Transcript 229-349-270-172

RIVER GANGA
A Project on Environmental Science focused on
wastewater and sewage treatment for a clean River
Ganga in future.
-By Pranav, Sagar, Vikas and Mayank
Introduction
The Ganga (गग ां) is a major river of the Indian subcontinent rising in the Himalaya Mountains
and flowing about 2,510 km (1,560 mi) generally eastward through a vast plain to the Bay of
Bengal. On its 1,560-mi (2,510-km) course, it flows southeast through the Indian states of
Uttar Pradesh, Bihar, and West Bengal. In central Bangladesh it is joined by the Brahmaputra
and Meghna rivers. Their combined waters (called the Padma River) empty into the Bay of
Bengal and form a delta 220 mi (354 km) wide, which is shared by India and Bangladesh. Its
plain is one of the most fertile and densely populated regions in the world. The Ganges alone
drains an area of over a million square km with a population of over 407 million. Millions
depend on water from the holy river for several things: drinking, bathing, agriculture, industry
and other household chores.
Ganga river known as Ganga Maata (गग ां म त ) or Mother Ganges is revered as a goddess
whose purity cleanses the sins of the faithful and aids the dead on their path toward heaven.
In most Hindu families, a vial of water from the Ganga is kept in every house. It is believed
that drinking water from the Ganga with one's last breath will take the soul to heaven. Hindus
also believe life is incomplete without bathing in the Ganga at least once in their lifetime.
Some of the most important Hindu festivals and religious congregations are celebrated on the
banks of the river Ganga such as the Kumbh Mela or the Kumbh Fair and the Chhat
Puja. Kumbh Mela is the largest religious gathering on Earth for Hindu peoples, where
around 70 million Hindus from around the world participated in the last Kumbh Mela at the
Hindu Holy city Prayaga (also known as Allahabad).
Map of Ganga
Pollution in Ganga River
Today, over 29 cities, 70 towns, and thousands of villages extend along the Ganga banks.
Nearly all of their sewage - over 1.3 billion liters per day - goes directly into the river, along
with thousands of animal carcasses, mainly cattle. Another 260 million liters of industrial
waste are added to this by hundreds of factories along the rivers banks. Municipal sewage
constitutes 80 per cent by volume of the total waste dumped into the Ganga, and industries
contribute about 15 percent. The majority of the Ganga pollution is organic waste, sewage,
trash, food, and human and animal remains. Over the past century, city populations along the
Ganga have grown at a tremendous rate, while waste-control infrastructure has remained
relatively unchanged. Recent water samples collected in Varanasi revealed fecal-coliform
counts of about 50,000 bacteria per 100 milliliters of water, 10,000% higher than the
government standard for safe river bathing. The result of this pollution is an array of waterborne diseases including cholera, hepatitis, typhoid and amoebic dysentery. An estimated
80% of all health problems and one-third of deaths in India are attributable to water-borne
diseases.The sacred practice of depositing human remains in the Ganga also poses health
threats because of the unsustainable rate at which partially cremated cadavers are dumped.
Hundreds of corpses burn on the line of wooden pyres. Soot-covered men bustle about,
raking in the still-glowing ashes, sweeping them into the river. Ganga is getting polluted dayby-day. Nearly 170 factories and tanneries located between Kannauj and Varanasi, covering an
area of 450 km, were found responsible for polluting the river by discharging wastes into it
without treatment,” Union Minister for Environment and Forests Jairam Ramesh told
reporters on August 28, 2010.
There is an urgent need to aware people and get started to stop its pollution and
degradation.
Ganga Action Plan
After two Ganga Action Plans failed to deliver the goods, seven major IITs of the country have
joined hands to find ways to clean up the national river. The Ganga Action Plan (GAP) was
initiated by the late Prime Minster Indira Gandhi, who called for a comprehensive survey of
the situation in 1979. In 1985, the government of India launched the Ganga Action Plan,
which was devised to clean up the river in selected areas by installing sewage treatment
plants and threatening fines and litigation against industries that pollute.
The 2006 official audit of the Ganga Action Plan has revealed that it has met only 39 per
cent of its sewage
treatment target. The 2006 official audit of the Ganga Action Plan has revealed that it has met
only 39 per cent of its sewage
treatment target. Moreover, the plan is behind schedule by over 13 years. According to the
legal counsel, Central Pollution Control Board, Mr Vijay Panjawani, even after spending Rs
24,000 crore, the Ganga remains as dirty as ever
A total of 146 industries are reported to be located along the river Ganga between Rishikesh
and Prayagraj. 144 of these are in Uttar Pradesh (U.P.) and 2 in Uttrakhand. Of the grossly
polluting industries in U.P., 82 industries have installed Effluent Treatment Plants (ETPs) and
are reported to be complying with the standards, 27 industries, though have installed ETPs are
not reported to be complying with the prescribed standards and 35 industries are reported to
have been closed.
