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The Development of Product for Greywater Treatment
Submitted in partial fulfilment of the requirements
For the degree of
Bachelor of Engineering
By
Shaikh Kashif Khurshid (14DCES72)
Under Guidance of
Prof. Junaid Maste
Assistant Professor, Civil Engineering
Anjuman-I-Islam’s Kalsekar Technical Campus,
Plot no. 2&3, Sector-16, near Thana naka, Khandagaon,
New Panvel, Navi Mumbai. 410206
2016-17
ii
Certificate
This is to certify that the project entitled “The Development of Product for Greywater
Treatment” is bonafied work of Shaikh Kashif Khurshid (14DCES72) submitted to the
University of Mumbai in partial fulfilment of the requirement for the award of degree of
“Bachelor of Engineering” in Department of Civil Engineering.
Prof. Junaid Maste
(Guide)
Dr. Rajendra B. Magar Dr. Abdul Razzak Honuntagi
(Head of Department) (Director)
iii
Project Report Approval for B.E.
This report is entitled “The Development of Product for Greywater Treatment” by Shaikh
Kashif Khurshid (14DCES72) approved for the degree of Bachelor of Engineering in
“Department of Civil Engineering”
Examiners Supervisors
1. 1.
2. 2.
iv
Declaration
I declare that this written submission represents my ideas in my own words and where others
ideas or words have been included. I have adequately citied and referenced the original sources.
I also declare that I have adhered to all principles of academics honesty and integrity and have
not misrepresents or fabricated or falsified any idea/data/fact/source in our submission. I
understand that any violation of the above will be cause for disciplinary action by the Institute
and can also evoke penalty action from the sources which have thus not been properly citied
or from whom proper permission has not been taken when needed.
Shaikh Kashif Khurshid
v
Acknowledgement
My heart quivers with the thrill for offering gratitude to those individuals who helped me in
completion of the opportunity to thank those who have contributed to it. Unfortunately, the list
of acknowledging no matter how extensive is always incomplete and inadequate. Indeed this
page of mention shall never be able to touch the horizon of generousness of those who tendered
their help to me. First of all, I would like to express my gratitude and respect to my project
guide Prof. Junaid Maste for his kindness in allowing me for introducing the present topic and
for their inspiring direction, constructive judgement and valuable propositions throughout this
project work. I sincerely thankful to him for his effort in improving our contents of this project.
I also thankful to Prof. Rajendra Magar (Head of Department) for assigning me this interesting
project and for his valuable suggestions and boosts at various stages of the work. A
combination of this nature could never have been attempted without reference to and
inspiration from the works of others whose details are mentioned in reference section. I
acknowledge our indebtedness to the whole civil department.
Last but not least, my sincere thanks to all our friends especially Mr. Atique Barudgar, who
have patiently extended all sorts of help for achieving this undertaking.
Shaikh Kashif Khurshid (14DCES72)
vi
Abstract
Nowadays world, the usage of water increases day by day and thus resulting the lots of sewage
production, and preserving of such a precious gift is now a major issue. As there are very less
source of fresh water available so the saving of water is a necessary task. Since there are various
treatment method to treat the wastewater but there is need of an efficient step to improve the
quality of a wastewater. The treatment based on the residential and commercial level is the next
step towards which the treatment of sewage and preserving the fresh water is to be done
simultaneously. “The development of product for greywater treatment” is required to treat the
greywater by passing through filter media which is placed beneath the kitchen sink cabin and
transferring and using the filtered water for cleaning and washing purpose which requires fresh
water. Thus for the above purposes various test is to be done i.e. Hardness, Alkalinity,
Turbidity, Chlorides, BOD, etc., and the result for the above mention tests were within the
permissible limit thus the filtered greywater can be used for the purpose for which the product
is been developed.
Keywords: Greywater, Filtration, Alkalinity, Biological Oxygen Demand (BOD).
vii
Table of Contents
Sr.No. Topic Pg.no.
1. Introduction…………………………………………….1
1.1 Background……………………………………….1
1.2 Greywater………………………………………....1
1.3 Advantages of Greywater Treatment……………..2
1.3.1 General……………………………………......2
1.3.2 Environmental Benefits…………………….....3
1.3.3 Economic Aspect……………………………...3
1.4 Aim of our Project………………………………...3
1.4.1 Need of the product for greywater treatment.....4
1.5 Objective of Current Experimental Work………....5
2. Literature Review………………………………………6
2.1 Review of Literature……………………………...6
2.2 Literature Summary………………………………16
3. Methodology…………………………………………...17
3.1 Materials………………………………………......17
3.1.1 Sand……………………………………..…….17
3.1.2 Gravels………………………………...……....18
3.1.3 Substrate……………………………...……….18
3.1.4 Activated Carbon…………………...…………19
3.1.5 Screen/Meshes……………………...…………19.
3.2 Material Requirements……………………………20
3.2.1 Sand…………………………………………...20
3.2.1.1 Washing of Sand………………………….20
3.2.2 Gravels………………………………………..21
3.2.3 Substrate………………………………………21
3.2.3.1 Washing of Gravels and Substrate……......21
3.3 Layering Methodology……………………………21
3.4 Experiments……………………………………….22
3.4.1 Turbidity………………………………..……..22
3.4.2 Hardness……………………………………....22
3.4.3 pH and Alkalinity……………………………...23
3.4.4 Total Dissolved Solids………………………...23
3.4.5 Biological Oxygen Demand…………………..23
4. Results and Discussion………………………………...25
5. Conclusion……………………………………………..27
6. References……………………………………………...28
viii
List of Figures
Fig. No. Name Pg. No.
