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Fractionation and characterisation of dissolved organic matter from


Bioresource Technology 83 (2002) 181–187

Fractionation and characterisation of dissolved organic matter from composting green wastes
A. de Guardiaa,*, S. Bruneta, D. Rogeaua,

G. Matejkab
a

Cemagref, Livestock and Municipal Wastes Management Research Unit, 17 avenue de Cucill, 35 044 Rennes cdex, France e e b National Engineering School of Limoges, Parc d’Ester-Technop^le, 87 068 Limoges cdex, France o e Received 1 May 1999; received in revised form 22 November 2001; accepted 28 November 2001

Abstract A new fractionation procedure using membrane ultra?ltration (UF), followed by chemical characterisation – measurement of total organic carbon (TOC), chemical oxygen demand (COD) and organic nitrogen and spectroscopic study – was applied to aqueous extracts of composting green wastes. Three membranes of molecular weight (MW) cut-o?s of 1, 10 and 100 kDa were used. The study demonstrated the ?rst step of the transfer of organic matter from the solids to the aqueous bio?lm surrounding the solids. The microbiological consumption of the dissolved organic matter mainly used molecules smaller than 1 kDa, while the aromatisation of the organic matter, observed after 100 days composting, involved molecules larger than 10 kDa. ? 2002 Elsevier Science Ltd. All rights reserved.
Keywords: Composting; Aqueous extract; Organic matter fractionation; Membrane ultra?ltration; Humi?cation; Green wastes

1. Introduction Composting becomes more and more an alternative treatment method of organic wastes. On the contrary to others, it allows treatment of small or big amounts of wastes and remains a cheap and robust process. In order to control the composting organic wastes transformations, drying, stabilisation, pathogen destruction, control of nitrogen content, etc. – it is necessary to improve the understanding of the phenomena ruling the process. These phenomena include microbiological metabolism and mass and heat transfers. Assuming microorganisms require enough moisture to live, it is often considered that most organic matter biodegradation occurs in a thin liquid phase, the ‘‘bio?lm’’, constituted by moisture surrounding and impregnating the solids (Inbar et al., 1990). At the beginning of a composting treatment, the microorganisms, living in the wastes, start utilising the biodegradable organic matter which is dissolved in the bio?lm. That consumption is responsible for heat production and temperature increase in the system. ConCorresponding author. Tel.: +33-2-2348-2133; fax: +33-2-23482115. E-mail address: amaury.de-guardia@cemagref.fr (A. de Guardia).
*

currently, the microorganisms produce enzymes which attack the solid organic fraction. This enzymatic attack leads to enrichment of bio?lm in molecules which the microorganisms can in turn easily utilise. Physical transfer from solid phase to liquid phase may be responsible for this enrichment too. Thus, the initial stage is the microbiological consumption of biodegradable organic matter. Some unfavourable conditions such as oxygen depletion, insu?cient moisture or very high temperature, may limit that microbiological activity. Depletion of nutrients, which means organic matter stabilisation, could also lower microbiological activity. The bio?lm surrounding the solids has often been extracted and analysed particularly in order to identify parameters indicative of organic matter stabilisation (Chanyasak and Kubota, 1981; Chanyasak et al., 1982; Hnninen et al., 1995; Jimenez and Garcia, 1989). These a studies exhibit evolutions which can be explained by means of the di?erent phenomena described above. Fractionation of the organic matter dissolved in the bio?lm followed by chemical characterisation of each fraction may also favour the understanding of these phenomena. Dissolved organic matter may be fractionated by macroreticular exchange resins which leads to separation and quanti?cation of hydrophobic and hydrophilic

0960-8524/02/$ - see front matter ? 2002 Elsevier Science Ltd. All rights reserved. PII: S 0 9 6 0 - 8 5 2 4 ( 0 1 ) 0 0 2 2 8 - 0

