new thinking on climate change (abbrev. ii)

8/8/2019 New Thinking on Climate Change (Abbrev. II)

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New Thinking on Climate ChangeBy D. Grant, New Deer-Turriff AB53 6SXScotland, U.K.

Could the anthopogenic increase in Atmospheric CO2 partly

arise from the ability of fulvate to elevate the degree of

supersaturation ( ) of CaCO3 in the sea?Is this the chemical mechanism of a postulated evasion

factor for supposed lack of applicability of Henrys Law

for the equilibration of CO2 between the atmosphere and the

sea?Anthopogenically degraded soils could have released sufficient fulvateinto the sea to increase the potential rate of release of CO2 from the sea

so as to add to the anthropogenic load of atmospheric CO2 derived fromthe burning of fossil fuels

There is believed to be an urgent need to slow climate change which

could damage the environment to such an extent as to put at risk the

continuation of the present type of human society or even thecontinued existence of the human species, but that a tipping point

situation may already be occurring or will occur sometime in the

foreseeable future when human intervention to prevent this will then

no longer be possible.

Even if the combustion of fossil fuel could be drastically curtailed it is

entirely possible that because this may not be the principal human

acitivity which is causing global warming, the cessation of the use of

coal and petroleum e.g. for electricity generation might only have anegligible effect on anthropogenically induced climate change.

This situation could arise if the current global warming and climate

change is being mainly caused by bad agricultural practices which

can drastically alter the humic matter homeostasis system of the soil

and sea.


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It is suggested that attempts to slow the current abnormal fast

climate change processes should include procedures for

reversing the degradation of agricultural soils since a

significant injection of CO2 and methane into the atmosphere

can arise from the degradation of the soil by agriculture (in

its widest sense). Direct input of greenhouse gases from the

soil could be of a similar or greater order of magnitude than

that produced from the industrial scale burning of fossil

fuels.

A further route of anthropogenically assisted injection of CO2into the atmosphere can arise from the degradation of

topsoils which caused an increase in the fulvate content of

the sea which may disturb the oceanic carbon cycle so as to

increase the sea surface CO2 concentrationwhich are

sometimes stated (probably wrongly) to equilibrate with the

atmospheric CO2 according to Henrys law.

Yet another mechanism by which soil degradation can affect

global warming is by the release of humic matter containing

(colored) dust into the atmosphere.If cosmic rays are also key players in the climate change

scenario then there is also urgent need to find out which

currently produced human emissions might augment such

effects via depletion of the ozone layer.

There could also be an negative impact of cosmic radiation on

soil humic matter stability.

Consider the ocean as a CO2 sink.

Has this been perturbed by human activities?

Evidence from ice cores suggests that such perturbation might

have started to show up even 7000 years ago. This idea is

The Ruddiman Hypothesis of Late Holocene Anthropogenic Global

Warming


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It is worth noting at the start of any discussion of climate change that

early farmers, some 7000 years ago, possibly by damaging the topsoil

organic matter in a manner similar to how modern farmers also achieve

this on a much larger scale, may have left a detectable anthropogenic

imprint on the atmospheric CO2 content preserved in the ice coreevidence. This suggests that a relatively sudden increase occurred (of up

to a few tens of ppm) in the amount of CO2 present in the atmosphere

at the same time 7000 years ago that agriculture started throughout

Eurasia.

But Elsig et al. (Nature 2009 461 507-510) suggested that the extra CO27000 years ago could not have come from the burning of the wood from

felled forests (which, by analogy with the current belief that burning of

fossil fuel is the prime cause of the present augmentation of atmospheric

CO2 is the first idea that come to mind to explain the additionalatmospheric CO2 7000 years ago even if the maximum amount of CO2which could have come from this source of carbon can be shown to be

much too small to account for the 7000 year old ice core evidence of

atmospheric CO2 content). Elsig et al., showed there was no plant matter13C deficit in the ice core CO2 evidence from the 7000 year old

atmosphere, so that the extra CO2 must most likely have come from the

sea which agrees with the possibility that terrestrial fulvate runoff

induced by agricultural soil degradation produced an increase in the

degree of supersaturation ( ) of CaCO3 (calcite) in the ocean 7000 yearsago. This has an equivalent effect on the ability of the ocean to release

CO2 gas to the atmosphere to an increase in the ocean temperature which

seems less likely to have arisen by the kind of anthropogenic effects

which the sparse human population present during the late Holcene were

capable of.

