Investigating Some Chemical, Morphological Characteristics and Contamination Risk Assessment of Heavy Metals in Sewage Sludge and Its Biochar at Different Temperatures

Document Type : Research Paper

Authors

1 Soil Sci. Dep. Shahrekord Univ., Shahrekord, Iran,

2 Prof. Soil Sci. Dep. Shahrekord Univ. Shahrekord, Iran

3 shahrekord university

10.22092/ijsr.2024.361168.695

Abstract

Pyrolysis is important as an economical and environmentally friendly technology to facilitate recycling and reduce the environmental risk of sewage sludge. The aim of this research was to study changes in the structure, specific surface area, and pores of biochar, and to evaluate the risk of heavy metals contamination due to pyrolysis of sewage sludge. Sewage sludge biochar was prepared under limited oxygen conditions at temperatures of 300, 400, 500, 600 and 700 0C. Specific surface area and pore analysis were determined using the N2 adsorption isotherm, BET equation, and scanning electron microscopy (SEM) images. The risk of lead and zinc contamination was assessed using the BCR fractionation method and contamination factors. The results showed that the specific surface of biochar under the influence of temperatures of 400, 500, 600 and 700 0C was 2.65, 3.65, 8.38, and 5.57 times that of sludge, respectively. By comparing the total volume and the average pore diameter, biochar had more porosity than sewage sludge. The main pores in the biochar were meso (8.34-19.98 nm). The morphological structure of the sewage sludge was smooth and irregular, and, in contrast to the biochars, they had more porous and uneven surface. The presence of honeycomb-shaped structures was detectable at high temperatures, especially at 600 ° C. The toxic response factor (Er) for sewage sludge and biochar was low. By converting the sewage sludge to biochar, the contamination factor (Cf) of Zn and Pb was reduced by more than 50%. The conversion of sewage sludge to biochar increased the specific surface, increased porosity, and stabilized carbon in the form of aromatic compounds. Due to the reduction of metal contamination factor and the possibility of environmental risk in biochar, these materials can be used as adsorbents or modifiers in different environments.

