SSF (1).ppt
-
Upload
vinod-baria -
Category
Documents
-
view
252 -
download
0
Transcript of SSF (1).ppt
-
The Slow Sand Filter Mystery Major Events in Slow Sand Filtration HistoryResearch at CornellParticle Removal MechanismsSearch for the Mystery CompoundSSF research by CEE 453
-
An old technology that is poorly understoodParticle removal improves with time!Until recently no one knew how particles were removed by slow sand filtersThe mystery is not yet solvedPotential for new useful knowledge
-
A.Valve for raw water inlet and regulation of filtration rateB.Valve for draining unfiltered waterC.Valve for back-filling the filter bed with clean waterD.Valve for draining filter bed and outlet chamberE.Valve for delivering treated water to wasteF.Valve for delivering treated water to the clear-water reservoirABCDEFFilter CakeSandGravelUnderdrains
-
1790 - SSF used in Lancashire, England to provide clean water for textile industry1829 - SSF used to filter municipal water (London)1850: John Snow established the link between drinking water (from a contaminated well) and Cholera1885- SSF shown to remove bacteria1892 - Cholera outbreak in Hamburg, Altoona saved by slow sand filters1980s - Giardia shown to be removed by SSF1990s - Cryptosporidium not always removed by SSF
-
In 1885 Percy F. Frankland used the recently devised 'gelatin process' of Robert Koch to enumerate bacteria in raw and filtered waterFrankland showed that filtration reduced the average bacteria concentration from Thames water 97.9%It is most remarkable, perhaps, that these hygienically satisfactory results have been obtained without any knowledge on the part of those who construct these filters, as to the conditions necessary for the attainment of such results. (Percy F. Frankland)
-
Large outbreak of Cholera in Hamburg17,000 cases; 8,600 deathsVery few cases in neighborhoods served by Altoona's filtered water supplyHamburg's sewers were upstream from Altoona's intake!Hamburg'swater intakeAltoona'swater intakeand filter bedsHamburg's seweroutfallsHamburgAltoonaElbe River
-
Milwaukee (March 1 to April 10 1993): an estimated 370,000 city residents suffered from diarrhea, nausea, and stomach cramps caused by CryptosporidiosisEvidence suggests that a substantial proportion of non-outbreak-related diarrheal illness may be associated with consumption of water that meets all current water quality standardsSlow sand filters shown to remove less than 50% of Cryptosporidium oocysts at an operating plant in British Columbia
-
How do slow sand filters remove particles including bacteria, Giardia cysts, and Cryptosporidium oocysts from water?Why dont SSF always remove Cryptosporidium oocysts?Is it a biological or a physical/chemical mechanism?Would it be possible to improve the performance of slow sand filters if we understood the mechanism?
-
Sampling tubeLower to collect sampleManifold/valve blockPeristaltic pumpsManometer/surge tubeCayuga Lake water(99% or 99.5% of the flow)Auxiliary feeds(each 0.5% of the flow)1 liter E. coli feed1 liter sodium azideTo wasteFilter cell with 18 cm of mediumSampling Chamber
-
Continuously mixed Cayuga Lake water0.050.11012345Time (days)Fraction of influent E. coli remaining in the effluent
-
Fraction of influent E. coli remaining in the effluent
-
Effluent particle count (Dnumber/l/Dparticle diameter)
-
long flagellum used for locomotion and to provide feeding currentshort flagellumstalk used to attach to substrate (not actually seen in present study)1 m
-
Mechanisms
-
The biological activity of microorganisms being removed in the filter column was not significant The biological activity of the filter biopopulation was only significant for removal of particles smaller than 2 m.Biofilms were expected to increase removal of particles larger than 2 m as well by increasing the attachment efficiency. The lack of biologically enhanced removal of particles larger than 2 m suggested that sticky biofilms did not contribute significantly to particle removal.
-
The immediate and reversible response of slow sand filters to sodium azide was consistent with bacterivory and inconsistent with particle removal by biofilms. Biologically mediated mechanisms together with physical-chemical mechanisms accounted for removal of particles smaller than about 2 m in diameter. In this research bacterivory was the only significant biologically mediated particle removal mechanism.Mechanisms
-
Day 5
-
Day 5
-
Physical-chemical particle removal mechanisms are significant in slow sand filters. Physical-chemical particle removal efficiency was greatest when particles previously had been retained by the filter (within the bed or in the filter cake) and was considered to be caused by attachment of particles to retained particles. Further work is necessary to determine what types of particles are most effective for filter ripening.