That this small human population could have been capable of perturbing

the oceanic fulvate balance and hence increased atmospheric CO2 further

suggests that the current much larger augmentation of atmospheric CO2occurring at the present time also arises, at least to a large degree, from a

similar disturbance of the carbonate balance of ocean caused by theagricultural enhancement of fulvate runoff into the sea, a process which

seems to have started some 7000 years ago but has become much more

intense since 1960 due to the increasing rate of world-wide degradation

of topsoils caused by modern industrial agricultural practices.

The fulvate inhibition of CaCO3 precipitation aphenomenon of potential interest to the abovediscussion was discussed by the author and

colleagues in a scientific paper drafted at the


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University of Aberdeen many years ago but delayedfor publication by non-scientific circumstances.The fully discussed text of that paper and the roughsketch of the diagrams (which were not completed

professionally at the time)is now made available to the public, vide infra.

(A list of related published scientific studies which had been put into print at the time of the cessation of

research activities has been posted on the internet by Prof. W.F. Long at

web. abdn.ac.uk/~bch118/publications20003march.doc)

INHIBITION OF CaCO3 (CALCITE) CRYSTALLIZATION BY HUMIC AND FULVIC

ACIDS

David Grant, William F. Long, Marion A. Ross, Jaqueline A. Somers and Frank B.

Williamson,

Department of Biochemistry, University of Aberdeen, Marischal College,

Aberdeen AB9 1AS, Scotland, U.K.

ABSTRACT

Humic and fulvic acids strongly inhibit the crystallization of CaCO3 (calcite)


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These soil-derived polymers may therefore affect fertilizer efficiency in

calcareous soils and influence marine carbonate and atmospheric CO2

concentrations.

It is possible that the anti-calcite activity of the polymers resides in an

oxidized polyethylene-like fraction since a uronic acid residue-containing

polysaccharide fraction from soil had lower anti-calcite activity and lignin

derivatives had no activity.

Because of their highly heterogeneous natures, it is likely that humic and

fulvic acids possess other ecologically relevant anti-crystallization activities

INTRODUCTION

Humic acid and fuvic acid are names given to colloidal organic fractions

obtained from soil by defined procedures involving dispersion of samples in aqueous

alkali, neutralization, separation of insoluble humic from soluble fulvic fractions,

and dialysis of the fractions (Schnitzer and Khan, 1978). These heterogeneous

polyanionic substances are agriculturally significant, because they stabilize soil

structure and stimulate root growth (Kononova, 1966; Schnitzer and Khan, 1978).

They are formed by chemical and biochemical alterations of matter chiefly of

microbial origin, and typically have 14C-dated residence time in soil of about 103

years (Schnitzer and Khan, 1978). They have been characterized by their

cation exchange capacity (Pleysier et al., 1986), by mass spectroscopy (Nager et al.,

1975), by ir spectroscopy (Schurukhina et al., 1973) and by nmr spectroscopy (Wilson

1984).

We have described the inhibition of the crystallization of calcite by a range of anionic


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polysaccharides derived from animal and algal tissues (Grant et al., 1989 a, b). Such

compounds may have crystallization inhibition function in vivo, and structural

analogues of them are of potential use as agents for the clinical augmentation of

endogenous crystallization modulatory factors.

Because of the broad structural similarity between these compounds and the soil-

derived polymers, and because soil-derived calcium salt crystallization inhibitors

may be important in the modulation of marine calcification (Morse, 1983) and in

increasing fertilizer efficiency in calcareous soils (Amer et al., 1985) , we examined

the effects of humic and fulvic acids on the crystallization of CaCO 3 (calcite).

