PROJECT ON :

Efficiency Assessment of Aeration Tank.A Case study in a paper and pulp industry, Unit: Tribeni.

Report for partial fulfillment of M.Sc in Environmental Science of University of Kalyani.

Presented by:Priyabrata Roy.

M.Sc, 4th SemesterDepartment of Environmental

ScienceUniversity of Kalyani.

Email: priyabrataroy2009@gmail.com

IntroductionIndustry is one of the major source of Waste Water in this civilized era. It is continuously polluting our environment. Minimization of pollution load of discharging waste & waste water is the primary goal. Most effective treatment for this purpose is Effluent Treatment Plant installation in the industry. I have carried out my project at a Paper and pulp industry, Unit: Tribeni. I have chosen this because: Paper industry is under RED category Industry.Discharging huge amount of waste water. Aeration process & activated Sludge Treatment are being followed by the industry.

Aims & Objectives. My aim is to study The Efficiency of Aeration Tank operation & The Overview of Environmental management System at the Paper mill, Tribeni.To achieve the aim following objectives are taken:

Understanding the Papermaking process. Effluent Treatment Plant Operation. Assessment the efficiency of Aeration Tank & its further modification.

EMS

An Overview of the ITC Ltd.(PSPD)

Study Area &Unit Profile Industry Unit: Tribeni is set up near the bank of Hooghly river, under Chandrahati G.P.2•A Specialty Paper Mill•Three Paper Machines ( PM:1,3&4)•Production 2012-13: 30387 MT•Annual Turnover = $ 240 Million•Certified ISO 9001, ISO14001 and OHSAS 18001

Specialty Papermaking Process.( Flow Chart)

Imported pulp & Broke paper.

Refiner

Head box

Forming & Press Section

Drier & Calender.

Refilling & Rewinder

Ro

bb

in Slitti

ng

Packing Despatch

Following Wastewater Treatment has been adopted by the paper mill.

Classification of Methods

Physical Processes

Chemical Processes

Biological Processes

ScreeningEqualization TankSedimentation

Alum DosingChlorination

Aerobic Waste Water Treatment( Aeration Tank).

ETP Operation Flow Chart.

Waste water Bar Screen Equalization Tank

Primary Clarifier Clarifloculator

Aeration Tank

Final Clarifier (1&2)

Discharge. Secondary Sludge

Primary Sludge

Retu

rn Slu

dge

A GENERAL STRUCTURE OF CLARIFIER

ETP Plant Picture.

Sampling Site.

Target Set by Paper Mill to maintain effluent discharge….Name of the Parameter.

WBPCB Benchmark.

Concentration in Waste Water.

pH 6.5-8.5 6.5-8.5

DO (mg/l) 3.5-4.5 3.0-3.5

MLSS (mg/l) 2000-4000 1500-3500

MLVSS Unknown 60

SVI <50 <75-100

BOD(mg/l) 30 25

COD(mg/l) 350 200

Waste water discharge (cu.M/T)

200 100 (by2007).

Results & Discussion.

Study of Aeration Tank pH.9:3

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19/3 20/3 21/3 22/3 24/3 25/3 26/4 27/3 28/3 29/3 30/3 31/3

7

7.2

7.4

7.6

7.8

8

8.2

WBPCB Standard.

pH of Inlet

pH of Outlet

TIME →

pH

Study of Aeration Tank D.O(mg/Lt).

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5

Mill Standard.

DO(mg/Lt) of Inlet

DO(mg/Lt) of Outlet

TIME

Con

c. in

mg/

Lt

MLSS STUDY OF AERATION TANK

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INLET MLSS/SS(mg/Lt)

0UTLET MLSS/SS(mg/Lt)

MILL STANDARD 3000

MLSS IN mg/Lt OF AERATION TANK INLET vs OUTLET.

TIME

Conc, in mg/Lt

SVI Study of Aeration Tank.9:3

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SVI OutletSVI InletMILL STANDARD

SVI of Aeration Tank (Inlet vs Outlet).

SVI

Time

MLVSS study of Aeration Tank.9:3

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MLVSS(%)of InletMLVSS(%)of OutletWBPCB Standard

MLVSS (%) INLET vs OUTLET.

Time

% o

f M

LVS

S

Graph of BOD in Final effluent with respect to WBPCB & Mill Standard.

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21/3

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25/3

27/3

29/3

31/3

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BOD OutletWBPCB StandardMILL Standard

BOD(mg/Lt) of final effluent

Con

c.

Time.

Graph of COD in Final effluent with respect to WBPCB & Mill Standard.

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21/3

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31/3

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COD Outlet

WBPCB Standard

MILL Standard

COD(mg/Lt) of final effluent

Con

c.

Time

Determine the Efficiency of Aeration Tank in Respect to DO(mg/Lt).

9:3

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Efficiency in respect to DO in Aeration Tank.

Efficiency in respect to DO in Aeration Tank.

% o

f E

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ienc

y

Time

Environmental Management System at Paper Industry, Unit: Tribeni

ITC strictly follows their own EHS Policy. This unit certified by ISO 9001, ISO14001 and

OHSAS 18001

Conclusion.

Different tests were performed in various sites with particular time inter time interval. After the experiment, I have got the result that,: pH is regularly maintained by Alum dosing. SVI in some case is higher than Mill Standard. Aeration process is 80%-85% efficient to increase the desired DO level. In respect to BOD & COD the Aeration process is 90% efficient to keep the desired level.So, the Aeration process in the said paper mill seem to be one of the best solution for treatment of effluents containing pulp & cellulosic mater.

Recommendation

Liquid dosing may be adopted instead of Solid DAP and Ammonia.Treated water can be used for regular purposes in Industries’s guest houses & Quarters.Try to maintain the concentration of MLSS with in 3000 mg/Lt. to get desired DO level.In every shift One Aerator may be stopped sequence wise to decrease energy consumption.DAP & Urea should be used in 5:1 ratio for obtaining better result & efficiency.

  

References.ENVIRONMENTAL CHEMISTRY-B.K.SHARMAENVIRONMENTAL ENGINEERING – G.N PANDEY & G.C CARNEYENVIRONMENTAL SCIECCE- S.C SANTRAA TEXT BOOK OF ENVIRONMENTAL SCIENCE- GUHA BAKSHI , SEN, BANERJEEINDUSTRIAL WATER POLLUTION CONTROL, 3RD edition – W.WESLEY ECKENFELDERSulfate reduction at low pH to remediate acid mine drainage Sánchez-Andrea, I.ab  , Sanz, J.L.a, Bijmans, M.F.M.c, Stams, A.J.M.bd  Journal of Hazardous Materials Volume 269, 30 March 2014, Pages 98-109Treatment of effluents from palm oil mill process to achieve river water quality for reuse as recycled water in a zero emission systemOthman, M.R.a  , Hassan, M.A.b  , Shirai, Y.c  , Baharuddin, A.S.a  , Ali, A.A.M.c  , Idris, J.d     Journal of Cleaner Production Volume 67, 15 March 2014, Pages 58-61Removal of dye and chemical oxygen demand (COD) reduction from textile industrial wastewater using hybrid bioreactorsKatal, R.a, Zare, H.b, Rastegar, S.O.a, Mavaddat, P.a, Darzi, G.N.b     Environmental Engineering and Management Journal Volume 13, Issue 1, 2014, Pages 43-50

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