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Adsorption of beryllium on peat and coals
Adsorption of beryllium on peat and coals CR. ESKENAZY
The adsorption and desorption of ionic beryllium has been investigated for seven samples (mainly peat and coal macerals), as a function of solution concentration and pH. High pH favours the adsorption of beryllium, which appears to be chemisorbed on acidic groups.
BERYLLIUMis one of the trace elements its distribution ciently studied.
constantly present in coals1-7, but and especially its mode of attachment have not been suffiIt has been assumed that absorption by the plant precursots,
and the formation of complexes are responsible for the presence of beryllium in coal17 3. This problem can be partly elucidated by studying the adsorption of beryllium on natural organic adsorbents under laboratory conditions, and in this paper we present the results of such investigations.
EXPERIMENTAL peat, two kinds of vitrinite
(Telenite I and II) and ulminite, xylite, semifusinite, and ‘vitrainized wood’ fragments. The samples were ground, passed through a 0.25 mm sieve and air-dried. Table I shows their properties. The adsorption tests were carried out in a weak hydrochloric acid solution of beryllium. Kakihana and Sillen* report that in such a solution beryllium is present in the form of Bes+,[BeaOH]a+ and [Bea(OH)a]a+. The ratio of these ions varies depending on the pH and the Beryllium concentration of the solution*. The quantity of beryllium adsorbed was determined by the difference in its concentration in the solution before and after the experiment. The methods used were a calorimetric method with beryllon (II), or for higher concentrations, the complexon phosphate methods. The functional groups were assayed by treating the adsorbents with barium hydroxide, the excess being titrated with hydrochloric acid. The specific surface was determined by the method of Kljacko-GureviBlO. Seven samples
were studied;
The following experiments were carried out: (1) Adsorption of beryllium under static conditions on the adsorbents (0.59) from solutions (50 ml) with pH 5 to 5.5 for 7 days. The adsorbent was then filtered and washed with distilled water (until the volume of filtrate was 200 ml). The beryllium content in this solution was determined. (2) Desorption with water. After washing, the adsorbent was refluxed with 100 ml of water for 1 h. The quantity of beryllium desorbed was estimated in the filtrate. 61
Origin
9.2 4.0 2.8 3.1 1.9 8.5 26.1
;:;
;:; 6.1
9.1
Ash
9.5
Moisture
63.7
63.4 68.1 71.6
67.5 68.3
60.9
C
3.6
4.2 6.2 6.2
4.6 6.1
5.1
H
-
0.8 1.7 0.6
0.9 1.5
N
-
4.5 1.6 5.6
2.9 i-3
S
Contents (% d.a.jI)
-
28.0 21.5 15.4
23.5 il.3
0
of the adsorbents
4.47:
2.34 2.15 2.02
2.64
33%
6.87
2.58 2.33 2.36
2.93 3.80
3-75
(OH + COOH) mg equiy/g mg equiv/g (d.a.f.)
used
-
1.36 1.54 1.455
T.33 1.47
Specific
gravity
4.5
2.3 7.0
li.8
i::+
Specific surface (m2/g)
a*
1.26 58.0 4.21 0.49 3.54 0.47
hglm2)
* a = a/s where a = adsorption (mg) from Table 2) and s is the specific surface t The specific surface of this sample was smaller than the sensitivity of the method used $ These results are not to be compared with the results for the other adsorbents because OH + COOH were determined after preliminary HCI treatment of the sample. A direct determination in this sample was impossible because Ba(OH)2 was consumed for the precipitation of iron extracted from the sample.
Transylvania peat Telinite IL Maritza, Bulg. Ulminate Maritza, Bulg. Xylire Maritza, Bulg. Telinite I Maritza, Bulg. Semifusinite Maritza Bulg. ‘Vitrainized wood’ Rodopa, Bulg. fragments
Sample
Table I. Characteristics
ADSORPTION OF BERYLLIUM ON PEAT AND COALS
(3) Desorption with 100 ml of 5% solution of tartaric acid under static conditions followed the desorption with water. (4) Alternatively, desorption of two of the samples with 1N HCl and two of the samples with HCl (pH 1.4) under static conditions was used after the water desorption. The results from the adsorption and desorption experiments are given in Table 2 and Fig 1. (5) The relation between the adsorption of beryllium on peat under static conditions and the pH of the solutions was studied (Fig 2).