Keywords

Main Subjects


  1. Agrafiotia, E., G. Bourasa, D. Kalderisb, and E. 2013. Biochar production by sewage sludge pyrolysis. JAAP. 101: 72–78
  2. Bogusz, A. and P. 2020. Effect of biochar addition to sewage sludge on cadmium, copper and lead speciation in sewage sludge-amended soil. Chemosphere. 239: 719-726.
  3. Breulmann, M., M. Van Afferden, R. A. Muller, Schulz, and C. Fuhner. 2017. Process conditions of pyrolysis and hydrothermal carbonization affect the potential of sewage sludge for soil carbon sequestration and amelioration. JAAP.124: 256-265.
  4. Dokht H.F, E. Dordipour, A.M.N. Seyed. 2017. Adsorption and desorption of lead in Iranian acid and alkaline soils amended with sewage sludge-derived biochar. JAEHR. 5: 59-69.
  5. Chen, T., Y. Zhang, H. Wang, W. Lu, Z. Zhou, and Y. Zhang. 2014. Influence of pyrolysis temperature on characteristics and heavy metal adsorptive performance of biochar derived from municipal sewage sludge. Technol. 164:47-54
  6. Fryda, L. and R.Visser. 2015. Biochar for soil improvement: Evaluation of biochar from gasification and slow pyrolysis. Agriculture. 5:1076–1115.
  7. Huang, H. and Z. Yuan. 2016. The migration and transformation behaviors of heavy metals during the hydrothermal treatment of sewage sludge: A Review. Bioresour. Technol. 200:991-998.
  8. Jin, J.W., Y.A. Li, J.Y. Zhang, S.C. Wu, Y.C. Cao, P. Liang, J. Zhang, M.H. Wong, M.Y. Wang, S.D. Shan, and P. Christie. 2016. Influence of pyrolysis temperature on properties and environmentalsafety of heavy metals in biochars derived from municipal sewage sludge. Hazard. Mater. 320: 417-426
  9. Jin, J. M. wang, Y. Cao, S .Wu, P. Liang, Y. Li , J. Zhang, J. Zang, M.H. Hung Wong, S. Shan, and P. Christie. 2017. Cumulative effects of bamboo sawdust addition on pyrolysis of sewage sludge: Biochar properties and environmental risk from metals. Technol 228: 218-22
  10. Karimi, F., G. Rahimi, Z. Kolahchi, A. Khademi, and J .Nezhad. 2019. Using Industrial Sewage Sludge-Derived Biochar to Immobilize Selected Heavy Metals in a Contaminated Calcareous Soil. Waste Biomass Valorization. 11: 2825–2836
  11. Khanmohammadi, Z., M. Afyuni, and M.R. Mosaddeghi. 2015. Effect of pyrolysis temperature on chemical and physical properties of sewage sludge biochar. J.Waste Manag. 33:275-283
  12. Lehmann, J., and S. Joseph. 2015. Biochar for environmental management: science, technology and implementation, Routledge.
  13. Lu, , H. Yuan, Y. Wang, H. Huang, and Y. Chen. 2016. Characteristic of heavy metals in biochar derived from sewage sludge Mater Cycles. Journal of Material Cycles and Waste Management 18:725–733.
  14. Mendez, A., M. Terradillos, and G. Gasco. 2013. Physicochemical and agronomic properties of biochar from sewage sludge pyrolysed at different temperatures.102:124-130
  15. Rauret, G., J.F. Lopez-Sanchez, A. Sahuquillo, R. Rubio, C. Davidson, A. Ure, and P. Quevauviller. 1999. Improvement of the BCR three step sequential extraction procedure prior to the certification of new sediment and soil reference materials. 1: 57–61.
  16. Racek, , J. Sevcik, T. Chorazy, J. Kucerik and P. Hlavinek. 2020. Biochar–Recovery Material from Pyrolysis of Sewage Sludge: A Review. Waste Biomass Valorization. 11:3677–3709.
  17. Singh C., S. Tiwari and J. S. Singh, 2020. Biochar: A Sustainable Tool in Soil Pollutant Bioremediation. Bioremediation of Industrial Waste for Environmental Safety. 475-494.
  18. Song, X.D., X.Y. Xue, D.Z. Chen, P.J. He, and X.H. Dai. 2014. Application of biochar from sewage sludge to plant cultivation: Influence of pyrolysis temperature and biochar-to-soil ratio on yield and heavy metal accumulation. 109: 213–220
  19. Tomczyk, A., Z. Sokołowska, and P. Boguta. 2020. Biochar phys[ icochemical properties: pyrolysis temperature and feedstock kind effects. Rev Environ Sci Biotechnol. 19:191–215
  20. Udayaga, W. C., A.Veksha, A. Giannis, Lisak, V.W.C. Chang, and T.T. Lim. 2018. Fate and distribution of heavy metals during thermal processing of sewage sludge. Fuel. 226, 721-744.
  21. Xie, T., B. Y.Sadasivam, K. R. Reddy, C. Wang, and K. Spokas. 2016. Review of the effects of biochar amendment on soil properties and carbon sequestration. Journal of Hazardous, Toxic, and Radioactive Waste. 20,

22.           Yang, X., J. Liu, M. Kim, H. Huang, K. Lu, X. Guo, L. He, X. Lin, L. Che, Z. Ye.  and H. Wang. 2016.  Environ effect of biochar on the extractability of heavymetals (Cd, Cu, Pb, and Zn) and enzyme activity in soil. Environ. Sci. Pollut. Res.  23:974-984.

  1. Yuan, X., Leng, H. Huang, X. Chen, H. Wang, Z. Xiao, Y. Zhai,  H. Chen, and G. Zeng. 2015. Speciation and environmental risk assessment of heavy metal in bio-oil from liquefaction/pyrolysis of sewage sludge. Chemosphere. 120:645–652
  2. Zhao, S., C.H. Feng, Y.R. Yang, J.F. Niu, and Z.Y. Shen. 2012. Risk assessment of sedimentary metals in the Yangtze Estuary: new evidence of the relationships between two typical index methods. J. Hazard. Mater. 242: 164–172.
  3. Zielinska, A., P. Oleszczuk, B .Charmas, J. Skubiszewska-Zieba, and Z. Pasieczna-Patkowska. 2015. Effect of sewage sludge properties on the biochar characteristic. JAAP. 112: 201–213.