MATERIALS AND METHODS

Humic acid and fulvic acid (preparation 1) were extracted from a non-calcareous

agricultural soil at Countesswells, Aberdeenshire, U.K. of 5.9% carbon content

and pH ca. 5 (Glentworth and Muir, 1963) by the method of Ogner (1973) ;

fuvic acid (preparation 2) was extracted from a polysaccharide-rich fraction of

climatic peat at Cairn oMount, Aberdeenshire, U.K. of 56% (w/w) carbon content

and pH 3.7 (Forsyth, 1946) by Soxhlet extraction with H2O. Sulphation/sulphonation

of the humic acid by the method of Wood and Mora (1958) converted it into a

material that was soluble in the pH 8.3 solution used for study of calcite

crystallization; the effect of sulphation/sulphonation on fulvic acid (preparation 1)

was also investigated.

Water-soluble sulphonated lignin derivatives (REAX 88B and REAX 100M) were

obtained from Westvaco, Charleston Heights, SC, U.S.A. Heparin from porcine

intestinal mucosa (lot no. 46C0035) and chondroitin 4-sulphate from whale cartilage

(lot no. 77CO187) were from Sigma Chemical Co Ltd., Poole U.K.; Na

pyrophosphate and Na tripolyphosphate were from Monsanto Chemical Company, St


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Louis, MO, U.S.A.

Ir spectra (Fig.1) were obtained by multiple specular reflectance in a Grubb

Parsons MkIII Spectrometer using films deposited on aluminium foil mirrors. The ir

spectra of humic acid (Fig1a) and fulvic acid (preparation 1) (Fig. 1b) were

similar to the previously published spectra of such materials (Shurukhina et al.,

1973). The ir spectrum of fulvic acid (preparation 2) (Fig. 1c) showed narrower

absorption bands, indicating more homogeneity than the other soil extracts; the

positions and intensities of the bands shown in Fig. 1c are typical of uronic acid-

containing polysaccharides. The spectra of sulphated/sulphonated humic acid (Fig

1e) were similar to those of the starting materials but showed additional absorbances

due to the presence of SO3- groups; the major absorbance at 1238 cm-1 was assigned

to the SO2- asymmetric stretching frequency. The ir spectra of lignin-derived

materials (Fig. 1 f, g) were similar to those of other soil-derived lignin fractions

(Farmer and Morrison, 1964) but had additional SO3- absorptions.

Crystallization studies were carried out as previously described (Grant et al.,

1989a). Briefly, this involved, for the study of calcite crystallization, the addition of

7.8 mg calcite seed crystals prepared according to the method of Reddy and

Nancollas (1971) to 60 cm3 of a solution containing CaCl2 (0.8mmol.dm-3) and

NaHCO3 20 mmol.dm-3

) and having a pH of 8.3 and a saturation index (Rogers et al.,

1985) of approximately 31. A similar seeded crystallization method (Liu and

Nancollas, 1975) was used for the study of BaSO4 crystallization. Crystallizations

were followed by conductivity measurement using a Philips model PW9527

conductivity meter with a Philips 9514/60 electrode, and also, in then case of BaSO4

crystallization studies using a nephelometer (Evans Electroselenium Ltd., Halstead,

Essex, U.K.). The dissolution of calcite seed crystals in dilute H2SO4 solution, and


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the effect of crystallization inhibitors on this process, were also followed by

conductivity measurements.

RESULTS

Figure 2 curve g shows the decrease in conductivity caused by crystallization of

calcite from a solution containing CaCl2 and NaHCO3, following addition of calcite

seed crystals to the solution. Figure 2 curves a-g show the effects of various additives

on the process. Fulvic acid (preparation 1) acted as a potent inhibitor of calcite

crystallization (Fig 2 curves a,c and g). Fulvic acid (preparation 2) was only weakly

inhibitory (Fig. 2 curve e).

Crystallization in its presence followed complex kinetics perhaps explained by the

formation of a soluble complex between Ca2+ and the polymer.

Humic acid could not be studied directly because of its insolubility at pH 8.3;

its soluble sulphated/sulphonated derivative (Fig. 2b) was of intermediate

effectiveness.

The lignin derivatives under the conditions used by us, either did not affect

the process of calcite crystallization (Fig 2f) or increased its rate (Fig. 2h).