Mechanisms
-
Chart2
0.00521739130.00292682930.00426299050.00090354610.00001611770.00073826330.00001316930.00050686730.00000904160.00214209970.00037096810.0000066174
0.00235418880.00392364790.00347826090.00040769760.00000727260.00060236410.00001074510.0006794960.0000121210.00235418880.00040769760.0000072726
0.00150583240.00205726410.00209968190.00026077960.00000465190.00036362220.00000648640.00035627630.00000635530.00267232240.00046279190.0000082554
0.00201484620.01946977730.01790031810.00034893040.00000622430.00309997110.00005529810.00337176950.00006014650.04262990460.00738263260.0001316933
0.0103499470.03902439020.04475079530.00179240030.00003197330.00774992770.00013824520.00675823080.00012055510.2547189820.04411214790.0007868838
0.01215270410.0466595970.04750795330.00210460120.00003754240.00822741140.00014676270.00808049340.00014414190.34570519620.059869110.0010679605
0.01136797450.05047720040.04856839870.0019687020.00003511820.0084110590.00015003860.00874162460.00015593530.39236479320.06794960330.0012121025
0.0107953340.05090137860.05132555670.00186953230.00003334920.00888854270.00015855610.00881508370.00015724570.38812301170.0672150130.0011989987
0.01041357370.05005302230.04835630970.00180341920.00003216990.00837432950.00014938340.00866816560.0001546250.41569459170.071989850.0012841734
0.00948038180.0494167550.04899257690.00164180930.0000292870.0084845180.0001513490.00855797710.00015265940.4135737010.07162255490.0012776215
0.00909862140.04793213150.04856839870.00157569620.00002810770.0084110590.00015003860.00830087050.00014807310.43054082710.07456091610.0013300368
0.0089713680.04559915160.04814422060.00155365850.00002771460.00833760.00014872820.00789684580.0001408660.42841993640.07419362090.0013234848
Completely Mixed
2 cm layer
Top Layer
Control
Time (min)
fraction remaining
Sheet1
in turb47.15NTU
in turb 238.2NTU
Control ColumnCompletely Mixed2 cm DepthTop Layer
ErrorErrorErrorError
Time (min)raw dataFraction Remainingpositivenegativeraw dataFraction Remainingpositivenegativeraw dataFraction Remainingpositivenegativeraw dataFraction Remainingpositivenegative
00.1010.002140.000370.000010.2460.005220.000900.000020.1380.002930.000510.000010.2010.004260.000740.00001
50.1110.002350.000410.000010.1110.002350.000410.000010.1850.003920.000680.000010.1640.003480.000600.00001
100.1260.002670.000460.000010.0710.001510.000260.000000.0970.002060.000360.000010.0990.002100.000360.00001
152.0100.042630.007380.000130.0950.002010.000350.000010.9180.019470.003370.000060.8440.017900.003100.00006
2012.0100.254720.044110.000790.4880.010350.001790.000031.8400.039020.006760.000122.1100.044750.007750.00014
2516.3000.345710.059870.001070.5730.012150.002100.000042.2000.046660.008080.000142.2400.047510.008230.00015
3018.5000.392360.067950.001210.5360.011370.001970.000042.3800.050480.008740.000162.2900.048570.008410.00015
3518.3000.388120.067220.001200.5090.010800.001870.000032.4000.050900.008820.000162.4200.051330.008890.00016
4019.6000.415690.071990.001280.4910.010410.001800.000032.3600.050050.008670.000152.2800.048360.008370.00015
4519.5000.413570.071620.001280.4470.009480.001640.000032.3300.049420.008560.000152.3100.048990.008480.00015
5020.3000.430540.074560.001330.4290.009100.001580.000032.2600.047930.008300.000152.2900.048570.008410.00015
5520.2000.428420.074190.001320.4230.008970.001550.000032.1500.045600.007900.000142.2700.048140.008340.00015