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fractions. So, Wershaw et al. (1995) and Mejbri et al. (1996) characterised leachates derived from composting piles. That method has also been used to fractionate humic acids from composts (Chefetz et al., 1996; De Nobili and Petrussi, 1988; Aoyama, 1996). Zhou et al. (2000) compared dissolved organic matter from sewage sludge and composted sludge on the basis of that fractionation. The gel permeation chromatography and the membrane ultra?ltration (UF) allow both fractionations as function of molecular sizes or weights in the bio?lm. The ?rst method leads to a chromatogram on which each signal corresponds to a liquid fraction collected at the exit of the permeation column. So Chanyasak et al. (1980, 1982) and Prudent et al. (1995) showed that the molecular weights (MW) of peptides, polysacharides and humic substances increased while composting. Trubetskaya et al. (2001) used that method to compare humic acids derived from soil and sewage sludge compost. The UF method uses a membrane with a speci?c MW cut-o?. It permits the separation of a liquid phase in one part containing molecules with MWs higher than cut-o? and another one containing molecules with MWs lower than cut-o?. Agbekodo and Legube (1995) used membrane UF to study distribution of dissolved organic carbon and its biodegradable part in natural surface water. They showed that biodegradable dissolved organic carbon was low in the fractions with MW higher than 10 kDa whereas fractions with MWs lower than 500 Da accounted for the ?rst 30% of total biodegradable dissolved organic carbon. Burdige and Gardner (1998) applied the same method to pore waters from estuarine and continental margin sediments. Gourdon et al. (1989) and Trbouet et al. (1996) both showed that e in land?ll leachates, molecules with MWs lower than 1 kDa accounted for most of the chemical oxygen demand (COD). Vidal et al. (2001) and Barker et al. (1999) investigated the MW distributions of several e?uents treated by anaerobic digestion. Garcia et al. (1993) studied hydrolase activity in the organic matter fractions of composting sewage sludge. The purpose of our study was to investigate if bio?lm UF could contribute to a better understanding of the composting process. The low biodegradation rate of composting green wastes led us to choose such substrates in our experiment. After characterisation of the global solid transformations occurring during their composting (De Guardia et al., 1998), the bio?lm surrounding the solids has been extracted and fractionated by UF. The UF fractions have been chemically characterised by measurement of pH, total organic carbon (TOC), COD, Kjeldahl, ammonium and organic nitrogen concentrations. These concentrations have been expressed in terms of mass evolution and we propose to explain here these evolutions.

2. Methods 2.1. Green wastes composting process Green wastes were brought to the composting plant by the inhabitants of the nearest agglomerations. They were composed of branches, leaves, weeds, and grass cuttings. The branches had low biodegradation rates and their structure would favour the pile aeration. The leaves, weeds and grass cuttings were ?ne solids; they are wetter and richer in nitrogen and their biodegradation rates are higher, than branches. After a few days of storage, the green wastes were ground and stacked in windrows on a cemented uncovered area. Each windrow had a trapezoidal crosssection (30 m ? 10 m and 3 m high) and an initial mass of 500–1500 t. The windrows were turned each 15–21 days by a mobile equipment. For the ?rst three months, in case of insu?cient moisture, water was sprayed from above. After six to seven months of composting, the product was separated using one rotative sieve of 10 mm, the undersized material being the compost and the oversized material being recycled in grinding at the beginning of the process. Bio?lm transformations occurring in one windrow stacked in April 1997 were characterised. The experiment lasted eight months. 2.2. On site sampling The windrow was sampled during each turning (De Guardia et al., 1998). When the mobile equipment was going through the windrow, it turned about 30 cm width of the pile. About 30 passages were necessary to turn the whole windrow. At each passage, we collected manually about 10 kg of product in the cross-trapezoidal section. At the end, all the collected samples were mixed together and the composite sample (ca. 300 kg) was reduced, by successive division in identical portions, to about 30 kg. 2.3. Aqueous solid–liquid extraction Considering the heterogeneity brought about by the biggest pieces of branches, the wet product was fractionated by sieving through a 25 mm square mesh. The oversized fraction always accounted for around 10% in weight. This constant and small percentage led us to consider the undersized fraction (< 25 mm) as the reactive product. About 100 g of the wet undersized fraction (< 25 mm) were extracted three times. Each extraction consisted in mixing the product (100 g) with 500 ml deionised water (pH ? 5:5, R > 10 MX cm). After 4 h agitation, the product was ?ltered and mixed once again with 500 ml deionised water. Finally, the three extracts were mixed together. The solution ob-