The effectiveness of the soil extracts were compared with that of other calcification

inhibitors by plotting Freundlich (1926) isotherms (Fig. 4).

The most effective soil polymers are apparently more than an order of magnitude

more active than the other calcification inhibitors studied.

Fulvic acid (preparation 1) and its sulphation/sulphonated product inhibited CaCO3

dissolution in 2.5x10-5 mol dm-3 H2SO4 solution showing a similar inhibitory

activity to sulphated polysaccharide calcification inhibitors (Fig. 5).

In related calcite crystallization experiments not reported in detail here, when

seed crystals were pre-incubated at 25o C for 30 min. with the additives, a higher


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level of inhibition was achieved.

Inhibition by soil extracts of the crystallization of BaSO4 (Table I) increased

in the order: fulvic acid (preparation 1) < sulphated/sulphated fulvic acid

(preparation1) < sulphated/sulphonated humic acid.

Conductivity measurements (not shown) made in the presence of sulphated/sulphated

soil extracts, suggested that strong chemical complexing occurred between

the soil extracts and Ba2+ ions.

Table 1

Effect of Soil Organic matter Fractions and Lignin Derivative on the Crystallization

of CaCO3 (Calcite) for Homogeneous Nucleation

Additive g/ml % of uninhibited rate

(from the ratio of thesecond order rate constants)

Fulvic acid No. 1 2.7 21.0

5.5 3.5

20. 0 ca. 0.5 a

100 0.0

Fulvic acid No 2 15.0 ca.12.5a


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Sulphated humic acid 20.0 0.5

Lignin derivatives

REAX 88 20.0 86.4

REAX 100M 20.0 310.0

Na tripolyphosphahte 2.0 0.5b

Na pyrophosphate 2.0 0.5b

Notes

a Ca2+ complexation occurs

b Inhibition occurs for only a limited period(dependent on the dose); for 2, 1, 0.5

and 0.2 g/ml tripolyphosphate this was 35, 30, 7 and 2 min., respectively;similar results were found with pyrophosphate except that the periods of activity were

greater) in a manner similar to that previously described for tripolyphosphateinhibition of BaSO4 crystallization (Liu & Nancollas, 1975).

Table Ia

Effect of Soil Organic Matter Additives on BaSO4 Crystallization

Additive g/ml % Uninhibited Rate from

Homogeneous Nucleation

Fulvic acid

(preparation 1) 30 3.2

Sulphated

Fulvic acid

(preparation 1) 2.5 38.

Heterogeneous Nucleation (on CaCO3 (calcite) seeds)

Fulvic acid(preparation 1) 2. 62.


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Sulphated fulvic acid

(preparation 1) 2. 8.6

Sulphate humic acid 2. 0.5

DISCUSSION

We examined the effects of modulators of CaCO3 (calcite) crystallization under

controlled conditions, using a procedure defined by previous workers (Reddy and

Nancollas, 1971). Because the rates of crystallization observed, and the degree and

type of inhibition seen in the presence of modulators depend strongly on the

experimental conditions used (especially those which slow reactions allow interaction

of seed crystals and inhibitor), caution needs to be applied in any comparison of our

results with those of others examining soil fractions. The present work (cf. Table I

and Fig.3) , however, supports preliminary observation of Berner et al. (1978) and

Inskeep and Bloom (1986a) that some humic substances derived from soil are very

potent inhibitors of CaCO3 (calcite) crystallization. Their and our results accord with

the suggestion that some water-soluble soil substances may permit high CaCO3

supersaturations in calacareous soils (cf. Amer et al., 1982, 1983). They also support

the proposal (Berner et al., 198) that soil-derived substances may stabilize marine

CaCO3 supersaturation, which varies form 2.5- to 5-5- fold, depending on latitude

(Whitfield and Watson,1983).

Since the formation of marine CaCO3 is a global drain on atmospheric CO2 (Kitanto,

1983), an investigation of the natural inhibitors of calcification may be ecologically

relevant. The possible effects of human activity on natural inhibitors might also be

considered. An increased potency and/or quality of terrestrial soil-derived

crystallization inhibitors might elicit an elevation of atmospheric CO2.


