GEOCHEMISTRY AND MICROBIOLOGY OF COASTAL AQUACULTURE DEMONSTRATION AND TRAINING PROJECT, GELANG PATAH, JOHORE BAHRU, MALAYSIA

Table 1
PRECIPITATION AT GELANG PATAH
(29 Nov.81–9 Dec.81)
Date*	Time	Vol.(m)†	Precipitation (mm)
29 Nov.81	start	-	-
30 Nov.81	08.30	7	1.4
1 Dec.81	08.30	0	0
2 Dec.81	10.00	27	5.4
3 Dec.81	08.00	0	0
4 Dec.81
5 Dec.81
6 Dec.81	08.00	76	15.2
7 Dec.81	08.00	0	0
8 Dec.81	08.00	32	6.4
9 Dec.81	08.00	32	6.4

* Collector usually left for 24 hours before emptying, except for 2.12–5.12.81 (70 h) and 7.12–9.12.81 (48 h).
† Collector had a diameter of 8 cm (500 m glass beaker) and a cross sectional area of 50 cm²

Table 2 (a)
GELANG PATAH - WATER ALKALINITIES AND TOTAL IRON
(meq/: 28.11.81–6.12.81)
Date	Sample	pH	Alkalinity (meq/)	Iron (mg/)
28.11.81	P-29 (draining)	7.50	1.58	-
28.11.81	P-29 (draining)	7.35	1.53	-
28.11.81	P-29 (draining)	7.33	1.52
29.11.81	P-29 (empty)	7.28	3.68
29.11.81	P-1	7.03	1.05	2.0
29.11.81	P-2	7.10	1.63	0.5
29.11.81	P-3	7.27	1.55	0.7
29.11.81	P-4	6.80	1.26	0.6
29.11.81	P-5	7.02	1.20	1.0
29.11.81	P-6	6.99	1.15	1.4
29.11.81	P-7	6.65	1.08	1.5
29.11.81	P-8	6.93	1.14	2.0
29.11.81	P-9	7.01	1.30	2.0
29.11.81	P-10	7.23	1.50	1.3
29.11.81	P-11	7.25	1.62	1.3
29.11.81	P-10	6.98	1.61	-
29.11.81	P-23	6.65	0.66	4.1, 2.8
29.11.81	P-25	6.53	0.54	2.4
29.11.81	P-26	7.30	1.53	0.6
29.11.81	P-27	6.93	1.01	1.2
29.11.81	P-28	6.97	1.43	1.7
29.11.81	P-29	7.50	1.53	2.1
29.11.81	P-29 (PM)	7.50	1.83	-
29.11.81	P-33	6.93	1.55	2.0
29.11.81	SG-2	7.30	1.38	0.7
29.11.81	PG-8	6.83	1.21	-
29.11.81	PG-25	7.31	1.40	1.3
29.11.81	Canal opp P-1	7.17	1.66	0.1
29.11.81	Stream opp MG-1	7.10	1.64	0.2
30.11.81	P-1	6.22	0.68	2.4
30.11.81	P-3	6.68	1.17	2.4
30.11.81	P-10	6.54	1.11	9.2
30.11.81	P-11	6.80	1.53	2.4
30.11.81	P-14	7.33	1.67	-
30.11.81	P-18	7.13	1.60	1.6
30.11.81	P-19	7.45	1.65	1.2
30.11.81	P-23	6.72	0.67	1.2
30.11.81	P-24	7.22	1.46	1.4
30.11.81	P-25	7.22	1.47	0.8
30.11.81	P-28	7.51	1.62	5.0
30.11.81	P-29	7.39	1.85	0.7
30.11.81	P-30	7.23	1.38	2.4
30.11.81	P-32	6.92	1.39	1.0
30.11.81	P-33	7.23	1.66	3.6
30.11.81	Stream opp PG 30	7.35	1.67	-