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tained was centrifuged at 3000 rpm for 10 min and the supernatant was ?ltered through a 8 lm membrane (Millipore MF SCWP) then through a 0.22 lm one (Millipore MF GSWP). The ?nal solution was called F0.22 lm. 2.4. Organic matter ultra?ltration Ultra?ltrations were performed using a 400 ml cylindrical cell equipped with magnetic agitation (Millipore UFXF) to reduce polarisation at the surface of membranes. These were ?at, circular membranes 76 mm diameter with MW cut-o?s of 1, 10 and 100 kDa. The membranes made of regenerated cellulose (Millipore YM) o?er a low proteic adsorption rate and are considered non-ionic. The range of cut-o?s was already tested by Garcia et al. (1993, 1995) and Trbouet et al. e (1996). Nitrogen was applied to pressurise the UF cell at 3 bars for membranes with MW cut-o? of 1 and 10 kDa and at 0.5 bar for membrane with MW cut-o? of 100 kDa. The water ?ow as a function of pressure was measured for each membrane and their resistances were calculated as follows: J ? DP =?Rm ? l?; where J is the water ?ow ?m3 m?2 s?1 ?, DP the pressure (Pa), Rm the membrane resistance ?m?1 ?, l is the dynamic viscosity of water (Pa s). The value of Rm is 8:68 ? 1013 m?1 for 1 kDa MW cut-o? membrane, 1:66 ? 1013 m?1 for 10 kDa and 3:04 ? 1012 m?1 for 100 kDa. The procedure of UF was as described in Fig. 1. Twohundred ml of F0.22 lm was introduced in the UF cell equipped with 100 kDa MW cut-o? membrane. After 175 ml was fractionated, 25 ml of deionised water were added to the 25 ml of F0.22 lm remaining and 25 ml of that mixture were subsequently fractionated. So we obtained 200 ml permeate and the addition of 175 ml water to the retentate, agitated for 10 min, also led to 200 ml additional retentate. The retentate R100 kDa

contained mostly molecules ?> 90%? with MW greater than 100 kDa and the permeate contained molecules with MW less than 100 kDa. With the same procedure, the permeate was fractionated on the membrane with MW cut-o? of 10 kDa and it led to a retentate R10 kDa containing molecules less than 100 kDa but greater than 10 kDa. The permeate was fractionated and it led to a retentate, R1 kDa, containing molecules with MW less than 10 kDa but greater than 1 kDa and to a permeate, F1 kDa, containing molecules smaller than 1 kDa. 2.5. Organic matter characterisation Each fraction obtained was characterised by measuring the following parameters: pH, TOC, COD, Kjeldahl and ammonium nitrogen concentrations. The pH was measured with a pH-meter (Hanna type HI 8424) and a pH-probe (Metrohm type 6.0232.500). TOC concentrations were measured with the analyser O.I. Analytical model 1010. COD concentrations were determined by dichromate oxidation according to the procedure described in norm NF T 90–101 (Oct. 1998). Total ammoniacal nitrogen was determined by steam distillation using MgO, followed by back titration of the boric acid distillates using sulfuric acid (0.1 M). Kjeldahl nitrogen was digested using the Kjeldahl procedure and distilled with NaOH (30%) (NF EN 25663, January 1994). Organic nitrogen was obtained by subtraction of ammoniacal nitrogen from Kjeldahl nitrogen.