Beryllium Fig I
linitial)lmgequiv/~Omll
Adsorption isotherms of beryllium at pH 5-5.5, 1 peat;
2 Telinite I; 3 Ulminite;
4 Xylite;
5 Telinite II; 6 Semifusinite
DISCUSSION
The possibility of adsorbing beryllium on peat and various types of coal under laboratory conditions permits its classification as a huminophilic element. The adsorption isotherms of the various adsorbents proved to be similar (Fig I). The adsorptive capacity of peat, vitrinite and xylite was almost the same, provided that the initial beryllium concentration of the solution was not greater than 0.22 mg equiv. Further increase of the initial concentration of beryllium in the solution led to considerable differences in the quantity adsorbed. Peat adsorbed beryllium most (2.09 mg equiv/g). The same value was found for UOaa+ (II) and a higher value for Gas+ (1.79 mg equiv)ra. 63
GR. ESKENAZY
Table 2 Adsorption
Sample
Peat
Telinite I
Ulminite
Xylite
Telinite II
Semifusinite
Initisl concn of Be”+ (mg/50 ml)
and desorption experiments
Equilib. concn of Be2+
Adsorption of Be2 + at pH 5-5.5
Desorption with water
Desorption with tartaric acid
(mg/50 ml)
(% of initial total)
(% of total adsorbed)
(% of total abdorbed)
1.0
0.01
2.0 3.0 5.0 10.0 0.5 1.0 2.0 5.0 10.0 0.5 1.0 5.0 IO.0 0.3 0.5 1.0 5.0 10.0 0.3 0.5 1.0 2.0 5.0 10.0 0.3 0.5 1.0 2.0 5.0 IO.0
0.05 0.12 0.72 5.28 0.01 0.03 0.45 1.67 5.93 0.01 0.04 2.00 6.63 0.03 0.06 0.20 3.11 7.20 0.02 0.03 0.08 0.55 1.93 7.13 0.20 0.30 0.50 1.13 340 8.37
98.8 97.7 96.0 85.6 47.2 98.2 97.1 77.6 66.6 40.7 97.2 96.0 6090 33.7 90.7 87.9 80.4 37.7 _
1.4 1.5 0.9 0.9 0.8 -
58.5 69.8 75.6 79.4 81.7 62.1 70.3 -
-
50.8 46.9 74.8 -
93.3 93.2 92.4 72.4 61.4 28.7 34.0 39,4 51.0 43.6 32.2 16.3
1.4 1.4 1.6 0.3 _
_ 0.65 0.54 0.06 0.15 7.3 8.1 7.6 3.7 0.7 2.3
25.5 41.5 51.4 67.5 80.7 44.6 _ 64,l 66.1 66.3 70.1 27.0 20.4 80.4 88.3 78.4 61.6 54.3 26.9
The samples had not been previously treated with water or hydrochloric acid to wash away any adsorbed ions which would cause to an increase in adsorptive capacity under laboratory conditions: therefore only such a quantity was adsorbed as would have been taken up under natural conditions if the solutions had contained a sufficient concentration of beryllium. Adsorption
of beryllium as a function
of the pH of the solutions
The adsorption of beryllium depends in general on the pH of the solutions; the same is true for all the other cations studied: Gas+, Ge4+, Zn2+ Ra2+, UOss+, Fesf. The adsorptive capacity increased with increasing pH from 2 to 6-7ts-‘6. Nevertheless the behaviour of the various cations showed certain 64
ADSORPTION
OF BERYLLIUM
ON PEAT AND COALS -~
differences. The adsorption of Ga3+ increased abruptly even at pH 2, in contradistinction to the smoother adsorption of Bea+ on the same adsorbent. The relation between the degree of adsorption and the pH can be elucidated by a comparison with the synthetic cation exchange resins. The adsorptive capacity of weakly acid and polyfunctional ion-exchange resins depends on
Fig 2 Adsorption
of beryllium on peat as a function of pH:
1, Adsorption capacity of different cation-exchange resins as a function of pH (Trostjanskajals); 2, SOsH; 3, COOH; 4, SOsH and OH ti
PH
the pH of the solutions. Cation-exchangers containing sulphonic acid groups ionize strongly in contact with acid, neutral or basic solutions, so that their capacity is almost independent of pH 171rs. The curves of the ion-exchangers studied by Trostjanskaja were compared with the adsorption curves of beryllium (Fig 2). It is evident that the variations in the adsorptive capacity of peat are quite similar to those of synthetic adsorbents containing carboxyl groups. The differences at pH 7 are due to the solubility of humic acids; the ion-exchange resins are stable under the same conditions. The relation between adsorptive capacity and pH for peat resembles that of polyfunctional synthetic ion-exchangers: a clear dependence changing smoothly with pH17. The pH dependence indicates that the cation-adsorption process in coals is connected with the dissociation of their functional groups and is determined by the binding of beryllium to these. Probably adsorption mechanism It may be supposed that the binding of beryllium results from specific