Table 2(b)
Date	Sample	pH	Alkalinity (meq/)	Iron (mg/)
1.12.81	P-1 (North end)	7.53	1.12
1.12.81	P-1 (South end)	≃7.5	1.15
1.12.81	P-10	7.02	1.54	1.6
1.12.81	P-23	6.90	0.83	(0.5)
1.12.81	P-25	7.20	1.74	0.5
1.12.81	P-28	7.12	1.51	1.4
1.12.81	P-29	7.51	1.78	0.8
1.12.81	Stream	7.42	1.70	0.4
2.12.81	P-1 (AM)	7.45	1.15	1.1
2.12.81	P-3 (AM)	7.43	1.56	0.6
2.12.81	P-10 (AM)	7.47	1.57	0.9
2.12.81	P-18 (AM)	7.48	1.68	0.5
2.12.81	P-20 (PM)	7.40	1.71	-
2.12.81	P-21 (PM)	7.58	1.52	-
2.12.81	P-23 (AM)	6.73	0.62	-
2.12.81	P-23 (PM)(bubbled)	7.08	0.69	-
2.12.81	P-23 (PM)(bubbled)	7.88	0.72	-
2.12.81	P-24 (AM)	7.40	1.64	0.9
2.12.81	P-25 (AM)	7.28	1.62	0.6
2.12.81	P-28 (PM)	7.36	1.65	-
2.12.81	P-29 (PM)	7.50	1.72	-
2.12.81	P-32 (PM)	7.46	1.58	-
2.12.81	P-33 (AM)	7.34	1.66	0.7
2.12.81	P-33 (PM)	7.42	1.70	-
5.12.81	P-3	7.51	1.59	0.6
5.12.81	P-10	7.39	1.57	0.6
5.12.81	P-11	7.20	1.65	2.4
5.12.81	P-14	7.42	1.71	0.4
5.12.81	P-14	7.36	1.70	0.8
5.12.81	P-15	7.10	1.52	0.7
5.12.81	P-16	6.74	1.40	4.6
5.12.81	P-21	6.56	1.34	5.1
5.12.81	P-28	7.02	1.53	1.1
5.12.81	P-30	6.55	1.18	-
5.12.81	P-30	7.33	1.44	-
5.12.81	Stream	7.50	1.60	0.5
5.12.81	Stream	7.50	1.74	-

Table 2(c)
Date	Sample	pH	Alkalinity (meq/)	Iron (mg/)
6.12.81	P-1	7.70	1.15	0.3
6.12.81	P-7	7.20	1.16	1.9
6.12.81	P-18	7.39	1.56	0.8
6.12.81	P-19	7.49	1.60	0.2
6.12.81	P-23	6.82	0.67	2.0
6.12.81	P-23	-	0.43	0.8
6.12.81	P-23 (bubbled)	7.58	0.68	0.7
6.12.81	P-23 (bubbled)	7.83	0.69	0.6
6.12.81	P-24	7.35	1.43	7.2
6.12.81	P-25	7.23	1.35	0.2
6.12.81	P-29	7.62	1.54	1.0
6.12.81	P-29	7.58	1.58	1.0
6.12.81	P-29 (bubbled)	8.12	1.56	-
6.12.81	P-32	7.01	1.39	0.3
6.12.81	P-33	7.46	1.60	2.0
6.12.81	Stream	7.46	1.63	-

Table 3
SUMMARY OF GELANG PATAH POND WATER NUTRIENT, SULFIDE AND MANGANESE MEASUREMENTS - NOVEMBER, DECEMBER 1981
Chemical Species	Concentration
NH₄	P-10	24 μM
	P-23	49 μM
	P-25	31 μM
	P-28	15 μM
	P-29	11 μM
	Stream	14 μM
NO^-₂	Several ponds	<0.1 μM
PO₄	Several ponds	<0.3 μM
HS^-	Several ponds	<0.01 μM
Mn	Several ponds	<0.05 ppm

Rust colored flocculant precipitate in Pond 23 (0.15 gm from 50 m volume): 63% Fe, by weight.

Table 4
SEDIMENTINTERSTITIAL WATER COMPOSITION - POND 29 - CENTER

	Cell No.*	Fe⁺², ⁺³ (ppm)	HS^- (μM)	SO₄⁼ (ppm)	NH₄⁺ (μM)	PO₄³ (μM)

	1	1.2		1300	25	<1
	2		<6
	3	1.1		1400	-	<1
H₂O	4		6
Sed	5	5.3		1100	66	<1
	6		<6
O₂	7	13		1200	-	<1
No O₂	8		<6
	9	40		1200	-	<1
	10		6
	11	38		1200	41	<1
	12		117
	13	2.3		1300	-	<1
	14		117
	15	9.3		1300	147	<1
	16		31
	17	1.4		1000	140	<1
	18		55
	19	3.2		900	487	<1

* Cells were located at approximately 1 cm intervals, with the first four above the sediment-water interface.

