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Free ammonia pretreatment improves anaerobic methane generation from algae

Journal Article


Abstract


  • Anaerobic methane generation from algae is hindered by the slow and poor algae biodegradability. A novel free ammonia (NH3 i.e. FA) pretreatment technology was proposed in this work to enhance anaerobic methane generation from algae cultivated using a real secondary effluent. The algae solubilisation was 0.05–0.06 g SCOD/g TCOD (SCOD: soluble chemical oxygen demand; TCOD: total chemical oxygen demand) following FA pretreatment of 240–530 mg NH3–N/L for 24 h, whereas the solubilisation was only 0.01 g SCOD/g TCOD for the untreated algae. This indicates that FA pretreatment at 240–530 mg NH3–N/L could substantially enhance algae solubilisation. Biochemical methane potential tests revealed that FA pretreatment on algae at 240–530 mg NH3–N/L is able to significantly enhance anaerobic methane generation. The hydrolysis rate (k) and biochemical methane potential (P0) of algae increased from 0.21 d−1 and 132 L CH4/kg TCOD to 0.33–0.50 d−1 and 140–154 L CH4/kg TCOD, respectively, after the algae was pretreated by FA at 240–530 mg NH3–N/L. Further analysis indicated that FA pretreatment improved k of both quickly and slowly biodegradable substrates, and also increased P0 of the slowly biodegradable substrate although it negatively affected P0 of the quickly biodegradable substrate. This FA technology is a closed-loop technology.

UOW Authors


  •   Nghiem, Long (external author)

Publication Date


  • 2019

Citation


  • Wang, Q., Sun, J., Liu, S., Gao, L., Zhou, X., Wang, D., . . . Nghiem, L. D. (2019). Free ammonia pretreatment improves anaerobic methane generation from algae. Water Research, 162, 269-275. doi:10.1016/j.watres.2019.06.065

Scopus Eid


  • 2-s2.0-85068264452

Start Page


  • 269

End Page


  • 275

Volume


  • 162

Abstract


  • Anaerobic methane generation from algae is hindered by the slow and poor algae biodegradability. A novel free ammonia (NH3 i.e. FA) pretreatment technology was proposed in this work to enhance anaerobic methane generation from algae cultivated using a real secondary effluent. The algae solubilisation was 0.05–0.06 g SCOD/g TCOD (SCOD: soluble chemical oxygen demand; TCOD: total chemical oxygen demand) following FA pretreatment of 240–530 mg NH3–N/L for 24 h, whereas the solubilisation was only 0.01 g SCOD/g TCOD for the untreated algae. This indicates that FA pretreatment at 240–530 mg NH3–N/L could substantially enhance algae solubilisation. Biochemical methane potential tests revealed that FA pretreatment on algae at 240–530 mg NH3–N/L is able to significantly enhance anaerobic methane generation. The hydrolysis rate (k) and biochemical methane potential (P0) of algae increased from 0.21 d−1 and 132 L CH4/kg TCOD to 0.33–0.50 d−1 and 140–154 L CH4/kg TCOD, respectively, after the algae was pretreated by FA at 240–530 mg NH3–N/L. Further analysis indicated that FA pretreatment improved k of both quickly and slowly biodegradable substrates, and also increased P0 of the slowly biodegradable substrate although it negatively affected P0 of the quickly biodegradable substrate. This FA technology is a closed-loop technology.

UOW Authors


  •   Nghiem, Long (external author)

Publication Date


  • 2019

Citation


  • Wang, Q., Sun, J., Liu, S., Gao, L., Zhou, X., Wang, D., . . . Nghiem, L. D. (2019). Free ammonia pretreatment improves anaerobic methane generation from algae. Water Research, 162, 269-275. doi:10.1016/j.watres.2019.06.065

Scopus Eid


  • 2-s2.0-85068264452

Start Page


  • 269

End Page


  • 275

Volume


  • 162