Averages18.9570.402060.069630.001240.4870.010330.001790.000032.2970.048720.008440.000152.3000.048780.008450.00015
Error
depth of column (cm)steady state removalpositivenegative
00.0490.0080.000
20.0490.0080.000
200.0100.0020.000
Control ColumnCompletely Mixed2 cm DepthTop Layer
ErrorErrorErrorError
Time (min)raw dataFraction Remainingpositivenegativeraw dataFraction Remainingpositivenegativeraw dataFraction Remainingpositivenegativeraw dataFraction Remainingpositivenegative
00.1030.002700.000470.000010.0610.001600.000280.000010.0720.001880.000330.000010.0790.002070.000360.00001
50.2310.006050.001050.000020.0690.001810.000310.000010.0560.001470.000250.000010.0880.002300.000400.00001
100.2000.005240.000910.000020.0510.001340.000230.000010.0500.001310.000230.000000.0540.001410.000240.00001
150.3270.008560.001480.000030.0690.001810.000310.000010.1130.002960.000510.000010.1690.004420.000770.00002
204.2600.111520.019310.000430.1810.004740.000820.000020.1120.002930.000510.000010.4710.012330.002140.00005
2515.1000.395290.068460.001510.1700.004450.000770.000020.1350.003530.000610.000010.7180.018800.003260.00007
3017.6000.460730.079790.001760.2790.007300.001260.000030.1400.003660.000630.000010.8130.021280.003690.00008
3516.1000.421470.072990.001610.1730.004530.000780.000020.1360.003560.000620.000010.8700.022770.003940.00009
4017.2000.450260.077980.001720.1700.004450.000770.000020.1300.003400.000590.000010.9380.024550.004250.00009
6016.7000.437170.075710.001670.1910.005000.000870.000020.1500.003930.000680.000011.1300.029580.005120.00011
8016.7000.437170.075710.001670.2240.005860.001020.000020.1420.003720.000640.000011.3100.034290.005940.00013
10017.0000.445030.077070.001700.1770.004630.000800.000020.1800.004710.000820.000021.3300.034820.006030.00013
Averages16.6290.435300.075390.001660.1980.005180.000900.000020.1450.003790.000660.000011.0160.026590.004600.00010
Error
depth of column (cm)steady state removalpositivenegative
00.0270.0050.00010
20.0040.0010.00001
200.0050.0010.00002
Turbidity Readings
Trial #Distilled WaterHigh Clay ConcentrationLow Clay Concentration
10.06424.20.846
20.05725.50.945
30.05924.90.81
40.0625.20.88
50.05625.80.77
60.05627.10.855
70.05728.50.903
80.05722.40.854
90.06124.70.893
100.056210.757
110.06822.70.992
120.0550.833
130.0620.781
140.0580.814
150.0590.851
160.0580.915
170.0560.82
180.0630.823
190.060.885
200.0560.945
Std Dev0.0033424.727270.85860
Average0.058902.134520.06174
% error0.056690.086320.07191
depth of column20cm
Determination of k
BPP Concentration (mg/cm^3)CinCoutdk
Control047.1518.95714200.04556
Long_Term038.2016.62857200.04159
Comp Mixed0.3578747.150.48686200.22866
Long-Term0.3578738.200.19771200.26319
2 cm3.5786547.155.2158621.10081
Long-Term3.5786538.200.3059122.41364
Top Layer71.5730347.155.694530.210.56914
Long-Term71.5730338.202.323340.213.99915
Weight of 50 mL of BPP50.377g
Weight of Organics0.437g
Weight of Inorganics0.519g
Total Weight of Dry Solids0.956g
Weight of Dry Solids in 30 mL0.573g
Sheet1
0.00090354610.00001611770.00073826330.00001316930.00050686730.00000904160.00037096810.0000066174
0.00040769760.00000727260.00060236410.00001074510.0006794960.0000121210.00040769760.0000072726
0.00026077960.00000465190.00036362220.00000648640.00035627630.00000635530.00046279190.0000082554
0.00034893040.00000622430.00309997110.00005529810.00337176950.00006014650.00738263260.0001316933