Table 5 SEDIMENT INTERSTITIAL WATER COMPOSITION - POND 29 - MARGIN
	Cell No.*	Fe⁺², ⁺³ (ppm)	HS^- (μM)	SO₄⁼ (ppm)	NH₄⁺ (μM)
	1	1		2000	16
	2
H₂O	3	2		2200	82
Sed	4		<6
	5	5		2000	31
	6		<6
	7	6		1900	38
	8		<6
	9	7		1900	62
	10		<6
	11	7		-	82
	12		<6
	13	7		1900	78
	14		<6
	15	29		1900	88
	16		<6
	17	11		1800	140
	18		<6
	19	14		1900	160
	20		≃6
	21	12		1900	160
	22		≃6
	23	13		1900	150
	24		<6
	25	<1		1900
	26		<6
	27	<1
	28		<6

* Cells were located at approximately 1 cm intervals, with the first three above the sediment-water interface.

Table 6
AIR BUBBLING EXPERIMENTS GATE I, POND 23 (2.12.81)
Time (h)	Control			Bubbled
Time (h)	Fe (ppm)	pH	Alkalinity (meq/)	Fe (ppm)	pH	Alakalinity (meq/)
0	-	-	-	4.9	6.81	0.67
0	-	-	-	2.6(F)	-	-
2	4.3	-	-	3.0	-	-
2	2.6(F)*	-	-	0.7(F)	-	-
4.3	5.6	6.80	-	3.0	7.80	0.68
4.3	1.6(F)	-	-	0.7(F)	-	-
Pump off overnight
0	3.4	6.85	-	1.5	7.35	-
0	1.5(F)	-	-	0.4(F)	-	-
2	3.3	6.96	-	3.1	7.79	0.69
2	0.5(F)	-	-	0.3(F)	-	-
II Stream Water (3.12.81)
0	0.5	6.95	-	0.5	6.96	≃1.6
0	0.1(F)	-	-	0.1(F)	-	-
0.5	-	7.10	-	-	8.21	-
1	-	7.13	-	-	8.25	-
2	0.3	7.14	-	0.3	8.26	-
2	0.0(F)	-	-	0.2(F)	-	-
2.5	0.2	7.20	-	0.5	8.26	≃1.6
2.5	0.1(F)	-	-	0.3(F)	-	-
III Pond 29 (6.12.81)
0	1.1	7.49	-	0.8	7.49	1.58
0	0.1(F)	-	-	0.2(F)	-	-
0.6	1.1	7.51	-	0.7	8.11	-
0.6	0.1(F)	-	-	0.1(F)	-	-
2.5	0.8	7.55	-	0.6	8.12	-
2.5	0.1(F)	-	-	0.1(F)	-	-
3	0.8	7.59	-	0.6	8.18	1.56
3	0.2(F)	-	-	0.1	-	-

* Sample filtered before analysis for iron.

Table 7
CARBON DIOXIDE PARTIAL PRESSURE CALCULATIONS

[H⁺] × [HCO₃-] = [H₂CO₃] × K₁
[H₂CO₃] = pCO₂ × K_{CO 2}
pCO₂ = [H⁺] × [HCO₃^-]/K₁ × K_CO₂

at S = 25‰ (Chlorinity = 13.8‰)

T = 25°C

K₁ = 10^-6.052 moles/liter

K_CO₂ = 3.12 × 10^-2 moles/liter-atmosphere

Bubbling Experiment	Water Source	Alkalinity (meq/)	pH	pCO₂ (x10^-6 atm)
I-Begin	Pond 23	0.67	6.81	3700
I-End	Pond 23	0.69	7.79	400
II-Begin	Stream	≃1.6	7.0-7.5	1800-5800
II-End	Stream	≃1.6	8.26	320
III-Begin	Pond 29	1.58	7.49	1800
III-End	Pond 29	1.56	8.18	370

Table 8
SOIL AND SEDIMENT POTENTIAL ACIDITY AFTER H₂ O₂ OXIDATION VS. pH*
(PLOTTED AS “×'s” in FIGURE 6)
Sample	meq/100g	Initial pH
T-1	(10)†	3.29
M-2a	10	3.22
M-3a	20	3.75
T-1 + 4.76% FeS₂	70	2.00
M-4¹	105	2.24
M-3a + 4.76% FeS₂	139	1.82
M-4¹ + 4.76% FeS₂	156	1.89
T-1 + 9.09% FeS₂	164	1.68
M-2a + 4.76% FeS₂	167	1.70
M-3a + 9.09% FeS₂	237	1.57
M-2a + 9.09% FeS₂	255	1.49

* Sample weights of 0.5g were oxidized with 20 m of 30% H₂O₂, transferred to centrifuge tubes with a final liquid volume of ≃25 m: a subsample of 10 m of clear solution was titrated to pH 7 within a few hours.