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Formation and dissolution of crystalline mineral phases such as those of BaSO4, are,

together with effects on CaCO3 crystallization, important in determining seawater

composition; the present results (cf. Table 1b) indicate that the soil extracts studied

inhibit the crystallization of BaSO4.

Because of their highly complex and heterogeneous nature, the soil-derived inhibitors

may possess a wide range of there ecologically relevant anti-crystallization activities,

e.g., through modulation of the physical states of iron and aluminium oxyhydroxide in

the soil (Hayes and Himes, 1986).

Stimulation of root growth by soil organic matter fractions (Kononova, 1966),

Schnitzer and Khan, 1978) may, in part, be related to the ability of such humic

materials to prevent the crystallization of sparingly soluble sulphates and phosphates

(Griffin and Jurinak, 1973) which would otherwise reduce the availability of applied

nutrients. Application of a synthetic crystallization inhibitor, pyrophosphate, has been

shown to prevent this (Amer and Mostafa, 1981; Amer et al., 1982; 1983).

As a result of studies involving unseeded CaCO3 crystallization, Kitano and Hood

(1965) suggested that the chelation of Ca2+ to various organic substances influences

the crystallographic form adapted by CaCO3 in the presence of these substances. Our

results suggests that the inhibitory effect of our most active soil extracts was not due

to chelation by them of Ca2+

, since the inhibitory effect was not accompanied

by a decrease in conductivity immediately on addition of the inhibitor to the

supersaturated solution. In contrast, addition of ethylenediaminetetra-acetic acid

(EDTA) to the supersaturated solution produced an immediate increase in

conductivity as Ca2+ was complexed, but the compound did not act as an inhibitor of

the seeded crystallization of CaCO3 (Grant et al 1989a).

Many inhibitors of CaCO3 crystallization appear to deactivate the seed crystal


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surfaces upon which crystal growth occurs, perhaps by binding to these surfaces

(Nancollas, 1979). Such an effect as surface adsorption accords with the Freundlich

isotherms produced in our experiments involving the soil-derived extracts, and also

with the relatively non-specific inhibition by them of the dissolution of CaCO3 under

acidic conditions. Various poly-carboxylic acids, including polysaccharides (Grant et

al., 1989 a, b) and oxidised polysaccharides (Kuriyamam et al., 1985) are inhibitors of

the crystallization of CaCO3, but are less active, by about1.5 orders of magnitude, on

a weight basis, than the fulvic acid (preparation 1) and humic acid fractions used here

(Fig 4); however, the inhibitory activity towards the dissolution of preformed CaCO3

crystals by the polysaccharide and soil-derived inhibitors was of the same order of

magnitude (Fig. 5). This suggests that the most active soil components have

particular specificity for CaCO3 crystal growth sites (which are possibly screw

dislocations in the crystal surface (Nancollas, 1979). The chemical nature of

fulvic and humic acids has not been unambiguously established but it is likely to be

highly heterogeneous and the fractions may contain plant-derived lignin. Indeed,

some described physical and chemical properties of these soil-derived substances may

be due to the presence of aromatic components including lignin (Flaig, 1964;

Schnitzer and Khan, 1978; Hayes and Himes, 1986).

The present results suggest that the crystallization inhibitory properties of the

fulvic and humic acid is not, however, due to the presence of this component no

is it due to relatively un-degraded anionic polysaccharides.

Their ir spectra (Fig. 1 of the most active humic and fulvic acid (preparation 1) are

different form the less active preparations which exhibits a polysaccharide-associated

absorption at 1430cm-1being assigned to the symmetric stretching vibration of the

carboxylate groups of uronic acid residues. This suggests that the active component of


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fulvic acid (preparation 1) and perhaps of the other very active marine-derived humic

acid and fulvic acid inhibitors reported by Berner et al. (1978) may not be

polysaccharide in nature.