0.00179240030.00003197330.00774992770.00013824520.00675823080.00012055510.04411214790.0007868838
0.00210460120.00003754240.00822741140.00014676270.00808049340.00014414190.059869110.0010679605
0.0019687020.00003511820.0084110590.00015003860.00874162460.00015593530.06794960330.0012121025
0.00186953230.00003334920.00888854270.00015855610.00881508370.00015724570.0672150130.0011989987
0.00180341920.00003216990.00837432950.00014938340.00866816560.0001546250.071989850.0012841734
0.00164180930.0000292870.0084845180.0001513490.00855797710.00015265940.07162255490.0012776215
0.00157569620.00002810770.0084110590.00015003860.00830087050.00014807310.07456091610.0013300368
0.00155365850.00002771460.00833760.00014872820.00789684580.0001408660.07419362090.0013234848
&A
Page &P
Completely Mixed
2 cm layer
Top Layer
Control
Time (min)
fraction remaining
Sheet2
0000.00035814640.00000788550.00027654340.00000608880.00032641190.000007186800.00046695040.0000102811
0000.00039894790.00000878390.00031281140.00000688740.00025387590.000005589700.00104723830.0000230577
0000.0002448090.00000539010.00023120850.00000509070.0002266750.000004990800.00090669980.0000199634
0000.00076616130.00001686910.00031281140.00000688740.00051228540.000011279300.00148245420.0000326401
0000.00213527810.00004701380.00082056330.00001806690.00050775190.000011179500.01931270610.0004252202
0000.00325505230.00007166860.00077069480.00001696890.00061202240.000013475300.06845583610.0015072359
0000.00368573470.00008115120.00126484620.00002784890.00063468990.000013974400.07978958370.0017567782
0000.00394414420.00008684070.00078429530.00001726830.00061655590.000013575100.07298933510.0016070528
0000.00425242210.00009362830.00077069480.00001696890.00058935490.000012976200.07797618410.0017168515
0000.0051228540.00011279310.00086589830.0000190650.00068002490.000014972500.07570943460.001666943
0000.00593888380.00013076020.00101550380.0000223590.00064375690.00001417400.07570943460.001666943
0000.00602955380.00013275650.00080242930.00001766760.00081602980.000017967100.07706948430.0016968881
&A
Page &P
Completely Mixed
2 cm layer
Top Layer
Control
Time (min)
fraction remaining
Sheet3
00.00844778850.0001506938
00.00843729440.0001505066
00.00178820270.0000318984
&A
Page &P
depth of column (cm)
fraction remaining
Sheet4
00.00460409210.0001013712
00.00065606210.0000144449
00.00089633750.0000197352
&A
Page &P
depth of column (cm)
fraction remaining
Sheet5
0.00844778850.00015069380.00460409210.0001013712
Scaling Measurements
Alison Humphries, Michael Steiger, David KeyserSlow Sand Filtration Research Project for Cee 453
&A
Page &P
Control
Control Long-Term
fraction remaining
0.0696286669
0.001242054
0.0753856132
0.0016598132
&A
Page &P
Top Layer
Top Layer Long-Term
fraction remaining
Sheet6
0.00178820270.00003189840.00089633750.0000197352
&A
Page &P
Completely Mixed
Completely Mixed Long-Term
fraction remaining
Sheet7
00.00843729440.000150506600.00065606210.0000144449
&A
Page &P
2 cm
2 cm Long-Term
fraction remaining
Sheet8
0
0
0
0
0
0
&A
Page &P
Concentration of BPP (mg/cm3)
k (1/cm)
Sheet9
&A
Page &P
Sheet10
&A
Page &P
Sheet11
&A
Page &P
Sheet12
&A
Page &P
Sheet13
&A
Page &P
Sheet14
&A
Page &P
Sheet15
&A
Page &P
Sheet16
&A
Page &P
&A
Page &P
&A
Page &P
&A
Page &P
&A
Page &P
&A
Page &P
&A
Page &P
&A
Page &P
-
C/CoTime (minutes)?
