Study of the Impact of Aerobic Digestion on the Waste Sludge Dewaterability of SBR System of Yazd Wastewater Treatment Plant

Document Type : Research Paper

Authors

1 Assistant Professor, Department of Civil Engineering, Isfahan University of Technology, Isfahan, Iran.

2 M.Sc. Student, Department of Civil Engineering, Isfahan University of Technology, Isfahan, Iran.

3 Senior Expert, Yazd Water and Wastewater Company, Yazd, Iran.

Abstract

Sludge treatment and disposal processes in wastewater treatment plants account for a significant portion of the total treatment costs. One of the most expensive parts of sludge treatment is chemical conditioning. Study of the effect of process chain on the conditioning and dewaterability can effectively optimize and reduce operating costs and increase the quality of effluent sludge. This paper investigates the impact of aerobic digestion of waste sludge in Yazd wastewater treatment plant by SBR method on its dewaterability. For this purpose, the waste sludge sample of the plant was aerated in the laboratory at different residence times from 1.5 to 7 days. Then the dewaterability of the sludge was measured by two methods of Specific Resistance to Filtration (SRF) and Tests of Time of Filtration (TTF) in two cases with and without chemical conditioning with cationic polyacrylamide. The results showed that sludge aeration for up to 3 days without conditioning led to the best sludge dewaterability. The best results were obtained at 1.5 days aeration for the conditioning mode with polymer, which improved the dewaterability up to 4.5 times in the optimum polymer dosage. In this case, the polymer dosage decreased by 30% compared to the non-aerated conditioned sludge. It indicates the effect of digestion retention time on dewaterability. At the beginning of the process, the decomposition of cellular material improves the release of water from solid particles. Still, its continuation reduces the dewatering capability due to reduced particle size and conversion to colloidal materials.

Keywords

References

 
امانعلی‎خانی، ش, سلمانی ندوشن، م.، احرام پوش، م.، و مختاری، م.، (1394)، "بررسی کارایی کمک منعقدکننده پلی آکریل آمید اصلاح‌شده با نانو ذرات آلومنیوم اکسید در آبگیری لجن تولیدی از تصفیه‎خانه فاضلاب شهر یزد"، مجله تحقیقات سلامت در جامعه, 1(4), 53-63.‎
APHA, AWWA, and WEF, (2017), Standard methods for the examination of wastewater, America Public Health Association, American Water Works Association, Water Environment Federation, Washington, DC, USA, 23th Edition.
Barbusiński, K., and Filipek, K., (2000), “Aerobic sludge digestion in the presence of chemical oxidizing agents part II. Fenton's reagent”, Polish Journal of Environmental Studies, 9(3), 145-149.
Bruus, J.H., Christensen, J.R., and Rasmussen, H., (1993), “Anaerobic storage of activated sludge: effects on conditioning and dewatering performance”, Water Science and Technology, 28(1), 109-116.
Christensen, M.L., Keiding, K., Nielsen, P.H., and Jørgensen, M.K., (2015), “Dewatering in biological wastewater treatment: a review”, Water Research, 82,14-24.
Cydzik-Kwiatkowska, A., Nosek, D., Wojnowska-Baryła, I., and Mikulski, A., (2020), “Efficient dewatering of polymer-rich aerobic granular sludge with cationic polymer containing hydrocarbons”, International Journal of Environmental Science and Technology, 17(1), 361-370.
Liu, C., and Wu, B., (2020), “Ultrasound enhanced zero-valent iron-activated peroxymonosulfate oxidation for improving dewaterability of aerobically digested sludge”, Chemical Engineering Journal, 392, 124850.
Ni, B.J., Yan, X., Sun, J., Chen, X., Peng, L., Wei, W., Wang, D., Mao, S., Dai, X., and Wang, Q., (2019), “Persulfate and zero valent iron combined conditioning as a sustainable technique for enhancing dewaterability of aerobically digested sludge”, Chemosphere, 232, 45-53.
Sivamani, S., Binnal, P., Cuento, A., Al-Shahri, A., Al-Mahri, M., Rafeet, M., Shamas, M., and Al-Awaid, A., (2020), “A comprehensive review of experimental studies on aerobic digestion of wastewater sludge”, Removal of Toxic Pollutants Through Microbiological and Tertiary Treatment, Book Chapter, Science Direct Pulication, 211-231.
Takdastan, A., Mehrdadi, N., Azimi, A.A., Torabian, A., and NABI, B.G.R., (2009), “Investigation of the excess sludge reduction in SBR by oxidizing some sludge by ozone”, Iranian Journal of Chemistry and Chemical Engineering, 28(4), 95-104.
Techobanoglous, G., Burton, F.L., and Stensel, H.D., (2014), Wastewater engineering: Treatment and reuse, McGraw-Hill.
Turovskiy, I.S., and Mathai, P.K., (2006), Wastewater sludge processing, John Wiley and Sons.
Turovskiy, I.S., (2001), “Technological improvements for the aerobic digestion of sludge”, Water Engineering and Management, Available on: https:// files. wwdmag.com/s3fs-public/ Sludge Digestion8 _01WEM.pdf
Wang, J., Chen, C., Gao, Q., Li, T., and Zhu, F., (2012), “Relationship between the characteristics of cationic polyacrylamide and sewage sludge dewatering performance in a full-scale plant”, Procedia Environmental Sciences, 16, 409-417.
Wang, X.M., Wang, X., Yang, M.H., and Zhang, S.J., (2018), “Sludge conditioning performance of polyaluminum, polyferric, and titanium xerogel coagulants”, Huan jing ke xue= Huanjing kexue, 39(5), 2274-2282.
Woo, B., (2008), “Sludge stabilization sustainability of aerobic digestion processes”, Research Document, USA, Available on: https://www.semanticscholar.org/ paper/Sludge-Stabilization-Sustainability-of-Aerobic-Woo/5c09f4f05e4654b30774556b1e4785bb5ff29803.
Zhang, Z., Zhou, Y., Zhang, J., Xia, S., and Hermanowicz, S.W., (2016), “Effects of short-time aerobic digestion on extracellular polymeric substances and sludge features of waste activated sludge”, Chemical Engineering Journal, 299, 177-183.
Journal of Water and Wastewater Science and Engineering
Volume 7, Issue 2
July 2022
Pages 34-41

Files

History

  • Receive Date: 18 September 2021
  • Revise Date: 11 December 2021
  • Accept Date: 30 December 2021

Share

How to cite

Statistics