Tentatively, we suggest that the inhibitory activity may reside in the principal

major non-polysaccharide, non-lignin component of humic and fulvic acid, e.g.

the oxidized polyethylene component of these soil-derived fractions (Grant, 1977,

Hayes and Himes, 1986). This consists of aliphatic, perhaps lipid-derived, polymers

of general composition (CH2)nC(O))X,(C)m(CH)(CH3)p, n>16,

in which X=OH or C< and which exhibit 13 FT and1H nmr spectra similar to those

of partly oxidised low-density polyethylenes (i.e. with a dominant 13C chemical shift

of = 30 which are present in virtually all soil types, being especially abundant inthe

smallest particles size fractions derived form terrestrial soils (Oades 1988), and are

major components of marine humic acid (Hatcher et al., 1980). They may modulate

soil aggregate structure (Chaney and Swift, 1984), perhaps by influencing soil

mineral structure through their hydrophobic character; this hydrophobic character

may contribute to the non-biodegradability of long-chain alkanes CH3(CH2)n>32CH3

in the soil (Potts et al., 1973). It has been reported that polymethylene-rich soil-

derived substances are strongly adsorbed on crystal surfaces in hydrophobic soils

(Mashum et al., 1988).

Some commercially used CaCO3 crystallization inhibitors, e.g. the polyphosphates

(Raistrick, 1949) are effective at low concentration, but retain their effectiveness

for only a short period, perhaps because crystal over-grow of the inhibitor-bound

crystal surfaces (Liu and Nancollas, 1975). In contrast, our results as well as

those of Berner et al. (1978) (see discussion in Morse, 1983), suggest that soil-


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derived inhibitors may retain their inhibitor activity indefinitely. Further work using

soil-derived fractions of defined origin and characteristics, and with carefully

controlled crystallization procedures, may reveal inhibitors of commercial potential,

and may illuminate ecological relevance of such substances.

REFERENCES

Amer, F. and Mostafa, H. E. (1981) Effect of pyrophosphate on orthophosphate

reactions in calcareous soils, Soil Sci. Soc. Am. J., 45 842-847

Amer, F., Khalil, M.A. and Diab, G.S. (1982) Agronomic effectiveness of

pyrophosphate as an additive to moncalcium phosphate and diammonium phosphatecalcareous soils, Soil Sci. Soc. Am. J. 46 572-583

Amer, F., Mahmoud,A.A. and Sabeet, V. (1985) Zeta potential and surface area of

calcium carbonate as related to phosphate sorption, Soil Sci. Soc. Am. J., 49, 1137-

1142

Berner, R.A., Westrich, J.P., Graber, R., Smith, J. and Martens, C.S. (1978)

Inhibition of aragonite precipitation from supersaturated seawater: a laboratory and

field study Amer. J. Sci., 278, 816-837

Chaney, K. and Swift, R.S. (1984) The influence of organic matter on aggregate

stability of some British soils, J. Soil Sci., 35, 223-230

Farmer, V.C. and Morrison R.I. (1964) Lignin in sphagnum and phragmites and in

peats derived from these plants, Geochimica et Cosmochimica Acta, 28, 1537-1546

Flaig, W. (1964) Effects of micro-organisms in the transformation of lignin to humic

substances, Geochimica et Cosmochimica Acta, 28, 1523-1535

Forsyth, W.G.C. (1946) A fractionation of soil organic matter with special reference

to the nitrogen constituents, Ph.D. dissertation, University of Aberdeen

Freundlich, H. (1926) Colloid and Capillary Chemistry, Methuen, London

Glentworth, R. and Muir, J.W. (1963) The Soils of the Country Round Aberdeen

Inverurie and Fraserburgh, Mem. Soil Surv. Gt. Br. Scot. Edinburgh, H.M.S.O.

