Science Project-Reuse and Recycling of Grey Water

  • Contributed by : Sreya Varsha Arun
  • Status : Student
  • Class : 10
  • School : Bharatiya Vidya Bhavan
  • Age : 15
  • Mode : Medium
  • Article type : Science Project
  • Target Age Group : 11-15 Years

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Project done By: Shreya Varsha Arun, Malavika Krishna,Tanmay Sahu, Abhishek Jayant Patil and Karthik Sudheer


Sustainable development aims at the sustainability of the natural resources for today’s generation and continues to meet the needs of future generations. The worldwide fascinated field of interest is the sustainability of domestic water. How to meet the future challenges?

In Arid region like Kuwait, the fresh water resources are limited and mostly dependent on sea water by desalination techniques. Excessive with drawl of water from the aquifers is prodigious either for industrial, domestic and agriculture purpose. As well the global impact is more that, no adequate rainfall to recharge the aquifers. If this continues, the future consequence on the limited water resources is going to have a great effect in the country.

Also enormous quantity of water is being wasted from the household after a single use. Keeping this in mind, there is a new way of approach to reuse the Grey Water by simple scientific principle of Filtration and Disinfection and to use for watering the lawns, car wash, firefighting, flushing toilets, and irrigation purpose. The treated Grey Water may be utilized for recharging the aquifers by artificial means. The aim of this project was Grey Water collection from the selected areas of Kuwait, treatment and analysis of the proposed study.

Keywords: Grey Water, Aquifer, Filtration, Disinfection



Shrinking of natural water resources, increase of population and modern life style demands the usage of Grey Water in Kuwait. Reuse of treated Grey water may reduce the consumption of fresh water in future and may be conserved for future generations. The production of fresh water is more expensive than treated Grey Water. Literature survey of A. Abusam,[1]Rawa Al-Jarallah,[2]   Jasem M[3]  and Ahmed Ibrahim Abd Alaziz [4]relates more closely the wise use of Grey Water, as there is an increasing demand of domestic water. The rate of consumption of water in Kuwait is more for car washings, cleaning of utensils when compared to laundry and shower. Kuwait Government had started "Tarsheed Project" to create the awareness to public about the importance and need for conservation of water. From 2009 different research studies were conducted for the consumption of domestic water and also specified the need of Grey Water use but not collected for the quality testing. Though, Grey Water has been used in many countries even without any treatment and growing different variety of plants yet Kuwait has not started using the Grey Water till today. Also the public has a fear in their minds that the Grey Water without treatment will affect their health conditions especially in the middle east. This made them not to use the Grey Water. Keeping in view and reviewing the data from the available literature, the present study involves reuse and recycling of the Grey Water by simple, easy and effective treatment and experimentation was carried out in the laboratory for the quality determination of Grey Water.

Grey Water is the water collected from kitchen sink, shower and washing machine. But the quality of different waste streams will be variable, depending on the types of cleaning products used and they may have an impact. The water characteristics that may affect include suspended solids (SS), nutrients, Biological Oxygen Demand (BOD), and microorganisms. Based on the parameters the grey water was treated. The preferred treatment for the Grey Water was slow sand filtration and disinfection using bleaching powder as a disinfectant.



  • Efficient use of grey water using cost effective treatment.

  • To check the plant growth and its edibility.

  • To use the treated Grey Water for recharging the Aquifers.


Despite of the global climatic changes, using treated Grey Water may sustain the water for next generations.



The purpose of this study was to illustrate the utilization of Grey Water in arid areas like Kuwait for the sustainability of water resources in future.



  • Slow Sand Filtration- The set up consists of different layers used for the filtration of Grey Water.

  • Disinfection- Filtered water was disinfected using bleaching powder.

  • Analysis- Physical, Chemical and Microbiological analysis was done to check the quality of the water to meet the specifications for irrigation.


Grey Water Treatment

  • Materials & Chemicals Used:

Used Plastic bottles, Glass bottles, Cotton, Activated Charcoal, Fine sand, Coarse sand, Small Gravel, Big Gravel, Tea Strainer and Bleaching Powder.

  • Grey Water Collection:

The sources of grey water are water from kitchen, shower and washing machine collected separately, blended and transferred into a clean glass bottle.

  • Grey Water sampling:

The sampling was carried out for three days continuously at Fahaheel, Salmiya and Farwaniya areas of few houses selected randomly.

  • Filtration Process:

  • A filtration system was set up to filter the grey water in each residence.

  • The filtration arrangement (bottom to top) is as follows:

  • Cotton- Acts as a slow porous filter

  • Activated Charcoal- Removes bacteria, odour and colour

  • Fine sand and Coarse sand- Trap Micro-organisms

  • Small Gravel and Big Gravel- Extra filtration

  • Coffee or tea strainer- To remove floating matter

  • Filtration was done by the above set up method.

  • Disinfection: The filtered water was disinfected using 0.05g of bleaching powder per one liter of filtered Grey Water.



All the samples were collected from the areas of Fahaheel, Salmiya and Farwaniya and analyzed for the following parameters with the support of third party laboratory. The results were tabulated in the respective tabular forms and the data was evaluated.

