2013 International Nuclear Atlantic Conference - INAC 2013 Recife, PE, , November 24-29, 2013 ASSOCIAÇÃO BRASILEIRA DE ENERGIA NUCLEAR - ABEN ISBN: 978-85-99141-05-2

EVALUATION OF POTENTIALLY INORGANIC TOXIC SUBSTANCES IN SEWAGE FROM TREATMENT PLANTS OF THE METROPOLITAN REGION OF BY SR-TXRF

Silvana Moreira1 and Silvana Turolla Broleze1

1 Departamento de Saneamento e Ambiente - FEC Universidade Estadual de Campinas Av. Albert Einstein, 951 13083-852 Campinas, SP [email protected]

ABSTRACT

The increased production of sludge is a consequence of the growth of the volume of treated sewage and of the number of Sewage Treatment Plants (STP) in Brazil and, it has demanded the search of alternatives for its final disposal. Amongst the some alternatives of disposal, the agricultural use is viable, a time that the sewage is rich in organic substances, macro and micronutrients necessary to the soil fertility. However, the illegal industrial releases at public sewage may contain the presence of elements that cause harm to human health and the environment as Pb, Hg, Cd, Cr and Se. This work evaluated the potentially inorganic toxic substances in the sewage, previously dried, of the STP Camanducaia in Jaguariúna city; Village Flora in Sumaré city; Praia Azul and Carioba in Americana city; Samambaia, Anhumas, Piçarrão and Barão Geraldo in Campinas city, SP, employing the Synchrotron Radiation Total Reflection X-Ray Fluorescence (SR-TXRF). The sewage of Treatment Plants of the Metropolitan Region of Campinas take care of CONAMA 375/06 legislation. However, so that it can be commercialized as fertilizing or conditioning of soils, it must take care of to Normative Instruction 27/06, needing to reduce the contents of Ni and Cr. One of the alternatives would be a bigger supervising in the generating sources, in order to improve the quality of the tributary of the stations, being adjusted the sewage to the Brazilian legislations.

1. INTRODUCTION

With population, demographic, economic, industrial and commercial development of the society, it was necessary to improve the quality of life by means of investments and action of hygiene and in basic sanitation, reducing infantile mortality and the proliferation of enteric illnesses of hydric propagation. However, this is not the reality in many countries and some regions of Brazil.

According the report of ONU, 40% of the world-wide population lacks of appropriate sanitation, contributing for a infantile mortality tax of 1.5 million children dead annually (PNUD, 2010).

In Brazil, 80.5% of the urban population has access to improved sanitation, however, only 45.7% of sewage is collected and of this total, only 34% is treated (IBGE, 2012). This reality shows how much is necessary to move towards in the sanitation services

In Campinas Metropolitan Region (CMR), the level of compliance with sewage collection increased from 85.72% in 2007 to 87.67% in 2012, and the treatment of the total collected had a significant increase from 34% to 66.68%, with a projection for 2013 of 72.58% of treated sewage. In 2007, the 19 municipalities of the CMR, only 13 had treatment plant wastewater, and of these, only Americana, Campinas, Jaguariúna, Sumaré, and had generation and take away, constant. In the municipalities of Paulínia, , Hortolandia, Itatiba and the treatment plants were recent without sufficient generation of sewage for removal. The other municipalities were with construction projects of treatment plants, but in 2012, only Artur Nogueira and Cosmopolis remained without treatmen plants. Since 2012 there is an executive project for delivery in November 2013, with a capacity of 100% treatment of municipal sewage (BROLEZE, 2013).

Most sludge in Brazil is launched in the water bodies without treatment, which, depending on the flow of sewage and the flow of the receiving body, usually impairs water quality, causing environmental damage and health risks of living beings, due to the possibility of water contamination besides cause discomfort due to odor and unpleasant aspect of the water (NUVOLARI, 2003).

In order to maintain water quality, Brazilian law requires a standard release of sanitary and industrial wastewater, so that does not affect the quality of receiving waters, allowing the various uses of these waters, particularly as a source for public supply, without risks to public health and the environment (CONAMA, 2005).

The average composition of the sewage is a mixture of 99.9% of water and 0.1% of solids, and in that total of solids, 70% are organic (proteins, carbohydrates, fats, etc.) and 30% inorganic (sand, salts, metals, etc.) conferring the characteristics of residuary waters (ALEM SOBRINHO, 2002).

