuration more preference will be given and thus highest rank of preference
was awarded to the configuration which have maximum contaminant removal
efficiency.

How to find the best filter configuration by
Simple Decision Maker Webware ?
• When the link is opened the Home page will delineate the procedure to be followed. First
of all convert the ranks to “Complement of Normalized Rank” by following the instruction in
the home page of the software.
• For the present example, we have four alternatives. So rank assigned to the alternatives
will be converted to its normalized rank by :
𝑥
4 + 1
where x is the rank assigned to the alternative.
and Complement of Normalized Rank will be calculated by :
{1 -
𝑥
4+1
}

Complement to Normalized Rank
Name of Filter
Configurations*
Cost of
procurement
(INR) /Rank
Number of Stages /Rank Cost of Maintenance
/Rank
Contaminant Removal
Efficiency (%) /Rank
Filter A 0.8 Activated Carbon 0.4 100 0.6 0.2
Filter B 0.6 Activated Carbon + UV Light 0.4 125 0.8 0.4
Filter C
0.4
Activated Carbon + Ion Exchange +
UV Light
0.6
250
0.4 0.6
Filter D
0.2
Activated Carbon + Reverse Osmosis
+ UV Light
0.8
500
0.4 0.8

Assigning Rank of Preference to the Criteria
• Now a Complement to Normalized Rank of Preference to the Criteria is
required to be assigned.
• For this example : Contaminant Removal Efficiency(CRE) will be the most
important criteria followed by Cost of Maintenance(M), Cost of
Procurement(P) and lastly the Number of Stages(S)(See Slide 10).
• Accordingly the Complement to Normalized Rank of Preference was
calculated and found to be equal to
• CRE : 0.8 > M : 0.6 > P : 0.4 > S : 0.2.
• After these values were entered in the place of Criteria go to AHP page to
find the results.
• For this example Filter A becomes the best filter due to very low cost of
maintenance and procurement. Filter D, although it has the best CRE but
due to high cost of procurement and maintenance it become the least
preferred alternative.

Assign Rank Window in Simple
Decision Maker
PLACE OF CRITERIA
PLACE OF ALTERNATIVE

AHP window of Simple Decision Maker Webware
PLACE OF RESULT

A SIMPLE TUTORIAL ON
ANALYTICAL HIERARCHY
PROCESS

EXAMPL
E
APPLICA
TION
HOWTO USE AHP
FOR SELECTION OF
WAVE ENERGY
CONVERTER IN
SHORELINE
PROTECTION

THE EXCEL SHEET USED
FOR THE EXAMPLE
PROBLEM

FIGURE SHOWING THE EXCEL SHEET USED FOR THE EXAMPLE P
PAGE 1
RETURN

FIGURE SHOWING THE EXCEL SHEET USED FOR THE EXAMPLE PROBLEM
PAGE 2
RETURN

Analytic Network Process
Dr. Mrinmoy Majumder
Course Name : Intro to Multi Criteria Decision Making Methods
Lecture No.06 out of 15
https://opticlasses.teachable.com
Follow me on :
RG : Mrinmoy Majumder
Twitter : kuttu80
Founding Honorary Editor
http://www.baipatra.ws
http://www.energyinstyle.website

What is Analytic Network Process
• The analytic network process (ANP) is a more general form of the
analytic hierarchy process (AHP)
• Used as a multi-criteria decision analysis method.
• AHP structures a decision problem into a hierarchy with a goal,
decision criteria, and alternatives where as the ANP structures it as a
network.

Example of
ANP
Decision Goal : To buy a car
Criteria : Cost and Speed
Alternatives : Mercedes Benz(M),
Jaguar(J), Toyota(T)
Aggregation Methods to be used :
Analytic Network Process

Please note:
• Step 1 to 4 : AHP Process (same
as AHP method)
• Step 5 to 8 : ANP Process

Step 1
• Compare each criteria with the other with respect to goal of the
decision problem
Goal : Buy a
car
Cost Speed Geometric
Mean(GM)
Normalized
Geometric
Mean(GM/S
um(GM)
Weightage
of Criteria
Cost 1 2/1
1.414
1.414/2.1
21 0.667
Speed 1/2 1
0.707
0.707/2.1
21 0.333
Rank of Criteria as per their significance : Cost : 1st Rank, Speed : 2nd Rank

