RIVER CLEANING PROJECT

Introduction:-

India desperately needs strategies to manage its human waste. Out of 22,900

MLD of waste-water generated in the country, only about 5,900 MLD (about 26%) is

treated before disposal. According to a survey by BORDA, a NGO, out of the 3,119 big

and small cities in India, only 217 (about 7%) have centralized sewage treatment plants

(STP). A closer analysis reveals that 73% of the STPs operate below their design capacity

with 7% of them being defunct. This clearly shows the failure of the centralized treatment

plants.

For this we need to look for a cost effective and non-sewerage paradigm of human

waste disposal. The capital intensive, water intensive and material intensive process of

urban waste management as practiced in the West works best for rich countries and not

for poor ones. If we assume that a family of 5 members consumes 675 liters at the rate of

135 liters per capita per day, then around 540 liters (80%) comes out as wastewater,

which can be treated and reused. This shows the potential for a decentralized system as

against a centralized system.

Water pollution has increased to such an extent that, rivers are being declared

“Dead”. The part of Yamuna River which flows through Delhi is declared as dead as no

living organism can sustain in that environment. If rigid steps are not taken same will be

the case in time to come with Mula Multha River. This is not just the case with these two

rivers but with many rivers in India and it needs a quick attention.

Our Proposal:- 1. Litter Trap.

2. Floating Islands (based on root zone technology).

3. Vermicompost from Water hyacinth.

LITTER TRAP:-

Litter Trap is a floating device installed at strategic locations along

waterways to collect and retain floating litter, vegetation and other floating

waste. Floats are attached in V shaped to which nets are attached which are

submerged in water. At the apex a submerged trap is attached to the floats.

Litter trap is required because the litter and vegetation (water hyacinth)

which will flow up to the floating islands will hamper their performance. Also this

litter if not trapped starts decomposing in the water which absorbs the valuable

oxygen and hence depletes the level of oxygen in water.

Our prototype:-

Result: - A lot of plastic bags were trapped in the trap when installed at boat club

COLLEGE OF ENGGINEERING PUNE (COEP) for an approximately 2 hours as seen

in picture.

Benefits of Litter Traps:-

Cost effective and requires little maintenance

Operates silently 24 hours a day without mechanical assistance.

Waste cannot be dislodged once trapped.

Quality, durable and corrosion resistant materials used.

Root Zone Technology:-

One of the most promising solutions is the Root Zone Treatment Technology,

which seems to be inspired by “Do as Nature Does”. The essential components of this

technology are:-

The reed type of wetland plants

The bed

Microorganisms

The reed bed houses a variety of bacterial strains (approximately 2500-3000),

both aerobic and anaerobic existing in the system that facilitates the extensive treatment.

These plants have a root system of rhizomes, containing thick hollow air passages, from

which fine hair roots hang down; vertical aerial shoots develop upwards from the

rhizomes. Oxygen from the leaves pass through the stem and rhizomes and is exuded

from the fine roots so that a thin oxygenated aqueous film less than 1mm thick surrounds

the hairs.

As the effluent is percolating through the plant bed, the capability to transfer

oxygen from atmosphere to root zone, bed area adjacent to the roots is saturated with

oxygen. This oxygen is utilized by the aerobic type of bacteria to biodegrade the organic

matter from the effluent into CO2, nitrogen, water and elemental sulphur, thus leaving

practically no sludge behind. The soil bed area where roots do not reach has anaerobic

bacterial population and also biodegrades the organic matter, reducing the Chemical

Oxygen Demand [COD] and Biological Oxygen Demand [BOD] of the effluent as it

flows further through the bed. During percolation, there is very fine filtration which

arrests the suspended organic matter along with some inorganic colloidal matter.

The microbial population is dominated by bacteria. Microorganisms form bio-

films around the lower stems that can then trap particles suspended in the waste water by

adsorption. This bacterium degrades most of the simpler organic materials which

contribute most to the BOD. Consequently they also degrade most of the larger molecules

that contribute to the COD.