During the steps of the treatment there is the generation of a byproduct called sludge, which is equivalent from 20 to 60% of the operating cost of the Treatment Plants. The alternatives of the final disposal can be: landfill, composting, incineration, land farming, co-processing industrial, agricultural recycling, among others.

The production of sludge is increasing due to the growth in the volume of sewage treated and the number of sewage treatment plants in Brazil, has demanded the search for alternatives for final disposition. The composting and agricultural use are viable alternatives since the sludge is rich in organic matter, macronutrients (N, P, S, Ca and Mg) and micronutrients (Cu, Fe, Mn, Zn, B, Mo, Co, Se, Ba, Na and Cl) needed for soil fertility (ANDREOLI, 2006).

Likewise some organic and mineral components confer beneficial characteristics, others may be undesirable from the point of view of health and environment, such as pathogens, organic and inorganic pollutants such as Pb, Hg, Cd, As, Cr and Se.

The main purpose of this work was the evaluation of potentially inorganic substances in sludge of Treatment Plants Camanducaia, in Jaguariúna, Vila Flora, in Sumaré, Praia Azul,

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Carioba, in Americana, Samambaia, Anhumas, Santa Mônica, Piçarrão and Barão Geraldo, in Campinas, SP, employing the Synchrotron Radiation Total Reflection X-Ray Fluorescence technique and compare the sludge sampled with the CONAMA nº 375/06 law and verify the possibility of composting and/or agricultural use of sludge in the soil

2. EXPERIMENTAL

This work was performed with Synchrotron Radiation Total Reflection X-Ray Fluorescence (SR-TXRF) technique due to high intensity of the primary bundle of radiation enabling a analytical sensitivity adequate to the evaluation of the contamination level by inorganic potentially toxic substances in the sewage samples of the treatment plants selected.

2.1. Sampling and Sampling Sites

Initially, it was necessary a contact with the management institutions of the treatment plants of sewage of the 12 cities of the Campinas Metropolitan Region in order to get the permission for sampling. However, only Americana, Campinas, Jaguariúna, Sumaré, Valinhos and Vinhedo have generation and removal of sewage constant. Of these cities, it was gotten permission for the removal of the sewage of the cities of Jaguariúna, Campinas, Sumaré and Americana.

Samples were collected from eight Sludge Treatment Plants, on the same day, in the interval between samples of approximately 15 days. Collection days the weeks were alternated during the period July-August 2010. The volume collected was about 01 kg, where after quartering the sample in the sampling site, according to NBR 10007/04 was removal 0.25 kg for analysis of the sludge quality.

2.2. Sampling Preparation

Samples were dried in an oven at a temperature of 50 ° C (± 5 ° C) with internal recirculation for 5 days. After drying, the samples were grounded in a spray container covered with agate, and then sifted, using a plastic sieve with an aperture of 1.5 mm, by performing the quartering for separating a representative aliquot for digestion, which was packed in a plastic bag for eventual repetition of the digestion and analysis of the sample if required.

For sample digestion the method used was the USPEPA 3050B. This method is a very strong acid digestion that will dissolve almost all elements that could become environmentally available. By design, elements bound in silicate structures are not normally dissolved by this procedure as they are not usually mobile in the environment. (USEPA, 1996).

An aliquot of 1 mL was removed from each sample and transferred to the Eppendorf tubes for SR-TXRF analysis. As an internal standard, 100 L of 102.5 mg/L gallium (Ga) was used. After this procedure, 5 L of the solution was pipetted on the sample holder (perspex) and dried with an infrared lamp.

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For each digestion procedure an analytical blank was prepared with the main purpose to eliminate the contaminations of the reagents employed. All samples, standards, and standard reference material were prepared in triplicate and were stored in Petri dishes to prevent contamination and placed into the desiccators.

2.3. Instrumentation

SR-TXRF analyses were performed at the Synchrotron Light Source Laboratory. Samples were measured for 100 seconds, and a polychromatic (white) beam with 200μm height and 5mm width was utilized for excitation in the energy range of 4-22 keV. The distance sample- detector was 11mm and the incidence angle was 1mrad. X-rays were detected with a Si(Li) semiconductor detector with 165 eV resolution at 5.9 keV. Figure 1 shows a diagram of the experimental setup.