3. Results and discussion 3.1. Bio?lm mass evolutions Considering the di?erent phenomena interfering in the process, microbiological consumption and mass and heat transfers, it seems important to describe the bio?lm transformations as exactly as possible. The expression of bio?lm transformations only in terms of concentrations is not satisfactory. For instance, as we can observe an increase in concentration, its expression in mass can show a decrease. The expression in mass accounts for the real transformations which can help understanding of the process, whereas evolution in concentration, increase or decrease, depends not only on product transformations but also on water evaporation. We chose to give both expressions, in concentration and in mass. To determine mass evolution as function of the composting time, the concentration (mg/g bio?lm) has to be multiplied by the total mass of bio?lm in the windrow (mBt: kg) at every time t. That mass is the sum of the mass of dissolved dry matter plus the mass of water. At a ?rst approximation the mass of dissolved dry matter can be neglected compared with the mass of water. By measure of organic matter of the sample at

Fig. 1. Membrane UF procedure.

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time t (OMt: ?) and considering the total mineral mass remains constant over the treatment, the total mineral mass at time t (mMMt: kg) remains equal to the initial total mineral mass (mMM0: kg), we can calculate the total dry mass of the windrow (mSt: kg). Then measure of moisture at time t (Ht: ?) allows calculation of the total bio?lm mass mBt. Measure of initial wet mass of the windrow (mH0: kg) and measure of its moisture H0 (?) and organic matter OM0 (?) allow calculation of the total mineral mass mMM0 (kg). mMM0 ? mH0 ? ?1 ? H0? ? ?1 ? OM0?; mMMt ? mMM0 ? mSt ? ?1 ? OMt?; then mSt ? mMM0=?1 ? OMt?; mBt ? mSt ? Ht=?1 ? Ht?: Table 1 gives moisture and bio?lm mass as functions of the composting time. The small decrease of moisture and bio?lm mass could be explained by atmospheric precipitation which hid water evaporation caused by increase of compost temperature. 3.2. Control of fractionation procedure Measure of TOC in the di?erent fractions F1 kDa, R1 kDa, R10 kDa, R100 kDa and addition of the corresponding masses allows calculation, to within 2–5%, mass of TOC found in F0.22 lm. This control allows validation of the fractionation procedure. 3.3. pH evolutions Fig. 2 shows the pH evolutions in each UF fraction. The fraction F0.22 lm exhibited an evolution already observed in composting (De Nobili and Petrussi, 1988; Inbar et al., 1993; Jimenez and Garcia, 1989; Sharma et al., 1997). At the beginning the pH was around 7–8, then, it decreased rapidly to reach 5 at 30 days and after 80 days treatment, the pH increased, ?rst rapidly then more slowly to reach its initial value. Such evolution of the pH was observed for each fraction. We suggest that the pH decreased when solid–liquid transfer and miTable 1 Moisture and bio?lm mass as functions of the composting time Composting time t (days) 15 29 80 114 133 148 182 203 Moisture Ht ()) 0.519 0.458 0.501 0.429 0.441 0.476 0.491 0.501 Bio?lm mass mBt (kg) 293 410 214 490 257 380 183 810 188 960 187 830 213 880 197 600

Fig. 2. pH evolution for each UF fraction.

crobiological degradation of dissolved organic matter increased. Transfer and biodegradation would be responsible for the acidi?cation of the bio?lm. Molecules transferred were mostly acids as the ?rst step of biodegradation would produce acids, but these would soon be oxidised to carbon dioxide. In a second step the decrease of transfer and the slowing down of biodegradation favour the return increase of pH. Fig. 2 shows that the least acid fraction is F1 kDa, that is the fraction containing the smallest molecules. The formation of carbonate and ammonium ions may explain why F1 kDa is more basic than the other fractions. The formation of complexes linking ions and organic matter might have modi?ed their speci?c acidity and this could partly explain the observed changes. 3.4. TOC and COD The changes of TOC concentrations and masses are described in Figs. 3(a) and (b). These evolutions are very similar. Yet the TOC mass evolution in F0.22 lm decreased between 80 and 114 days, whereas the TOC expressed in concentration slightly increased during that same period. The decrease in mass corresponded to a

Fig. 3. (a) and (b). Evolutions of TOC in concentrations and in masses for each UF fraction.

