Presentation1 -final

1 Kanuwana,Ja-ela.

LANKEM CEYLON (PLC)ROBBIALAC PAINTS

Presented by :C.D.Karunasena Internal supervisor : Prof. R.M.G.RajapakseExternal supervisor : Mr. S.K.Fernando

2 Projects assigned

Determination of chemical oxygen demand Determination of biological oxygen demand Determination of total suspended solids

3 Wastewater treatment process• Industrial effluents should be well treated prior to

release in to water resources in order to prevent environmental pollution.

• Industries practice good wastewater treatment

• Waste water treatment process is employed.

4 Wastewater treatment process

Quantitative measures of wastewater condition

• Industrial effluents should be well treated prior to release in to water resources in order to prevent environmental pollution.

• Biological oxygen demand (BOD)• Chemical oxygen demand (COD)

• Total suspended solids (TSS)




Components Preliminary treatment Secondary treatment Tertiary treatment Disinfection.

• Industrial effluents should be well treated prior to release in to water resources in order to prevent environmental pollution.




Preliminary treatment

• In primary treatment, the incoming flow is slowed in large tanks which allow the dirt, gravel, and other heavier-than-water components of the waste stream to settle out. Grease, oil, and other floatables are also removed here.

• Coagulants and flocculants treated


Secondary treatment

• Removes the residual organics and suspended solids.

• Aerobic biological treatment processes.

• Aerobic biological treatment is performed in the presence of oxygen by aerobic microorganisms that metabolize the organic matter in the wastewater, thereby producing more microorganisms and inorganic end-products (principally CO2, NH3, and H2O).


Tertiary treatment

• This is employed when specific wastewater constituents which cannot be removed by secondary treatment must be removed.

• Individual treatment processes are necessary to

remove nitrogen, phosphorus, additional suspended solids, refractory organics, heavy metals and dissolved solids.


Disinfection

• Disinfection is the final step in the sewage treatment process and is designed to kill enteropathogenic bacteria and viruses that were not eliminated during the previous stages of treatment.

10 Wastewater treatment processWastewater treatment area in Lankem paints

Primary settling tanks


Primary settling tanks


Tube settler


Sand filtration tank

14 Projects assigned




16 Chemical oxygen demand determination of wastewater effluent sample

• Chemical oxygen demand (COD) is a measure of the organic matter content that is susceptible to oxidation by dissolved oxygen.

• Oxidative action of oxygen is resembled by the strong oxidant potassium dichromate K2Cr2O7


The organic chemical content is oxidized by using dichromate resembling the action of oxidation by oxygen.

Known amount of dichromate is added in excess to a known volume of sample and allowed to react with all organic matter present.

After reaction remaining dichromate is determined by back titration with standard FAS(ferrous ammonium sulfate) solution in the presence of ferroin indicator.

Dichromate sulfate reflux method


Standard potassium dichromate solutuion : 0.0417 M(primary standard grade)

Sulfuric acid reagent Standard ferrous ammonium sulfate(FAS) titrant :

Aproximately 0.25M Ferroin indicator HgSO4 (Mercuric sulfate) Potassiumhydrogen phthalate(KHP)

Reagents


Dichromate reflux method A

fter cooling down the mixture was diluted to twice with distilled water

Procedure

Finally was titrated against standard FAS solution the color change from blue-green to reddish brown.

Similar procedure was performed for a blank solution.


Dichromate reflux method

Organic matter + O2 ----------------->x CO2 + y H2O

If organic matter is oxidized by acid Cr2O72-

2/3 Cr2O72- + 4e +28/3H+ ---------->4/3Cr3+ + 14/3 H2O

Oxygen reduced to water oxidizing the organic matter O2 + 4e- + 4H+ --------------------->2H2O



O2 + 4e- +4H+ ---------------> 2H2O

Cr2O72- + 14H+ +6e- ------>2Cr3+ + 7H2O

2/3 Cr2O7

2- = O2



Back titration with FAS

Cr2O72-+ 14H+ + 6Fe2+ ------------->2Cr3+ + 7H2O + 6Fe3+

stoichiometric ratio Cr2O72- : Fe2+ = 1:6



End point determined by Ferroin indicator

Color change blue-green to reddish brown.


Dichromate reflux methodBurette readings obtained

Titrant with standard dichromate solution

Initial burette reading/cm3

Final burette reading/cm3

Difference/cm3

FAS 0.00 10.60 10.60

Blank 0.00 12.45 12.45Sample 0.00 22.20 22.20


Dichromate reflux methodResults

The COD of effluent sample = 4084.91 ppm Maximum allowed(Central Environmental Authority) = 250.00 ppm





28 Biological oxygen demand determination of wastewater effluent sample

Biological oxygen demand is a quantitative measure of the presence of microorganisms in the water sample that are responsible for the consumption of dissolved oxygen for their metabolism.


Measured by using conventional titrimetric method oxygen demanded by microorganisms soon after the

sample was taken out was measured oxygen demanded by microorganisms after five days’

time in the water was determined BOD determined for 5 days by subtracting the oxygen

demand values


MnSO4 solution :4.80 g of MnSO4.4H2O and diluted upto 10 ml

Alkali-iodide–azide reagent: by dissolving 5.00 g of NaOH and 1.35 g NaI and adding it to

dissolved 0.01 NaN3 and diluted upto 10 ml water. Starch indicator Standard Thiosulfate solution of 0.025 M

Reagents:


Procedure:The amber colored bottle was allowed to incubate for five days without fixing and after that by adding MnSO4 solution and alkil-iodide-azide O2 was fixed.

