Modelling the anaerobic digestion behaviour of proteins in thermally treated sludge using a new biomass transfer kinetic model
- 22 Downloads
In this study, a newly developed biomass transfer kinetic model was utilized for studying anaerobic digestion behaviour of proteins in sludge from two different thermally treatment processes [i.e., the thermal hydrolysis process (THP) and intermediate thermal hydrolysis processes (ITHP)]. Three different experimental runs comprising a high-level protein load (HLPL) (2000 < X < 3000 mg/L), intermediate-level protein load (ILPL) (1000 < X < 2000 mg/L), and low-level protein load (LLPL) (X < 1000 mg/L) were allowed to undergo anaerobic degradation for 312 h to monitor changes in total protein concentration. Analysis of protein degradation kinetics revealed that the first-order model was inappropriate for studying AD behaviour of protein in thermally treated sludge. However, the biomass transfer kinetic model provided an excellent fitting for the experimental data. In addition, it was observed that the anaerobically digested ITHP-treated sludge displayed higher values for the initial hydrolysis rate and overall biomass transfer coefficient at HLPL as compared to the anaerobically digested THP-treated sludge. Furthermore, step-wise kinetics was blamed on variability in the rates of utilizing highly soluble hydrozylate protein fractions present in the liquid phase in comparison to the slowly degradable proteins present in the liquid–solid sludge interface.
KeywordsThermally treated sludge Step-wise degradation Biomass transfer Anaerobic digestion Kinetics
The authors would like to thank Thames Water Utilities for funding this research work. This work is a collaborative research project between the University of Surrey and Thames Water Utilities, UK and University of Port Harcourt, Nigeria.
Compliance with ethical standards
Conflict of interest
We declare that there was no conflict of interest associated with the preparation of this article.
- 1.Vaa M (1993) Toward more appropriate technologies? Experience from the water and sanitation sector, research report 94 Nordiska Afrikainstitutet Uppsala.Google Scholar
- 3.Shana A, Ouki S, Asaadi M, Pearce P (2011) Application of an innovative process for improving mesophilic anaerobic digestion of sewage sludge; Proceedings from 16th European biosolids and organic Resources conferenceGoogle Scholar
- 4.Eastman JA, Ferguson JF (1981) Solubilization of particulate organic carbon duringthe acid phase of anaerobic digestion. J Water Pollut Control Fed 53:352–366Google Scholar
- 6.Chen N, Liu Y, Liu N, Wang S (2012) Energy balance of thermal hydrolysis and anaerobic digestion on waste activated sludge. World Automation Congress (WAC), IEEE, pp 1–3.Google Scholar
- 11.Shana A (2015) Application of an innovative process for improving mesophilic anaerobic digestion of sewage sludge. PhD Dissertation, University of Surrey, Gilford UKGoogle Scholar
- 13.Watson JD, Hopkins NHR, Roberts JW, Steitz JA, Weiner AM (1987) Cells obey the laws of chemistry. Molecular biology of the gene. The Benjamin/Cummings Publishing Company, Menlo Park, pp 25–64Google Scholar
- 15.Shana A, Ouki S, Asaadi M, Pearce P (2012) Influence of intermediate thermal hydrolysis process on the kinetics of anaerobic digestion of sewage sludge. Chem Eng Transac 29:267–1272Google Scholar
- 17.Christopher WA, Novak JT, Murthy SN (2009) Thermal hydrolysis of the lipid and protein fractions of wastewater sludge: implications for digester performance and operational considerations. Water Environ Fed 12:3918–3922Google Scholar
- 18.Fernandes XA, Kimber L (1990) WRc Standard (Biodegradability) test for amenability of sewage sludge to anaerobic digestion; report No.UM1053, WRc Swindon, UK.Google Scholar
- 19.Lowry OH, Rosebrough JN, Farr AL, Randall JR (1951) Protein measurement with Folin phenol reagent. Department of pharmacology, Washington University, school of medicine, St. Louis, Missori.Google Scholar
- 22.Gonzalez VM (2006) Enhanced gas production in mesophilic anaerobic digestion. A Thesis Submitted in Fulfilment of the Requirement for the Degree of Doctor of Philosophy, the University of Surrey.Google Scholar
- 23.Asaadi M (2008) Review of the performance of an advanced digestion process In: 13th European Biosolids and Organic Resources Conference and Workshop, November 10–12, Lancashire UKGoogle Scholar