solid waste part-ii
TRANSCRIPT
![Page 1: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/1.jpg)
L-48SOLID WASTE MANAGEMENT PART-II
ENVIRONMENTAL ENGINEERING-II
![Page 2: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/2.jpg)
HAZARDOUS WASTE : INTRODUCTION
![Page 3: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/3.jpg)
Definition
Solid wastes are considered a hazardous waste if it exhibits one of the four characteristics
IGNITABILITY CORROSIVITY REACTIVITY TOXICITY
![Page 4: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/4.jpg)
Ignitability
Ignitable wastes can create fires under certain conditions, are spontaneously combustible, or have a flash point less than 60 °C (140 °F).
Examples: waste oils and used solvents.
![Page 5: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/5.jpg)
Corrosivity
Corrosive wastes are acids or bases (pH less than or equal to 2, or greater than or equal to 12.5) that are capable of corroding metal containers, such as storage tanks, drums, and barrels.
Example: Battery acid
![Page 6: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/6.jpg)
Reactivity
Reactive wastes are unstable under "normal" conditions.
They can cause explosions, toxic fumes, gases, or vapors when heated, compressed, or mixed with water.
Examples : lithium-sulfur batteries and explosives.
![Page 7: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/7.jpg)
Toxicity
Toxicity - Toxic wastes are harmful or fatal when ingested or absorbed (e.g., containing mercury, lead, etc.).
When toxic wastes are land disposed, contaminated liquid may leach from the waste and pollute ground water.
Toxicity is defined through a laboratory procedure called the Toxicity Characteristic Leaching Procedure (TCLP)
Examples: wastes containing heavy metals Pb, hg etc
![Page 8: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/8.jpg)
![Page 9: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/9.jpg)
STORAGE AND TRANSPORTATION
![Page 10: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/10.jpg)
Indian scenario
MSWM is a major problem in Indian cities Average waste generated in India is 500
gram /person /day according to pollution control board(PCB 2000)
Typical rate of waste generation increase in India is 1.3% annually
Studies reveal that 90% of municipal wastes is disposed of unscientifically in open dumps.
![Page 11: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/11.jpg)
Onsite storage
Storage of wastes before final disposal is done at three levels:
1) At sourceSolid wastes are often stored at the source in containers until they are picked up by waste collectors (collection crew) or taken out to be thrown into an open space or a community bin.
![Page 12: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/12.jpg)
2) At community levelCommunity bins are used in crowded and narrow market areas, which is a common feature of most developing countries.
Because of the high cost of door to door collection many waste management authorities have introduced community bins.
![Page 13: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/13.jpg)
3) At transfer stationsTransfer stations are established, for economic reasons in cities, which have long haulage distances to final disposal sites.
Smaller collection vehicles bring in the wastes collected at their source of generation or from the community bins and larger vehicles transport them away to final disposal sites.
Transfer stations are also used as collection and sorting points for recycling materials
![Page 14: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/14.jpg)
Most of the collection systems followed in India are:
1) Door to door collectionThis system is used in narrow streets where a collection truck cannot reach individual houses.
The house places the filled containers outside their doors when the waste collectors arrive.
![Page 15: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/15.jpg)
2) Curbside collectionThis method is used in wider streets, where the collection trucks can pass through conveniently.
The house owners leave the waste containers at the edge of the pavement.
The waste collectors collect the waste from the curbside or empty the containers into the vehicle as it passes through the street at a set time and day and return the containers.
![Page 16: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/16.jpg)
3) Block collectionThe collection vehicles arrive at a particular place or a set day and time to collect waste from the households. Households bring their waste containers and empty directly into the vehicle.
4) Community binsCommunity storage bins are placed at convenient locations, where the community members carry their waste and throw it.
![Page 17: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/17.jpg)
Community bins
![Page 18: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/18.jpg)
![Page 19: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/19.jpg)
Transport of solid waste
1. Autorikshaws :- these are 3 or 4 wheelers have covered bodies. Capacities are limited to ½ to ¾ tonnes are used for narrow localities where large vehicles can not go.
![Page 20: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/20.jpg)
Small - collecting vehicles
![Page 21: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/21.jpg)
2. Trailors
Capacity – 2 to 3 tonnesUsed for localities where trucks can not
goLoading is done manuallyThey are of tilting tipping type, hence
unloading can be done automatically.