Grant, D. (1977) Chemical structure of humic substances, Nature, 270,709-710

Grant, D., Long, W.F. and Williamson, F.B., (1989a) Inhibition by

glycosaminoglycans of CaCO3 (calcite) crystallization Biochem J. in press

(Added note to original text: this appeared in Biochem. J.1989 259 41-45)


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Grant, D., Long, W.F. and Williamson, F.B., (1989b) Inhibition by carrageenans of

CaCO3 (calcite) crystallization; to be submitted to Biochem J.(Added note to original text: the submission of this paper forpublication, like that of the present one was not proceeded with becauseof an unexpected sudden close down of the research group which at thetime was thought to be temporary but it turned out to be permanent)

Griffin, R.A. and Jurinak, J.J. (1973) The interaction of phosphate with calcite, Soil

Sci. Soc. Am. Proc., 37, 847-850

Hatcher, P.G. Towan, R. and Mattingly, M.A. (1981) 1H and 13C NMR of marine

humic acids, Org. Geochem., 2, 77-85

Hayes, M.H.B. and Himes, F.L. (1986) Nature and properties of humus-mineral

complexes, Interactions of Soil Minerals with Natural Organics and Microbes. Soil

Sci. Soc. Amer. Special Publication No. 17 pp103-150

Inskeep, W.P. and Bloom, P.R (1986a) Kinetics of calcite precipitation in the

presence of water-soluble organic ligands, Soil Sci. Soc. Am. J., 50, 1167-1172

Inskeep W.P. and Bloom P.R. (1986b) Calcium carbonate supersaturation in soil

solutions of calciaquolls, Soil Sci. Soc. Am. J., 80, 1431-1437

Kitano Y. (1983) Calcification and atmospheric CO2, Biomineralizaiton and

Biological Metal Accumulation. Ed. Westbroek, P and De Jong E.W., Reidel,

Dordrecht, pp89-98

Kitano, Y. and Hood, D.W. (1965) The influence of organic material on thepolymorphic crystallization of calcium carbonate,

Geochimica et Cosmochimica Acta, 29, 29-41

Kononova, M. M. (1966) Soil Organic Matter, Pergamon Press, Oxford

Kuriyama, Y., Kajiwara, S. and Ozaki, F. (1985) United States Patent Specification

No. 4,561,982

Liu, S.-T. and Nancollas, G.H. (1975) The crystal growth and dissolution of barium

sulfate in the presence of additives, Journal of Colloid and Interface Science, 52, 582-

592

Mashum M., Tate M.E., Jones G.P. and Oades, J.M. (1988) Extraction and

characterization of water-repellent materials from Australian soils, J. Soil Sci., 39, 99-

109

Morse, J.W. (1983) The kinetics of calcium carbonate dissolution and precipitation,

Reviews in Mineralogy, 11, 227-394

Nager, B.R. , Waight, E.S., Meuzelaar, H.L.C. and Kistemaker, P.G. (1975) Studies

and the structure and origin of soil humic acids by Curie point pyrolysis in direct

combination with low-voltage mass spectrometry, Plant and Soil, 43, 681-685


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Nancollas, G.H. (1979) The growth of crystals in solution, Advances in Colloid and

Interface Science, 10, 215-252

Oades, J.M. (1988) The retention of organic matter in soils, Biogeochemistry, 5, 35-

70

Ogner, G. (1973) Permanganate oxidation of methylated and unmethylated fulvic

acid, humic acid and humin isolated from raw humus, Acta Chem. Scand., 27, 1601-

1612

Pleysier, J., Janssens, J. and Cremers, A. (1986) A clay suspension stability end points

titration method for measuring cation exchange capacity of soils, Soil Sci. Soc. Am.

J., 50, 887-891

Potts J.E., Clendinning R.A. and Ackart W.A. (1973) Proc. Symp. Degradability of

Polymers and Plastics, 27-28 Nov., 1973, Plastics Inst. London 12-1, -12-10

Raistrick, B. (1949) The influence of foreign ions on crystal growth from solution 1.

The stabilization of the supersaturation of calcium carbonate solutions by anions

possessing O-P-O-P-O chains, Disc. Faraday Soc., 5, 234-237

Reddy, M.M. and Nancollas , G.H. (1971) The crystallization of calcium carbonate I.

