Study on the co-operative effect of kitchen wastewater for harvest and enhanced pyrolysis of microalgae

Microalgae biofuels have received extensive attention as a new generation of renewable energy. However, the cost of cultivation and harvest limits the large-scale use of microalgae. An innovative method for harvesting microalgae through flocculation using kitchen wastewater (KWW) and further co-pyrolysis to enhance the crude bio-oil production was proposed. Flocculation efficiency of KWW for Scenedesmus obliquus showed the highest value of 94.09%. Compared with centrifugation and chemical flocculation (CF), the thermogravimetric curve of the sample after KWW flocculation showed different pattern. In addition, bio-oil yield of microalgae harvested through KWW flocculation was also the highest among the three studied harvest methods, reaching 55.59%. Gas chromatographic mass spectrometry (GC-MS) analysis of bio-oil showed that addition of KWW could promote the production of esters and hydrocarbons in comparison to the microalgae harvested by centrifugation or CF.