Leachate Treatment

ESTIMATION OF LANDFILL CAPACTIY

Current waste generated per year, W = 0 tons/yr.

Estimated of rate of waste generation per yr. (use rate of population growth

where waste generation growth rate estimates not available),x

= 0%

Landfill age,n = 0 yr.

Waste gerneration after n years

= 0 tons/yr.

Total waste generattion in n years (T) in tons =

= 0 tons

Density of waste = 0.85 t/cu.m

Total volume of waste in n years (Vw)

= 0 cu.m

Total Volume of daily cover in n years, Vdc (on the basis of 15 cm soil cover on

top and sides for lift height of 1.5 to 2m)

= 0 cu.m

Total volume required for components of liner system and of cover system ( on the

assumption of 1.5m thick liner system (including leachate collection layer) and

1.0 m thick cover system (including gas collection layer)

= 0 cu.m

(k =0.25 for 1.0 m high landfill, 0.125 for 20 m high landfill and 0.08 for 30 m high

landfill. This is valid for landfills where width of landfill is significant larger than

the height)

Volume likely to become available within 10 years due to settlement/

biodegradation of waste

= 0 cu.m

(m = 0.10 for biodegradable waste; m will for less than 0.05 for incinerated/inert

waste)

First estimate of landfill capacity (Ci) = 0

REFERENCES CALCULATIONS OUTPUT

W 1 +𝑥

100

𝑛

1

2W+W 1 +

𝑥

100

𝑛

n

𝑉𝑤= T/0.85 (cu.m)

𝑉𝑑𝑐= 0.1𝑉𝑤(cu.m)

𝑉𝑐= k𝑉𝑤(cu.m)

𝑉𝑠= m𝑉𝑤

𝐶𝑖= 𝑉𝑤 + 𝑉𝑑 +𝑉𝑐 − 𝑉𝑠

REFERENCES CALCULATIONS OUTPUT

Gunapo Landfill Area = 9 hectares

= 90000 m2

Peak Daily Maximum rainfall, Pmax = 155.6 mm/day

(was recorded in the month of October)

Avg .Potential evapotranspiration, PET = 5.3 mm/day

Effective rainfall, R =

= 150.3 mm/day

Bagchi Runoff coefficent = 0.3

Table 13.4

pg 282

Therefore, leachate generated = 4058.1 m3/day

REFERENCES CALCULATIONS OUTPUT

CALCULATING LEACHATE FLOW

The leachate generated from the landfill site can be

calculated by:

Leachate generation = runoff coefficent * operational

area * effective rainfall

Assumptions:

1. No infiltration into the landfill fromm outside areas

𝑃 − 𝑃𝐸𝑇

Assumptions 1. Landfill Surfaces 2. Runoff coefficient/ infiltration rate to landfill

surface • Active Tipping area - areas where waste is being

actively tipped • Temporary working area - either site formation areas

or areas which have been temporarily restored • Permanent restored - areas which have been permanently

