Combustion effect on the physical, chemical, mineralogical, and microstructural compositions of urban sewage sludge

Fouzia Benoudjit, Messaoud Hachemi


This paper investigates the combustion of the urban sewage sludge from 550 to 1000˚C with
the aim of studying the evolution that occurs on the composition of the sewage sludge during the
heat treatment process. Several analyses have been carried out: pH, X-ray fluorescence, and atomic
absorption spectrometry. The results of the experiments indicate that increasing the temperature
increases the basic character, the amount of major and minor elements in the obtained sewage
sludge ash. These phenomena are due to the richness of the sludge in the organic matter, which
led to a considerable volume reduction when the sludge was combusted. The X-ray fluorescence
analysis of the sewage sludge ash showed an increase in the amount of aluminosilicates, which
constitute the reactive part in a pozzolanic material. The atomic absorption spectrometer analysis of
the heavy metals in the ash showed that their respective concentrations depend on their melting and
boiling points. The calcium carbonates decomposition, observed by X-ray diffractometry, occurred
during the combustion of the sludge between 650 and 700˚C. The scanning electron microscopy
showed morphological changes in the sewage sludge ash when the temperature increases. The size
of the ash grains increased due to agglomeration, and sintering occurs. It can be concluded that
the combustion of the dried sewage sludge leads to an ash, whose properties are interesting for its
valorisation in building materials.


combustion; heavy metals; microstructural analysis; organic matter; sewage sludge ash.

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Abrego, J., Arauzo, J., Sanchez, J. L., Gonzalo, A., Cordero, T. & Rodrıguez-Mirasol, J. 2009. Structural

changes of sewage sludge char during fixed-bed pyrolysis. Industrial & Engineering Chemistry Research,

: 3211- 3221.

Al Sayed, M. H., Madany, I. M. & Buali, A. R. M. 1995. Use of sewage sludge ash in asphaltic paving

mixes in hot regions. Construction and Building Materials, 9(1): 19 -23.

Baeza-Brotons, F., Garces, P., Paya, J. & Saval, J. M. 2014. Portland cement systems with addition of

sewage sludge ash. Application in concretes for the manufacture of blocks. Journal of Cleaner Production,

: 112- 124.

Bhatty, J. I. & Reid, K. J. 1989. Lightweight aggregates from incinerated sludge ash. Waste Management

& Research, 7: 363- 376.

Bianchini, A., Bonfiglioli, L., Pellegrini, M. & Saccani, C. 2015. Sewage sludge drying process integration

with a waste-to-energy power plant. Waste Management, 42: 159 -165.

Bouzid, J., Elouear, Z., Ksibi, M., Feki, M. & Montiel, A. 2008. A study on removal characteristics of

copper from aqueous solution by sewage sludge and pomace ashes. Journal of Hazardous Materials,

: 838 -845.

Cheeseman, C.R. & Virdi, G.S. 2005. Properties and microstructure of lightweight aggregate produced from

sintered sewage sludge ash. Resources, Conservation and Recycling, 45: 18- 30.

Chen, J. C., Wey, M. Y. & Ou, W. Y. 1999. Capture of heavy metals by sorbents in incineration flue gas. The

Science of the Total Environment, 228: 67- 77.

Chen, M., Blanc D., Gautier M., Mehu J. & Gourdon R. 2013. Environmental and technical assessments

of the potential utilization of sewage sludge ashes (SSAs) as secondary raw materials in construction.

Waste Management, 33: 1268- 1275.

Chen, T. & Yan, B. 2012. Fixation and partitioning of heavy metals in slag after incineration of sewage

sludge. Waste Management, 32: 957- 964.

Corella, J. & Toledo, J. M. 2000. Incineration of doped sludges in fluidized bed. Fate and partitioning of

six targeted heavy metals. I. Pilot plant used and results. Journal of Hazardous Materials, B80: 81- 105.

Cusidó, J. A. & Cremades, L. V. 2012. Environmental effects of using clay bricks produced with sewage

sludge: Leachability and toxicity studies. Waste Management, 32: 1202 -1208.

Cyr, M., Coutand, M. & Clastres, P. 2007. Technological and environmental behaviour of sewage sludge

ash (SSA) in cement-based materials. Cement and Concrete Research, 37: 1278- 1289.

Donatello S. & Cheeseman, C. R. 2013. Review: Recycling and recovery routes for incinerated sewage

sludge ash (ISSA): A review. Waste Management, 33: 2328 -2340.