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real elimination of organic carbon whereas the concentration increase was caused by water evaporation; that is a decrease in mass of bio?lm. However, Fig. 3(b) shows TOC mass in F0.22 lm ?rst increased then it slowly decreased to its initial value after 120 days and it increased towards the end of the treatment. The F1 kDa fraction was responsible for the variations of F0.22 lm up to 120 days, it accounted for the largest part of the bio?lm. The molecules smaller than 1 kDa are the most sensitive to aerobic biodegradation. The other fractions accounted for small and similar parts of TOC mass in the bio?lm and remained fairly constant over the treatment, with the exception of a slight increase of R100 kDa after 150 days, which could be explained by accumulation in the bio?lm of molecules of MW > 100 kDa. This accumulation could have been caused by a solid–liquid transfer or polymerisation of smallest molecules (Chanyasak et al., 1980). In the same way as for TOC, COD concentrations and masses had virtually the same evolution (Figs. 4(a) and (b)). COD mass in F0.22 lm ?rst increased then decreased quickly until 120 days and the decrease went on more slowly till the end of treatment. Once again the F1 kDa fraction was mostly responsible for the variations of F0.22 lm and accounted for 30–50% of this. The COD masses in the other fractions remained fairly constant over the treatment. COD masses evolutions con?rm the previous interpretation. The molecules transferred from solid to the bio?lm then consumed by microorganisms were mostly molecules smaller than 1 kDa. COD indicates the oxidation level of these molecules too. So whereas TOC masses exhibited a slight increase after 120 days, COD masses slightly decreased, and this may prove stabilisation of organic matter to biological degradation. The diminution of COD/TOC ratio had the same meaning (Fig. 5).

Fig. 5. COD/TOC ratio evolution for each UF fraction.

3.5. Absorption spectra of the water extracts Absorption spectra of the UF fractions in the ultraviolet and visible light regions exhibited a high absorption in the low wavelength region which regularly decreased as wavelength increased. The same pattern was noted by Prudent et al. (1995) for humic substances. Absorptions of aqueous extracts at 280, 465, 665 nm and the ratio Abs. 465/Abs. 665 have been widely studied by Chen et al. (1977), Mathur et al. (1993) and Gressel et al. (1995). Optical density at 254 nm (OD) has been studied in order to characterise aromatisation of organic matter in natural surface water (Martin-Mousset et al., 1997) or in land?ll leachates, (Mejbri et al., 1996). Both groups studied the ratios Abs. 254 nm/TOC or COD/Abs. 254 nm which removes mass variations. Fig. 6 shows evolution of ratio Abs. 254 nm/TOC, TOC in g l?1 , for each UF fraction. At the beginning there is, for each fraction, a decrease of ratio Abs. 254 nm/TOC which might have been explained by increase of TOC in the bio?lm caused by increase of transfer from solid to bio?lm. From the 30th day to the end of treatment, the ratio slightly increased for the fractions F1 kDa and R1 kDa but remained the smallest. At the 80th day, the ratio of R100 kDa increased but decreased after 120 days, whereas for fraction R10 kDa the ratio sharply increased from the 120th to the 200th day. The increase of ratio Abs. 254 nm/ TOC in fractions R100 kDa and R10 kDa implied aromatisation of organic matter in these fractions. Figs. 7(a) and (b) give evolution in concentrations and in masses of organic nitrogen in each fraction. Ammonium ions were collected in F1 kDa fractions, thus organic nitrogen corresponded to Kjeldahl nitrogen

Fig. 4. (a) and (b). Evolutions of COD in concentrations and in masses for each UF fraction.

Fig. 6. Evolution of ratio Abs. 254 nm/TOC for each UF fraction.

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fractions also exhibited aromatisation of the biggest molecules, which mechanism will have to be investigated.

