References

1. L.H. Mikkelsen, K. Keiding, Physico-chemical characteristics of full scale sewage sludges with implications to dewatering, Water Res., 36 (2002) 2451–2462.
2. B. Bień, J.D. Bień, Dewatering of sewage sludge treated by the combination of ultrasonic field and chemical methods, Desal. Water Treat., 199 (2020) 72–78.
3. B. Bień, The impact of coagulant PIX 113 modified by ultrasonic field on sewage sludge dewatering, Desal. Water Treat., 117 (2018) 175–180.
4. S. Tanaka, T. Kobayashi, K. Kamiyama, M.L. Bildan, Effects of thermochemical pre-treatment on the anaerobic digestion of waste activated sludge, Water Sci. Technol., 8 (1997) 209–215.
5. M.C. Lu, C.J. Lin, C.H. Liao, R.Y. Huang, W.P Ting, Dewatering of activated sludge by Fenton’s reagent, Adv. Environ. Res., 7 (2003) 667–670.
6. G.R. Chang, J.C. Liu, D.J. Lee, Co-conditioning and dewatering of chemical sludge and waste activated sludge, Water Res., 35 (2001) 786–794.
7. C. Bougrier, C. Albasi, J.P. Delgenes, H. Carrere, Effect of ultrasonic, thermal and ozone pre-treatments on waste activated sludge solubilisation and anaerobic biodegradability, Chem. Eng. Process., 45 (2006) 711–718.
8. E. Zielewicz, Effects of ultrasonic disintegration of excess sewage sludge, Top. Curr. Chem., 374 (2016) 67,
   doi: 10.1007/s41061-016-0068-5.
9. M. Zieliński, M. Dębowski, M. Krzemieniewski, P. Rusanowska, M. Zielińska, A. Cydzik-Kwiatkowska, A. Głowacka-Gil, Application of an innovative ultrasound disintegrator for sewage sludge conditioning before methane fermentation, J. Ecol. Eng., 19 (2018) 240–247.
10. M. Worwąg, Effect of sewage sludge sonication parameters on the content of organic compounds in the supernatant liquid, Desal. Water Treat., 199 (2020) 66–71.
11. C.H. Zhou, Y. Ling, M. Zeng, X.Y. Li, Influence of microwave and ultrasound on sludge dewaterability, Adv. Mater. Res., 955–959 (2014) 2074–2079.
12. C. Zhou, Y. Ling, M. Zeng, Y. Li, Analysis of particle size distribution and water content on microwave/ultrasound pretreated sludge, Chin. J. Environ. Eng., 11 (2017) 529–534.
13. Ł. Skórkowski, E. Zielewicz, The influence of energy input on the particle size of disintegrated excess sludge in the ultrasonic disintegration process, Water Sci. Technol., 2017 (2018) 679–685.
14. Ł. Skórkowski, E. Zielewicz, A. Kawczyński, B. Gil, Assessment of excess sludge ultrasonic, mechanical and hybrid pretreatment in relation to the energy parameters, Water, 10 (2018) 1–15.
15. S.H. Yoon, H.S. Kim, S. Lee, Incorporation of ultrasonic cell disintegration into a membrane bioreactor for zero sludge production, Process Biochem., 39 (2004) 1923–1929.
16. C.P. Chu, D.J. Lee, B.-V. Chang, C.S. Liao, Observations on changes in ultrasonically treated waste activated sludge, Water Res., 35 (2001) 1038–1046.
17. E. Gonze, S. Pillot, E. Valette, Y. Gonthier, A. Bernis, Ultrasonic treatment of an aerobic activated sludge in a batch reactor, Chem. Eng. Process., 42 (2003) 965–975.
18. E.R. Sarabia, J.A. Gallego-Juarez, G. Rodriguez-Corral, L. Elvira-Segura, I. Gonzalez-Gomez, Application of highpower ultrasound to enhance fluid/solid particle separation processes, Ultrasonics, 38 (2000) 642–646.
19. C.P. Chu, B.V. Chang, G.S. Liao, D.S. Jean, D.J. Lee, Obervations on changes in ultrasonically treated
    waste-activated sludge, Water Res., 35 (2001) 1038–1046.
20. S. Na, Y.U. Kim, J. Khim, Physiochemical properties of digested sewage sludge with ultrasonic treatment, Ultrason. Sonochem., 14 (2007) 281–285.
21. C. Bourgrier, H. Carrere, J.P. Delgenes, Solubilisation of waste-activated sludge by ultrasonic treatment, Chem. Eng. J., 106 (2005) 163–169.