Folgueras, M.B., Alonso, M. & Díaz, R.M. 2013. Influence of sewage sludge treatment on pyrolysis and

combustion of dry sludge. Energy, 55: 426- 435.

Fytili, D. & Zabaniotou, A. 2008. Utilization of sewage sludge in EU application of old and new methods-A

review. Renewable and Sustainable Energy Reviews, 12: 116- 140.

Gavalda, D., Scheiner, J.D., Revel, J.C., Merlina, G., Kaemmerer, M., Pinelli, E. & Guiresse M. 2005.

Agronomic and environmental impacts of a single application of heat-dried sludge on an Alfisol. Science

of the Total Environment, 343: 97 -109.

Groß, B., Eder, C., Grziwa, P., Horst, J. & Kimmerle, K. 2008. Energy recovery from sewage sludge by

means of fluidised bed gasification. Waste Management, 28: 1819 -1826.

Han, J., Xu, M., Yao, H., Furuuchi, M., Sakano, T., Kanchanapiya, P. & Kanaoka, C. 2006. Partition of

heavy and alkali metals during sewage sludge incineration. Energy & Fuels, 20: 583- 590.

ISO 11265: 1994. Soil quality – Determination of the specific electrical conductivity.

ISO 5667 -13: 1997. Water quality – Sampling – Part 13: Guidance on sampling of sludges from sewage and

water treatment works.

ISO 5667- 15: 1999. Water quality – Sampling – Part 15: Guidance on preservation and handling of sludge

and sediment samples.

Khiari, B., Marias, F., Zagrouba, F. & Vaxelaire J. 2004. Analytical study of the pyrolysis process in

wastewater pilot station. Desalination, 167: 39- 47.

Kuntz, J., Nassr-Amellal, N., Lollier, M., Schmidt, J. E. & Lebeau, T. 2008. Effect of sludges on bacteria

in agricultural soil. Analysis at laboratory and outdoor lysimeter scale. Ecotoxicology and Environmental

Safety, 69: 277- 288.

Li, H., Zou, S., Li, Y. & Jin, Y. 2013. Characteristics and model of sludge adhesion during thermal drying.

Environmental Technology, 34(6): 807- 812.

Lin, D. F., Luo, H. L. & Sheen, Y. N. 2005a. Glazed tiles manufactured from incinerated sewage sludge ash

and clay. Journal of the Air & Waste Management Association, 55: 163- 172.

Lin, D.F., Lin, K.L., Chang, W.C., Luo, H.L. & Cai, M.Q. 2008. Improvements of nano-SiO2 on sludge/

fly ash mortar. Waste Management, 28: 1081 -1087.

and Concrete Research, 35: 1999 -2007.

Lin, K.L., Chiang, K.Y. & Lin, C.Y. 2005b. Hydration characteristics of waste sludge ash that is reused in

eco-cement clinkers. Cement and Concrete Research, 35: 1074 -1081.

Lin, M., Ning, X. A., Liang, X., Wei, P., Wang, Y. & Liu, J. 2014. Study of the heavy metals residual in

the incineration slag of textile dyeing sludge. Journal of the Taiwan Institute of Chemical Engineers,

: 1814- 1820.

Liu, Z., Qian, G., Sun, Y., Xu, R., Zhou, J. & Xu, Y. 2010. Speciation evolutions of heavy metals during the

sewage sludge incineration in a laboratory scale incinerator. Energy & Fuels, 24: 2470 -2478.

Luo, H. L. & Lin, D. F. 2007. Study the surface colour of sewage sludge mortar at high temperature.

Construction and Building Materials, 21: 90 -97.

Magdziarz, A. & Werle, S. 2014. Analysis of the combustion and pyrolysis of dried sewage sludge by TGA

and MS. Waste Management, 34: 174- 179.

Merino, I., Arévalo, L. F. & Romero, F. 2007. Preparation and characterization of ceramic products

by thermal treatment of sewage sludge ashes mixed with different additives. Waste Management,

: 1829 -1844.

Monteroa, M.A., Jordán, M.M., Almendro-Candel, M.B., Sanfeliu, T. & Hernández-Crespo, M.S. 2009

(a). The use of a calcium carbonate residue from the stone industry in manufacturing of ceramic tile

bodies. Applied Clay Science, 43: 186 -189.

Monteroa, M.A., Jordán, M.M., Hernández-Crespo, M.S. & Sanfeliu, T. 2009b. The use of sewage

sludge and marble residues in the manufacture of ceramic tile bodies. Applied Clay Science, 46: 404- 408.