adsorption processes, which lead to the formation of chemical compounds of various stabilities. The mechanisms of such processes are very difficult to study owing to the complex chemical composition and structure of peat and coal adsorbents. The presence of functional groups, chiefly OH and COOH, makes possible ion-exchange reactions, which probably represent the first stage of adsorption. There is no definite relation between the functional group content and the absolute adsorption (u) of the various adsorbents. A qualitative comparison of the adsorbents used according to the functional groups and a (Table 1) gives the following series: According to OH and COOH: telinite II>peat>ulminite>telinite >xylite > semifusinite According to a: telinite II>ulminite>telinite 65 F-E
I
I>peat>xylite>semifusinite
__
~__
~____
GR.
ESKENAZY
It is evident that decrease of the functional groups brings about a reduction of beryllium adsorbed per unit surface area. Peat is the only exception. The fact that the adsorption is of a chemical nature is proved also by its irreversibility: on lowering the beryllium content in the solution at equilibrium (water treatment at high temperatures) only an insignificant quantity is desorbed. A higher percentage of desorption occurs for semifusinite, which has the lowest adsorptive capacity. When tartaric and hydrochloric acids are used as desorption agents, the percentage of desorption is much higher, because ionic-bound beryllium is probably desorbed. That part of the beryllium that is not extracted by tartaric and hydrochloric acid is probably attached to the organic matter by coordinate or covalent links. The genesis of the coals is also of major importance for their adsorption properties. Xylite and vitrinite are formed during a brief or long gelation of the lignin-cellulose tissues. Gelation favours the adsorption processes particularly. Semi-fusinite is partly oxidized lignin-cellulose tissue, which may explain its lower adsorption activity. Most interesting is the fact that the sample of vitrinized wood does not adsorb beryllium at all. The filtrate of this sample contains a large quantity of iron. It is likely that beryllium, because it is bivalent, cannot compete with Fea+. According to the empirical rule of Kunin for the ion-exchange resins at low concentrations and ordinary temperatures, the extent of exchange increases with increasing valency of the exchanging ionlg. In fact, an insignificant1 quantity of Gas+ (0.12 mgequiv/g) is adsorbed on the same sample. To check whether Fe3+ had really blocked all the ion exchanging sites, part of this samples was treated with hydrochloric acid (1 :l) till the reaction for Fd+ was negative. The sample thus prepared was tested for beryllium adsorption under the same conditions as for the other adsorbents. Beryllium was not adsorbed though the OH and COOH concentrations were high after hydrochloric acid treatment (Table I). Thus the above explanation does not account for the anomalous adsorption properties of this sample. In general the experiments lead to the conclusion that solutions with pH from 3 to 7 containing beryllium permit its irreversible binding on peat and various types of coal. Geochemistry Department University of Sofia, Bulgaria
(Received
23 April 1969)
REFERENCES 1 Sianduicheuko, T., Zubovic, P. and Sheffey, N. Geol. Survey Bulletin, 1961, 1084-K 2 Jedwab, J. Bull. Sot. Belge Geol., Paleontol. et Hydrol. 1960, 69, 1 3 MachaCek, V., Sulcek, Z. and Vacl, J. Vestn. Ustred. ustavu geol. 1962, 37, 4 4 MinEev, D. and Gr. Eskenazy Ann. Univ. of Sofa, Geol. and Geogr.