The spectra obtained were analyzed using the Quantitative X-ray Analysis System for Windows (WinQxas) software package provided at no charge by the International Atomic Energy Agency (IAEA) (SIMABUCO, 1993).

3. RESULTS

3.1. System Calibration

The system calibration was performed by the determination of the experimental sensitivity for each element with known concentrations contained in the standard solutions for K and L series. The standards were measured during 100 s, and the spectra obtained were adjusted with the WinQXAS software.

After the determination of the experimental sensitivity the values were fitted as function of atomic number. The curves of the relative sensitivity for K and L series are present in the Figures 2 and 3, respectively.

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2 SRi= exp (-0.0252 Z + 1.6205 Z - 26.0482) R² = 0.9971 1

experimental fitting

0.1 Relative Sensitivity Relative

0.01 19 21 23 25 27 29 31 33 35 37 39 41 Atomic Number

Figure 2: Experimental and fitted relative sensitivity (SRi) experimental for K series.

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Figure 3: Experimental and fitted relative sensitivity (SRi) experimental for L series.

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3.2. Minimum Detection Limit

The minimum detection limit (MDL) is the least quantity that can be statistically discriminated from the background. The minimum detection limit can also be used to compare diverse analytical methodologies. The MDL was calculated by the equation (LADISICH et al, 1993):

I (BG ) C MDL  3. i i  p (1) i t I  S p Ri

Where Ii, is the signal intensity of element i in the sample; Ip is the signal intensity of the internal standard (P) in the sample; Cp is the concentration of the internal standard (P) in the sample; SRi is the relative sensitivity for element i; BGi corresponds to the background signal intensity (counts per second) and t is time in seconds.

Using the equation above the minimum detection limits were calculated for the elements presents in the samples, for a measuring time of 100 s (BAHUR, et al. 2001). Following the experimental values were adjusted and so fitted as showed in the Figure 4.

2 LMDi = 0.0250 Z - 1.5357 Z + 20,4743 R² = 0.9984

100.00

) )

1 -

10.00 Experimental Fitting

1.00

dry dry material

0.10 MinimumDetection Limit(mg.kg 0.01 15 17 19 21 23 25 27 29 31 33 35 37

Atomic Number

Figure 4: Minimum Detection Limit for the elements of K series in sewage samples.

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For elements present in the samples and belonging to L series, was not possible to fit a curve because only the elements Ba and Pb were detected in the analyzed samples, showed in the Table 1.

Table 1: Minimum Detection Limit (mg kg-1) for Ba and Pb elements.

Detection Standard Confidence Variation Element Limit Deviation Interval Coefficient Ba 0.0612 0.0037 0.0009 6.09 Pb 0.0873 0.0103 0.0026 11.80 n=60, α = 95%

3.3. Methodology Validation

In order to validate the methodology used, an analysis of standard reference material was performed. The standard material used was domestic sludge provided by the National Institute of Standards & Technology (NIST 2781).

Table 2 gives the comparison between the certified values and the values measured. Fifteen measurements were made, over 150 seconds. The confidence interval was calculated for a value of α=0.05 (95% confidence level) representing the level of significance, which varies from 0 to 1.

As can be seen the measured values agree with the certified values, indicating a good fit of the sensitivity curves and the appropriateness of the methodology used for the analysis of domestic sewage.

Table 2: Comparison of certified and measures values (mg kg-1), with relative errors of the standard reference material NIST 2781 analyzed by SR-TXRF.

Certified Value Measured Value Relative Error Element (mg kg-1) (mg kg-1) (%) Calcium 36440 ± 1830 37579 ± 54 3,03 Vanadium 82 ± 4 79 ± 7 -3,34 Chromium 143 ± 14 157 ± 3 8,74 Manganese 745 ± 33 718 ± 13 -3,74 Ferro 24300 ± 2100 23841 ± 177 -1,93 Nickel 72 ± 6 70 ± 2 -3,58 Copper 601 ± 16 616 ± 2 2,43 Zinc 1120 ± 34 1145 ± 4 2,22 Barium 570 ± 65 595±19 4,16 Lead 183±15 187±3 1,93

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3.4. Sludge Concentrations

The results obtained were compared with the environmental laws.