Monzo, J., Paya, J., Borrachero, M.V. & Corcoles, A. 1996. Use of sewage sludge ash (SSA)-cement

admixtures in mortars. Cement and Concrete Research, 26(9): 1389- 1398.

Monzo, J., Paya, J., Borrachero, M.V. & Girbes, I. 2003. Reuse of sewage sludge ashes (SSA) in cement

mixtures: the effect of SSA on the workability of cement mortars. Waste Management, 23: 373- 381.

Monzó, J., Payá, J., Borrachero, M.V. & Peris-Mora, E. 1999. Mechanical behavior of mortars containing

sewage sludge ash (SSA) and Portland cements with different tricalcium aluminate content. Cement and

Concrete Research, 29: 87 -94.

NF EN 12176: 1998. Caractérisation des boues – Détermination de la valeur du pH.

NF EN 12879: 2000. Caractérisation des boues – Détermination de la perte au feu de la matière sèche.

NF EN 12880: 2000. Caractérisation des boues – Détermination de la teneur en matière sèche et de la teneur

en eau.

NF EN 197- 1: 2001. Ciment – Composition – Spécifications et critères de conformité – Partie 1 : Composition,

spécifications et critères de conformités des ciments courants.

Pan, S. C., Tseng, D. H., Lee, C. C. & Lee, C. 2003. Influence of the fineness of sewage sludge ash on the

mortar properties. Cement and Concrete Research, 33: 1749 -1754.

Pena, A., Mingorance, Mª D., Guzman-Carrizosa, I. & Fernandez-Espinosa, A. J. 2015. Improving

the mining soil quality for a vegetation cover after addition of sewage sludges: Inorganic ions and

low-molecular-weight organic acids in the soil solution. Journal of Environmental Management,

: 216- 225.

Pigamo, A., Besson, M., Blanc, B., Gallezot, P., Blackburn, A., Kozynchenko, O., Tennison, S., Crezee,

E. & Kapteij, F. 2002. Effect of oxygen functional groups on synthetic carbons on liquid phase oxidation

of cyclohexanone. Carbon, 40: 1267 -1278.

Romdhanaa, M. H., Lecomte, D., Ladevie, B. & Sablayrolles, C. 2009. Monitoring of pathogenic

microorganisms contamination during heat drying process of sewage sludge. Process Safety and

Environmental Protection, 87: 377- 386.

Tay, J. H. & Show, K. Y. 1992. Utilization of municipal wastewater sludge as building and construction

materials, Resources, Conservation and Recycling, 6: 191 -204.

Tuan, B. L. A., Hwang, C. L., Lin, K. L., Chen, Y. Y. & Young, M. P. 2013. Development of lightweight

aggregate from sewage sludge and waste glass powder for concrete. Construction and Building Materials,

: 334 -339.

Valdecantos, A., Cortina, J. & Vallejo, V. R. 2011. Differential field response of two Mediterranean tree

species to inputs of sewage sludge at the seedling stage. Ecological Engineering, 37: 1350 -1359.

Vassilev, S. V., Kitano, K., Takeda, S. & Tsurue, T. 1995. Influence of mineral and chemical composition of

coal ashes on their fusibility. Fuel Processing Technology, 45: 27 -51.

Wang, K. S., Chiou, I. J., Chen, C. H. & Wang, D. 2005. Lightweight properties and pore structure of

foamed material made from sewage sludge ash. Construction and Building Materials, 19: 627- 633.

Wang, L., Skjevrak, G., Hustad, J. E. & Grønli, M. G. 2012. Sintering characteristics of sewage sludge

ashes at elevated temperatures. Fuel Processing Technology, 96: 88 -97.

Weng, C. H., Lin, D. F. & Chiang, P. C. 2003. Utilization of sludge as brick materials. Advances in

Environmental Research, 7: 679- 685.

Werther, J. & Ogada, T. 1999. Sewage sludge combustion. Progress in Energy and Combustion Science,

: 55- 116.

Yan, R., Liang, D. T., Laursen, K., Li, Y., Tsen, L. & Tay, J. H. 2003. Formation of bed agglomeration in a

fluidized multi-waste incinerator. Fuel, 82: 843 -851.

Zhang, F. S., Yamasaki, S. I. & Nanzyo, M. 2001. Application of waste ashes to agricultural land-effect of

incineration temperature on chemical characteristics. The Science of the Total Environment, 264: 205 -214.


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