66
1965, 58, 1
ADSORPTION OF BERYLLIUM ON PEAT AND COALS _______~ 5 Minkev,
D. and Gr. Eskenazy Ann. Univ. of Sofia, Geol. and Geogr. 1966, 59, 1
6 Goldschmidt, V. M., Peters C. Nach. Ges. Wiss. Giittingen Math. Phys. Kl., 1932
7 Beus, A. A. ‘Geochemistry Moscow, 1960
of beryllium and genetic types of beryllium deposits’
8 Kakihana, H. and Sillen, L. G. Acta ChemI &and. 1956, p. 10 9 Knipovik, J. N. and Mora^cevsky, J. W. Analysis mineralnovo sirie Leningrad, 1959 10 Kljacko-Gurewic, A. L. Izvest. Acad. of Science USSR (Chim) 1961, p 10 11 Szalay, A. Geochim. et Cosmochim. Acta, 1964, 28, 10 12 Eskenazy Gr. Fuel Lond. 1967,56, 187 13 Sterbak, 0. W. Min. sirie, WZMS 1962, p 6 14 Roskova, E. W. and Sterbak, 0. W., Saakjan, W. M. Min. sirie, WIMS
1962,
~6 15 Titaeva, N. A. Geochemistry 1967, p. 12
16 Kovalev, B. A. and Bensman, W. R. DokE. Akad. Nauk. Bel. SSR 1967, 11, 9 17 Griessbacb, R. ‘Austauschadsorption
in Theorie und Praxis’, Berlin, 1967
18 Trostjanskaja, E. B. ‘Cation exchange synthetic resins’, Trudi Comm. Analyticheskoi Chimie, Moscow, 1955, Vol. 6 19 Kunin R. and Myers R. J. ‘Ion exchange resins’, New York, 1950
67 E’
The adsorption and desorption of ionic beryllium has been investigated for seven samples (mainly peat and coal macerals), as a function of solution concentration and pH. High pH favours the adsorption of beryllium, which appears to be chemisorbed on acidic groups.
BERYLLIUMis one of the trace elements its distribution ciently studied.
constantly present in coals1-7, but and especially its mode of attachment have not been suffiIt has been assumed that absorption by the plant precursots,
and the formation of complexes are responsible for the presence of beryllium in coal17 3. This problem can be partly elucidated by studying the adsorption of beryllium on natural organic adsorbents under laboratory conditions, and in this paper we present the results of such investigations.
EXPERIMENTAL peat, two kinds of vitrinite
(Telenite I and II) and ulminite, xylite, semifusinite, and ‘vitrainized wood’ fragments. The samples were ground, passed through a 0.25 mm sieve and air-dried. Table I shows their properties. The adsorption tests were carried out in a weak hydrochloric acid solution of beryllium. Kakihana and Sillen* report that in such a solution beryllium is present in the form of Bes+,[BeaOH]a+ and [Bea(OH)a]a+. The ratio of these ions varies depending on the pH and the Beryllium concentration of the solution*. The quantity of beryllium adsorbed was determined by the difference in its concentration in the solution before and after the experiment. The methods used were a calorimetric method with beryllon (II), or for higher concentrations, the complexon phosphate methods. The functional groups were assayed by treating the adsorbents with barium hydroxide, the excess being titrated with hydrochloric acid. The specific surface was determined by the method of Kljacko-GureviBlO. Seven samples
were studied;
The following experiments were carried out: (1) Adsorption of beryllium under static conditions on the adsorbents (0.59) from solutions (50 ml) with pH 5 to 5.5 for 7 days. The adsorbent was then filtered and washed with distilled water (until the volume of filtrate was 200 ml). The beryllium content in this solution was determined. (2) Desorption with water. After washing, the adsorbent was refluxed with 100 ml of water for 1 h. The quantity of beryllium desorbed was estimated in the filtrate. 61
Origin
9.2 4.0 2.8 3.1 1.9 8.5 26.1
;:;
;:; 6.1
9.1
Ash
9.5
Moisture
63.7
63.4 68.1 71.6
67.5 68.3
60.9
C
3.6
4.2 6.2 6.2
4.6 6.1
5.1
H
-
0.8 1.7 0.6
0.9 1.5
N
-
4.5 1.6 5.6
2.9 i-3
S
Contents (% d.a.jI)
-
28.0 21.5 15.4
23.5 il.3
0
of the adsorbents
4.47:
2.34 2.15 2.02
2.64
33%
6.87
2.58 2.33 2.36
2.93 3.80
3-75
(OH + COOH) mg equiy/g mg equiv/g (d.a.f.)
