Several chemical and microbiological parameters were tested during a 140 day period to characterize the stabilization process of a paper processing wastewater sludge composted with straw. The parameters indicate two months as a suitable period for the establishment of an equilibrium in the decay process, although some parameters show that compost reaches an acceptable level of stability in 30 days. Evaluation of stability in the end-product is difficult to define by only one parameter, whether it be chemical or biological.
Aoac (1955), Methods of Analysis , Association of Official Agricultural Chemists, Banta, Menasha, Wisconsin, U.S.A.
2.
Bertoldi, M. de, Vallini, G. & Pera, A. (1983), The biology of composting: A review, Waste Management & Research, 1, 157-176.
3.
Bremner, J.M. (1965), Total nitrogen. Inorganic forms of nitrogen. Organic forms of nitrogen. In Methods of Soil Analysis (C. A. Black et al. Eds), pp. 1149-1255. American Society of Agronomy, Madison, Wisconsin, U.S.A.
4.
C.N.R. (1983), Analisi della fitotossicità della sostanza organica in decomposizione mediante bioassaggio con Lepidium sativum. (Analysis of decomposing organic matter phytotoxicity by Lepidium sativum bioassay). In Metodi Analitici per i Fanghi ; Quad. I.R.S.A. n: 64 (1) cap. 8, 1-3 (Roma).
5.
Finstein, M.S., Cirello, J., Mac Gregor, S.T., Miller, F.C. & Psarianos, K.M. (1980), Sludge composting and utilization rational approach to process control. Final report. U.S. EPA, Rutgers University, NJ, U.S.A.
6.
Harada, Y. & Inoko, A. (1980), The measurement of cation-exchange capacity of composts for the estimation of degree of maturity, Soil Science and Plant Nutrition, 26, 127-134.
7.
Harada, Y., Inoko, A., Tadaki, M. & Izawa, T. (1981), Maturing process of city refuse compost during piling, Soil Science and Plant Nutrition, 27, 357-364.
8.
Harper, S.H.T. & Lynch, J.M. (1981), The chemical components and decomposition of wheat straw leaves, internodes and nodes, Journal of the Science of Food and Agriculture, 32, 1057-1062.
9.
Herman, W.A., McGill, W.B. & Dormaar, J.F. (1977), Effects of initial chemical composition on decomposition of roots of three grass species, Canadian Journal of Soil Science, 57, 205-215.
10.
Kaila, A. (1956), Determination of the degree of humification in peat samples, Maataloustieteellinen Aikakauskirja, 28, 18-30.
11.
Kuwatsuka, S. & Shindo, H. (1973), Behavior of phenolic substances in the decaying process of plants. Identification and quantitative determination of phenolic acids in rice straw and its decayed product by gas chromatography, Soil Science and Plant Nutrition, 19, 219-227.
12.
Levi-Minzi, R., Riffaldi, R. & Saviozzi, A. (1986), Organic matter and nutrients in fresh and mature farmyard, Agricultural Wastes, 16, 225-236..
13.
Muller, J.F. (1939), Some observations on base exchange in organic materials, Soil Science, 25, 229-237.
14.
Pochon, J. & Tardieux, P. (1962), Technique d'analyse en Microbiologie du Sol. (Analytical Tecniques in Soil Microbiology). Ed. de La Tourelle, St Mandè, France.
15.
Salfeld, J.C. & Söchtig, H. (1977), Composition of the soil organic matter system depending on soil type and land use. In Soil Organic Matter Studies, p. 227-235. I.A.E.A., Vienna , Austria.
16.
Schnitzer, M. & Khan, U. (1972), Humic Substances in the Environment. M. Dekker, New York, U.S.A.
17.
Spohn, E. (1978), Determination of compost maturity, Compost Science, 19, 26-27.
18.
Stentiford, E.I. & Pereira-Neto, T.J. (1985), Simplified systems for refuse/sludge composts, Biocycle, 26, 46-49.
19.
Sugahara, K. & Inoko, A. (1981), Composition analysis of humus and characterization of humic acid obtained from city refuse compost, Soil Science and Plant Nutrition, 27, 213-224.
20.
Zucconi, F., Forte, M., Monaco, A. & de Bertoldi, M. (1981a), Biological evaluation of compost maturity, Biocycle, 22, 27-29.
21.
Zucconi, F., Pera, A., Forte, M. & de Bertoldi, M. (1981b), Evaluating toxicity of immature compost, Biocycle, 22, 54-57.
