Use of chlorella for the treatment of the soft-shelled turtle processing wastewater

Abstract

The capability of Chlorella vulgaris to remove nitrogen in the form of ammonium ions from the soft-shelled turtle processing wastewater in a local agricultural products limited company (in Hangzhou, China) was studied. The soft-shelled turtle processing wastewater was found to include high concentrations of nitrogen (107.63±4.84 mg/L) in the form of ammonium (NH4+) with the small amounts of nitrite (0.32±0.04 mg/L on annual average) at pH 6.7 and to be suitable for growing Chlorella vulgaris. When Chlorella vulgaris was cultivated in a batch mode, a majority of the nitrogen concentration was dramatically removed after a lag-phase period. The total biomass weight gained during the entire cultivation period balanced out well with the nitrogen removed from the culture medium. These results indicate that Chlorella vulgaris has potential to remove nitrogen (i.e., ammonium ion) and nitrite at a reasonable uptake rate from wastewater while being cultivated using the soft-shelled turtle processing wastewater. © Maxwell Scientific Organization, 2013.