1. Greywater from College Canteen 2
3.1 Sand 17
3.2 Gravels 18
3.3 Substrate 19
3.4 Activated Carbon 19
3.5 Meshes 20
3.6 Sand before washing 20
3.7 Sand after washing 20
3.8 Cleaning of Gravels and Substrate 21
3.9 Turbidity before Filtration 22
3.10 Turbidity after Filtration 22
3.11 While performing BOD experiments 24
4.1 Isometric view of Product 26
4.2 Front view of Product 26
4.3 Top view of Product 26
List of Tables
Table No. Name Pg. no.
1.1 Minimum domestic water consumption
(Annual Average) for Indian Towns and
Cities
4-5
3.1 Depth of filtering media 21
4.1 Results 25
2
Chapter 1
INTRODUCTION
1.1 Background
Environmental pollution is a global concern because of the harmful effects on public health
and the environment. The irresponsible disposal of untreated wastewater into surface waters,
soil and groundwater results in polluted water resources and environmental damages.
1.2 Greywater
Greywater is a wastewater fraction which is not heavily polluted. It includes wastewater
from hand wash basins, showers, kitchen sinks and household appliances like washing
machines or dishwashers and excludes toilet wastewater. The Fig.1. Gives us a view of a
greywater sample collected from the college canteen. The major pollutants are thus derived
from soaps, shampoos, detergents, sweat, dead skin, hairs, oil, and grease (from kitchen
wastewater) and might include bacteria and pathogens. However, the contamination by
pathogens in greywater is considered to be very low due to the absence of toilet wastewater.
The amount of greywater is directly related to the water consumption of the residents and to
the appliances used in the household. The average greywater production per person varies
between 30 to 120 litre depending on access to piped water and people´s habits and their
culture. In practice, the greywater flows can be roughly estimated based on surveys with the
target population. If water meters are installed the greywater amount can be approximated as
75% of the total water consumption of the household (25% is estimated to be used for toilet
flushing). A more detailed calculation of the greywater volumes and flows from the number of
residents and the connected appliances is possible and should be conducted by trained
professionals.
2
The composition of greywater strongly depends on the behaviour of the inhabitants and the
individual choice of soaps and detergents in the household. Therefore, the overdosing of
shampoos and detergents, as well as the use of strong detergents (e.g. with high sodium content,
phosphate content or chlorine), should be avoided.
Fig. 1. Greywater from College Canteen
1.3 Advantages of Greywater Treatment/Recycling:
The following points are the advantages of a greywater treatment based on general,
enviromental & economical aspects.
1.3.1 General
Greywater Recycling saves water and reduces the amounts of fresh, high quality
drinking water by substituting the water demand not intended for drinking.
On-site greywater treatment reduces the volume of wastewater that must be diverted to
more costly sewage and septic treatments.
Greywater contains one-tenth the nitrogen content of backwater of which half of it is
organic and more easily filtered and removed by biological uptake in plants.
3
Greywater is rich in phosphorous, potassium, and nitrogen, making it a good nutrient
or fertilizer source for irrigation.
Localized Greywater systems decrease freshwater use for transportation and treatment
of wastewater
The use of greywater for irrigation reincorporates nutrients from the waste stream into
the land-based food chain, rather than contributing to surface and ground water
pollution via sewers and septic systems.
Greywater diversion is particularly well-suited for small-scale or decentralized
wastewater systems and can be implemented in either a rural or urban setting.
1.3.2 Environmental Benefits:
Greywater systems bring significant savings in fresh drinking water in addition to reducing the
amounts of generated wastewaters, thus easing the pressure on the environment. In general,
low energy systems should be preferred over high expenditure systems.
1.3.3 Economic Aspects:
Greywater reuse should be viewed not only in terms of economic performance but its more
significant social and environmental benefits in contributing towards sustainable development
and resource use. For individual domestic greywater systems the most efficient and effective
technologies involve simple diversion and in-line surge tanks with coarse filtration with
subsurface garden watering and irrigation purposes only. More sophisticated systems that
involve storage, fine filtration, biological treatment and UV disinfection and pumping offer
greater economic value when used for toilet flushing, laundry washing and garden irrigation
applications. Tertiary treatment systems such as biological processes are most efficient and
effective for multi-dwelling applications, where more favourable scales of economy and
greywater quality can be achieved by connecting many users to the system.
1.3 Aim of the project:
The following information give us a brief idea for the need of greywater treatment for
residential and commercial purposes:
4
1.3.1 Need of the product for greywater treatment:
With a diverse population that is three times the size of the United States but one-third the
physical size, India has the second largest population in the world. According to the World
Bank, India has taken significant steps to reduce poverty but the number of people who live in
poverty is still highly disproportionate to the number of people who are middle-income, with
a combined rate of over 52% of both rural and urban poor.
Although India has made improvements over the past decades to both the availability and
quality of municipal drinking water systems, its large population has stressed planned water
resources and rural areas are left out. In addition, rapid growth in India's urban areas has
stretched government solutions, which have been compromised by over-privatization.
Regardless of improvements to drinking water, many other water sources are contaminated
with both bio and chemical pollutants, and over 21% of the country's diseases are water-related.
