Presetntation About Construction Wetlanddsl

8/18/2019 Presetntation About Construction Wetlanddsl

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PROJECT NO : C/11/59

GROUP MEMBERS : HASAN, H.M. (E/11/146),

RAJAPAKSHE,R.M.S.T.(E/11/317)

SPERVISED BY : MRS.G.M.P.R. WEERAKOON

PPLIC BILITY OF

CONSTRUCTED WELT ND FOR

W STEW TER TRE TMENT


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WHAT IS A CONSTRUCTED WETLAND

A constructed

wetland is anartificialwetlandcreated for the

purpose oftreatinganthropogenicdischarge such

as municipal orindustrialwastewater,storm water

runoff


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• Water, media, microbes and vegetation are the four main componentsused for create a CW.

• Contaminants are removed mainly by physical mechanisms, such as

filtration or sedimentation, and biochemical interactions, such asmicrobial degradation.

• Wetland vegetation plays an important role in treatment of wastewaterin a constructed wetland.

• Oxygenation by roots has been shown to have a significant impact on

important mechanisms of wastewater treatment in CWs.• The fluctuation of water level in CWs may cause the variation of ROR.

And also hence efficiency of the treatment system will vary.


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TYPES OF A CONTRUCTED WETLAND

Constructed wetlands

Surface flow wetlands

(SFW)

Sub surface flow wetlands

(SSFW)

Vertical flow system Horizontal flow system


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POLLUTANT REMOVAL PROCESSORS

Pollutants removed processes

Organic materials (measured asBOD)(Dissolved) Biodegradation

Suspended solids Filtration and settling at Inlet

Nitrogen Plants uptake and volatilizationSedimentationMicrobial uptake

Phosphorous SedimentationFiltrationAbsorptionPant and microbial uptake

Pathogens Natural die-offSedimentationFiltration

Heavy metals SedimentationAbsorption

Plant uptake


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LITERATURE REVIEW• Wastewater treatment is much needed in nowadays due to the

lack of good quality fresh water resources (Llorens et al., 2011)

• Major pollutant sources are domestic sewage, municipal andindustrial wastewaters, agricultural runoff, urban drainage andlandfill leachate.

• Compare to ww treatment systems the Constructed Wetlands(CWs) are more significant as a secondary or tirtiary treatment

for domestic wastewater (Headley et al., 2012) as a lowcare/low maintenance treatment system CWs are the cheaperthan all other treatment systems.

• Constructed wetlands are manmade wetlands that utilizenatural processes involving wetland soil, vegetation, and

microbial community associated to assist in treatingwastewater (Kadlec and Knight, 1996)


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Continue……

• Low care/Low maintenance plants cattails (Typha) are the plantsmost often associated with wetlands around the world. The larger,native varieties. They do work well and seem to have a positiveimpact on treatment. They take work to control and in later years

may need to be removed. (Sim, C.H. 2003)

• The plant type (Root Oxygen release) and water level are the mainparameters that considered at the removal efficiency of

Biochemical oxygen demand (BOD5), Chemical oxygen demand(COD), Fecal coliform (FC), Total Coliform (TC) CWs.


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Continue……

• The aerobic processes require higher oxygen concentration (Garciaet al., 2005; Wiessner et al., 2005) in the CW

• Oxygen release from wetland plants in CWs varied in differentgrowing stages of plant life cycle and the capacity of oxygen

release of wetland plants could be influenced by plant species. (Jian Zhang & Haiming Wu & Zhen Hu &Shuang Liang & Jinlin Fan2014)

• Dissolved oxygen in wastewater can make it more aerobic and

improve the pollutant removal activity. Several previous studieshave revealed that efficiency of wetlands could be enhanced byfluctuation in water level (Stein et al., 2003; Tanner et al., 1999)where increasing dissolving of oxygen was noted during the water-level variation.


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OBJECTIVES

• To evaluate the effect of water level fluctuation on efficiency of the

horizontal sub-surface flow CW.

• To estimate the effect of water level fluctuation on Oxygen release

rate of Typha angustifolia (Narrow leaf Cattail) plant.


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SCOPE

Conduct a laboratory experiment to evaluate the

effect of water level fluctuation on pollutant removal

efficiency in Constructed Wetland by using synthetic

wastewater.


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METHODOLOGY1.Wetland set-up

Horizontal Sub-surface flow wetlands will be used.

140 cm 50 cm

60 cm

2 inch metal

3/4 inch metal Impermeable layer


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2.Macrophytes

• Young Typha angustifolia plants are collected frompanideniya area.

