Treatment of biogas slurry from pig industry by Chlorella vulgaris

Chlorella vulgaris is domesticated with different concentration of biogas slurry in this experiment. The obtained superiority algae in high concentration biogas slurry is used for treating biogas slurry from pig industry. The results show that in the condition of aeration, Chlorella vulgaris can efficiently utilize the nutrients of biogas slurry and make it highly purified. After treated by Chlorella vulgaris for ten days, the mainly organics indexes: COD, suspended solids, NH₄⁺-N and TP are down to 162.3, 52, 14.66 mg/L and 7.57 mg/L, respectively. The removal rates are 77.61%, 91%, 94.76% and 80.03% respectively. The results are much lower than national standard regulation of water pollutants maximum permission daily discharge concentration of 400, 200, 80 mg/L and 8 mg/L in intensive pig industry.