† All other samples of T-1 which were analyzed previously had potential acidities of <1 meq/100g.

Table 9
PEROXIDE OXIDATION EXPERIMENTS
Sample	Sample weight (g)	Final Solution volume (m)	pH	Acidity (pH 7) (meq/100g)
M-2a*	5	40	3.02	10
M-2a*	1	26.2	3.13	9.6
M-2a*	0.5	24.9	3.22	10
M-2b*	5	40	2.82	8.6
M-2b*	5	22.4	2.35	14
M-2c*	5	40	2.85	9.0
M-2c*	1	25.9	3.13	9.5
M-3a+	5	40	3.89	6.2
M-3a+	1	38.3	3.92	18
M-3a+	0.5	25.4	3.75	20
M-3b+	1	37.2	3.79	17
M-3c+	5	40	3.83	7
M-3c+	1	24.6	3.89	16
M-3e§	5	40	4.48	4.6
M-4†	5	40	2.23	30
M-4†	1	21.6	2.08	151
M-4†	0.5	31.4	2.51	136
M-4†	0.5	20.4	2.24	105
T-1Δ	5	40	4.99	0
T-1Δ	1	18.1	5.40	0.4
T-1Δ	0.5	28.2	3.29	10
T-2	5	40	6.71	0
T-2	1	19.6	6.10	0.3
T-2	1	28.4	6.60	0.1

* Replicate soil samples from a large sample collected on the south dike of Pond 29.
⁺ Replicate sediment samples from a large sample collected near the south end of Pond 29.
§ Sample source as for other M-3 samples, but only particles >400 microns in size included.
† Dike soil from a new private pond facility in southeastern Johore State.
Δ Dike soil from a government aquaculture research station in Thailand.
Dike soil from a traditional aquaculture pond in Thailand.

Table 10
PYRITE ADDITION EXPERIMENTS*
(PEROXIDE OXIDATION)
Sample	Initial Acidity (meq/100g)	Final Acidity (meq/100g)	Δ (meq/100g) measured	Δ (meq/100g) theoretical†	Δ measured theoretical
T-1+4.76% FeS₂	10	70	60	159	.38
T-1+9.09% FeS₂	10	164	154	303	.51
M-2a+4.76% FeS₂	10	167	157	159	.99
M-2a+9.09% FeS₂	10	255	245	303	.81
M-3a+4.76% FeS₂	20	139	119	159	.75
M-3a+9.09% FeS₂	20	237	217	303	.72
M-4'+4.76% FeS₂	105	156	51	159	.32

* Samples (0.5g dry weight) were oxidized in 30% H₂O₂ (20m), with heating to destroy residual H₂O₂ and titrated with NaOH (0.1N) to pH 7. Known amounts of FeS₂ powder were added to duplicates of samples T-1, M-2a, M-3a and M-4' and then carried through the same procedure.

† Maximum theoretical production of acidity was assumed to be 4 meq of H⁺ for each mM of FeS₂.

Table 11
COMPUTED POTENTIAL ACIDITY AS A FUNCTION OF END POINT pH*
Sample	Titration Volume (m) pH 7	Titration volume (m) pH 8	Titration volume (m) pH 8.5
T-1	0.02	-	0.034	-
T-2	0.004	0.02	0.05	-
M-2c	0.366	-	0.521	1.42
M-2a	0.368	-	0.519	1.60
M-4	2.17	2.67	2.87	1.32
M-3a	0.474	0.647	0.863	1.82
M-3b	0.452	0.612	0.771	1.71
M-3c	0.651	0.895	>1.0	>1.54

* Base (0.1 N NaOH) was added from a microburet to a sample volume of 10 m.