THE MODEL:

The model is a prototype of a vertical flow reed bed. A tank of dimensions

1.48m X 1.06m X 0.54 m was filled in 3 layers for 2/3rd

of its total depth. The lowest

layer is filled with 20mm aggregates. The layer above it is filled with aggregates of size

10mm. The topmost layer is filled with coarse sand and then a layer of fine sand is laid

on top. The tank is given a slope of 1 in 10. This gradation provides an efficient media for

filtration. Plants which are to be grown on the bed are so chosen that they serve the

purpose of treatment of the specific waste water. It should be an easily available annual

shrub with soft roots. The plants we used are Canna. The inlet system consists of a tank

of dimension 1.06m X 0.68m X 0.4m and provided with a head of 0.5m. The water from

Mula River was used as the waste water at the inlet. Drip irrigation technique was utilized

to supply the waste water as input.

While the vertical flow reed bed system is quite efficient, it is not feasible to be

used in the treatment of river water on a large scale both economically and practically.

The floating island technique would overcome this drawback.

OUR MODEL

FLOATING ISLANDS:

Floating islands are artificially vegetated islands that float on the calm and

polluted waterscape of reservoir, ponds etc. The artificial floating eco-system enhances

self purification capacity of water bodies by supplying extra air through hollow

vegetation stem. Hence the floating eco-system holds good for restoration of lakes and

other static water bodies.

To understand the concept of floating islands, we can compare it with naturally

occurring water hyacinth. Water hyacinth grows on polluted water bodies and spreads

rapidly. The hyacinth absorbs nitrogen and phosphorous from the water. At the same time

it creates an unfavorable anaerobic condition. A mat of Water hyacinth depletes oxygen

completely and allows formation of free carbon dioxide. This gas then reacts with water

to form carbonic acid which decreases the pH of water. Due to presence of this, acid

carbonates are converted into bicarbonates. Rate of organic matter production is very

high and dead organic matter is accumulated in the water body at the bottom. This

organic matter starts decomposing initially aerobically when oxygen is present, and then

anaerobically when oxygen is depleted. This anaerobic condition kills all the life from the

water and the extra organic matter load remains just near the roots of the plants. So the

whole mat starts floating and islands are formed.

The artificially created floating island treats the water while at the same time

avoiding the creation of anaerobic conditions. Nature takes care to purify water that is

polluted up to a certain limit. Micro-organisms required for the treatment of water are

inherently present in the water. However they are inactive until they get an appropriate

substrate. The floating islands provide this substrate and enable treatment of water. Along

with the microorganisms, the plants are also a vital part of the system removing nitrogen,

phosphates etc and creating aerobic condition by supplying oxygen to the water.

The Mula River flowing adjacent to the college is highly polluted. Effluents are

added to the river water from the nearby industries and households. pH tests show the

existence of acidic water. The low flow rate of the river would give a retention time for

the efficient working of a floating island. The approximate depth of river in the area

adjoining the college is 9-10 m. And the approximate width is 26-30 m.

Our Proposal:

We propose to construct patch of floating islands across the MULA River for

a stretch of 10m i.e. 30 m X 10 m. The island would consist of small units. The units are

built of PVC pipes and coir .The PVC pipes provide the necessary buoyancy required for

floating the bed and the coir provides the substrate for the growth of plants and

microorganism. A coir sheet of 0.15m thickness wrapped in jute cloth form the bed. The

plants are embedded in the bed with roots coming out from the other end which treat the

water. This setup is initially constructed on the shores to accustom the plants to the waste

water to be treated and the surviving plants are then put up in the actual bed.

The dimensions of each unit would be 2.5 m X 1.2 m. We have prepared one such

unit. And 150 such units would be required to span the entire proposed width.

Once the system has been fully established the roots would grow up to a depth of

1m. This depth is sufficient to treat slow flowing rivers like MULA significantly. The

efficiency increases with time and also as the plants acclimatize to the specific conditions

prevailing at the site. The bed would be functional for about 8 months. The beds would

not be operational only during rainy season and in case of floods, wherein they would

have to be removed and kept on the shores. The unit is very light and can be easily

handled by 2 people and can be offloaded easily. The maintenance of such beds is

minimal and requires only trimming of overgrown plants at regular intervals. The plants

provided are annual and also improve the aesthetics of the river. It also provides habitat

for the fauna. The energy required is only solar and that too only for the photosynthesis

of the plants. Also, no chemicals are required for the functioning of the system. Also as it

an enhancement of root zone treatment system, sludge is not produced

This technology is highly effective in tropical countries like India, and the

application of this system would certainly help in reducing the pollution load of the

rivers.