Step 2
• Compare each alternative with every other alternatives with respect
to criteria
Criteria : Cost M J T Geometric
Mean
Normalized
GM= GM/sum
of all GM
M 1 3/2 3/1 1.651 0.500
J 2/3 1 2/1 1.101 0.333
T 1/3 1/2 1 0.550 0.167
Rank of Alternative as per their significance with respect to cost: M : 1st Rank, J : 2nd Rank, T : 3rd Rank
You can also directly use the numerical equivalent of the ranks(say R)

Numerical Equivalent of Ranks ( R )
• R
• = {1 – Rank of alternative or criteria / (n +1) }
• here n is total number of alternatives or criteria

Step 3
to criteria
Criteria : Speed M J T Geometric
Mean (GM)
Normalized
Geometric
Mean
M(3) 1 1/3 1/2
0.550 0.167
J(1) 3/1 1 3/2
1.651 0.500
T(2) 2/1 2/3 1
1.101 0.333
Rank of Alternative as per their significance with respect to speed: J : 1st Rank, T : 2nd Rank, M : 3rd Rank

Step 4
• Now multiply the weightage of the Criteria with the weightage of the
alternative for that criteria and calculate the row wise average. Normalize
the average to find the weight of significance of the alternatives :
Cost
(Weight of
significance) :
0.667
Speed
(Weight. of
significance) :
0.333
Average Normalized
Average
M 0.667x0.500 0.333x0.167
0.195 0.389
J 0.667x0.333 0.333x0.500
0.194 0.389
T 0.667x0.167 0.333x0.333
0.111 0.222
END OF AHP

Step 5 : Start of ANP
• Compare each criteria with the other with respect to the alternatives
Alternative :
Mercedes
Benz
Mean(GM)
Normalized
Geometric
Mean(GM/S
um(GM)
Weightage
of Criteria
Cost 1 2/1
1.414
1.414/2.1
21 0.667
Speed 1/2 1
0.707
0.707/2.1
21 0.333
Check the rank and numerical equivalent of rank for Mercedes with respect to Cost and Speed. Then use
the same numerical equivalent of the rank at the time of comparison. For example while comparing Cost
and speed for M, use Rc / RS
RC and RS is the R of M for Cost and Speed criteria respectively

Step 6
to criteria
Alternative :
Jaguar
Mean(GM)
Normalized
Geometric
Mean(GM/Sum
(GM)
Weightage of
Criteria
Cost 1 1/2
0.707
0.707/2.1
21 0.333
Speed 2/1 1
1.414
1.414/2.1
21
0.667
Check the rank and numerical equivalent of rank for J with respect to Cost and Speed. Then use the same
numerical equivalent of the rank at the time of comparison. For example while comparing Cost and speed
for J, use Rc / RS
RC and RS is the R of J for Cost and Speed criteria respectively

Step 7
to criteria
Alternative :
Toyota
Mean(GM)
Normalized
Geometric
Mean(GM/Sum
(GM)
Weightage of
Criteria
Cost 1 1/2
0.707
0.707/2.1
21 0.333
Speed 2/1 1
1.414
1.414/2.1
21
0.667
Check the rank and numerical equivalent of rank for Toyota with respect to Cost and Speed. Then use the
same numerical equivalent of the rank at the time of comparison. For example while comparing Cost and
speed for T, use Rc / RS
RC and RS is the R of T for Cost and Speed criteria respectively

Step 8
• Now multiply the weightage of the Alternatives with the weightage of
the Criteria for that alternative and average. Normalize the average to
find the updated weights of Criteria
M
(Weight of significance as
estimated in the last step
of AHP) : 0.389
J (Weight of significance
as estimated in the last
step of AHP) : 0.389
T(Weight of
significance as
estimated in the last
step of AHP) : 0.222
Average
Normalized
Average
Cost 0.389x0.667 0.389x0.333
0.222x0.333 0.154 0.462
Speed 0.389x0.333 0.389x0.667
0.222x0.667 0.179 0.538
The weightage of importance depicted in the last column shows the updated weights of the criteria. The entire
process of AHP is repeated with the updated weights of criteria. If the difference between the existing weights
of the alternatives and the new weights of alternatives is more than 0.0001 then the ANP process is again
repeated followed by the AHP process and so on until the difference of new and old weight does not exceed
0.0001.