![Page 22: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/22.jpg)
3. Trucks
Capacity- 5 to 10 tonnesThey are of tilting tipping type so
unloading is automatic
![Page 23: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/23.jpg)
![Page 24: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/24.jpg)
![Page 25: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/25.jpg)
![Page 26: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/26.jpg)
![Page 27: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/27.jpg)
Disposal of refuseRefuse or solid waste can be finally
disposed of by the following methods
1.Controlled tipping
2.Filling of low lying area (Land-filling)
3.Dumping into the sea
4.Pulverization
5.Incineration
6.Composting
![Page 28: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/28.jpg)
1. Controlled tippingThis method is adopted where there is
adequate Land is available.Refuse is tipped in hollows of depth 1 to 2
m.Coarse material is tipped at the bottom while
fine material is tipped on the top surface.Tips are covered with soil so as to seal the
top surface.After 12 months decomposition is complete.Area of 0.3 to 0.5 m2/cap/yr is required
![Page 29: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/29.jpg)
2. Filling of low lying area (LANDFILL)
A landfill is the place where we dispose our waste by burying them inside the earth.
It is the most common and oldest method to dispose our waste.
It is used to dispose hazardous as well as non –hazardous waste and solid municipal waste.
This kind of waste disposal is eco- friendly.
![Page 30: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/30.jpg)
Garbage is dumped into low lying areas.
Dumping is done in the layers of 1-2 m and each layer is covered by thickness of good earth (0.2 m thick)
A rest of 2-3 weeks is given before dumping the second layer
Each layer is compacted
![Page 31: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/31.jpg)
Land filling
![Page 32: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/32.jpg)
![Page 33: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/33.jpg)
Advantagesi. Simplest and economical
ii. No plant/ equipment are required
iii. Separation of solid waste is not required
iv. No byproducts are generated
v. Low lying area can be reclaimed
![Page 34: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/34.jpg)
Disadvantages
i. Proper sites may not be available nearby
ii. Large land area are required
iii. Leachate problems in rainy season
iv. Leachate may pollute the ground water
![Page 35: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/35.jpg)
3. INCINERATION:Incineration is the process of removal
of waste through thermal combustion.
Wastes are collected and burnt them in incinerators (boilers) at temperatures greater than 6000C
During burning, the heat is converted into energy.
![Page 36: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/36.jpg)
Only thing we have to consider is during this process is there is a chance of release of some toxic substances during burning.
This method destroys the waste instead of disposing or storing it, and offers better solution.
Volume of waste reduces considerably.
![Page 37: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/37.jpg)
Advantagesi. Most hygienic method
ii. No odour trouble or dust nuisance
iii. Heat generated can be used to generate power
iv. Lesser space required for disposal of residues
v. No effect of weather conditions.
vi. Can burn variety of refuses
vii. Clinker can be used in road construction
![Page 38: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/38.jpg)
Disadvantages
1. Large initial cost
2. Problem of air pollution
3. Special attention shall be given to dispose residues
4. High stacks are needed to dispose flue gases.
![Page 39: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/39.jpg)
4. Trenching This method is adopted when low lying aera is
not available. Trench size – length= 4 to 10 m, width =2 to
3 m and depth = 1 to 2 m Trenches are filled with refuse/garbage in the
layers of 15 cm. On the top of each layer 5 cm thick layer of
night soil or animal dung is placed in semi liquid form
On the top local soil is placed After 6 months compost is available for use.
![Page 40: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/40.jpg)
5. Dumping into the seaSolid waste can also be disposed into the
sea.Waste has to be carried 15 to 20 km into
the sea.The depth at disposal point should not be
less than 30 mSolid waste may float on the top surface of
water.During stormy weather disposal is not
possible.
![Page 41: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/41.jpg)
6. Pulverization
Dry refuse is pulverized to powdered form without changing its chemical form.
Powdered refuse can be used as manure.
Not commonly practiced in India.
![Page 42: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/42.jpg)
7. COMPOSTING
![Page 43: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/43.jpg)
COMPOSTING:Composting is the oldest form of solid
waste treatment method. The municipal waste consists of 50 – 60 % of organic matters.
These organic wastes are converted into usable forms by using micro organisms such as fungi, bacteria. The fungi or bacteria convert the organic waste into humus.
