Effects of rhamnolipid on organic carbon sources in waste activated sludge digestion by autothermal thermophilic micro-aerobic digestion
The VFA(Volatile Fatty Acid)produced during the digestion of surplus sludge can be used as an additional carbon source for nitrogen and phosphorus removal in waste water treatment process.In order to evaluate effects of surfactants on the effective carbon source in the Autothermal Thermophilic Micro-Aerobic Digestion system(ATMAD)and promote the development of internal carbon sources by using RL(Rhamnolipid)as a typical biosurfactant.The results show that the amount of VFA significantly increased with an appropriate amount of RL,and the main indexes such as SCOD,VFA,protein and polysaccharide in the supernatant were highly improved.The sludge dissolution effect significantly increased with an addition of RL by 0.02～0.07g/gTSS.The release of soluble organic matter and accumulation of VFA in the reaction system increased and be up to the highest and fastest when the RL dosage was 0.07g/g TSS.In addition,increasing the concentration of bacteria related to acid production fermentation(such as Bacteroides and Clostridium)could effectively promote the accumulation of volatile fatty acids.Evidently,an appropriate dosage of rhamnolipid can lead to a high feasibility and practicability for developing high-quality external carbon sources ATMAD system.
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维普