Vermicompost:-

It is expected that a large amount of water hyacinth will get trapped in the litter

trap and instead of just dumping it anywhere we thought of using it to make

vermicompost. Due to its high water content, it helps to maintain the moisture content

in the pit thereby accelerating the process of composting and enhancing its quality.

Vermicompost is a heterogeneous mixture of decomposing vegetable or food

waste, bedding materials, and pure vermicast. Vermicast is worm humus or worm

manure, is the end-product of the breakdown of organic matter by some species of

earthworm and contains water-soluble nutrients and bacteria. Vermicompost is an

excellent, nutrient-rich organic fertilizer and soil conditioner. Compost made from

water hyacinth is twice a good as normal compost. As water hyacinth has large

amount of nitrogen and phosphorus it turns out to be good compost. Making compost

form hyacinth needs less labor, the process is very cheap and simple and the results

are comparatively good.

Experiment:- Material- Water hyacinth, diluted cow dung and Earth worms.

Amount of material: cow dunk – 1bucket

Earthworms- 100 g

Ratio: - cow dung: water hyacinth =1:2 (by weight)

Procedure-

Take half a bucket of cow dung and dilute it.

Chop the water hyacinth in medium size.

Put a 2cm thick layer of undiluted cow dung.

Put a layer of coped water hyacinth and cover the water hyacinth with diluted

dung

Put some earth worms on each layer and repeat the procedure

Benefits:- Enriches soil with micro-organisms.

Improves water holding capacity.

Enhances germination, plant growth, and crop yield.

Improves root growth and structure.

Economic.

Low capital investment.

Use of water hyacinth assists the process of composting.

Activities Done:-

Survey: After conducting some tests on the water samples collected from the Boat Club at

College Of Engineering Pune, Prof. Thanedar advised us to do a survey of the Mula

River right from the Khadakwasla dam, the place where the actual Mula River enters the

City premises.

So our team got a map of Pune city and followed the river channel through all the

villages and major parts of city. At every place wherever there was an outlet of drainage

let into the river water, some data was collected. Data collected mainly was that of the

environmental conditions around that place, the type and quantity of vegetation, the

quality of river water as well as that sewage water, the type of litter observed on the

banks of the river etc.

Locations we came across during our survey

See the difference yourself…!!!

This picture was taken after a drain had let out its sewage out into the river.

You can clearly see the difference in the color and the state of the river. So now if we

do not take some rigid steps quickly we know what disastrous condition would be of

our river.

After a study of all the data collected, a conclusion was drawn that it is difficult to

just clean up a patch and that if we have to really work out some way to trap all the

effluents and litter right at the source. So we our team is working upon a technique which

can be used trap the litter and treat the water before it is let into the river.

Wetland: In this technique we have combination of both the methods which we are

proposing for our college. It mainly consists of four zones;

1. Pretreatment Zone.

2. Inlet Zone.

3. Ephemeral Zone.

4. Wetland Zone.

Pretreatment zone consist of litter trap which will mainly trap litter of 20 mm and

above size.

Inlet zone will function as energy dissipation and sedimentation zone. This will

reduce the velocity of water thereby allowing settling of coarse sediments.

Ephemeral zone will consist of leaf traps which will trap organic matter from

reaching the wetland zone which can seriously harm the efficiency of that wetland.

Wetland zone as the name suggest will be having a horizontal flow reed bed planted

with various types of plants which will treat the water in very natural way.

To prove that this technique will be useful, we want to make a prototype.

Construct a channel and conduct some experiments. For this some monetary help will be

needed. We are sure that we would get positive results and so we can have hard

evidences to say that this technique works wonder and saves our rivers.

Systematic Representation Of Wetland