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To determine the water quality parameters of the Buriganga river
To predict the Humic Acid structure of the Buriganga River bottom sediment
To study the complexation behavior between HA- Metals (Iron, Cadmium, Chromium, Manganese, Lead, Nickel and Calcium)
SAMPLE COLLECTION SAMPLE ANALYSIS Nine sediment samples were collected from the Buriganga river.
Eighteen water samples were collected from the Buriganga river.
The water samples were analyzed by AAS and UV-Visible for metal ions and anions
Humic acid was extracted from the sediments according to IHSS
Characterization and study of complexation with metals of extracted HA was carried out with IR, FTIR, SEM, EDX and CHNS analyzer.
Sampling stations:a) First Buriganga Bridgeb) Arsene gate, Gudara Ghat c) Sadar Ghat First Jettyd) Shaym Bazar Ghate) Sadar Ghat Main Terminalf) Sadar Ghat Fruit Bazarg) Ahsan Manzil Ghath) Second Buriganga Bridgei) Imamganj Paan Ghat j) Dhaka Dockyard k) Toil Ghatl) Keraniganj Police Ghatm) Kamrangir Chor Ghatn) Shoari Ghato) Solimullah MedicalCollege Ghatp) Jora bridge, Kamrangir Chorq) Forashganj Ghatr) Faridabad Launch Terminal
River bottom sediments
Dried under sun for 5 hours + Broken piece of shell & small dust removed
Dried sample (100g)
+ 1 M HCl (up to pH 1~2) + 0.1 M HCl (10mL Liquid/ 1g dried sample)
Solution (pH=1 to 2)
Centrifugation(700 rpm 5min)
Shaking for 1 hour
+1.0M NaOH (up to pH =7.0)
ResidueSupernatant+ 0.1 M NaOH (at N2)
Solution (pH ~ 11)
Shaking for 4 hour + Settle overnight
Centrifugation (1500 rpm 15 min)
Supernatant Residue
+ 6 M HCl (up to pH = 1.0) + Stand for 12~16 hour
Centrifugation (1000 rpm 10 min)
Supernatant- Fulvic acid
Precipitate
+ 0.1 M KOH + solid KCl (0.3M [K+])
Centrifugation (2000 rpm 10 min)
Liquid HA Precipitate
Dried in oven (50oC)
Solid HA
Figure 2: Flow Chart of extraction procedure of Humic Acid
Samples Fe2+/3+
mg/L
Pb2+
mg/L
Cd2+
g/L
Cr3+/6+
mg/L
Ni3+
mg/L
Ca2+
mg/L
Mn2+
mg/LWa 0.08 0.13 4.00 0.01 0.04 33.38 0.03Wb 0.06 0.12 2.00 0.06 0.07 52.56 0.01Wc 0.1 0.15 3.00 0.03 0.07 22.68 0.02Wd 0.12 0.12 0.80 0.02 0.04 24.34 0.04We 0.04 0.11 8.00 0.03 0.03 22.56 0.01Wf 0.04 0.12 2.00 0.01 0.06 22.62 0.07Wg 0.14 0.12 1.00 0.01 0.04 19.04 0.05Wh 0.22 0.20 0.75 0.02 0.01 20.58 0.04Wi 0.04 0.002 7.50 0.08 0.06 49.30 0.01Wj 0.32 0.04 2.00 0.04 0.07 31.50 0.11Wk 0.26 0.02 4.90 0.02 0.06 19.22 0.03Wl 0.1 BDL 0.40 0.01 0.05 14.70 0.01Wm 0.12 0.004 12.00 0.01 0.05 59.00 0.05Wn 0.18 0.04 8.50 0.03 0.04 14.66 0.01Wo 0.04 0.02 6.00 0.01 0.07 25.22 0.02Wp 0.22 0.03 16.70 0.09 0.06 20.76 0.03Wq 0.30 0.03 5.80 0.01 0.05 27.78 0.09Wr 0.28 0.04 2.00 0.03 0.02 21.04 0.02
WHO std (drinking) 0.30 0.01 5.00 0.05 - 200.00 0.10
Std. for Fishing water 0.30 0.01 5.00 0.10 - - 0.10
Table 1: Observed values of metal ions of Buriganga river with standard values
Figure 5: FTIR Spectrum of Extracted Humic Acid
(d)
Wave no.(cm-1) Region (cm-1)
Type of vibration
3280(a),3300(d),3280(g), 3280(i)
3400-3200, 3570-3450
H- bonded OH group
3000(i) 3050-3000 Aromatic C-H stretching
2960(a),2920(d),2920(g),2960(i)
2960-2850 Stretching of CH2, CH3 group
2960(a),2930(d),2960(g),2560(i)
3000-2500 OH stretch of H-bonded –COOH
1550(a),1560(d),1580(g) 1610-1550 Carboxylate anion
1650(a), 1650(d),1640(g),1655(i)
1650-1450 Aromatic C=C stretching
1400(a),1400(d),1400(g),1400(i)
1485-1340 CH deformation of CH3
1260(i) 1265-1200 Symmetric –COO- stretching
