Sodium citrate and potassium permanganate promote the production of short-chain fatty acids in waste activated sludge and its mechanism

LUAN Hui-lin; WANG Zheng-jiang; LIANG Kang; LIU Tuo-hong; LUO You-lin; WEN Si-jing; LI Zhen-lun

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China Environmental Science ›› 2026, Vol. 46 ›› Issue (3) : 1426-1433.

Sodium citrate and potassium permanganate promote the production of short-chain fatty acids in waste activated sludge and its mechanism

LUAN Hui-lin, WANG Zheng-jiang, LIANG Kang, LIU Tuo-hong, LUO You-lin, WEN Si-jing, LI Zhen-lun

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Abstract

In this study, the effect of sodium citrate (CA) combined with potassium permanganate (PM) pretreatment strategy on the acid production efficiency of waste activated sludge (WAS) anaerobic fermentation was investigated, and the promotion mechanism of CA synergistic PM significantly increased the accumulation of short-chain fatty acids (SCFAs). The results showed that, the production of SCFAs after CA and PM pretreatment reached a peak of 15777.54mg COD/L on the 6th day, which was increased by 6.41 times and 3.18 times compared with the control group and the PM group, respectively. At the same time, the proportion of acetic acid in SCFAs was also significantly increased. The reason is that CA and PM pretreatment enhance the structural destruction of extracellular polymer (EPS) in the sludge, release a large amount of soluble organic matter, and provide a richer substrate for microbial metabolism. Microbial community analysis further revealed that pretreatment reduced the overall diversity of microbial communities, significantly enriched functional flora related to hydrolysis and acid production, and inhibited SCFAs-depleting flora.

Key words

waste activated sludge / volatile fatty acids / sodium citrate / potassium permanganate / microbial community

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LUAN Hui-lin, WANG Zheng-jiang, LIANG Kang, LIU Tuo-hong, LUO You-lin, WEN Si-jing, LI Zhen-lun. Sodium citrate and potassium permanganate promote the production of short-chain fatty acids in waste activated sludge and its mechanism[J]. China Environmental Science. 2026, 46(3): 1426-1433

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