used
-
1.36 1.54 1.455
T.33 1.47
Specific
gravity
4.5
2.3 7.0
li.8
i::+
Specific surface (m2/g)
a*
1.26 58.0 4.21 0.49 3.54 0.47
hglm2)
* a = a/s where a = adsorption (mg) from Table 2) and s is the specific surface t The specific surface of this sample was smaller than the sensitivity of the method used $ These results are not to be compared with the results for the other adsorbents because OH + COOH were determined after preliminary HCI treatment of the sample. A direct determination in this sample was impossible because Ba(OH)2 was consumed for the precipitation of iron extracted from the sample.
Transylvania peat Telinite IL Maritza, Bulg. Ulminate Maritza, Bulg. Xylire Maritza, Bulg. Telinite I Maritza, Bulg. Semifusinite Maritza Bulg. ‘Vitrainized wood’ Rodopa, Bulg. fragments
Sample
Table I. Characteristics
ADSORPTION OF BERYLLIUM ON PEAT AND COALS
(3) Desorption with 100 ml of 5% solution of tartaric acid under static conditions followed the desorption with water. (4) Alternatively, desorption of two of the samples with 1N HCl and two of the samples with HCl (pH 1.4) under static conditions was used after the water desorption. The results from the adsorption and desorption experiments are given in Table 2 and Fig 1. (5) The relation between the adsorption of beryllium on peat under static conditions and the pH of the solutions was studied (Fig 2).
Beryllium Fig I
linitial)lmgequiv/~Omll
Adsorption isotherms of beryllium at pH 5-5.5, 1 peat;
2 Telinite I; 3 Ulminite;
4 Xylite;
5 Telinite II; 6 Semifusinite
DISCUSSION
The possibility of adsorbing beryllium on peat and various types of coal under laboratory conditions permits its classification as a huminophilic element. The adsorption isotherms of the various adsorbents proved to be similar (Fig I). The adsorptive capacity of peat, vitrinite and xylite was almost the same, provided that the initial beryllium concentration of the solution was not greater than 0.22 mg equiv. Further increase of the initial concentration of beryllium in the solution led to considerable differences in the quantity adsorbed. Peat adsorbed beryllium most (2.09 mg equiv/g). The same value was found for UOaa+ (II) and a higher value for Gas+ (1.79 mg equiv)ra. 63
GR. ESKENAZY
Table 2 Adsorption
Sample
Peat
Telinite I
Ulminite
Xylite
Telinite II
Semifusinite
Initisl concn of Be”+ (mg/50 ml)
and desorption experiments
Equilib. concn of Be2+
Adsorption of Be2 + at pH 5-5.5
Desorption with water
Desorption with tartaric acid
(mg/50 ml)
(% of initial total)
(% of total adsorbed)
(% of total abdorbed)
1.0
0.01
2.0 3.0 5.0 10.0 0.5 1.0 2.0 5.0 10.0 0.5 1.0 5.0 IO.0 0.3 0.5 1.0 5.0 10.0 0.3 0.5 1.0 2.0 5.0 10.0 0.3 0.5 1.0 2.0 5.0 IO.0
0.05 0.12 0.72 5.28 0.01 0.03 0.45 1.67 5.93 0.01 0.04 2.00 6.63 0.03 0.06 0.20 3.11 7.20 0.02 0.03 0.08 0.55 1.93 7.13 0.20 0.30 0.50 1.13 340 8.37
98.8 97.7 96.0 85.6 47.2 98.2 97.1 77.6 66.6 40.7 97.2 96.0 6090 33.7 90.7 87.9 80.4 37.7 _
1.4 1.5 0.9 0.9 0.8 -
58.5 69.8 75.6 79.4 81.7 62.1 70.3 -
-
50.8 46.9 74.8 -
93.3 93.2 92.4 72.4 61.4 28.7 34.0 39,4 51.0 43.6 32.2 16.3
1.4 1.4 1.6 0.3 _
_ 0.65 0.54 0.06 0.15 7.3 8.1 7.6 3.7 0.7 2.3
25.5 41.5 51.4 67.5 80.7 44.6 _ 64,l 66.1 66.3 70.1 27.0 20.4 80.4 88.3 78.4 61.6 54.3 26.9