One concern is that India may lack overall long-term availability of replenishable water
resources. While India's aquifers are currently associated with replenishing sources, the country
is also a major grain producer with a great need for water to support the commodity. As with
all countries with large agricultural output, excess water consumption for food production
depletes the overall water table.
As per IS: 1172-1993 (Basic Requirements of Water Supply, Drainage and Sanitation), the
minimum domestic water consumption (Annual Average) for Indian Towns and Cities with
Full Flushing System are:
Table no. 1.1
Use Consumption in litres per
head per day (l/h/d)
Drinking 5
Cooking 5
Bathing 75
Washing of Clothes 25
Washing of Utensils 15
Washing and Cleaning of
houses and residencies
15
5
Lawn Watering and
Gardening
15
Flushing of WC 45
Total 200
The total volume of greywater to be collected from kitchen sink = Washing of Utensils (15) +
Washing and Cleaning of houses and residencies (15) = 30 l/h/d, and this water can be used for
either gardening or toilet flushing, thus saving the fresh water which is reserved for gardening
and toilet flushing and it can be supplied to the area where there is scarcity of water and it also
helps to reduce the sewage generation thus reducing the load on a sewage treatment plant.
1.5 Objective of Current Experimental Work:
The points listed below describes the basic objective of the project which are:
To develop a Product for reuse of Greywater for its economical and beneficial use.
To substitute the use of precious drinking water with the treated one in various
applications viz. gardening, washing, toilet flushing etc.
To reduce the amounts of fresh water consumption as well as wastewater production,
in addition to reducing the water bills.
To asses various quality checks of the product as per Indian standards.
To use the treated greywater as a replacement of fresh water in fire demand.
6
Chapter 2
LITERATURE REVIEW
2.1 Review of Literature :
A brief outline of different literatures approaches along with few important references is
presented in the subsequent paragraph as follows.
1. Shower wastewaters installation has been characterized in terms of physical, chemical
and microbiological parameters and two treatment technologies has been investigated
at U.S. militaries arid region by Burrows W.D. et al (1991)4. Microfiltration cartridges
with a nominal pore size of 0.2 µm achieved consistent removals of 75±15% of total
organic carbon (TOC) and better than 99% of turbidity from synthetic shower water
containing 50 to 100 mg/L of TOC as soap. An alternative treatment technology utilized
powdered activated carbon and coagulation/flocculation/sedimentation followed by
diatomaceous earth filtration. A TOC reduction of 70±15% was achieved in three
separate studies, although at a cost of 1 g/L or more of powdered activated carbon.
Revised quality criteria for recycled shower water had been developed with guidance
from the National Research Council. Parameters which can practically be measured in
the field are primarily associated with microbiological safety. Therefore, the safety of
recycled shower water with respect to chemical contamination must depend on design
considerations.
2. Increasing demands on water resources for domestic, commercial, industrial, and
agricultural purposes had made water reclamation and reuse an attractive option for
conserving and extending available water supplies by Crook J. et al (1996)6. Also,
many water reuse projects were implemented to eliminate a source of contamination in
surface waters or as a least-cost alternative to meeting stringent discharge requirements.
Reclaimed water applications range from pasture irrigation to augmentation of potable
water supplies. Water reclamation and reuse criteria were principally directed at health
7
protection. There are no federal regulations governing water reuse in the U.S.; hence,
the regulatory burden rests with the individual states. This has been resulted in differing
standards among states that have developed criteria. The paper was summarized and
compared the criteria from some states that had been developed comprehensive
regulations. Guidelines published by the US. EPA and the rationale behind them are
presented for numerous types of reclaimed water applications.
3. Continuing moves towards full cost recovery for potable water and the impending
privatization of water supplies in the Melbourne area had enhanced public interest in
the reuse of wastewater, and particularly the domestic use of greywater, efforts were
taken by Diana Christova-Boal et al (1996)5. Victoria University of Technology,
together with support from Melbourne Water and the Department of Health and
Community Services, had investigated the practicalities, costs and social attitudes of
using greywater in and around the home. Four “typical” Melbourne homes were
selected and plumbed to utilize greywater for toilet flushing and garden irrigation.
Social surveys were conducted by mail and phone to homeowners to determine
perceived attitudes towards greywater reuse. Greywater from baths, showers, laundry
troughs and washing machines is being examined for physical, chemical and
microbiological parameters to determine the potential health and environmental risks
associated with reuse. Soil tests were also undertaken on gardens to determine any long-
term detrimental effects that might occur as a result of using greywater. The paper
described the greywater testing, results of filtration and filter designs, appropriate
disinfectants, and physical findings to date.
4. Greywater consists 60-70% of the domestic in-house water demand, and thus could be
an alternate water source for toilet flushing. However, although conceived as rather
“clean”. It may be polluted and thus pose potential health and aesthetic risks. The paper
presented by Noah I. Galil et al (1999) characterizes the quantity and quality of various
domestic greywater sources and their relative contributions, in regard to reuse for toilet
flushing. The dishwasher was found to be a major contributor of organic matter and
nutrients while the bath & shower were signalled out as major contributors of faecal
coliforms. Six different scenarios were explored, in each a different greywater source
8
was excluded from the “main” greywater stream and the effects on the quality and
quantity of the raw “main stream” were studied. Then the water saving potential in the
domestic sector was assessed with Israel serving as a case study representing semi-arid
country suffering from water shortage. The realistic proportional penetration ratio in 20
years in Israel was estimated at 20-35% and the consequent national water saving
potential at 25-50 MCM/y – a substantial saving. Greywater reuse for toilet flushing in
the domestic sector will enhance the sustainable use of water within the urban
environment.