For Pb, Cu, Cr, Ni, Zn and Ba all sludge samples of the treatment plants were in according with the CONAMA 375 law.

The concentrations measured for the sludge samples were bellow the limits established by CONAMA 375/06 for Pb (300 mg kg-1) and the limit for agricultural use defined by the Normative Instruction 27/06 (150 mg kg-1) as showed the Figure 5.

The limit for Cu (1500 mg kg-1) showed in the Figure 6 and Zn (2800 mg kg-1) in the Figure 9 established by CONAMA 375/06 was not surpassed for all sludge samples.

For Cr all sludge samples according the CONAMA 375/06 law that established the maximum permissive value of 1000 mg kg-1 (Figure 7). However, Cr concentrations for Camanducaia and Piçarrão Treatment Plants exceeded the Normative Instruction (IN 27/06), of Brazilian Ministry of Agriculture and Livestock (MAPA) that limited the value in 200 mg kg-1.

For Ni all sludge samples were in according with the CONAMA 375/06 (420 mg kg-1) (Figure 8). However the concentrations for all sludge samples surpassed the limit of 70 mg kg-1 established for agricultural use defined by Normative Instruction IN 27/06.

Figure 5: Lead concentration (mg kg-1) in sewage samples.

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Figure 6: Copper concentration (mg kg-1) in sewage samples.

Figure 7: Chromium concentration (mg kg-1) in sewage samples.

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Figure 8: Nickel concentration (mg kg-1) in sewage samples.

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Figure 9: Zinc concentration (mg kg-1) in sewage samples.

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4. CONCLUSIONS

All sludge samples present concentrations in according with the CONAMA 375/06 law for the treatment plants studied. However, for the sludge can be transformed into a product of safe use in agriculture, with certificate and registration, you must meet other legislation, the Regulatory Instruction 27/06 of Brazilian Ministry of Agriculture and Livestock.

This is more restrictive for the limit of inorganic substances in products containing sludge, requiring a reduction in the concentrations of Ni and Cr. An alternative would be a greater control in the generating sources in order to improve the quality of the tributary station (ANDREOLLI et al. 2006). This alternative is in line with sustainability.

Composting could be another way of reducing the Ni, Cr and Cu concentrations. Because by incorporating the carbon source to sludge, to balance the C / N ratio, would dilute the sludge, reducing concentrations surplus, adjusting the final product to the IN 27/06, turning into a product of safe use in agriculture.

ACKNOWLEDGMENTS

The authors wish to thank the National Council for Scientific and Technological Development (CNPq) for financial support (Processes 474007/2007-3 and 308432/2007) and the Synchrotron Light Source Laboratory for the measurements (D09B – XRF beamline, Project 10970).

REFERENCES

1. P. Além Sobrinho, Tratamento de esgoto e produção de lodo. In: M. T. M. Tsutiya, et al. Biossólidos na agricultura, Editora ABES, , Brasil (2002). 2. C. V. Andreoli, Alternativas de uso de resíduos do saneamento. Projeto PROSAB, , Editora ABES, São Paulo, Brasil (2006). 3. C. V. Andreoli, M. Von Sperling, F. Fernandes, Lodo de esgoto: Tratamento e disposição final, Departamento de Engenharia Sanitária e Ambiental; Universidade Federal de ; Companhia de Saneamento do Paraná, (2001). 4. K. Baur, S. Brennan, B. Burrow, D. Werho, P. Pianetta, Laboratory and synchrotron radiation total-reflection X-ray fluorescence: new perspectives in detection limits and data analysis. Spectrochimica Acta Part B: Atomic Spectroscopy, 56, pp. 2049 – 2056 (2001). 5. BRASIL, Ministério da Agricultura, Pecuária e Abastecimento. Decreto nº 4.954, de 14 de janeiro de 2004. Aprova o Regulamento da Lei nº 6.894, de 16 de dezembro de 1980, que dispõe sobre a inspeção e fiscalização da produção e do comércio de fertilizantes, corretivos, inoculantes ou biofertilizantes destinados à agricultura, e dá outras providências. Diário Oficial da União, Brasília, DF. p. 2, 15 jan. 2004. Seção 1. 6. BRASIL, Ministério da Agricultura, Pecuária e Abastecimento. Instrução Normativa nº 27 de 05 de junho de 2006. Estabelece nos Anexos I, II, III, IV e V os limites no que se

