Copper bioaccumulation in an upflow anaerobic sludge blanket reactor

The main objective of this work was to study the capacity of bioaccumulation of copper in an upflow anaerobic sludge blanket (UASB) reactor, for the treatment of acid mine drainages (AMD). UASB reactor of 0.8 L was fed with sodium acetate, the organic loading rate (OLR) was set at 2.0 gCOD/L d, and experiments were performed in the reactor during 115 days. After 30 days, the COD removal efficiency was 90%. In the stationary stage, the higher production methane was 0.253 L/L d. The reactor was added with 20 mgCu(II)/L during 30 days. The copper bioaccumulation was 98% and it was accumulated gradually in sludge until reaching a 61.6 mgCu(II)/gTS. The toxicity study demonstrated that the copper concentration at which the level of specific methanogenic activity (SMA) of the biogranules was reduced to 50% of the control (IC50), was 280 mgCu(II)/L.