22. Y.U. Kim, B.I. Kim, Effect of ultrasound on dewaterability of sewage sludge, Jpn. J. Appl. Phys., 1 (2003) 5898–5899.
23. E. Gonze, S. Pillot, E. Valette, Y. Gonthier, A. Bernis, Ultrasonic treatment of an aerobic activated sludge in a batch reactor, Chem. Eng. Process., 42 (2003) 965–975.
24. S. Pilli, P. Bhunia, S. Yan, R.J. LeBlanc, R.D. Tyagi, R.Y. Surampalli, Ultrasonic pretreatment of sludge: a review, Ultrason. Sonochem., 18 (2011) 1–18.
25. X. Yin, X.P. Lu, P.F. Han, Y.R. Wang, Ultrasonic treatment on activated sewage sludge from petro-plant for reduction, Ultrasonics, 44 (2006) 397–399.
26. R. Dewil, J. Baeyens, R. Goutvrind, Ultrasonic treatment of waste activated sludge, Environ. Prog., 25 (2006) 121–128.
27. F. Wang, M. Ji, S. Lu, Influence of ultrasonic disintegration on the dewaterability of waste activated sludge, Environ. Prog., 25 (2006) 257–260.
28. X. Feng, H.Y. Lei, J.C. Deng, Q. Yu, H.L. Li, Physical and chemical characteristics of waste activated sludge treated ultrasonically, Chem. Eng. Process., 48 (2009) 187–194.
29. C.P. Chu, D.J. Lee, C.S. You, J.H. Tay, Weak ultrasonic pretreatment on anaerobic digestion of flocculated activated biosolids, Water Res., 36 (2002) 2681–2688.
30. M. Saha, C. Eskicioglu, J. Marin, Microwave, ultrasonic and chemo-mechanical pretreatments for enhancing methane potential of pulp mill wastewater treatment sludge, Bioresour. Technol., 102 (2011) 7815–7826.
31. Y.Q. Zhao, Correlations between floc physical properties and optimum polymer dosage in alum sludge conditioning and dewatering, Chem. Eng. J., 92 (2003) 227–235.
32. I. Zawieja, L. Wolny, Ultrasonic disintegration of sewage sludge to increase biogas generation, Chem. Biochem. Eng. Q., 27 (2013) 491–497.
33. K.A. Nickel, U Neis, Ultrasonic disintegration of biosolids for improved biodegradation, Ultrason. Sonochem., 14 (2007) 450–455.
34. C.P. Chu, B.V. Chang, G.S. Liao, D.S. Jean, D.J. Lee, Observations on changes in ultrasonically treated waste activated sludge, Water Res., 35 (2001) 1038–1046.
35. J. Kopp, J. Müller, N. Dichtl, J. Schwedes, Anaerobic digestion and dewatering characteristics of mechanical disintegrated excess sludge, Water Sci. Technol., 36 (1997) 129–136.
36. P. Wolski, I. Zawieja, Effect of ultrasound field on dewatering of sewage sludge, Arch. Environ. Prot., 38 (2012) 25–31.
37. C.P. Chu, B.V. Chang, G.S. Liao, D.S. Jean, D.J. Lee, Observations on changes in ultrasonically treated waste–activated sludge, Water Res., 35 (2001) 1038–1046.
38. C.P. Chu, D.J. Lee, Experimental analysis of centrifugal dewatering process of polyelectrolyte flocculated waste activated sludge, Water Res., 35 (2001) 2377–2384.
39. Z. Qian, R.D. Sagers, W.G. Pitt, The effect of ultrasonic frequency upon enhanced killing of P. aeruginosa biofilms, Ann. Biomed. Eng., 25 (1997) 69–76.
40. D. Prasad, J.G. Henry, A. King, Coliform inactivation in sludge by copper sulfate, Can. J. Civ. Eng., 20 (1993) 814, doi: 10.1139/ l93-106.
41. S. Biggs, M. Habgood, G.J. Jameson, Y.D. Yan, Aggregate structures formed via a bridging flocculation mechanism, Chem. Eng. J., 80 (2000) 13–22.
42. A. Canales, A. Pareilleux, J. Rols, G. Goma, A. Huyard, Decreased sludge production strategy for domestic wastewater treatment, Water Sci. Technol., 30 (1994) 97–106.
43. M. Worwąg, Recovery of phosphorus as struvite from sewage sludge and sewage sludge ash, Desal. Water Treat., 134 (2018) 121–127.