Wastewater

Anaerobic digestion

Methane

Composite number

Engineering

Sewage treatment

Materials science

Sewage sludge

Bioenergy

Denitrification

Biochemistry

Carbon fibers

Nitrogen

Food science

Waste management

Organic chemistry

Acidogenesis

Biofuel

Environmental science

Composite material

Chemistry

Carbon source

Pulp and paper industry

Fermentation

Bioresource Technology

Wastewater treatment plants face the problem of a shortage of carbon source for denitrification. Acidogenic fermentation is an effective method for recovering short-chain fatty acids (SCFAs) as a carbon source from sewage sludge. Herein, the most recent advances in SCFAs production from primary sludge and waste activated sludge are systematically summarised and discussed. New technologies and problems pertaining to the improvement in SCFAs availability in fermentation liquids, including removal of ammoniacal nitrogen and phosphate and extraction of SCFAs from fermentation liquids, are analysed and evaluated. Furthermore, studies on the use of recovered SCFAs as a carbon source for denitrification are reviewed. Based on the above summarisation and discussion, some conclusions as well as perspectives on future studies and practical applications are presented. In particular, the recovery of carbon source/bioenergy from sewage sludge must be optimised considering nutrient removal/recovery simultaneously.

Short-chain fatty acids recovery from sewage sludge via acidogenic fermentation as a carbon source for denitrification: A review