Acknowledgements
(a)

The authors would like to thank the Angers Agglomeration District and particularly Mr Brisset and his colleagues from green wastes composting treatment plant. The advice and ?nancial support from the Wastes Techniques and Agriculture and Food Departments of The French Agency For Environment and Energy Management are gratefully acknowledged.
(b)

References
Fig. 7. (a) and (b). Evolutions of organic nitrogen in concentrations and in masses for each UF fraction. Agbekodo, M.K., Legube, B., 1995. Distribution du CODB d’une eau de surface ayant subi deux types de traitements di?rents. Environ. e Technol. 16, 657–666. Aoyama, M., 1996. Fractionation of water-soluble organic substances formed during plant residue decomposition and high performance size exclusion chromatography of the fraction. Soil Sci. Plant Nutr. 42 (1), 31–40. Barker, D.J., Mannucchi, G.A., Salvi, S.M.L., Stuckey, D.C., 1999. Characterisation of soluble residual chemical oxygen demand (COD) in anaerobic wastewater treatment e?uents. Water Res. 33 (11), 2499–2510. Burdige, D.J., Gardner, K.G., 1998. Molecular weight distribution of dissolved organic carbon in marine sediment pore waters. Mar. Chem. 62 (1–2), 45–64. Chanyasak, V., Yoshida, T., Kubota, H., 1980. Chemical components in gel chromatographic fractionation of water extract from sewage sludge compost. J. Ferment. Technol. 58, 533–539. Chanyasak, V., Kubota, H., 1981. Carbon/organic nitrogen ratio in water extract as measure of composting degradation. J. Ferment. Technol. 59, 215–219. Chanyasak, V., Hirai, M., Kubota, H., 1982. Changes of chemical components and nitrogen transformation in water extracts during composting of garbage. J. Ferment. Technol. 60, 439–446. Chefetz, B., Hatcher, P., Hadar, Y., Chen, Y., 1996. Chemical and biological characterisation of organic matter during composting of municipal solid wastes. J. Environ. Qual. 25, 776–785. Chen, Y., Senesi, N., Schnitzer, M., 1977. Information provided on humic substances by E4/E6 ratios. Soil Sci. Soc. Am. J. 41, 352– 358. De Guardia, A., Rogeau, D., Begnaud, F., Quinio, S., 1998. Characterisation of green wastes’ transformations occurring while composting. In: Martinez, J. (Ed.), Proceedings of the Eighth International Conference of the European Cooperative Research Network. Recycling of Agricultural, Municipal and Industrial Residues in Agriculture, Rennes, France, 26–29 May 1998. Cemagref, France, pp. 185–202. De Nobili, M., Petrussi, F., 1988. Humi?cation index (HI) as evaluation of the stabilization degree during composting. J. Ferment. Technol. 66, 577–583. Garcia, C., Hernandez, T., Costa, F., Ceccanti, B., Ganni, A., 1993. Hydrolases in the organic matter fractions of sewage sludge: changes with composting. Bioresource Technol. 45, 47–52. Garcia, C., Ceccanti, B., Masciandro, G., Hernandez, T., 1995. Fractionation and characterisation of humic substance fractions with di?erent molecular weights, obtained from animal wastes. Soil Sci. Plant Nutr. 41, 649–658.

in fractions R100 kDa, R10 kDa, R1 kDa and to Kjeldahl nitrogen minus ammonium ions in F0.22 lm and F1 kDa fractions. Organic nitrogen (Figs. 7(a) and (b)) and COD (Fig. 4) exhibit quite similar variations for each fraction. Once again the fraction F1 kDa accounts for the changes observed in F0.22 lm. The increase of organic nitrogen in the ?rst 30 days was caused by solid–liquid transfer and its diminution has often been explained by consumption of amino acids and proteins by microorganisms (Chanyasak et al., 1980, 1982; Iannotti et al., 1994).

