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Abstract
Water is one resource that has no substitute. Even though water covers three quarters of the planet, 97% of the Earth's water is saline water.Less than 3% of water is fresh water. In the recent years, many events have occurred which point towards the decreasing fresh water resources of the world. Greywater is good alternative resources.Greywater recycling is the viable option that can be very useful in the water arid areas.The aim of the study is Evaluation and Performance study on Greywater Treatment.The treatment was carried out by using sedimentation tank and upflow -downflow roughing filters.Comparing the treated greywater quality parameters with the WHO standards. Since the intended use of water is for irrigation and toilet flushing,the required treatment standards are therefore less stringent as compared to that for drinking purposes.
Greywater is maximum generated in Sollampallam located in Salem. In that area
laundries are practiced.From that area about 5000 liters of grey water are generated out daily.
Introduction
Water is becoming a rare resource in the world. Consequent to rapid growth in population and increasing water demand, stress on water resources in India is increasing and per capita water availability is reducing day by day. In India per capita surface water availability in the years 1991 and 2001 were 2300 m3 and 1980 m3 respectively and these are projected to reduce to 1401 and 1191 m3 by the years 2025 and 2050 respectively (Kumar et al., 2005).
International Water Management Institute (IWMI) predicts that by 2025, one person in three will live in conditions of absolute water scarcity (IWMI, 2003). It is therefore essential to reduce surface and ground water use in all sectors of consumption, to substitute fresh water with alternative water resources and to optimize water use efficiency through recycle and reuse options. Many Mediterranean countries are investing in wastewater reclamation and reuse due to high evaporation and evapotranspiration, low rainfall and increased demand for water for irrigation (Angelakis et.al. 2001).Due to rapid industrialization and development, there is an increased opportunity for grey water reuse in developing countries such as India. Grey water is commonly defined as wastewater generated from bathroom, laundry and kitchen.
Equally, in water scare developing countries,
Key words: Greywater, Roughing Filters, Water resources ,Waste water.
Objective of the project
The main objective of this investigation is
The overarching aim of this project was to provide detailed information on the evaluation and performance study on grey water treatment.
Assembling and testing of laboratory scale grey water treatment system have been carried out.
The main research aim is comparing the treated grey water with the WHO standards is suitable for the purpose of using irrigation and toilet flushing.
Scope of the Project
There are four reasons why grey water may need to be treated
To remove substances that may be harmful to human health.
To remove substances that may be harmful to plants and soil.
To remove substances that may be harmful to the environment.
To remove substances that may clog the irrigation system.
Literature Review
Al-Jayyousi, 2003, the treated grey water which is generated from bathroom and clothes washing in Ashram schools is used for toilet flushing and watering plant in the garden of school premises. However, treatment for kitchen wastewater, will generally require more sophisticated technologies and processes to address the high BOD and fatty solids generated hence kitchen wastewater is not considered in this application.
Sandeep Thakur et.al (2009) Journal of Environmental Science and Sustainability, studied the grey water recycling using filtration. Since the intended use of water is for irrigation and toilet flushing the required treatment standards are therefore less stringent as compared to that for drinking purposes therefore the grey water is acceptable for reuse. From the above study it can be concluded that that grey water recycling can be the viable option in the present situation of water scarcity.
Jefferson.B et.al (1999), studied the technologies for domestic wastewater recycling. Grey water quality varies considerably but can be considered to be of a similar strength to domestic sewage. Storage is required to balance the imbalance in the dynamic of water demanded by toilet flushing and irrigation. Residence time in systems dramatically affects the characteristics of grey water. Membrane bioreactors meet all the applicable water quality standards but are currently costly.
Peche.R.T.,et.al (1999) studied the Grey Water- a Potential Source of Water for Construction. The types of grey water used in this study met the standard specification mentioned in various codes but should be disinfected before use. Grey water reduces the initial and final setting time but that reduction is marginal and still within the prescribed limits. Increase in compressive strength has been observed when grey water was used. It may be due to higher alkalinity than potable water.
Application
Greywater treatment process varies from simple devices that divert grey water for direct application such as irrigation to complex systems involving screen,sedimentation tanks, filtration. However, the basic objective is to initiate process of grey water treatment and keeping cost-effectiveness as a basic theme, simple treatment systems for non-contact use are described. This manual provides acceptable solutions for reuse of grey water that satisfies the performance objective and requirements. It may be appropriate for persons contemplating a grey water reuse system to consult a wastewater system designer or other suitably qualified person to consider the options available. To design a grey water system an estimation of grey water generation is required and the site then needs to be evaluated for the possible reuse of grey water.
Quantification of Greywater:
Determination of grey water generation and flow rate is the first requirement in the design of grey water collection, treatment and reuse system. Reliable data on existing and projected flow rate must be available for the cost-effective grey water treatment system design. The possible reuse options as previously described also determines treatment design. According to the Central Public Health and Environmental Engineering Organisation (CPHEEO) water supply demand for Indian cities provided with piped water supply with sewerage amounts to 135 litres per capita per day. Break up of water demand. Grey water accounts to 2/3 of total water consumption.