Industrial Wastewater Treatment
Industrial wastewater treatment covers the mechanisms and processes used to treat waters
that have been contaminated in some way by anthropogenic industrial or commercial
activities prior to its release into the environment or its re-use.
Treatment of industrial wastewater:
Solids removal: Most solids can be removed using simple sedimentation techniques with the
solids recovered as slurry or sludge. Very fine solids and solids with densities close to the
density of water pose special problems. In such case filtration or ultrafiltration may be
required. Although, flocculation may be used, using alum salts or the addition of
polyelectrolytes.
Oils and grease removal: The wastewaters from large-scale industries such as oil refineries,
petrochemical plants, chemical plants, and natural gas processing plants commonly contain
gross amounts of oil and suspended solids. Those industries use a device known as an API oilwater separator which is designed to separate the oil and suspended solids from their
wastewater effluents. The API separator is a gravity separation device designed is based on
the specific gravity difference between the oil and the wastewater because that difference is
much smaller than the specific gravity difference between the suspended solids and water.
The suspended solids settles to the bottom of the separator as a sediment layer, the oil rises
to top of the separator and the cleansed wastewater is the middle layer between the oil layer
and the solids. Typically, the oil layer is skimmed off and subsequently re-processed or
disposed of, and the bottom sediment layer is removed by a chain and flight scraperThe water
layer is sent to further treatment consisting usually of a Electroflotation module for additional
removal of any residual oil.
Activated sludge process: Activated sludge is a biochemical process for treating
sewage and industrial wastewater that uses air (or oxygen) and microorganisms to
biologically oxidize organic pollutants, producing a waste sludge (or floc) containing
the oxidized material. In general, an activated sludge process includes:
(1) An aeration tank where air (or oxygen) is injected and thoroughly mixed into the
wastewater.
(2) A settling tank (usually referred to as a "clarifier" or "settler") to allow the waste
sludge to settle. Part of the waste sludge is recycled to the aeration tank and the
remaining waste sludge is removed for further treatment and ultimate disposal.
Trickling filter process: A trickling filter consists of a bed of rocks, gravel, slag, peat
moss, or plastic media over which wastewater flows downward and contacts a layer
(or film) of microbial slime covering the bed media. Aerobic conditions are
maintained by forced air flowing through the bed or by natural convection of air. The
process involves adsorption of organic compounds in the wastewater by the
microbial slime layer, diffusion of air into the slime layer to provide the oxygen
required for the biochemical oxidation of the organic compounds. The end products
include carbon dioxide gas, water and other products of the oxidation. As the slime
layer thickens, it becomes difficult for the air to penetrate the layer and an inner
anaerobic layer is formed.
Sewage Treatment
Sewage treatment, or domestic wastewater treatment, is the process of removing contaminants
from wastewater and household sewage, both runoff (effluents) and domestic. It includes physical,
chemical, and biological processes to remove physical, chemical and biological contaminants.
Process:
Sewage can be treated close to where it is created, a decentralised system, (in septic tanks,
biofilters or aerobic treatment systems), or be collected and transported via a network of pipes and
pump stations to a municipal treatment plant, a centralised system, (see sewerage and pipes and
infrastructure). Sewage collection and treatment is typically subject to local, state and federal
regulations and standards. Industrial sources of wastewater often require specialized treatment
processes (see Industrial wastewater treatment).
Sewage treatment generally involves three stages, called primary, secondary and tertiary treatment.
Primary treatment consists of temporarily holding the sewage in a quiescent basin where heavy
solids can settle to the bottom while oil, grease and lighter solids float to the surface. The settled
and floating materials are removed and the remaining liquid may be discharged or subjected to
secondary treatment.
Secondary treatment removes dissolved and suspended biological matter. Secondary treatment is
typically performed by indigenous, water-borne micro-organisms in a managed habitat. Secondary
treatment may require a separation process to remove the micro-organisms from the treated water
prior to discharge or tertiary treatment.
Tertiary treatment is sometimes defined as anything more than primary and secondary treatment
in order to allow rejection into a highly sensitive or fragile ecosystem (estuaries, low-flow rivers,
coral reefs,...). Treated water is sometimes disinfected chemically or physically (for example, by
lagoons and microfiltration) prior to discharge into a stream, river, bay, lagoon or wetland, or it can
be used for the irrigation of a golf course, green way or park. If it is sufficiently clean, it can also be
used for groundwater recharge or agricultural purposes.
Sewage Treatment Plant
Thank You