LANDFILL OPERATION PERIOD

Active 1 0.9

Temporary 0.3 4.9

0.3 3.2

9

Year Annual precipitation/mm Active Tipping Area

1981 2603.2 23428.8

1982 2179.1 19611.9

1983 2341.2 21070.8

1984 2089.2 18802.8

1985 2093.0 18837

1986 2050.5 18454.5

1987 1454.4 13089.6

1988 2137.1 19233.9

1989 1486.1 13374.9

1990 1736.3 15626.7

Avg. 2017.0

POST CLOSURE PERIOD

Runoff coeff 0.1

Year Annual precipitation/mm Active Tipping Area

1981 2603.2 0

1982 2179.1 0

1983 2341.2 0

1984 2089.2 0

1985 2093.0 0

1986 2050.5 0

1987 1454.4 0

1988 2137.1 0

1989 1486.1 0

1990 1736.3 0

Avg. 2017.0

Estimated Leachate

Temporary Restored Area Other m3/year m3/day

38267.04 24990.72 86686.6 237.4974 52242.12 MGD

32032.77 20919.36 72564.0 198.8056 2.748812 L/s

34415.64 22475.52 77962.0 213.5944

30711.24 20056.32 69570.4 190.6037

30767.1 20092.8 69696.9 190.9504

30142.35 19684.8 68281.7 187.073

21379.68 13962.24 48431.5 132.6891

31415.37 20516.16 71165.4 194.9738

21845.67 14266.56 49487.1 135.5812

25523.61 16668.48 57818.8 158.4076

Estimated Leachate

Temporary Restored Area Other m3/year m3/day

0 23428.8 23428.8 64.18849 14119.49 MGD

0 19611.9 19611.9 53.73123 0.742922 L/s

0 21070.8 21070.8 57.72822

0 18802.8 18802.8 51.51452

0 18837 18837.0 51.60822

0 18454.5 18454.5 50.56027

0 13089.6 13089.6 35.86192

0 19233.9 19233.9 52.69562

0 13374.9 13374.9 36.64356

0 15626.7 15626.7 42.81288

𝐿𝑜 = 𝐸𝑅 𝐴 + 𝐿𝑊 + 𝐼𝑅𝐶𝐴 + 𝐸𝑅 𝑙 ] − [𝑎𝑊

Where:

Lo = Leachate produced (m3)

ER = effective rainfall(use actual rainfall (R) for active cells) m

A = area of cell(m2)

LW = liquid waste(also includes excess waste from sludge (m3)

IRCA = infiltration through restored and capped areas (m)

I surface area of lagoons (m2)

a absorptive capacity of waste (m3/t)

Design flow, F = 237.497 m3/day

52242.1 MGD

Assumed Detention period ,t = 2 day

Volume of tank, VE = 474.995 m3

104484 MGD

Assumed Depth of liquid column = 5 m

Total Area required

for the equalization = 94.999 m2

No of tanks proposed = 1

Area required for

for the equalization tank = 94.999 m2

For a rectangular tank:

Length to Breadth ratio = 1

Tank Breadth = 10 m

Tank Llength = 10 m

For a circular tank:

Tank Diameter = 10.998 m

Typically eqauliztion is sized to provide 2-5 day storage

REFERENCES CALCULATIONS OUTPUT

EQUALIZATION TANK

Equalization can be provided via an above-grade steel

tank witin secondary containinment. A benefit of a

storage tank is that it is enclosed to minimize odour

generation at the facility and heat is retained.

12 hr detention

http://nptel.ac.in/courses/Webcourse-contents/IIT-KANPUR/wasteWater/Lecture%2021.htm

http://wcec.wm.com/resource-documents/05_06_Supporting%20Documents/Supporting%20Document%203%20-%20Leachate%20Treatment%20Alternatives.pdf

http://books.google.tt/books?id=JqhsYW47bkoC&pg=PA315&dq=leachate+equalization+tank+design+detention&hl=en&sa=X&ei=_BxQU56QHZDKsQToz4DwBw&ved=0CCcQ6AEwAA#v=onepage&q=leachate%20equalization%20tank%20design%20detention&f=false

http://wcec.wm.com/resource-documents/05_06_Supporting%20Documents/Supporting%20Document%203%20-%20Leachate%20Treatment%20Alternatives.pdf

http://books.google.tt/books?id=JqhsYW47bkoC&pg=PA315&dq=leachate+equalization+tank+design+detention&hl=en&sa=X&ei=_BxQU56QHZDKsQToz4DwBw&ved=0CCcQ6AEwAA#v=onepage&q=leachate%20equalization%20tank%20design%20detention&f=false

http://books.google.tt/books?id=JqhsYW47bkoC&pg=PA315&dq=leachate+equalization+tank+design+detention&hl=en&sa=X&ei=_BxQU56QHZDKsQToz4DwBw&ved=0CCcQ6AEwAA#v=onepage&q=leachate%20equalization%20tank%20design%20detention&f=false

Year 1981 1982 1983 1984 1985 1986

Mean daily precipitation/mm 7.4 6.2 6.6 5.9 5.9 5.8

Annual precipitation/mm 2603.2 2179.1 2341.2 2089.2 2093.0 2050.5

Min. daily precipitation/mm 0.0 0.0 0.0 0.0 0.0 0.0

Max. daily precipitation/mm 155.6 77.5 65.3 67.2 88.9 118.4

Total No. days > 1 190.0 186.0 178.0 160.0 165.0 161.0

1987 1988 1989 1990 Avg.

4.1 6.0 4.2 4.9 5.7

1454.4 2137.1 1486.1 1736.3 2017.0

0.0 0.0 0.0 0.0 0.0

47.9 87.6 73.4 67.0 84.9

129.0 161.0 138.0 168.0 163.6

Waste to landfill per day = 253 tonnes

= 253000 kg

REFERENCES CALCULATIONS OUTPUT

LANDFILL PROPERTIES