5. Water reuse in Germany had gained in significance in the last 10 years. Several
greywater systems, build according to guidelines introduced in 1995, operate today
with no public health risk. Two greywater treatment systems was described in the paper
by Erwin Nolde (1999): a rotary biological contactor (RBC) built in 1989 for 70
persons, and a fluidized-bed reactor for a one-family household built in 1995 as the
biological stage for the treatment of household greywater for use in toilet flushing. Both
systems was optimized in the following years with consideration of a minimal energy
and maintenance demand. As numerous investigations had been shown, biological
treatment of the greywater was indispensable in order to guarantee a risk-free service
water for reuse applications other than potable water.
6. The composition of grey wastewater depends on sources and installations from where
the water was drawn, e.g. kitchen, bathroom or laundry. The chemical compounds
present originate from household chemicals, cooking, washing and the piping. In
general grey wastewater contains lower levels of organic matter and nutrients compared
to ordinary wastewater, since urine, faeces and toilet paper are not included. The levels
of heavy metals are however in the same concentration range. The information
regarding the content of xenobiotic organic compounds (XOCs) was limited. From the
study done by Eriksson E. et al (2002)10, states that 900 different XOCs were identified
as potentially present in grey wastewater by the use of tables of contents of household
chemical products.
7. A sampling campaign was conducted in order to characterise the quality and quantity
of individual domestic greywater streams. Based on the results concluded by E.
9
Friedler (2002)11, various scenarios of inclusion and / or exclusion of different
greywater streams were explored, and their implication for on-site greywater treatment
and reuse options are discussed. Domestic greywater was found to contribute as much
as 55-70% of the specific daily load of TSS and BOD in municipal sewage. The kitchen
sink was signalled out as a major contributor of VSS, COD, and BOD with 58%, 42%
and 48%, of their total daily load respectively. The washing machine was established
as a significant contributor of sodium, phosphate and COD (40%, 37% and 22% of the
total load). The dishwasher, although contributing only 5% of the flow, was found to
be a significant contributor of phosphate and boron. The wash basin was found to be
the least polluting appliance. As "demand" for greywater within the urban environment
is lower than its "production", it is logical to recycle only the less polluted greywater
streams. In order to explore the consequences of the above concept on discharge
volume, pollutants loads and concentrations, 18 scenarios were studied, in each at least
one stream was excluded from the combined greywater stream. Exclusion of the joined
stream of the kitchen sink plus the highly polluted streams of the washing machine
(wash + 1st rinse) and dishwasher (pre-rinse + wash) significantly improved greywater
quality, with the advantage of leaving enough greywater to be reused (65-70 l/c/d).
8. The aim of this paper published by Al-Jayyousi et al (2003)1 was to assess the role of
greywater reuse in sustainable water management in arid regions. Moreover, it intended
to document the experience of greywater reuse in Jordan. Greywater (GW) was the
water collected separately from sewage flow that originates from clothes washers,
bathtubs, showers and sinks, but does not include wastewater from kitchen sinks,
dishwashers, or toilets. Dish, shower, sink, and laundry water comprise 50–80% of
residential wastewater. GW is used in groundwater recharge, landscaping, and plant
growth. A case study on GW reuse in Jordan was presented to shed some lights on its
role in sustainable water management. To operationalize this concept, water was
viewed as an economic good and a finite resource that should be valued and managed
in a rational manner. The study concluded that current environmental policies should
aim to control pollution and to maximize recycling and reuse of GW within households
and communities. Decentralized GW/wastewater management offers more
opportunities for maximizing recycling opportunities.
10
9. Greywater use was a recognized way to conserve water and increase agricultural output.
There remain concerns about health and environmental risks associated with its use.
The International Development Research Centre (IDRC) had supported five projects in
the West Bank, Lebanon and Jordan on the use of greywater. The results of research on
related social, economic, technical and policy issues was presented by Bino et al
(2004)3. The projects was found to be community acceptance was essential if
technological solutions were to be succeeded. The implementation of greywater
strategies should take place within the framework of the new World Health
Organization (WHO) guidelines.
10. In India, the water shortage is one of the major issues coming from the rural areas area
which necessitates grey water treatment options generated from domestic sources in
rural areas and need for conceptualizing a treatment scheme to reduce cost. The paper
presented by Vijaya V. Shegokar et al (2007)7 states the design of laboratory scale
grey water treatment system, which was restricted to five stages of physical operations
such as raw grey water unit, sedimentation, first filtration unit of sand and gravel,
second dual filtration and storing unit for treated grey water . The sample was collected
from the Ashram School in rural area, taluka Tivsa of Amravati District. The research
work was related to the physio-chemical characterization of grey water samples,
treatability studies were carried out for the treatment of grey water by using low cost
technological options and to minimize the pollutant load from grey water. The results
showed that nylon rope filter showed better performance in the filtration stage as
compared to dual filters, and individually used activated carbon filter and zea maize
fodder filter. Hence, this treatment technology could be considered as a viable
alternative to conventional treatment systems in rural areas.
