Separation of Cellulose fromWastewater and Valorisation via Pyrolysis: A Case Study in the Czech Republic

Separation of Cellulose fromWastewater and Valorisation via Pyrolysis: A Case Study in the Czech Republic

WoS Article

Currently, the recovery of resources from urban wastewater (WW) represents a priority. On this topic, the potential recovery of cellulose for its subsequent reuse in different sectors is gaining interest. In this work, a large-size conventional wastewater treatment plant (WWTP) was selected as a case study. A preliminary mechanical treatment was used, with the aim of separating, quantifying, and characterizing cellulose in WW. The results suggest that the per-capita production of dry primary cellulosic sludge (D-PCS) is equal to 1.46 ± 0.13 kgD-PCS PE−1 y−1, with an average calorific value of 21.04 MJ kg−1DM. Cellulosic fibres have an average length of >100 µm and a thickness of 2–5 µm. The D-PCS was subsequently treated via medium-temperature pyrolysis; a total of 29.5% of the initial D-PCS was converted into pyrolyzed primary cellulosic sludge (P-PCS) and only 26% into pyrolytic gas. More than 44.5% of the dried cellulose can be converted into pyrolytic oil. Moreover, three different scenarios of recovery have been considered, and the impact of cellulose separation in terms of COD fluxes entering the WWTP and potential energy recovery has been studied. The results suggested that, in this case study, the potential separation of the primary cellulosic sludge from the influent water flux would have no significant impact on COD load entering the biological treatments and biogas production in the anaerobic digestion of the secondary sludge.

Currently, the recovery of resources from urban wastewater (WW) represents a priority. On this topic, the potential recovery of cellulose for its subsequent reuse in different sectors is gaining interest. In this work, a large-size conventional wastewater treatment plant (WWTP) was selected as a case study. A preliminary mechanical treatment was used, with the aim of separating, quantifying, and characterizing cellulose in WW. The results suggest that the per-capita production of dry primary cellulosic sludge (D-PCS) is equal to 1.46 ± 0.13 kgD-PCS PE−1 y−1, with an average calorific value of 21.04 MJ kg−1DM. Cellulosic fibres have an average length of >100 µm and a thickness of 2–5 µm. The D-PCS was subsequently treated via medium-temperature pyrolysis; a total of 29.5% of the initial D-PCS was converted into pyrolyzed primary cellulosic sludge (P-PCS) and only 26% into pyrolytic gas. More than 44.5% of the dried cellulose can be converted into pyrolytic oil. Moreover, three different scenarios of recovery have been considered, and the impact of cellulose separation in terms of COD fluxes entering the WWTP and potential energy recovery has been studied. The results suggested that, in this case study, the potential separation of the primary cellulosic sludge from the influent water flux would have no significant impact on COD load entering the biological treatments and biogas production in the anaerobic digestion of the secondary sludge.

cellulose reuse; mechanical pretreatment; resource recovery; solid carbonaceous product; wastewater treatment

cellulose reuse; mechanical pretreatment; resource recovery; solid carbonaceous product; wastewater treatment

DJORDJEVIĆOVÁ, D.; MIINO, M.; RAČEK, J.; CHORAZY, T.; HLAVÍNEK, P.; VRANAYOVÁ, Z.

2025

05.04.2024

MDPI

Basel, Schwitzerland

2079-9276

Resources-Basel

13

4

Swiss Confederation

1

11

11

https://www.scopus.com/record/display.uri?eid=2-s2.0-85191424813&origin=resultslist&sort=plf-f&src=s&sid=ff055f43da66a9e002fdcc819c2a8a37&sot=b&sdt=b&s=TITLE-ABS-KEY%28Separation+of+Cellulose+from+Wastewater+and+Valorisation+via+Pyrolysis%3A+A+Case+Study+in+the+Czech+Republic%29&sl=121&sessionSearchId=ff055f43da66a9e002fdcc819c2a8a37&relpos=0

http://hdl.handle.net/11012/245538

resources-13-00051