• 8 plants are planted in a wetland.• To avoid the shock of sudden feeding of synthetic

wastewater, the wastewater application is started afterall wetlands have been fed with tap water for one week.

•

Assume the average light intensity andevapotranspiration are not significantly differs duringthe study period.

• Except the continuous inflow, no watering is providedto the wetlands.

• The extent of the experimental period was 6 monthsfrom April to September 2016, because the typicalgrowing season of Typha is normally during the April toSeptember period.


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3.Wetland arrangement

• 6 wetlands are prepared, 3 with a static water level (namely

S1,S2,S3), 3 with fluctuating water level (namely F1,F2,F3).• Each wetland will be fed with 28 ml/min wastewater flow rate.

• only 4 wetlands will be planted.

• S3 and F3 are control wetlands( No plants).

S1 F1 S2 F2 S3 F3


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4. Flow manipulation• For the calculations we took porosity as 0.4 from previous

year project.

Assuming HRT for static condition is 3.5days;continuous flow of wastewater is supplied to

each wetland is 28 ml/min

• For the fluctuating flow wetlands, the height of the survivalpipe is changed from 50 cm to 40cm.

• There for the HRT changes from 3.5 days to 2.8 days.

• Multichannel peristaltic pump is used to supply water to the 6wetlands


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50 cm

40 cm

50 cm static water level

50 cm water level for 3.5 days40 cm water level for 3.5 days


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5. WastewaterWastewater is prepared synthetically in laboratory.

Compounds

Expected Quality of wastewater

compound Concentration (mg/l)

Glucose/sugar 150

Sodium acetate 300

Peptone 15

NH4Cl 140

KH2PO4 35MgSO4.7H2O 30

FeSO4.7H2O 5

sludge 1

Water quality index Concentration (mg/l)

BOD5 200

COD 400


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6. Water quality monitoring

these quality parameters will be

measured every 2 weeks.

Removal efficiency can be calculated using following equation;

efficiency = Ci− Co × 100%

Ci

where Ci = the concentration of nutrient supplied to wetland (mg/l

Co = the concentration of nutrient in the effluents from the

wetland (mg/l).

BOD5 COD TSS

FC TC DO

pH Temperature 2.5 weeks interval


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7. Plant growth monitoring

The relative growth rate on a plant

dry biomass basis will be calculated bybelow equation;

growth rate = log (Wf - Wi)

∆t

where W i = the total dry biomass at the beginning of theexperiment (g),

W f = the total dry biomass at the end of thexperiment,

and t = the length of the experiment

Shoot height

Shoot Density

Number of leaves


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8. Root Oxygen Release (ROR)

The rate of O2 release through thypa roots is estimatedcolorimetrically with Ti3+ - citrate solution at 4 weeks (Kludze et al.1993)

During the destructive sampling of plants, one undamaged sampleplant from the CW will be used to quantify the ROR.

Ti 3+ citrate

Ti 3+citrate

S2

F2


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BUDGETTEST Item Quantity Rate Amount(Rs)

BOD5 MnSO4 100g 100g/600.00 600.00

NaOH 125g 500g/700.00 175.00

NaI 50g 100g/1500.00 750.00

Na2S2O3·5H2O 50g 500g/2500.00 250.00

H2SO4 (98%) 250ml 500ml/1500.00 750.00

NH4-N Nestler Region 50ml 500ml/8000.00 800.00

Methyl Alcohol 25ml 50ml/4000.00 2000.00

Minaral stabilizer 25ml 50ml/3000.00 1500.00

NO3-N powder pillow 35 190.00 per one 6650.00

TSS Filter paper 35 50.00per one 1750.00

TN Filter

paper(0.45µm)

35 150.00 per one 5250.00

Argan 0.00

Metal 1.26 m3 4000 5040.00

Cement 1.5kg 18 27.00

Water tank 1/2 tank 12000 6000.00

Plastic mesh for

planting

27 pots 50 1350.00

Cleaning 500 500.00

Plastering 1500 1500.00

Typha plants 27 20 540.00

Total without pump 32907.00

Peristaltic pump 1 pump 140000 140000.00

Total 172907.00


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TIME SCHEDULESemester Semester 7

Week 1

2

1

3

1

4

1

5

1

6

17 1 2 3 4 5 6 7 8 9 1

0

11 1

2

1

3

1

4

1

5Preparation ofwetland setup

Feedingwastewater

Sampling

Test samples

Preliminary dataanalysis

Data analysis

Interpret data

Finalize thereport


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THANK YOU

Documents

Presetntation About Construction Wetlanddsl