11. Household greywater (sullage), which are all the wastewater produced in the house in
exception of the toilet wastewater(black water) part of the solution to ecological
problems on dwindling water supply source will be water reuse gaining popularity,
people increasingly consider greywater from their residences as a resource to be
separated from the wastewater stream and reused in their landscapes. Such reuse of
greywater reduced the amount of wastewater entering sewers or onsite wastewater
treatment systems, reduces demands to use potable water for other residential uses like
11
flushing of toilet christens and irrigation and helped preserve limited water supplies for
essential uses like human consumption. In the course of this research project done by
Okwori Jenkeri Emmanuel (2007) an economically model of greywater re-
circulatory system with entirely natural process of treatment rapid sand filtration was
constructed and installed in an urban house. In which bathing waste water (greywater)
generated from the members of the home was re-cycled for purpose of flushing the
toilet mainly and irrigation, the quality of the treated effluent of the constructed system
were tested and the model was found to be 90% colloidal removal efficiency and the
cost implication of the model is at $64,909.
12. A low cost system was designed for the recycling and reuse of waste water from a
laundry unit by Jamil Ahmad et al (2008)15. The unit was associated with a petroleum
refinery in Pakistan. A survey was made to check the quantity and quality of waste
water generated. The unit was discharging 1.90 m3/day of waste water into the natural
water course. A small size sand and gravel filter was made from 0.00125 m sand, 0.0125
and 0.025 m gravels. The sand and two sizes of gravels were arranged in three layers.
Each layer was 0.10 m deep. The three layers were placed in a stainless steel hopper
and waste water was passed through the filter. Both, the waste water and treated water
were analysed and compared with tap water.
The physical and chemical parameters considered were pH, turbidity, total suspended
solids (TSS), total dissolved solids (TDS), chemical oxygen demand (COD),
biochemical oxygen demand (BOD), total hardness (TH) and iron contents. The results
showed that the filtration process reduced the pH, turbidity, TH and TSS to acceptable
limit and TDS to some extent. On the other hand it had negligible effect on COD and
BOD. The treated water was ranked as low-grade water and was found to be suitable
for use in the laundry unit for the first rinse only. Based on the obtained results large-
scale treatment process was designed for the waste water. It was a low cost treatment
system consisting of sedimentation and filtration. It was found that the total capital and
operating cost per year of the system was US$ 1343. The daily saving of water was
1.80 m3 with a payback period of only 1 year in one case and half year in the second
case. In the first case the price of fresh water was taken as US$ 2.2/m3 and in the second
case as US$ 4.4/m3.
12
13. The recycling of greywater is an integral part of a water management system owing to
the scarcity of fresh water resources. This article presented by Vijayaraghavan
Krishnan et al (2008)18 explored the effectiveness of an aerobic sequencing batch
reactor in treating nutrient-deficit and nutrient-spiked dark greywater for agricultural
reuse. The dark greywater in the present investigation had a COD: N: P ratio of
100:1.82:0.76, while the preferred ratio for biological oxidation is 100:5:1 (COD,
chemical oxygen demand). The aerobic oxidation of nutrient-deficit and nutrient-spiked
dark greywater with a COD:N:P ratio of 100:2.5:0.5; 100:3.5:0.75 and 100:5:1 resulted
in outlet COD values of 64; 35; 15 and 12 mg L−1, with a corresponding BOD5 value
of 37; 22; 10 and 8 mg L−1 at 36 h hydraulic retention time (HRT). Hence treatment of
nutrient-added dark greywater at a COD: N: P ratio 100:3.5:0.75 and 100:5:1 for 36 h
HRT complied with the Malaysian discharge standards for agricultural activities.
Treated greywater has the potential for consideration as a resource, since it can be used
as a supplement or replacement for potable water in landscape irrigation and other
agricultural activities in rural and urban areas. Moreover, the level of greywater
treatment is dictated by the final water quality requirement.
14. Greywater is the part of domestic wastewater that is free of feces. The volume and
concentration of this separately collected wastewater flow depend on the consumer
behavior and vary according to its source. The average amount of greywater produced
per day in a German household is 70l per person, which is more than 50% of the total
wastewater production. This figure corresponded with the average figures provided for
Chinese households (80 l per person/day, GB/T 50331-2002), but significantly
exceeded the South African average of 20 l per person and day. Compared to domestic
wastewater, greywater generally contains less organic pollutants, less nutrients but a
high amount of tensides. The effluent from bath tubs, showers or wash hand basins
contains for example a by approx. two decimal orders lower number of total and fecal
coliform bacteria (Escherichia coli).
Due to its relatively low content of pollutants, greywater was easy to treat with MBRs.
The pollutants contained were decomposed by the bacteria of the activated sludge tank.
The following membrane filtration unit separates the treated greywater from the
13
activated sludge. The treated greywater was of high quality and hygienically safe so
that it can be reused, alone or combined with rain water, for toilet flushing water,
laundry washing or for irrigation purposes.
15. Within the scope of the SANSED II research project HUBER has been successful in
adapting the MBR system for greywater treatment to the specific conditions in Vietnam
and testing the system in operation in a small city in the Mekong delta, South Vietnam
was done by Stefania Paris et al (2008). The wastewater from kitchen sinks and the
bathrooms of a dormitory on the campus of Can Tho University was clarified in the
HUBER Grey Use plant over a period of three months. The project aim was the
production of high quality service water from greywater for safe reuse as toilet flush
water.
