ENVIRONMENTAL BEHAVIOR OF SOILS AND MIXTURES OF SOIL-WHITEWASH MUD

Sociedade de Investigações Florestais R. Árvore, Viçosa-MG, v.28, n.3, p. 459-464, 2004 1 Recebido para publicação em 27.8.2003 e aceito para publicação em 08.6.2004. 2Federal University of Viçosa, Professor-Viçosa, MG, Brazil-machado@.ufv.br mpfontes@mail.ufv.br 3Federal University of Viçosa, Graduate Student-Viçosa, MG, Braziljmauricio@uaimail.com.br; 4Federal University of Viçosa, Graduate StudentViçosa, MG, Brazilrpereira@buynet.com.br 5Federal University of Uberlândia, Graduate Student Uberlândia, MG, Brazil ENVIRONMENTAL BEHAVIOR OF SOILS AND MIXTURES OF SOIL-WHITEWASH MUD1


INTRODUCTION
The terms pollution and contamination are being heavily used in the current days.For Crathorne et al. (1996), they are mistakenly taken as synonymous in the everyday common language usage.In the scientific field they have different meanings.The term contamination is used to designate a chemical substance in a sample without evidence that it causes pro-

COMPORTAMENTO AMBIENTAL DE SOLOS E MISTURAS SOLO LAMA-DE-CAL
RESUMO -O presente estudo buscou observar o comportamento de solos em seu estado natural e em misturas, em diferentes teores, com o resíduo sólido industrial denominado lama-de-cal.A pesquisa foi conduzida com amostras de solos típicas da região de Alagoinhas, Bahia-Brasil.A análise química por via úmida e espectrofotometria de absorção atômica foram usadas para obter a classificação do resíduo sólido industrial.Testes de solubilização, lixiviação, analise de raios X e microscopia eletrônica de varredura foram executados.Os resultados indicaram que a lama-de-cal não é inerte, mas com grande capacidade de retenção de metais pesados, em grande parte devido à presença de caulinita e goethita na fração argila dos solos.Palavras-chave: Solos, resíduo sólido industrial, lama-de-cal, comportamento ambiental blems.The term pollution is used in cases where the presence of the substance is harmful.Pollutants are therefore chemical substances that cause damage to the environment.There are several types of pollution, going from the simple thermal pollution to the input of heavy metals in the environment.
Industrial waste is one of the main responsible factors for environmental pollution, being originated

MACHADO, C.C. et al.
from cooling processes, washing, discharges, extractions, impregnations, chemical treatments, among others.It is one of the great concerns nationally and worldwide (ROCCA et al., 1993).
The reuse of industrial by-products represents one of the technological alternatives for application for those residues.Works with that focus are being developed in laboratories of the Federal University of Viçosa, MG, (UFV), where the utilization of some of these residues in pavements of forest highways is sought.Particularly one residue with great potential for reutilization is whitewash mud, coming from the cellulose and paper industry.Thus, the environmental aspect of its utilization becomes of fundamental relevance.
The present study has therefore the following objectives: (a) to characterize chemically and mineralogically the industrial solid residue called whitewash mud; (b) to carry through the classification of this material as related to its environmental potential danger when used together with soil samples.

Samples of soils
Two samples of soils, coming from Klabin-Bacell company, Alagoinhas, Bahia -Brazil, were used in the study.The samples were identified as:

Laboratory Testing Program
The laboratory tests with the soil samples in natural state and in mixtures with the whitewash mud consisted of the following: determination of the trace elements Cu, Cd, Cr, Fe, Pb, Zn and Mn by atomic absorption spectrophotometry (ABNT, 1987a -NBR 10004); (b) soil classification of: leaching test by determination of Cd, Cr and Pb (ABNT, 1987b-NBR 10005), solubilization test by determining the contents of Cr, Pb, Cd, Fe, Mn and Na (ABNT, 1987c-NBR 10006); (c) textural analysis and cation exchange capacity (EMBRAPA, 1990); (d) determination of the organic carbon content (WALKLEY, 1947); and (e) X-ray diffraction for determination of clay fraction minerals (FORMOSO, 1984).

Determination of trace elements
The determination of trace elements present in the soil samples and in the mixtures soil-whitewash mud was performed according to Standards 10004 of ABNT (ABNT, 1987a).The results of the soil samples and the mixtures soil-whitewash mud are shown in Tables 1 and 2.
Table 1 shows the presence of iron, zinc and manganese in the Sand and Gravel Soil samples.A larger concentration of iron, zinc and manganese was observed in the Sand Soil samples.
Table 2 shows that the concentration of the elements copper, iron, zinc and manganese decreased with the increasing the concentration of whitewash mud in the gravel soil mixtures, but it increased in sandy soil mixtures.

Soils classification in relation to the degree of pollution
Soil classification in relation to the pollution level was carried out according to the ABNT's Standards 10005 and 10006 (ABNT, 1987b,c).Environmental behavior of soils and of soil ...

Results of the leaching tests
Table 3 shows the results of the leaching tests with soil samples and mixtures of soil-whitewash mud.For both situations it was noticed that some elements were below the detection limit (ND).Tables 3 and 4 present the contents of several trace elements, including sodium, obtained in the leaching and solubilization tests.The simple inspection and comparison of the values obtained in relation to the values controlled by Standard 10004 of ABNT (Tables 5 and 6) suggest that the whitewash mud can be classified as a non-inert material because of the sodium high concentration found in these tests.

Results of the textural analysis of soils and mixtures of soil-whitewash mud
Table 7 presents a synthesis of the main results for the textural analysis of natural soil and mixtures soil-whitewash mud in different concentrations.

Table 1 -
Amount of trace elements of natural soil samples ND = Not detected SS 1 , SS 2 and SS 3 are subsamples of the sand soil samples.GS 1 GS 2 and GS 3 are subsamples of the gravel soil samples.
Table4shows the results of the solubilization tests with soil samples and soil-whitewash mud.

Table 3 -
Contents of Cd, Cr and Pb in µg/mL in soil and mixture leaching tests Tabela 3 -Conteúdos de Cd, Cr e Pb (µg/mL) nos ensaios de lixiviação de solos e misturas de solo-lama-de-cal

Table 5 -
Maximum allowable values in the extract from the leaching tests Tabela 5 -Valores máximos permissíveis no extrato dos ensaios de lixiviação