SMART USE OF WATER AND ENER
DOMESTIC HOUSEHOLDS

How water is utilized in domestic
households ?
• Washing and Cleaning
• FlushingToilets
• Bathing
• Cooking
• Gardening
“Most high-efficiency washers use only 15 to 30 gallons
(56.8 to 113.6 L) of water to wash the same amount of
clothes as older washers (29 to 45 gallons per load (109.7 to
170 L).” in USA.
In the US “Older toilets can use 3.5, 5, or even up to 7
gallons of water with every flush. Federal plumbing
standards now specify that new toilets can only use up to
1.6 gallons per flush (GPF), and there are high efficiency
toilets that use up to 1.28 GPF.”
Indian Standards : Maximum amount of water allowed to be
used by a person per day : “Bathing: 55 litres; Toilet
flushing: 30 litres; Washing of clothes: 20 litres; Washing the
house: 10 litres; Washing utensils: 10 litres; Cooking: 5
litres; Drinking: 5 litres”.
In USA, estimated use of water per person per day is about
80-100 gallons whereas in India the standard(IS 1172 ) is
135L/35.66 gallons per person but actual use varies widely.

Groundwater
based
Households
(GWS)
• The required amount of water is
withdrawn by electric pumps or
tube wells from underground
aquifers
• Water may be “heavy and hard”
• Can be contaminated
• Presence of Iron and Fluorine
sometimes Arsenic
• Scarcity : When adjacent water
table is decreased during summer

Surface Water Based Households
(SWS)
Withdraws water from surface water sources like
rivers, lakes, ponds etc. with the help of electric
pumps and pipelines/canals which brings the
water from the source to consumers. More the
length of the pipelines more will be energy
utilized by the pump
May be contaminated with coliform and
algae : the concentration of the algae or
bacteria depends on the amount of dissolved
oxygen.
Presence of “Iron/Fluorine/Arsenic/Oil and
Grease/Suspended as well as dissolved
matters”

Consumes Municipal/Treated Water
(MS)
• Uses submersible pumps to withdraw water.
• Supplied by the municipality after treatment.
• As purified, minimum chance of contamination.
• Reduced amount of heavy metal concentration.
• Minor amount of dissolved and/or suspended solids.
• Increased amount of dissolved oxygen.
• Free of Oil and Grease.
• Expensive.
• Infrequently supplied in some places.
• Sometimes taste and colour of the supplied water becomes untenable.
• Amount of chlorine may be more compared to the surface or ground water sources.

Consumes Water from Surface Water Treatment
Plant(SWTP)
• House hold is fed by the treated water from SWTP .
• May have greater amount of chlorine.
• Turbidity may be high which make the transparency low.
• Chance of contamination during supply and in the supply lines.
• Dissolved oxygen will be high which may effect the taste of the
water.
• Expensive due to the treatment process, so wastage of water will
effect the bill paid by the consumer.

Consumes Water from Waste Water Treatment
Plant(WWTP)
• The house hold is fed by treated water from WWTP.
• Such water have a higher chance of contamination compared to
other sources
• Probability of the presence of chemical compounds will be more.
• Dissolved oxygen may not be as high as the water received from
other sources which may effect the taste and quality of the
water
• Presence of faecal coliform and bacteria will be more compared
to the supply received from the SWTP
• Highly Expensive, more than SWTP, for the advanced treatment
process adopted for purification of the waste water, so wastage
of water will effect the bill paid by the consumer

Consumes Water from Treated Rain Water
• Water is withdrawn from the rain water harvesting tank or
recharge pits.
• Contamination chance is high and depend on the tank and
supply lines used.
• Chance of contamination during supply and in the supply
lines.
• Suspended solids and turbidity will be high compared to
SWTP but lower compared to WWTP.
• Cheap but quality is .doubtful and will depend upon the
treatment mechanism adopted by the system.
• Quantity that can be treated and supplied for consumption
is uncertain and depend upon the amount and frequency of
rainfall along with the volume of the storage tank.