16. Greywater treatment and reuse systems were constructed in residential schools
(Schools) in Madhya Pradesh, India and treated greywater was used for toilet flushing
and irrigating the food crops. Cost–benefit analysis was done by Sam Godfrey et al
(2009) and was undertaken for greywater reuse by considering internal and external
costs and benefits. The internal costs consist of construction of a greywater reuse
system as well as the operation and maintenance costs. The construction cost (material
and labour costs) equalled Indian Rupee (INR) 50,300 (1 USD = 42.5 INR) and
operation and maintenance cost is INR 5725 per year. Internal benefits were estimated
to be INR 30,000 per year due to the reduction in tank water. Appropriate valuation
methodologies were applied to monetize external benefits such as savings on water
infrastructure, reuse of pollutants such as nitrogen, phosphorus and potassium
(equivalent to market cost of chemical fertilizer). Monetary values of external benefits
and costs in terms of environmental and health benefits were derived by using scientific
references. The environmental and health benefits were estimated as INR 44,000 and
INR 793,380 respectively. In summary, the internal and external benefits of greywater
reuse were substantially higher than the internal and external costs.
17. In India, the quarrel between the budding human populace and the planet’s unchanging
supply of freshwater and falling water tables has strained attention the reuse of grey
water as an alternative water resource in rural development. The paper presented by
Bhausaheb L. Pangarkar et al (2010)2 shows the finest design of laboratory scale grey
14
water treatment plant, which was a combination of natural and physical operations such
as primary settling with cascaded water flow, aeration, agitation and filtration, hence
called as hybrid treatment process. An economical performance of the plant for
treatment of bathrooms, basins and laundries gray water showed in terms of deduction
competency of water pollutants such as COD (83%), TDS (70%), TSS (83%), total
hardness (50%), oil and grease (97%), anions (46%) and cations (49%). Hence, this
technology could be a good alternative to treat gray water in residential rural area.
18. In India, the per capita water availability is reducing day by day due to rapid growth in
population and increasing water demand. Greywater treatment and reuse is one of the
feasible options in developing countries like India to overcome this problem. A
greywater collection, treatment and reuse system was designed and implemented in an
urban household having a water requirement of 165 litre per capita per day (lpcd) and
a greywater generation rate of 80 lpcd. An up flow–down flow greywater treatment
plant having a screening, sedimentation, filtration and disinfection as major treatment
processes was constructed and treated greywater was used for toilet flushing and to
irrigate the vegetables in the backyard of the household. Greywater characterization
indicates that COD and BOD are sufficiently reduced during the treatment and there
was also substantially reduction in Escherichia coli count. The payback period of this
greywater treatment and reuse system was estimated to be 1.6 year and was successfully
completed by Deepika Mandal et al (2010).
19. The use of treated grey water (GW) for irrigation in home gardens is becoming
increasingly common in Jordan. In this study done by H. Al-Hamaiedeh et al (2010)
the treated GW produced from 4-barrel and confined trench (CT) treatment units were
used for irrigation of olive trees and some vegetable crops. The quality of treated and
untreated GW was studied to evaluate the performance of treatment units and the
suitability of treated GW for irrigation according to Jordanian standard. Effect of treated
GW reuse on the properties of soil and irrigated plants at Al-Amer villages, Jordan, has
been investigated. The results showed that salinity, sodium adsorption ratio (SAR), and
organic content of soil increased as a function of time, therefore leaching of soil with
fresh water was highly recommended. The chemical properties of the irrigated olive
15
trees and vegetable crops were not affected, while the biological quality of some
vegetable crops was adversely affected.
20. To overcome the emerging crisis of water, greywater represents a significant resource
of water if considering recycling or uses not requiring a drinking water quality a study
was carried out by Katell Chaillou et al (2011). Samples of greywater were taken from
a few households. Their characterization led to results similar to those in literature.
However, they showed a lack of phosphorous in C/N/P ratio. Nevertheless, it was
shown that, in our study, median as more appropriate than mean. The potential
treatment steps studied during this work were sand bed filtration, adsorption onto
granular activated carbon (GAC), and sanitation by chlorine. The sand bed which was
supplied with sequential feedings led to a very good removal of total suspended solids
(TSS; and consequently of turbidity) as well as to a 30% COD decrease. However, the
organic matter withdrawal was more efficient by adsorption onto GAC. The
chlorination of greywater was efficient to decrease the microbial population. Therefore,
following the reclaimed water quality which would be required treatment might imply
all steps or just one or two. This kind of low-cost device could thus be implemented for
reuse such as irrigation, agricultural need, or urban use.
21. Safe and sufficient quantity of water is necessary for a healthy growth of human beings.
The gap between water demand and available water supply is increasing day by day.
Proper sanitation, especially decentralized approach, can solve the problem of water
supply and wastewater management and that can be done by reuse of greywater.
Typically, from a household, greywater (GW) flow is around 65% of the total
wastewater flow. Further light greywater is around 50% of the total GW. Hence, GW
has a high potential for recycle and reuse. The aim of this article presented by Dilip M.