Table:1 Physical&Chemical Analysis of Grey Water

Table:2 Metal Analysis of Grey Water

Table:3 Micro Biological Analysis of Grey Water

As per the results of physical &chemical, metal and microbiological analysis tabulated, most of the parameters were in the range of KEPA specifications. The analysis results were different for the three areas because the Grey Water Collected was entirely based on the type of detergents, soaps and dish washing liquid used. On the average of the three selected areas results, the treated Grey Water contains appreciable levels. The graphical representations of the few parameters are as follows.


Table:4 Physical& Chemical Parameters of Grey Water Analysis

Figure 1
Average pH of the three areas between the KEPA limits         

Figure 2 Average Electrical Conductivity of the three areas                   

Figure 3- Total Dissolved Solids Comparison of the three areas, Average Value and KEPA limit        


Figure 4 Average Salinity of the three areas                                                         

Table:5 Nutrients of Grey Water Analysis

 Figure 5 Nutrients Comparison of the three areas using KEPA limits   

The graphical representation results of the Physical &Chemical parameters, Nutrients- phosphate, nitrate and potassium reflects the use of treated Grey Water for irrigation purpose. Initially plantation was done using the treated Grey Water by planting gram seeds for a week during the month of July which had grown well. (Figure 6)

Figure 6 Green Gram Plant

Next the plant growth was verified for two chili plants a week, using normal water and treated Grey Water. There is an equal increase in the height of the plants irrespective of the water used. (Figure 7&8)

Figure 7 & 8 Comparison of Chili plant height using Normal and treated Grey Water

(The leaves represent tomato plant and not chili)


The edibility of the plant was not tested but based on the analysis results of metals and nutrients gives a clear picture that plant is edible. Even though, micro biological parameters of the analysis are high which may not lead to threat for crops.


In general, Municipal wastewater treatment plants in Kuwait use sand filtration and chlorination and to an advanced level ultra-filtration (UF) and reverse osmosis (RO) for the production of domestic water. The present study on reuse and recycle of Grey Water using sand filtration and disinfection is more easy, rapid, effective and economical when compared to the fresh water production. Hence the treated Grey Water can be used for watering the lawns, cleaning of cars, firefighting and flushing toilets etc. By the graphical representation of the results the samples meet the KEPA specification criteria indicating that Grey Water may be used for the irrigation like drip or sprayed irrigation in Kuwait .Grey water may also be used for subsurface irrigation of ornamental plants like jute, fruit trees like mango, orange etc and best suitable for mature saplings like paddy which have considerable tolerance to salinity, sodium compounds, and high pH levels.


According to statistical data collected from the literature, [1] the rate of water consumption in Kuwait per day is more than one million cubic meter on average. So, there is a demand of water at present and in near future. To meet the future challenges of sustainable water resources in Kuwait, the best way is practicing the recycled Grey Water for normal domestic usage like watering the lawns, cleaning of cars, flushing of toilets, firefighting and for irrigation to reduce the fresh water production.


  • In near future, to study about the use of different types of charcoal materials like wood charcoal, coconut shell charcoal etc for further reduction cost of treated Grey Water.

  • Comparison studies of the Aquifer water quality in terms of chemical & microbiological analysis and treated Grey Water testing from different areas of Kuwait.

  • Studies on recharge of the Aquifer using treated Grey Water by small scale filtration pit set up in the residential areas of Kuwait.


The authors would like to thank the Principal Mr. T.Prem Kumar, Vice principal in arranging the requirements and the Science HOD who has reviewed the write up, our beloved parents for their continuous assistance, and constant support throughout the duration of the project study.  Finally, we would like to express our intense appreciation to our internal and external guides Mrs. Frenny and Dr. S V V Dhanu Radha in guiding us with their suggestions and for successful completion of the project


  1. Abusam; Reuse of greywater in Kuwait; International Journal of Environmental Studies,Vol. 65, No. 1, February 2008, 103–108

  2. Rawa Al-Jarallah; The Potential for Reusing Grey Water and its Generation Rates for Sustainable Potable Water Security in Kuwait; Journal of Engineering Research; Vol 1(1), June 2013, 97-112

  3. A Ibrahim Abd Alaziz et al; The Reuse of Grey water Recycling For High Rise Buildings in Kuwait Country; Int. Journal of Engineering Research and Applications; Vol 4 (3), Version (1), March 2014, 208-215

  4. Jasem M. et. al; House hold demand for water: A case study in Kuwait; Kuwait J. Sci. Eng. Vol 30(1), 2003

  5. Eth DUWS; Grey water Treatment On Household Level In Developing Countries –
    A State of The Art Revi

  6. The Governance of Technology: Grey Water and Recycled water systems;


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One Reply to “Science Project-Reuse and Recycling of Grey Water”

  1. Dear Shreya and other contributers,
    It is an outstanding science project.You need to be congratulated for; reveiw of literature,methodology and scientific inferences. The support extented by your school and the guidance of your science teachers is appreciated. You need to be specialy appreciated for selecting a topic which is having a social relevance. Our country will have a glorious future if young scientific minds are motivated. The environmental relevance of reuse and recycling of grey water using these simple tools will help to make our planet cleaner and greener. Let this platform of nurture these budding scientists.