Contaminants
• SWTP
• Aluminium, Arsenic, Asbestos,
• Barium, Beryllium, Boron,
• Cadmium, Cobalt, Copper, Cyanides,
• Iron
• Lead, Mercury
• Nickel, Nitrogen
• Selenium, Silver.
• WWTP
• Non-regulated trace organic ECs including pharmaceuticals
• Illicit drugs
• Personal care products
• SWS
• sludge, brine disposal from the petroleum industry, mine wastes, deep-well disposal of liquid
wastes, animal feedlot wastes, ...
• GWS
• Nitrates, Pharmaceuticals & Personal Care Products

Problems
• Physical : Scarcity of Water : Most of the water supplied to a household
is actually wasted. The practice of recycling is not widely observed and
also avoided due to misconceptions related to the quality of the water.
Sometimes due to head difference between the source and consumers
water flow gets reversed and phenomena like water hammering occurs
which have the capacity to damage the pipelines.
• Chemical : Poor quality of water. The concentration of Dissolved Oxygen
depend upon the presence of dissolved and suspended solids specially
the bio-degradable products. As a result the taste and visibility of the
supplied water get affected most of the times
• Biological : The supplied water is often contaminated by organic wastes
released from other households which leads to the presence of various
types of microorganism. Tests show that contaminants affect the health
of the consumers and many time is the sole reason for health related
disasters.

Major Problem
• Scarcity of Water : Both amount and
frequency of supply is unreliable and
irregular
• Degradation in the quality of supplied
water
• Another problem which is an indirect
problem of the previous two problems is :
• Wastage of electrical energy in pumping
• To maintain supply, water has to be pumped
frequently
• Degraded quality of water can corrode the
internal materials of the pump(if submerged)
• Which will lead to a reduction in pumping
efficiency
Solution
 Water has to be conserved at least at
the side of the consumers
 Different types of water filter can be
used to treat the supplied water.

Pattern of Consumption
Time of Use Type of Use

Time
• Frequent Use : The water consumption is frequent and
practiced at an regular interval.
• Example :
• Washing and Cleaning
• Flushing Toilets
• Bathing
• Cooking
• Infrequent Use : The consumption of water is irregular. It
happens at an interval of one or more days.
• Example:
• Water used in Gardening

Type
• Drinking : For consumption by the residents of the household
• Washing : For washing the clothes
• Cleaning : For cleaning the car/floor/utensil etc.
• Cooking : For cooking the foods
• Gardening : For watering the garden
• Other uses

Location of Water Used within a
Household
Washing and Cleaning, Bathing ,Flushing Toilets etc.Bathrooms
CookingKitchens
GardeningGarden Tank
Multi - Purpose
Ceiling or Ground
water Tank
Other

Idea to conserve water :
• Use a holding tank in every locations where water is used.
• The volume of the tank must equal to 1.5 times the amount of
water (per day) required at that location.
• A sensor to detect water level can be placed there to measure the
water level of the tank and a minimum depth can be earmarked
so that once the level crosses this mark the tank will be refilled

Idea to conserve water :
(CONTD.)
• The tanks will be attached to the main supply and from the tank
water may be distributed to the taps, toilets etc. of that location
only.
• The replenishment of the tank may also be monitored and some
cutting off threshold may be implemented to prevent over use.
• During the lean period of water supply the tank will conserve the
water

Idea to conserve water contd. :
• A tank is generally located in the roof top in a house from where the water is supplied
to each of the location of water use.
• All the sub-tanks mentioned previously can be connected to this main tank .
• A level detecting sensor can be used here also, for automatic replenishment of tank
and also to prevent over withdrawal of water, if a cutting off threshold is implemented
in this aspect.
• Once the threshold is crossed, further replenishment of the tank will be prevented if
not manually overridden or if the duration of refill is over.
• The volume of the tank must also be equal to the 1.5 times the total volume of all the
sub-tanks.
• The 0.5 times is kept as a free body or buffer within which the water use generally
varies even during the time of uncertainty. The previous data for water use can be
utilized to detect the amount of water required by the household(Standard in India is
135l per person per day).
• This type of arrangement can save sufficient amount of water which is generally
flushed out after use.
• Here the use of water is also monitored by the implementation of water level
detectors. This type of monitoring help to avoid unnecessary use of water and
conserve the supplied water for later use.