Ghaitidak et al (2013) was to reveal the present state of art in GW treatment and to
identify the further scope for research. Present article contains a review on per capita
GW generation, GW characteristics, and its treatment. Around 22 treatment systems
comprising different treatment processes are discussed in detail for removal efficiency
of pollutants, effluent concentrations and their compliance with wastewater reuse
guidelines and standards. Constructed wetland and filtration were found efficient in the
removal of most of the reuse parameters compared to other technologies. Anaerobic
16
followed by aerobic system with post disinfection unit may be a sustainable option for
GW treatment for reuse. There is a need to develop the technologies for GW treatment
at household level to increase the reuse practices at grass root level. Further, there is
need of development of flow diagram with different technologies bye targeting the type
of reuse (flushing, gardening, agriculture, etc.).
2.2 Literature Summary:
As in India, there is a scarcity of fresh water in various areas thus we decided by referring the
above projects, the development of a product for treatment of Greywater in an economical and
effective use, the product is mainly going to use under the kitchen sink, which can be used in
the replacement of fresh water required in various residential or commercial purposes.
17
Chapter 3
METHODOLOGY
3.1. Materials:
Following are the materials (with their size) described below are to be used in the development
of product for greywater treatment:
3.1.1. Sand
Sand is a naturally occurring granular material composed of finely divided rock and
mineral particles. It is defined by size, being finer than gravel and coarser than silt. Sand
can also refer to a textural class of soil or soil type; i.e. a soil containing more than 85%
sand sized particles by mass.
Sand is used as one of the filtering layer produces very high quality water free
from pathogens, taste and odour without the need for chemical aids. Sand filters, apart
from being used in water treatment plants, be used for water purification in singular
households as they use materials which are available for most people. The grain size is
around or less than 0.1mm in diameter, a sand filter removes all inorganic materials.
The Size of Sand varies from 150µ to 600µ. Fig. 3.1 shows image of sand which was
used as a filter medium in the project.
Fig. 3.1. Sand
18
3.1.2. Gravels
Gravel is an important commercial product, with a number of applications and will be
used in the development of product for greywater treatment, it is categorized into
granular gravel (2 to 4 mm or 0.079 to 0.157 in) and pebble gravel (4 to 64 mm or 0.2
to 2.5 in).
Gravels traps small bugs or organisms, algae, suspended dirt, any other large particles
in the water. The Size of gravels varies from 20mm to 30mm as a filter medium
followed by different samples.
Fig. 3.2. Gravels
3.1.3. Fish Tank Gravels/ Substrate
The substrate of an aquarium refers to the material used on the tank bottom, and may
have a polymer seal to ensure it does not affect water chemistry. Gravel sold specifically
for use in aquaria is chemically inert. It is commonly composed of quartz or other lime-
free minerals. The most important purpose of using the substrate in our filtering media
is, as it entraps the greasy matters thus filtering the greywater more effectively. The
Size of fish tank gravel varies from 20mm to 30mm as filter medium used in the project.
Fig.3.3 shows image of fish tank gravel used as filtering medium for treating the
sample.
19
Fig. 3.3. Fish Tank Gravels/Pebbles
3.1.4. Activated Carbon
Pelletized activated carbon as shown in fig. 3.4 below, produced from anthracite coal
by a high temperature activation process under stringent quality control. It has a large
surface area, high mechanical hardness, and excellent pore volume and chemical
stability.
Activated carbon works via a process called adsorption, whereby pollutant molecules
in the fluid to be treated are trapped inside the pore structure of the carbon substrate.
Active charcoal carbon filters are most effective at removing chlorine, sediment,
volatile organic compounds (VOCs). The Size of activated charcoal used in the project
are 20mm to 30mm followed by use of different samples. Fig.3.4 indicate the image of
charcoal used in the project.
Fig. 3.4. Activated Charcoal
4.1.5. Screens/Meshes
A mesh is a barrier made of connected strands of metal, fiber, or other flexible/ductile
materials and are available in market of various sizes and materials, used for larger
particle sized materials, greater than 44 micron (325 Mesh).
20
The purpose of meshes or screens in the project is to separate the filtering materials and
preventing intermingling between the materials.
Fig. 3.5. Screens
3.2. Material Requirements:
3.2.1. Sand
Sand used as filtering layer should be well cleaned, as if the sand is used without
washing thus increasing the turbidity and various parameters
3.2.1.1 Washing of Sand
In the first trial unwashed sand was used as filter medium due to which the sample
gave unwanted results as the turbidity was more than that of water sample to be
treated. Then in the next trial washed sand was used a filter medium which provide a
permissible result as per the limit. Therefore it became necessary to wash the sand
before it can be used as a filter medium.
Fig. 3.6. Before washing Fig. 3.7. After washing
21
3.2.2. Gravels
Gravels should be well cleaned, chemically inert and should have less absorption of
water so as to avoid loss in discharge.
3.2.3. Fish Tank Gravels/Substrate
Substrate should be chemically inert and should be well cleaned.
3.2.3.1 Washing of gravels and fish tank gravels:
The gravels and the fish tank gravels can be washed and reused after it had been used
as filtering medium for the waste water sample. Fig.3.8 shows image while cleaning
the gravels and the fish tank gravels.
Fig. 3.8. Cleaning of Gravels and Substrate
3.3. Layering Methodology:
The layering of the filtering materials is done in 3 depth condition, viz. Minimum depth,
Average depth and Maximum depth. The depth of each filtering materials is shown below in
the tabular format.