The samples had not been previously treated with water or hydrochloric acid to wash away any adsorbed ions which would cause to an increase in adsorptive capacity under laboratory conditions: therefore only such a quantity was adsorbed as would have been taken up under natural conditions if the solutions had contained a sufficient concentration of beryllium. Adsorption
of beryllium as a function
of the pH of the solutions
The adsorption of beryllium depends in general on the pH of the solutions; the same is true for all the other cations studied: Gas+, Ge4+, Zn2+ Ra2+, UOss+, Fesf. The adsorptive capacity increased with increasing pH from 2 to 6-7ts-‘6. Nevertheless the behaviour of the various cations showed certain 64
ADSORPTION
OF BERYLLIUM
ON PEAT AND COALS -~
differences. The adsorption of Ga3+ increased abruptly even at pH 2, in contradistinction to the smoother adsorption of Bea+ on the same adsorbent. The relation between the degree of adsorption and the pH can be elucidated by a comparison with the synthetic cation exchange resins. The adsorptive capacity of weakly acid and polyfunctional ion-exchange resins depends on
Fig 2 Adsorption
of beryllium on peat as a function of pH:
1, Adsorption capacity of different cation-exchange resins as a function of pH (Trostjanskajals); 2, SOsH; 3, COOH; 4, SOsH and OH ti
PH
the pH of the solutions. Cation-exchangers containing sulphonic acid groups ionize strongly in contact with acid, neutral or basic solutions, so that their capacity is almost independent of pH 171rs. The curves of the ion-exchangers studied by Trostjanskaja were compared with the adsorption curves of beryllium (Fig 2). It is evident that the variations in the adsorptive capacity of peat are quite similar to those of synthetic adsorbents containing carboxyl groups. The differences at pH 7 are due to the solubility of humic acids; the ion-exchange resins are stable under the same conditions. The relation between adsorptive capacity and pH for peat resembles that of polyfunctional synthetic ion-exchangers: a clear dependence changing smoothly with pH17. The pH dependence indicates that the cation-adsorption process in coals is connected with the dissociation of their functional groups and is determined by the binding of beryllium to these. Probably adsorption mechanism It may be supposed that the binding of beryllium results from specific
adsorption processes, which lead to the formation of chemical compounds of various stabilities. The mechanisms of such processes are very difficult to study owing to the complex chemical composition and structure of peat and coal adsorbents. The presence of functional groups, chiefly OH and COOH, makes possible ion-exchange reactions, which probably represent the first stage of adsorption. There is no definite relation between the functional group content and the absolute adsorption (u) of the various adsorbents. A qualitative comparison of the adsorbents used according to the functional groups and a (Table 1) gives the following series: According to OH and COOH: telinite II>peat>ulminite>telinite >xylite > semifusinite According to a: telinite II>ulminite>telinite 65 F-E
I
I>peat>xylite>semifusinite
__
~__
~____
GR.