Chart3
0.10.03278688520.02014423080.020952381
0.03485714290.00928961750.031250.0256709957
0.01714285710.00928961750.07163461540.0761904762
0.01485714290.01147540980.07884615380.0883116883
0.020.00765027320.09567307690.0956709957
0.02171428570.00874316940.10384615380.1004329004
0.02228571430.00983606560.16298076920.1064935065
0.02114285710.01803278690.43221153850.1173160173
0.0240.02295081970.56250.1995670996
0.02914285710.03661202190.71634615380.4588744589
0.03714285710.0497267760.70673076920.70995671
0.05314285710.09453551910.70192307690.7186147186
0.07942857140.22404371580.77403846150.8311688312
slurry
Alum
distilled control
tap water control
David, Edwin
Edwin HuhCEE 453
David SausenLab 11
Slow Sand Filter 1
1 g alum in 100 mL distilled water titrated to pH = 7.50
This ripening agent was added to the filter and thoroughly mixed prior to starting the pump.
Slow Sand Filter 2
50 mL sludge
This ripening agent was added to the filter and thoroughly mixed prior to starting the pump.
AlumSludge
Influent Turbidity (NTU)3139
Effluent Turbidity (NTU)
Time (min)
03.444.6
51.351.59
100.461.07
150.230.42
200.160.37
250.580.16
300.170.25
350.40.21
400.480.09
450.110.15
500.070.13
550.380.07
average NTU after 20min:0.293750.17875
Fractional Removal:0.99052419350.9954166667
% Removal:99.052%99.542%
Steve, Kevin
Steven Kundrot and Kevin Lapus
Thursday Lab Section
Overview: We used the bolton point sludge water to for to rippening agents. The first
rippening agent was to be the alum from the sludge and the second was to be the sludge
itself without the alum. The alum was extracted using .1N HCl acid. Then both agents
were neutralized to pH 7. The alum solution was added to column #1 and the sludge slurry
was added to column #2.
Initial Turbidity:12.8Initial Turbidity:14.4
Sand Column #1Sand Column #2
Alum SupernatantSludge w/o Alum
Time (min)TurbidityFraction RemainingTime (min)TurbidityFraction Remaining
52.270.18513.70.95
101.70.13108.220.57
151.840.14158.880.62
200.8490.07204.970.35
250.3690.03252.70.19
300.2580.02302.230.15
350.310.02352.060.14
400.1760.01402.130.15
450.1490.01452.080.14
500.2590.02502.090.15
550.1970.02552.470.17
600.180.01603.530.25
Avg. Frac. Removed:0.056Avg. Frac. Removed:0.319
Amy, Yin
Slow Sand Filtration Lab DataThursday Lab - Anne & Yin
This is similar to David and Edwin's experiment (with distilled water instead of tap water and bacteria instead of clay)
SlurryAlum Floc
InfluentTimeTurbidityInfluentTimeTurbidity
014.8014.5
7017.57018.3
Time (min)Distilled water turbidity (NTU)Tap water turbidity (NTU)
EffluentTimeTurbidityFraction RemainingEffluentTimeTurbidityFraction RemainingInfluent20.823.1
51.7510.00%50.63.28%50.4190.484
100.613.49%100.170.93%100.650.593
150.31.71%150.170.93%151.491.76
200.261.49%200.211.15%201.642.04
250.352.00%250.140.77%251.992.21
300.382.17%300.160.87%302.162.32
350.392.23%350.180.98%353.392.46
400.372.11%400.331.80%408.992.71
450.422.40%450.422.30%4511.74.61
500.512.91%500.673.66%5014.910.6
550.653.71%550.914.97%5514.716.4
600.935.31%601.739.45%6014.616.6
651.397.94%654.122.40%6516.119.2
distilleddistilled
influent17.518.320.823.1
TimeslurryAlumdistilled controltap water control
50.10.03278688520.02014423080.020952381
100.03485714290.00928961750.031250.0256709957
150.01714285710.00928961750.07163461540.0761904762
200.01485714290.01147540980.07884615380.0883116883
250.020.00765027320.09567307690.0956709957
300.02171428570.00874316940.10384615380.1004329004
350.02228571430.00983606560.16298076920.1064935065
400.02114285710.01803278690.43221153850.1173160173
450.0240.02295081970.56250.1995670996
500.02914285710.03661202190.71634615380.4588744589
550.03714285710.0497267760.70673076920.70995671
600.05314285710.09453551910.70192307690.7186147186
650.07942857140.22404371580.77403846150.8311688312
Amy, Yin
slurry
Alum
distilled control
tap water control
Todd, Mark
Todd and Mark's DataThey extracted polymer from sludge that had been treated with acid to remove the alum.