Table no. 3.1. Depth of filtering media
Layer & Materials Min. depth
(cm)
Max. depth
(cm)
Avg. depth
(cm)
1. Sand 10 20 15
2. Activated Carbon 15 25 20
3. Substrate 15 25 20
4. Gravels 10 20 15
Total 50 90 70
22
3.4 Experiments:
Following are the experiments conducted to check the permissible range for which the project
is being done:
3.4.1. Turbidity
Turbidity is caused by particles suspended or dissolved in water that scatter light
making the water appear cloudy or murky. Particulate matter can include sediment -
especially clay and silt, fine organic and inorganic matter, soluble coloured organic
compounds, algae, and other microscopic organisms.
High turbidity levels can also cause physical damage to leaf surfaces by abrasion and
by smothering.
Due to turbid water, the photosynthesis rate decreases as there is lack of light emitting
in the water, thus reducing the one of the food source of plants. Fig.3.9 & Fig.3.10
shows the reading of samples before and after filtration. The turbidity range should lie
< 5 NTU.
Fig. 3.9. Turbidity before filtration Fig. 3.10. Turbidity after filtration
3.4.2. Hardness
Water hardness is another major problem in most city water and wells. Hard water is
caused by an excess amount of minerals in your water. Ironically, these excess minerals
are the same minerals found in most complete plant nutrients. The problem is the heavy
concentrations cause massive salt build-up on the roots and in the media which can
cause nutrient lockout of varying degrees. At the very least your plants won’t uptake a
proper balance of all the nutrients they require. At worst the plant can stop getting major
nutrients required for normal growth which will eventually cause the plant to die. The
most common cause of hard water is excess calcium, magnesium, iron and sulphur.
23
Range: 200 mg/l (desirable) – 600 mg/l (permissible)… as per drinking water standards
of BIS (IS: 10500:2012).
3.4.3. pH and Alkalinity
Irrigation and Gardening water tests should always include both pH and alkalinity
tests. A pH test by itself is not an indication of alkalinity. Water with high alkalinity
(i.e., high levels of bicarbonates or carbonates) always has a pH value 7 or above, but
water with high pH doesn't always have high alkalinity. This is important because
high alkalinity exerts the most significant effects on growing medium fertility and
plant nutrition.
Range: 1. pH: 6.5 – 8.5
2. Alkalinity: 30 – 60 ppm
3.4.4. Total Dissolved Solids
High levels of total dissolved solids do not correlate to hard water, as water softeners
do not reduce TDS. Water softeners remove magnesium and calcium ions, which
cause hard water, but these ions are replaced with an equal number of sodium or
potassium ions. This leaves overall TDS unchanged.
Range: 500mg/l (desirable) – 2000mg/l (permissible)…. As per BIS: 10500:2012.
3.4.5. Biological Oxygen Demand (BOD)
Biochemical Oxygen Demand (BOD, also called Biological Oxygen Demand) is the
amount of dissolved oxygen needed (i.e., demanded) by aerobic biological organisms
to break down organic material present in a given water sample at certain temperature
over a specific time period. The BOD value is most commonly expressed in milligrams
of oxygen consumed per litre of sample during 5 days of incubation at 20 °C and is
often used as a surrogate of the degree of organic pollution of water.
The BOD is one of the important parameters which is to determine the level of dissolved
oxygen, this used to find out the level of oxygen, so as to check the suitability of water
for gardening purpose. Fig.3.11 shows image while performing the BOD experiment.
24
Fig.3.11. While performing BOD experiments
The limit of BOD should lie between range: 200mg/l – 300mg/l for drinking water.
25
Chapter 4
RESULT AND DISCUSSION
The results are shown for three depth in tabular format viz. Minimum depth, Average depth
and Maximum depth.
Table no. 4.1. Results
S.No. Parameters Wastewater Min. depth
(cm)
Avg. depth
(cm)
Max. depth
(cm)
1 Turbidity (NTU) 12.7 3.4 3.4 3.2
2 Hardness (mg/l) 513 453 451 420
3. pH 9 8.5 8.5 8
4. TDS (mg/l) 705.16 523.59 519.34 491.83
5. BOD (mg/l) 52.13 37.24 36.97 22.45
DISCUSSION:
From the above results we can get to know that the water can be used for cleaning floor
& flushing purpose, and as the depth of the material increases the rate of filtration
increases. Fresh sample is needed for every experiment as stale sample can give error
in the readings. Turbidity of the sample for wastewater was far improved as the depth
of the material layers increases. And also the other parameters of the experiments were
also in the permissible range.
Product Details:
From the above mentioned experimental works, the following product is been
developed, which is use to filtered the greywater passing from the kitchen sink and the
filtered greywater can be used for above mentioned purposes.
27
Chapter 5
CONCLUSION
After the experimental work for treatment of greywater, the following points are
concluded for the development of product for greywater treatment
The depth of filtering media changes the little amount of readings thus it is concluded
that the depth of materials can be kept minimum i.e. 50cm (Overall depth).
The filtered water passes from filtering media can be used for the gardening, cleaning
and flushing purposes
As the filtered water are within the permissible limit, the use of water for gardening
does not affect the plants, as it will help the environment to keep it safe more effectively.
As the minimum depth (overall) of materials can be provided thus it will treat the
greywater more economically for household use.
Use of maximum depth (overall) of materials, it will increase the efficiency of the
treatment of greywater.
28
Chapter 6
REFERENCES
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Recommended