1120(a),1130(i) 1126-1100 C-O stretching of COOH
1070(a) ~1100,~1050
-C-O stretching in aliphatic OH
700,830,880(a),700,860,880(d) 840-690 Aromatic disubstituted
Table 2: FTIR analysis of extracted Humic Acid
Figure 8: SEM image of extracted Humic Acid (Buriganga River)
Figure 7: SEM image of Standard Humic Acid
Element CHNS Analysis (% Weight)
EDX (% Weight)
C 63.25 62.36
H 4.514 Not quantified
N 0.75 3.16
S 0.763 3.71
O 30.72 25.88
Table 3: Elemental Composition of extracted HA with CHNS and EDX analyzers
Figure 9: EDX Spectrum of Extracted HA
Figure 6: Proposed structure of Extracted Humic Acid
OH
COOH
HOOH
COOH
O
HO
O
NCHCOOH
RO
O
O
NH
OH
CHCH
RO
CHCH
N
OCH2
CH
O
O
OO
OHCOOH
COOH
OO
O
OH
H
Figure 10: SEM image of Humic Acid and Fe Complex
Figure 11: EDX Spectrum of HA-Iron (II) Complex
pH
1 2 3 4 5 6 7 8 9 10 11 12 13
Tran
smita
nce%
75
80
85
90
95
100
Rem
oval
%88
90
92
94
96
98
100
102
Tranmitance % vs pHRemoval % vs pH
pH
1 2 3 4 5 6 7 8 9 10 11 12 13Tr
ansm
itanc
e%
88
90
92
94
96
98
100
102
Rem
oval
%
88
90
92
94
96
98
100
102
Transmitance % vs pHRemoval % vs pH
Figure 12: Complexation study of HA with Iron (II) Sulphate at different pH at 254 nm
Figure 13: Complexation study of HA with Iron (II) Sulphate at different pH at 436 nm
Concentration of Iron (II) X 10-3 M
0.1 0.3 0.5 0.7 1.0 1.3 1.5 1.7
pH
5.2
5.4
5.6
5.8
6.0
6.2
6.4
6.6
6.8
Con
duct
ance
X 1
0-2
S
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
Concentration of Fe vs pH Concentration of Fe vs Conductance
OCC
RC
a b
Concentration of Iron X 10-3 M
0.1 0.3 0.5 0.7 1.0 1.3 1.5 1.7
Degr
ee o
f Com
plexa
tion
at 2
54 n
m
70
75
80
85
90
95
100
Degr
ee o
f Com
plexa
tion
at 4
36 n
m
30
40
50
60
70
80
90
100
Conc of Fe vs at 254 Conc of Fe vs at 436
Figure 15: Degree of Complexation inpercentage with the variation of
concentration of Iron (II) Sulphate
Figure 14: Jar test of Iron (II) - HA complexation
Metal - HA Complex Optimum pH
values
Optimum concentrations X 10-3 MBy Jar test By Spectrophotometric test
Iron (II) - Humic Acid 7 0.70 - 1.00 0.70Cadmium (II) - Humic Acid
9 0.45 - 0.70 0.55
Chromium (III) - Humic Acid
3 0.48 - 0.70 0.44 - 0.50
Manganese (II) - Humic Acid
9 0.70 - 1.19 1.50 - 1.51
Lead (II) - Humic Acid 6 - 10 0.45 - 0.70 0.46 - 0.50
Nickel (II) - Humic Acid
10 0.67 - 1.00 0.70 - 1.45
Calcium (II) - Humic Acid
8 1.18 - 1.50 1.24 - 1.30
Table 4: Summary of Metal - HA Complexation study
The formation of Metal - Humic acid complex is controlled by the number of coagulant (metal ion) species and two dynamics aspects:
(i) the reconformation of humic network (ii) the collision rate of destabilized particles.
An overall shrinkage of anionic humic network is indeed expected upon binding of cationic coagulant species which promotes the formation of intra- and inter-particle hydrophobic domains according to the extent of charge neutralization.
The collision rates determines the variations in precipitation volume in the range of optimal concentration of coagulants.
MECHANISM OF METAL - HUMIC ACID COMPLEXATION
The Buriganga river water is highly polluted
The Humic Acid Structure of Buriganga river sediment is slightly different than of other places. It contains aromatic hydrocarbons, large amount oxygen containing groups
The Buriganga river Humic Acid makes complexes with the metals.
This complexation or coagulation process can be used to remove the high concentration of metals from the surface water of this river.
THANK YOU