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refere às concentrações máximas admitidas para agentes fitotóxicos, patogênicos ao homem, animais e plantas, metais pesados tóxicos, pragas e ervas daninhas. Diário Oficial da União, Brasília, DF. p. 15, 9 jun. 2006. Seção 2. 7. S. T. Broleze. Avaliação da qualidade do lodo das estações de tratamento de esgoto de parte da região metropolitana de Campinas empregando a fluorescência de raios x por reflexão total com radiação síncrotron. Dissertação (mestrado) – Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo. Campinas, (2013). 8. CONAMA. Resolução nº 375 de 29 de agosto de 2006. Define critérios e procedimentos, para o uso agrícola de lodos de esgoto gerados em estações de tratamento de esgoto sanitário e seus produtos derivados, e dá outras providências. Conselho Nacional do Meio Ambiente - CONAMA, Diário Oficial da União, Brasília, DF. p. 141 - 146, 30 ago. 2006. Seção 1. 9. CONAMA. Resolução nº 357 de 17 de março de 2005. Dispõe sobre a classificação dos corpos de água e diretrizes ambientais para o seu enquadramento, bem como estabelece as condições e padrões de lançamento de efluentes, e dá outras providências. Conselho Nacional do Meio Ambiente - CONAMA, Diário Oficial da União, Brasília, DF p. 58-63, 18 mar. 2005. Seção 1. 10. CONAMA. Resolução nº 430 de 13 de maio de 2011. Dispõe sobre as condições e padrões de lançamento de efluentes, complementa e altera a Resolução nº357, de 17 de março de 2005 do Conselho Nacional do Meio Ambiente - CONAMA, Diário Oficial da União, Brasília, DF, n. 92, p. 89, 16 mai. 2011. Seção 1. 11. A. R. Coscione, T. A. R. Nogueira, A. M. M. PIRES. Uso agrícola de lodo de esgoto: avaliação após a Resolução no 375 do CONAMA. : FEPAF, (2010). 12. B. F. Faria, S. Moreira. Evaluation of Heavy Metals in Solid Waste Disposal Sites in Campinas City, Brazil Using Synchrotron Radiation Total Reflection X Ray Fluorescence. Applications of Nuclear Techniques / AIP Conference Proceedings. Vol. 1412, pp. 286- xxx, (2011). 13. Metcalf & Eddy, Inc., Tchobanoglous, G., Burton, F. L., Stensel, H. D., Wastewater Engineering: treatment and reuse. Ed. McGraw-Hill, New York, (2003). 14. S. Moreira, C. B. Vieira, B. Coraucci Filho, R. Stefanutti, E. F. O. Jesus, Study of the metals absorption in culture corn irrigated with domestic sewage by SR-TXRF. Instrumentation Science and Technology, 33(1), 73-85, (2005). 15. A. Nuvolari, Esgoto sanitário: coleta, transporte, tratamento e reuso agrícola, Ed. Blucher, São Paulo, (2003). 16. C. R. R. Pinheiro, J. B. Sígolo, Metais pesados e elementos associados do lodo de esgoto da ETE - Região Metropolitana de São Paulo diante do fator sazonalidade. Geochimica Brasiliensis, 21(2), pp. 151 - 166, (2007). 17. PNUD – Notícias: Em saneamento, Brasil rural é pior que Sudão e Afeganistão. Disponível em: http://www.pnud.org.br. 3 p. Acesso em 08/03/2011. 18. S. M. Simabuco. Emprego da fluorescência de raios-x por dispersão de energia no estudo da dinâmica da vinhaça no solo. Tese (Doutorado) - Instituto de Pesquisas Energéticas e Nucleares, Universidade de São Paulo, São Paulo, (1993). 19. M. T. Tsutiya, J. B. Comparini, P. Além Sobrinho, I. Hespanhol, P. C. T. Carvalho, A. J. Melfi, W. J. Melo, M. O. Marques. Biossólidos na agricultura. 2ª ed. - São Paulo: ABES/SP, (2002).

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