Both the fixed solutions were treated with conc H2SO4 minimum amount to dissolve the precipitate

Finally were titrated against standard S2O32-

solution


2(Mn2+ ------------------------- > Mn4+ + 2e) in alkali O2 + 2H2O + 4e ------------- > 4OH- 2Mn2+ + O2 + 2H2O ------ > 2Mn4+ + 4OH-

Formed Mn4+ ions are then precipitated as MnO2.2H2O

Reactions:


By adding conc H2SO4 followed by KI this precipitate is dissolved generating I2 which can be then determined by titrating with Na2S2O3

MnO2 + 4H+ 2e- ----------- > Mn2+ + 2H2O2I- ------------------------------ > I2 + 2e-________________ MnO2 + 2I- +4H+ ---------- > I2 + Mn2+ + 2H2OI2 + 2S2O3

2- ------------------ > 2I- + 2S2O32-

Reactions:


Readings obtained:

Trial Initial burette reading/ml

Final burette reading/ml

Difference/ml

Standardization of S2O3

2-0.00 9.80 9.80

Colorless bottle

9.80 24.20 14.40

Amber colored bottle

24.20 31.00 5.80


Biological oxygen demand of the sample = 67.33 ppm

Maximum allowed(Central Environmental Authority) = 30.00 ppm

Results:





38 Determination of total suspended solids(TSS) in waste water sample

• TSS can be conveniently determined by using a glass microfiber filter paper.

• Sample along with suspended solids can be filtered to the filter paper and the dry mass increase quantitatively gives a measure for the TSS in ppm.



• Sample along with suspended solids can be filtered to the filter paper and the dry mass increase quantitatively gives a measure for the TSS in ppm.



Facilitates fine particle retention and high flow rate

Good loading capacity

Pore size 0.7 µm

41 Determination of total suspended solids(TSS) in waste water sampleProcedure:

Next the filter paper was dried again in oven for 20 min

The dry mass was weighed.

42 Determination of total suspended solids(TSS) in waste water sampleProcedure:

Filtration apparatus used for the filtering of suspended solids

43 Determination of total suspended solids(TSS) in waste water sampleReadings:Dry mass of filter paper before filtering/g

Dry mass of filter paper after filtering/g

Mass of suspended solids/g

0.0948 0.1120 0.0172

44 Determination of total suspended solids(TSS) in waste water sampleResults:

TSS of the effluent sample = 172.0 ppm

Maximum allowed (Central Environmental Authority) = 50.0 ppm


Conclusion

Current water treatment procedure employed is not sufficient and exceeds the maximum recommended by Central Environmental Authority

46 Suggestions for decreasing COD, BOD, TSS Moving on to a better primary treatment

Introduction of a new sand filtration method

47 Suggestions for decreasing COD, BOD, TSS Moving on to a better primary treatment• Usage of polyaluminium chloride instead of alum or ferric chloride

0.15 g/250.0 ml 0.15 g/250.0 ml 0.15 g/250.0 ml FeCl3 Alum PACl

48 Suggestions for decreasing COD, BOD, TSS Introduction of a sand filtration method

• Sand filtration greatly reduces COD,BOD and TSS

49 References

• Apha method for COD,BOD determination

• Kemmer, Frank N. (1979). The Nalco Water Handbook. Pages 230-238

• Patterson, James W. (1980). Wastewater Treatment Technology

• http://www.cea.lk/web/index.php/en

http://www.cea.lk/web/index.php/en

50

Thank you!

External supervisor : Mr. S.K.FernandoInternal supervisor : Prof. R.M.G.Rajapakse

51

52


Chemical oxygen demand determination Biological oxygen demand determination Total suspended solids determination

Water vapor permeability test for two weather coating products


Chemical oxygen demand determination Biological oxygen demand determination Total suspended solids determination

Water vapor permeability test for two weather coating products

55 Determination of water vapor permeability of thin films of two Robbialac paint coating products

Water vapor permeability of thin paint films is determined using upright cup method.

Color of silica gel is used to detect water vapor passage through the film.

Dry silica gel is blue in color whereas it turns pink upon absorption of water.


Procedure Two coating products were taken and four thin films were made which are

2.5mm in thickness easysil 505 treated and the standard.

1. Aquatuff standard 2. Aquatuff trial(esasil 505 treated) 3. Weathercoat standard 4. Weathercoat trial(esasil 505 treated)


Procedure Silica gel was dried in oven for 4 hours and 10 g of blue beads were

placed in four identical 100ml beakers and was quickly covered airtight with the films 1 to 4 respectively.

Then all the four labeled beakers were sealed with grease and were placed in a water vapor saturated chamber for two days

The color change were noted qualitatively


Procedure

59 Determination of water vapor permeability of thin films of two Robbialac paint coating productsResults

Before After

Aquatuff

Weathercoat


Conclusion

• Weathercoat has more water vapor permeability than Aquatuff

• Adding easasil 505 additive increases water vapor permeability

Presentation1 -final

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