![Page 44: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/44.jpg)
The humus is rich in carbon and nitrogen content, can be used as natural fertilizing medium for growing plants.
This method is cheap as well as safe.
![Page 45: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/45.jpg)
![Page 46: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/46.jpg)
performed by aerobic microorganisms;
decomposition of organic matter; (organic acids, amino acids, sacharides) occurs;
consuming of O2 and release of CO2 and energy;
high rate of composting process; temperature - up to 55-60° С.
I. First stage: active (thermophilic)
![Page 47: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/47.jpg)
Decomposing of more complicated organic molecules;
Most of the microorganisms die from lаck of “food”; Lower rate of the process; Temperature - up to 40 - 45° С; Duration – few weeks
humification!
Waste appearance before and after composting process
II. Second stage: cooling
![Page 48: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/48.jpg)
III. Third stage: maturation Temperature is equal to the ambient;
A completely disinfected high quality compost is formed as a result
![Page 49: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/49.jpg)
1. Temperature Thermophilic (45 –750C) and Mesophillic (10-
450C). Above this temperature Microorganisms
inactivated or die off. Affected by its climatic surroundings and
method of aeration. In a windrow highest temperature reached in
centre, lower at edges.
Environmental Factors Affecting Composting
![Page 50: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/50.jpg)
2. pHAnaerobic digestion the pH level covers a
narrow range (pH 6.5 to 7.5)Aerobic- pH so broad difficulties rarely
encountered with too high or too low pH in composting.
During the early stages the pH usually drops (down to about pH 5.0) because of organic acid formation.
![Page 51: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/51.jpg)
3. Aeration (Anaerobic & Aerobic)Anaerobic: Advantages
a) minimisation of the loss of nitrogenb) less costly
Disadvantages include:a) Slowness of decompositionb) Absence of high temperaturesc) The presence of un-decomposed intermediatesd) The un-pre-processed appearance of the product
![Page 52: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/52.jpg)
AerobicAerobic composting benefits from:
a) A rapid rate of degradation
b) Elevated temperature levels
c) Absence of putrefactive matter
Oxygen uptake reflects intensity of microbial activity.
![Page 53: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/53.jpg)
4. Moisture ContentMoisture content and oxygen availability
are closely related If the moisture content of the mass is so
high as to displace the air from the interstices (voids between particles) anaerobic conditions will develop within the mass .
Woodchips, straw and hay can be as high as 75 to 80% whereas paper (upon becoming wet, collapses and forms mats) has a permissible moisture content of 55 to 60%.
![Page 54: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/54.jpg)
5. Substrate
The waste (referred to as the substrate) should contain all necessary nutrients.
Macronutrients Micronutrients Carbon (C) Cobalt (Co) Nitrogen (N) Manganese (Mn) Phosphorous (P) Manganese (Mg) Potassium (K) Copper (Cu)
Only available if they are in a form that can be assimilated by the microbes.
![Page 55: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/55.jpg)
Certain groups of microbes have an enzymatic complex that permits them to attack, degrade and utilize the organic matter found in freshly generated waste.
Others can only utilize decomposition products (intermediates) as a source of nutrients.
![Page 56: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/56.jpg)
Carbon: Nitrogen Ratio (C: N) The C: N ratio of the waste to be
composted is the most important factor that requires attention.
A large percentage of the carbon is oxidized to carbon dioxide by the microbes in their metabolic activities .
The C: N of the substrate should fall within the range of 20-25:1.
Mmicroorganisms such as bacteria and fungi grow best with the proper level of Carbon and Nitrogen.
![Page 57: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/57.jpg)
METHODS OF COMPOSTING
![Page 58: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/58.jpg)
1. Composting by trenching
Trench is 4 to 10 m long, 2 to 3 m wide, 0.7 to 1 m deep.
Trenches are filled with garbage/refuse layers of 15 cm thick.
On the top of each layer night soil/ animal dung is spread in semi liquid form.
On the top layer 10 cm thick local soil is laid
![Page 59: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/59.jpg)
Within 2 to 3 days decomposition process starts.