What about quality of water ?
• Instead of using a water purification unit in the kitchen or
bathrooms the same may be installed at the outlet of the main
tank.
• This will ensure that the water will be first treated and then
disbursed to different location of water use.
• But the pumps are mainly effected from direct contact of the
supplied water.

What about quality of water ?
(CONTD.)
• That is why, if a filtration unit is used at the inlet nozzle through
which water is supplied to a household by the municipality, then
the treated water will only reach the pumping arrangement and
as it will be devoid of corrosive agents, it will not rust the pump
and its internal materials.
• The same arrangement may be implemented in the inlet from the
well or outlet of a rain water harvesting tank if the water is taken
from groundwater or surface water sources or from the rain water
tank.
• The treatment unit at the inlet may not be highly sophisticated
but it must ensure the removal or reduction of the
concentration of heavy metals, dissolved and suspended solids.

SUBTANK
SUPPLYTANK
TANK
TREATMENT
UNIT
PIPELINE
SCHEMATIC DIAGRAM OF THE ARRANGEMENT FOR SMART USE OF WATER AND
ENERGY
Water
level
indicatorElectric
Pump

What s next ?
• Water is conserved at a level required to maintain the disbursement of
supply among the different location of the water use.
• As the water level is monitored the use of pump will be minimum, only
during the replenishment.
• The number of times of replenishment is also monitored. Overuse of the
pump will be prevented as a result of the monitoring.
• The water is supplied as per the need of the location of different water
use. The wastage will be minimum as water can be used only if required.
• The treatment unit at the inlet of the tank or towards the pump unit will
ensure that suspended matters and corrosive agents can be filtered
before supplying the water to the pumps.
• The economic liability of sensors and treatment unit will be much lesser
compared to the conventional arrangement of water if only the cost of
pumping and repumping is considered.

ACKNOWLEDGEMENTS
Data and texts were collected from the following sources for which I want to show my gratitude :
• A review on emerging contaminants in wastewaters and the environment: Current knowledge,
understudied areas and recommendations for future monitoring
• http://www.sciencedirect.com/science/article/pii/S0043135414006307
• ClothesWasher | Home WaterWorks
• www.home-water-works.org/indoor-use/clothes-washer
• Toilet | Conserve H2O - RegionalWater Providers Consortium
• www.conserveh2o.org/toilet-water-use
• How much water does an urban citizen need? by S.Vishwanath on Feb 15,2013
• http://www.thehindu.com/features/homes-and-gardens/how-much-water-does-an-urban-
citizen-need/article4393634.ece
• How much water does the average person use at home per day?
• https://water.usgs.gov/edu/qa-home-percapita.html

SIMPLE DECISION MAKER
BY ANALYTICAL HIERARCHY PROCESS
https://tinyurl.com/y4g2slld

Recent Jobs in
Water Quality
Engineering
• SUEZ International is looking for Global Supplier Quality System Analyst in
Bangalore,Karnataka,India Link for More Details : https://g.co/kgs/ob4EX7
• Organization : https://www.suezwatertechnologies.com/
• AECOM India Private Limited requires Consultant (Environment & Water
Quality) in J&K in India. Link for More Details : https://g.co/kgs/7pZRoi
• Organization : http://www.aecom.com/
• Toruise.com is in the search for a Water Quality Analyst in Mumbai,
Maharashtra, India. Link for More Details : https://g.co/kgs/pRN29v
• Organization : http://www.toruise.com
• ESRI India requires GIS Industry Solutions Manager Water to be located at
India.Link for More Details : https://www.timesjobs.com/job-detail/gis-industry-
solutions-manager-water-esri-india-10-to-13-yrs-jobid-
L5HiKrkC09BzpSvf__PLUS__uAgZw==
• Organization : https://www.esri.in/en-in/home
• United Nations Human Settlements Programme offers home based
employment as a Wastewater and Water Quality Data Technical Specialist.
Link for More Details : https://careers.un.org/lbw/jobdetail.aspx?id=146806
• Organization : https://careers.un.org/

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