#3 - polymer extraction from residual sludge w/ 100mL 0.1 NaOH
Influent14.9NTU
NTUNTU
timeYellowBlue (sludge)
547.511.1
1039.87.37
15175.06
207.182.3
25.53.771.51
32.52.321.43
382.111.44
452.11.5
501.921.52
Danusha, Cynthia
Tuesday's lab
I think the sludge had been treated with base and then with acid in an attempt to extract both alum and polymer.
The polymer was extracted with acid.
timeturbidity fraction remaining of sludgeturbidity fraction remaining of polymer
200.0820.053
250.10.044
300.0770.049
350.0990.077
400.0680.055
450.0630.047
500.0550.046
Analysis #2: since steady state is hard to define. Simply compare the
turbidity data for one time.
Analysis #3:
L (cm)=16
filtercoefficient (1/cm)
with sludge0.0249616289
without sludge0.0088531573
Erik, Nader
We ran the controls using no ripening agents, just one control with tap water, and one with distilled water.
Thursday Lab
Time (min)Distilled water turbidity (NTU)Tap water turbidity (NTU)
Influent20.823.1
50.4190.484
100.650.593
151.491.76
201.642.04
251.992.21
302.162.32
353.392.46
408.992.71
4511.74.61
5014.910.6
5514.716.4
6014.616.6
6516.119.2
Tuhina, Masako, Steven
Tuhina Ghosh, Masako Iwata, Steven Kao
April 13, 1998
Description:
Ripening Agent Preparation:
Treatment A:
Centifuge 200 mL of Cayuga Lake sludge solution.
Pour off supernatant and add about 100 mL of 1 N NaOH.
Mix thoroughly and centrifuge again.
Remove and save alum-rich supernatant for treatment A.
Treatment B:
Take remaining sludge and add about 100 mL of NaOH again.
Mix thoroughly and centrifuge again.
Pour off supernatant and save remaining sludge for treatment B.
Treatment A is alum extract using NaOH and neutralized to pH of 7.
Treatment B is sludge without alum.
Time (min)Treatment A turbidity (NTU)Treatment B turbidity (NTU)
0129310
55.71.9
102.030.93
151.30.05*
200.180.05
250.070.11
300.070.06* = bad data?
350.070.05
400.060.06
450.1*0.04
500.25*0.06
Influent turbidity23.929.8
Joye, Travis
Joye Thaller
Travis Kluegel
CEE 453
Slow Sand Filtration Lab
We received sludge which had already been washed with acid and centerfuged
twice. We washed it a third time with acid and removed the supernatent.
The sludge was then washed with a base and centerfuged. The supernatent
is the polymer which we tested in the slow sand filter. After washing the sludge a
second time with a base, we removed the supernatant and used the remaining
sludge in the second slow sand filter.
The stir bar was not initially in use during the first 35 min. of the experiment but
was turned on before the 40 min. reading. Also, we did not shake the slow sand
filters to mix the polymer and sludge until after 40 minutes had elapsed.
TimePolymer (NTU)Sludge (NTU)
Influent36.6031.00
50.510.67
103.751.32
153.720.39
200.450.49
250.380.37
300.390.37
35*0.420.38
400.423.77
After Shaking
5:003.503.65
5:042.680.86
5:091.760.68
5:191.460.60
5:301.440.50
*Stir bar was added to tank
Kathy, Amy
Not yet received
-
Successfully extracted a coagulant from Cayuga Lake Seston using 1.0 N HClThe CLSE fed filters removed up to 99.9999% of the influent coliforms.Analysis of the CLSENonvolatile solids was 44% of the TSSVolatile solids was 56% of the TSSAluminum was dominant metal
-
Groups of 4Assemble filter apparatusMeasure head loss, flow rate, turbidityCoat filter with CLSEObserve _______________Challenge filter with kaolinObserve ________and _______Control?increased head lossturbidityhead loss