ESKENAZY
It is evident that decrease of the functional groups brings about a reduction of beryllium adsorbed per unit surface area. Peat is the only exception. The fact that the adsorption is of a chemical nature is proved also by its irreversibility: on lowering the beryllium content in the solution at equilibrium (water treatment at high temperatures) only an insignificant quantity is desorbed. A higher percentage of desorption occurs for semifusinite, which has the lowest adsorptive capacity. When tartaric and hydrochloric acids are used as desorption agents, the percentage of desorption is much higher, because ionic-bound beryllium is probably desorbed. That part of the beryllium that is not extracted by tartaric and hydrochloric acid is probably attached to the organic matter by coordinate or covalent links. The genesis of the coals is also of major importance for their adsorption properties. Xylite and vitrinite are formed during a brief or long gelation of the lignin-cellulose tissues. Gelation favours the adsorption processes particularly. Semi-fusinite is partly oxidized lignin-cellulose tissue, which may explain its lower adsorption activity. Most interesting is the fact that the sample of vitrinized wood does not adsorb beryllium at all. The filtrate of this sample contains a large quantity of iron. It is likely that beryllium, because it is bivalent, cannot compete with Fea+. According to the empirical rule of Kunin for the ion-exchange resins at low concentrations and ordinary temperatures, the extent of exchange increases with increasing valency of the exchanging ionlg. In fact, an insignificant1 quantity of Gas+ (0.12 mgequiv/g) is adsorbed on the same sample. To check whether Fe3+ had really blocked all the ion exchanging sites, part of this samples was treated with hydrochloric acid (1 :l) till the reaction for Fd+ was negative. The sample thus prepared was tested for beryllium adsorption under the same conditions as for the other adsorbents. Beryllium was not adsorbed though the OH and COOH concentrations were high after hydrochloric acid treatment (Table I). Thus the above explanation does not account for the anomalous adsorption properties of this sample. In general the experiments lead to the conclusion that solutions with pH from 3 to 7 containing beryllium permit its irreversible binding on peat and various types of coal. Geochemistry Department University of Sofia, Bulgaria
(Received
23 April 1969)
REFERENCES 1 Sianduicheuko, T., Zubovic, P. and Sheffey, N. Geol. Survey Bulletin, 1961, 1084-K 2 Jedwab, J. Bull. Sot. Belge Geol., Paleontol. et Hydrol. 1960, 69, 1 3 MachaCek, V., Sulcek, Z. and Vacl, J. Vestn. Ustred. ustavu geol. 1962, 37, 4 4 MinEev, D. and Gr. Eskenazy Ann. Univ. of Sofa, Geol. and Geogr.
66
1965, 58, 1
ADSORPTION OF BERYLLIUM ON PEAT AND COALS _______~ 5 Minkev,
D. and Gr. Eskenazy Ann. Univ. of Sofia, Geol. and Geogr. 1966, 59, 1
6 Goldschmidt, V. M., Peters C. Nach. Ges. Wiss. Giittingen Math. Phys. Kl., 1932
7 Beus, A. A. ‘Geochemistry Moscow, 1960
of beryllium and genetic types of beryllium deposits’
8 Kakihana, H. and Sillen, L. G. Acta ChemI &and. 1956, p. 10 9 Knipovik, J. N. and Mora^cevsky, J. W. Analysis mineralnovo sirie Leningrad, 1959 10 Kljacko-Gurewic, A. L. Izvest. Acad. of Science USSR (Chim) 1961, p 10 11 Szalay, A. Geochim. et Cosmochim. Acta, 1964, 28, 10 12 Eskenazy Gr. Fuel Lond. 1967,56, 187 13 Sterbak, 0. W. Min. sirie, WZMS 1962, p 6 14 Roskova, E. W. and Sterbak, 0. W., Saakjan, W. M. Min. sirie, WIMS
1962,
~6 15 Titaeva, N. A. Geochemistry 1967, p. 12
16 Kovalev, B. A. and Bensman, W. R. DokE. Akad. Nauk. Bel. SSR 1967, 11, 9 17 Griessbacb, R. ‘Austauschadsorption
in Theorie und Praxis’, Berlin, 1967
18 Trostjanskaja, E. B. ‘Cation exchange synthetic resins’, Trudi Comm. Analyticheskoi Chimie, Moscow, 1955, Vol. 6 19 Kunin R. and Myers R. J. ‘Ion exchange resins’, New York, 1950
67 E’