Table 12
GELANG PATAH - POND 29
(WEIGHT PERCENTAGES - XRF)
Element	Dike Soil			Pond Sediment
Element	M-2a*	M-2b*	M-2c*	M-3a†	M-3b†	M-3c†	M-3d†
Si	34	35	34	29	28	27	27
Al	11.3	12.2	11.9	10.2	10.0	9.2	9.9
Fe	3.1	3.0	3.1	5.0	4.6	4.6	4.2
Mg	0.2	0.2	0.2	0.3	0.4	0.3	0.4
Ca	<0.05	<0.05	<0.05	0.23	0.30	0.27	0.16
Na	0.1	0.1	0.08	≃4	≃7	≃9	≃7
K	1.5	1.3	1.4	1.4	1.2	1.2	1.0
P	0.01	0.01	0.01	0.02	0.02	0.02	0.02
Mn	-	0.03	0.02	-	0.02	0.02	0.02
S	1.00	1.03	1.00	1.20	1.38	1.31	1.02
∑	51.3	53.0	51.8	51.3	48.3	52.9	50.7
Organic matter Δ	5.1	5.4	5.5	6.5	5.9	5.7	5.5

* Replicate dike soil samples from a large sample from on site.
† Replicate sediment samples from a large sample from one site.
Δ Organic matter measured by oxidation overnight at 375°C after drying at 130°C.

Table 13
OTHER AQUACULTURE SYSTEM DIKE SOILS
(WEIGHT PERCENTAGES - XRF)
Santee Estates Dike Soil	Thailand Dike Soil
Johore, Malaysia

Element	M-4*	M-4'*	T-1†	T-lc§	T-2+
Si	24	24	11	7	29
Al	7.7	8.2	2.6	1.8	8.4
Fe	3.7	3.3	≃7	5.6	8.2
Mg	0.8	0.7	0.4	0.2	2.5
Ca	0.82	0.81	0.15	0.12	0.96
Na	0.7	0.8	≃40	>30	0.3
K	1.6	1.3	1.0	0.5	1.8
P	0.04	0.04	0.05	0.04	0.08
Mn	-	0.03	0.3	0.2	0.3
S	4.06	4.10	0.5	0.8	1.8
Organic MatterΔ	32.7	31.8	4.8	-	5.2

* Replicate dike soil samples from one site.
† Aquaculture station soil particles ground to fine powder.
§ Aquaculture station soil particles <400 μ.
⁺ Dike soil from traditional aquaculture farm near aquaculture research station.
Δ Organic matter measured by oxidation overnight at 375° C after drying at 130°C.

Table 14
GELANG PATAH - MISCELLANEOUS SAMPLES
(WEIGHT PERCENTAGES - XRF)
Element	Resinous Yellow dike materials		Red dike materials	Pond water hydroxide precipitate	Ash from Johore brick kilns
Element	M-1	M-6	M-7	M-8	M5a	M5b
Si	2	0.7	6	0.5	11	9
Al	0.7	0.2	3.8	0.03	2.7	4
Fe	0.6	0.6	28	0.1	1.5	1.2
Mg	<0.1	<0.1	<0.1	14	6	5.7
Ca	0.04	<0.05	0.07	0.5	19	19
Na	0.03	0.02	0.03	27	0.03	0.04
K	0.1	0.06	0.1	0.07	3.7	5.6
P	0.005	0.005	0.01	0.005	1.2	1.2
Mn	0.2	0.3	<.01	0.01	0.1	0.1
S	0.6	0.3	0.9	≃4	3.1	5.2
∑	4.4	2.2	39	46	49	51

Table 15
EXCESS ACIDITY, SULPHUR AND IRON IN SOILS AND SEDIMENTS
	Potential Excess Acidity (meq/100g)	Equivalent* FeS₂ (wt %)	ΣS by XRF (wt %)	ΣFe by XRF (wt %)
M-2†	10	0.30	1.0	3.0
M-3§	20	0.61	1.3	4.6
M-4Δ	130	3.9	4.1	3.5
T-1	0.4	0.01	0.5	7
T-2⁺	0.2	<0.01	1.8	8

* Assuming 4 meq H⁺ for each mM FeS₂ = 33 meq H⁺/100g of sample.
† Gelang Patah dike soil (P-29).
§ Gelang Patah sediment (P-29).
Δ Santee Estates dike soil.
Thailand aquaculture research station dike soil.
⁺Thailand traditional aquaculture dike soil.

Table 16
LEACHING EXPERIMENTS*
Sample	pH	Alkalinity (meq/)
Distilled H₂O leach of P-29 dike soil - First	3.64	-6.2
Distilled H₂O leach of P-29 dike soil - Second	3.98	-2.5
Distilled H₂O leach of P-29 dike soil - First & Second†	3.90	-3.9
Distilled H₂O leach of P-29 dike soil - large particles	3.93	-3.4
Stream H₂O leach of P-29 sediment	4.78	+0.1
Distilled H₂O leach of Ash	9.23	+1.7
Distilled H₂O leach of Ash mixed with distilled H₂O leach P-29 dike soil - large particles	4.78	-1.4
Distilled H₂O leach of Ash, followed by leach of P-29 dike soil (two step leach experiment)	4.02	-10.6
Stream H₂O stored with P-31 dike soil for 1 week	4.36	-0.1

* All experiments involved equal weights of solids and liquids.
† 1254 ml of H₂O were added to 1254g of dry soil yielding 465m of leach-first; then 1489 ml of H₂O were added to the same wet soil yielding 660 ml of leach-second; the two leach H₂O's were pooled after 50 ml of each portion was withdrawn to measure alkalinity.