Because of decomposition temperature raises up to 750C
Refuse gets stabilized after 4 to 5 months and turns brown in colour
Manure is sieved through 12.5 mm sieve to separate out stones, bricks etc
Sieved manure is applied to farms
![Page 60: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/60.jpg)
2. Open windrow composting In India, 50-60% of municipal solid waste is
organic waste. Considering the climatic conditions and other
factors, composting of organic waste is excellently suited for India and Windrow composting is the best option to deal with the huge volume of bio-degradable waste.
Windrow composting is the available best model for stabilization of the biodegradable portion of the MSW.
![Page 61: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/61.jpg)
Refuse is dumped on ground in the form of 0.6m to 1 m high, 6 m long and 1 to 2 m wide piles at about 60% moisture content.
Pile is covered with night soil, cow dung, cattle urine etc.
Temperature during process is 750C After this pile is reversed (turned up)Within 4-6 weeks compost/manure is
ready
![Page 62: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/62.jpg)
![Page 63: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/63.jpg)
Windrow turner
![Page 64: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/64.jpg)
Static pile composting
![Page 65: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/65.jpg)
3. Indore method Refuse, night soil, animal dung etc are
placed in small brick lined pit 3m x 3 m x 1 m deep in alternate layers of 7.5 cm to 10 cm height so as to take total height of 1.5 m
DDT or any other insecticide can be added to prevent flies breeding
The material is turned regularly for period of 8-12 weeks. Water is sprayed on dried material during overturning
Manure/compost is ready after 4 months
![Page 66: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/66.jpg)
3 m
3 m
![Page 67: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/67.jpg)
The advantages of this method are:
1. the process can be kept under control and runs smoothly, because the heap is turned regularly;
2.compost is produced in a short time.Disadvantages of this method are:
1. it requires much water;
2. it is very labour intensive.
![Page 68: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/68.jpg)
4. Bangalore method In Bangalore method refuse is stabilized
anaerobically.Earthen trenches of size 10m x 1.5m x
1.5m deep are filled up in alternate layers of refuse and night soil or animal dung.
The material is covered up with 15 cm layer of good earth and left for decomposition for 4-5 months.
The compost is ready after 4-5 months
![Page 69: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/69.jpg)
10 m
1.5 m
1.5 m
1.5 m
![Page 70: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/70.jpg)
The major advantages of the Bangalore Method are:
1.a saving of water;
2. it requires less labour, because the heap is not turned over during the decomposition process.
![Page 71: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/71.jpg)
Disadvantages of the Bangalore Method are:
1. more disease germs and weed seeds survive due to the temperature during decomposition;
2. the decomposition process is more difficult to control because the heap has to be kept continually covered;
3. it is a less suitable method for those with little or no experience in composting.
![Page 72: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/72.jpg)
5. Mechanical composting Indore and Bangalore methods are suitable
for small cities and towns to decompose the garbage.
Mechanical compost plants of 200 tonnes/day and above capacity have been made for converting the city waste into compost.
Before that, the non compostable material such as bricks, stones, iron pieces, broken glass pieces, rubber, plastics etc. are removed.
![Page 73: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/73.jpg)
Advantages of composting
Reduces mass and volume
- lower hauling costs
• Reduces odour
• Pathogens are destroyed
• Kills weed seeds
• Improves transportability as volume gets reduced
• Good Soil conditioner
![Page 74: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/74.jpg)
• Improves nutrient qualities
- the nutrients from compost are
released slowly and steadily
• Decreases pollutants
- stabilizes the volatile nitrogen into
large protein particles, reducing losses
• Land application when convenient
Saleable product
• Increases water retention of soil
![Page 75: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/75.jpg)
Disadvantages
• Loss of ammonia (N)• Time and labour involved• More Cost of equipment (initial and
operating)• Land required for composting• Marketing required for sale
![Page 76: Solid waste Part-II](https://reader034.vdocuments.site/reader034/viewer/2022051617/55b106afbb61ebdf598b4691/html5/thumbnails/76.jpg)
Theory QuestionsQ1. Explain theory of composting.
Q2. Enlist different methods of composting and explain any one method in detail.
Q3. Discuss factors affecting composting process.
Q4. What are advantages and disadvantages of composting?
Q5. Draw a neat sketch of ‘Landfill’.
Q6. Write short notes on
1. Landfill
2. Effects of solid waste on human and environment
3. Bangalore method of composting
4. Indore method of composting 5. Incineration of MSW