4. Conclusions The study reported here shows that fractionation of dissolved organic matter by membrane UF is a useful method for a preliminary fractionation study of bio?lm surrounding the solids in composting organic wastes. That fractionation with membranes of MW cut-o? of 100, 10, 1 kDa followed by the chemical characterisation of the fractions, i.e. measure of TOC, COD and organic nitrogen expressed preferably in masses, con?rmed that the organic matter dynamics occurring during composting de?nitely involve the bio?lm. Changes observed in TOC, COD and organic nitrogen can be explained by solid to liquid transfer, enzymatic attack and microbiological consumption of dissolved organic matter. Membrane UF showed that the smaller the organic molecules are, the more sensitive they seem to be to the aerobic treatment. It would be interesting to identify which molecules are concerned in these transformations. The study of absorption at 254 nm of the di?erent

A. de Guardia et al. / Bioresource Technology 83 (2002) 181–187 Gourdon, R., Comel, C., Vermande, P., Veron, J., 1989. Fractionation of the organic matter of a land?ll leachate before and after aerobic or anaerobic biological treatment. Water Res. 23, 167–173. Gressel, N., McGrath, A.E., McColl, J.G., Powers, R.F., 1995. Spectroscopy of aqueous extracts of forest litter. I: Suitability of methods. Soil Sci. Soc. Am. 59, 1715–1723. Hnninen, K., Miikki, V., Kovalainen, J., 1995. Chemistry of the hot a water extracts of biowaste composts. Fresenius Environ. Bull. 4, 570–575. Iannotti, D.A., Grebus, M.E., Toth, B.L., Madden, L.V., Hoitink, H.A.J., 1994. Oxygen respirometry to assess stability and maturity of composted municipal solid waste. J. Environ. Qual. 23, 1177– 1183. Inbar, Y., Chen, Y., Hadar, Y., Hoitink, H.A.J., 1990. Key factors analysed, new approaches to compost maturity. Biocycle 31, 64–69. Inbar, Y., Hadar, Y., Chen, Y., 1993. Recycling of cattle manure: the composting process and characterization of maturity. J. Environ. Qual. 22, 857–863. Jimenez, E.I., Garcia, V.P., 1989. Evaluation of city refuse compost maturity: a review. Biol. Wastes 27, 115–142. Martin-Mousset, B., Crou, J.P., Lefebvre, E., Legube, B., 1997. e Distribution et caractrisation de la matire organique dissoute e e d’eaux naturelles de surface. Water Res. 31, 541–553. Mathur, S.P., Dinel, H., Owen, G., Schnitzer, M., Dugan, J., 1993. Determination of compost biomaturity. II. Optical density of water extracts of composts as a re?ection of their maturity. Biol. Agri. Hort. 10, 87–108.

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Mejbri, R., Matejka, G., Lafrance, P., 1996. Composition de la matire e organique des lixiviats de dcharge: e?et du lagunage ar. e ee Journes Informations Eaux 74, 1–20. e Prudent, P., Domeizel, M., Massiani, C., Thomas, O., 1995. Gel chromatography separation and U.V. spectroscopic characterization of humic-like substances in urban composts. Sci. Total Environ. 172, 229–235. Sharma, V.K., Cantidelli, M., Fortuna, F., Cornacchia, G., 1997. Processing of urban and agro-industrial residues by aerobic composting: review. Energy Convers. Manage. 38, 453–478. Trbouet, D., Coupannec, F., Morin, D., Pron, J.J., Jaouen, P., e e Qumeneur, F., 1996. Fractionnement et caractrisation des e e lixiviats. Journes Informations Eaux 73, 1–16. e Trubetskaya, O.E., Trubetskoj, O.A., Ciavatta, C., 2001. Evaluation of the transformation of organic matter to humic substances in compost by coupling sec-page. Bioresource Technol. 77, 51– 56. Vidal, G., Videla, S., Diez, M.C., 2001. Molecular weight distribution of Pinus radiata kraft mill wastewater treated by anaerobic digestion. Bioresource Technol. 77, 183–191. Wershaw, R.L., Llaguno, E.C., Leenheer, J.A., 1995. Characterisation of compost leachate fractions using NMR spectroscopy. Compost Sci. Utilization 3 (3), 47–52. Zhou, L.X., Yang, H., Shen, Q.R., Wong, M.H., Wong, J.W.C., 2000. Fractionation and characterisation of dissolved organic matter derived from sewage sludge and composted sludge. Environ. Technol. 21 (7), 765–771.


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