Isotope exchange and kinetics, J. Colloid and Interface Sci., 36, 166-172

Rogers, L.A., Tompson, Q.B., Maty, J.M. and Durrett, L.R. (1985) Oil and Gas

Journal, 83 97-106

Schnitzer, M. and Khan, S.U. (1978) Humic Substances in the Environment, Marcel

Dekker , New York

Shurukhina, S.I., Shurukhin, V.V. and Tarlakov, Yu. P. (1973) Study of humus

extracts by infrared spectroscopy, Pochvovedeniye 146-149

Whitfield, M. and Watson, A.J. (1983) The influence of biomineralization on the

composition of seawater,

Biomineralization and Biological Metal Accumulation. Ed. Westbroek, P. and DeJong, E.W., Reidel, Dordrecht, pp57-72

Wilson, M.A. (1984) Soil organic matter maps by nuclear magnetic resonance J. Soil

Sci., 35, 209-315

Wood, J.W. and Mora, P.T. (1958) Synthetic polysaccharides. III. Polyglucose

sulfates, J. Amer. Chem. Soc. 80, 3700-3702

FIGURES

(Note added to original text: these Figures were underconstruction when the research project was shelved. These


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preliminary diagrams intended for professional upgrading arehowever available and while not being of high standard, contain

the essential information referred to in the main text)


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20/27


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Fig. 1 Ir spectra 400-4000cm-1 of the samples studied

(a) humic acid

(b) fulvic acid (prepn. 1)

(c) fulvic acid (prepn. 2)

(d) sulphated/sulphonated humic acid

(e) sulphated sulphonated fulvic acid (prepn. 1)

(f) sulphated lignin REAX 88B

(g) sulphated lignin REAX 100M


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Fig. 2

Effect of additives on crystallization of CaCO3

curves (a) (c) (d) fulvic acid (prepn. 1) 100, 5.5 and 2.8 g/ml

(b) sulphated /sulphonated humic acid 20 g/ml

(e) fulvic acid (prepn. 2) 15 g/ml

(f)(g) lignin derivs. REAX 88B, REAX 100M 20 g/ml respectively(h) no additive


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Fig. 3

Effect of additives on crystallization of CaCO3 -second order rate plots

Effect of fulvic acid (prepn. 1)

m refers to the conductivity readings, mi and mo being the initial and final

values

Fig. 4


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Freundlich (1926) Isothem Plot

Homogeneously nucleated crystallization of CaCO3 (calcite)

Comparison of fulvic acid with other inhibitors

a, water extract of soil (data from Inskeep & Bloom (1968b)

b, fulvic acid (prepn. 1)

c, fulvic acid (prepn. 2)

b*sulphated /sulphonated humic acid

d, heparan sulphate

e, heparin,

f, chondroitin 4-sulphate

(data for curves d-f were from Grant et al., 1988a)

Fig. 5


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Freundlich (1926) Isotherm Plot, CaCO3 Dissolution

CaCO3 1.6 mg/60ml 2.5x10-5 mol dm-3 H2SO4 solution; sulphated humic

acid, fulvic acid (prepn. 1); heparin; sulphated pectin

ACKNOWLEDGEMENTS

We thank Dr. M.V. Cheshire, Macaulay Institute, Aberdeen, for samples

of humic and fulvic acids, Mrs Marion Ross for preparation

Of sulphated humic acid, Mrs Jacqueline Somers for the data on the

inhibition of calcite crystallization by tripolyphosphate and

pyrophosphate, the Cancer Research Campaign and the Scottish Home

and Health Department for grants supporting work in this laboratory.

The above text of a manuscript dated 20 Feb 1988, with modifications

suggested in hand written


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inserts by (Prof) WF Long dated 21 Feb 1989 of a paper intended for

submission to an academic journal

was one of a series of papers dealing with natural inhibitors of the

crystallization of CaCO3

produced by

the Polysaccharide Research Group of the University of Aberdeen Department

of Molecular and Cell Biology

(jointly headed by W.F. Long and F.BV. Williamson) in which a humic matter

led anthropogenic

climate change hypothesis is briefly suggested. One of the intended series of

(three plus) papers

(Grant, D. et al., Biochem J 1989, 259, 41-45) achieved being submitted prior

to termination (for un-stated reasons) of

the Scottish Home and Health Department contract which had funded the

work. The other manuscripts

were retained (with permission) by D.Grant (the principal author) for future

publication


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.

new thinking on climate change (abbrev. ii)

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