Table 17
OTHER WATER SAMPLE ALKALINITIES
Date	Sample	pH	Alkalinity (meq/)
12/7/81	Puddle in laterite following rain shower	4.46	+0.1
12/7/81	Puddle on dike near P-30,31 following rain shower	2.87	-11.8
12/7/81	Runoff from dike following rain shower	2.74	-15.3
12/7/81	P-20 following rain shower, prior to stocking with shrimp	7.30	+1.30
12/8/81	Pond filled for 6 months at Sante Estates*	5.12	0.01
12/8/81	Pond A filled for 1 week at Sante Estates*	6.88	0.83
12/8/81	Pond B filled for 1 week at Sante Estates*	7.06	0.74

* Samples collected from brackish water ponds (=25‰) at new private aquaculture project in southeastern Johore State.

Table 18
ALKALINITY (meq/^-1) and pH of INCUBATED POND WATER/SOIL LEACHATE MIXTURES
Day	Leachate strength	Water only alkalinity	pH	Water over sediment alkalinity	Sediment pH
	0	1.83	7.50	1.83	7.50
0	20	0.92	6.55	0.92	6.55
	50	0.03	4.77	0.03	4.77
	100	-3.91	3.90	-3.91	3.90
	0	2.10	8.29	0.49	6.70
3	20	0.87	7.42	0.22	6.40
	50	0.16	4.70	0.25	6.20
	100	-0.13	4.03	0.07	4.66
	0	-1.44	3.21	0.42	6.64
8	20	0.63	7.39	0.19	5.08
	50	-0.01	4.69	0.21	5.59
	100	-0.02	3.88	0.06	9.17

Table 19

ESTIMATES OF TOTAL POTENTIAL ACIDITY IN DIKES OF GELANG PATAH AQUACULTURE SYSTEM

Area = 10 ha = 10⁵m²

Soil Depth = 1 m (assumed thickness which can react with the water).

∑ Volume = 10⁵ m³
∑ Mass = 10⁵ t (assumed density = 1g/lm)
If potential acidity = 10 meq/100g
then total moles of acid available = 10 ⁷

If potential acidity = 100 meq/100g
then total moles of acid available = 10⁸
Use same ∑ mass as above,
assume 1% by weight pyrite
then total pyrite present = 10³t

If 4 moles of H⁺ produced per mole of pyrite
then total moles of acid available = 3 × 10⁷

Total Acid Potential: 10⁷ – 10⁸ moles

Table 20

ESTIMATES OF RATES OF REMOVAL OF ACIDITY AT GELANG PATAH AQUACULTURE SYSTEM

Exchange of Pond Water by Present Practices

10 ha × (10²m) ²/ha × 1 m/4 days = ≃ 2 × 10⁴ m³/day If 20% of alkalinity in water is removed (1.6 meq/→1.3 meq/)
Leaching of Dike Soils by Precipitation
III. Maximum Leaching of Dike Soils by Filling Entire System with Stream Water-Acidity from leaching experiments (-6 meq/ of alkalinity) ≃ 20 × as effective per unit volume of water as present pond water exchange.

If filled to 2 meters depth (8 × daily exchange depth) 20 × 8 = 160 160 × 6 × 10³ moles of acid = 10⁶ moles of acid per fill
1 ton of Limestone = 2 × 10⁴ moles of alkalinity
1 ton of Magnesium Limestone = 2.2 × 10⁴ moles of alkalinity
1 ton of Ash = 2 moles of alkalinity

Figure 1
Gelang Patah Pond Layout

Figure 2
Gelang Palah Water Alkalinities

Figure 3
Gelang Palah Water Iron Concentrations (Total)

Figure 4
Sediment Interstitial Water Pond 29-Center

Figure 5
Sediment Interstitial Water Pond 29-Margin

Figure 6
Potential Acidity vs. pH

Figure 7
GELANG PATAH WATER-SEDIMENT INCUBATION EXPERIMENTS