Details

Autor(en) / Beteiligte

• Zhang, Jing
• Peng, Yong-zhen
• Zhang, Lin-hua
• Li, Jun
• Wei, Jia
• Zheng, Zhao-ming
• Zhang, Kai

Titel

Improving the resistance of Anammox granules to extreme pH shock: The effects of denitrification sludge EPS enhanced by a fluctuating C/N ratio cultivation on granules

Ist Teil von

• The Science of the total environment, 2021-04, Vol.763, p.144610-144610, Article 144610

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2021

Quelle

MEDLINE

Beschreibungen/Notizen

• This study investigated the effects of denitrification sludge EPS enhanced (DS-EPSCN) by a fluctuating carbon and nitrogen ratio (C/N) cultivation strategy on the properties of Anammox granules under extreme acid or alkaline shock. The results showed that the DS-EPSCN significantly improved the nitrogen removal performance of low-density Anammox granular sludge (Granules-L) and high-density Anammox granular sludge (Granules-H) under extreme acid shock (pH 5.0). The contents of high-molecular-weight substances (such as aromatic proteins and polysaccharides) in the DS-EPSCN rose markedly, contributing to a substantial increase in the flocculation efficiency under acidic conditions and increasing the granule stability. In addition, abundant amounts of N-butyryl-dl-homoserine lactone (C4-HSL) and N-hexanoyl-dl-homoserine lactone (C6-HSL) in the DS-EPSCN promoted the granule activity. However, under extreme alkaline shock (pH 10.5), the flocculation efficiency of the DS-EPSCN was poor, and the addition of DS-EPSCN had no influence on the stability of the granules but improved the activity of the Granules-H. The reason was that the release mechanism of the endogenous acyl-homoserine lactone (AHL) signals in the Granules-H was activated by the exogenous C4-HSL and C6-HSL in the DS-EPSCN under alkaline conditions, leading to increased Granules-H activity. This research provides a novel approach to enhance the resistance of Anammox granular sludge to extreme pH shock. [Display omitted] •DS-EPSCN enhanced the property of granules-L and granules-H in extreme acid shock.•DS-EPSCN promoted the activity of granules-H under extreme alkaline shock.•Fluctuating C/N ratio cultivation increased the AHLs content in DS-EPSCN.•Fluctuating C/N ratio cultivation improved the flocculation efficiency of DS-EPSCN.