| Montmorillonite was used as adsorption material to study the effects of different dosages and pH
on COD, TP, TN, NH4
+
-N, Zn, Cu, Cr, As, Mn and Ni of biogas slurry, and the interaction between physicochemical
properties and heavy metals of biogas slurry was clarified. The results showed that the adsorption capacity of COD,
TN, NH4
+
-N, TP, Zn and Cu in biogas slurry decreased with the increase of the montmorillonite dosage of 0~50 g/L,
and the removal rate increased and then tended to be balanced. At the dosage of 30 g/L, the adsorption effect was better.
Under the proper condition with pH of 6.5~9.5, montmorillonite can effectively absorb TP, Zn and Cu in biogas slurry,
with maximal removal rate of 84.3%, 86.8% and 94.5%, and it has a poor adsorption effect on TN, NH4
+
-N and Cr.
According to the adsorption capacity and removal rate, the appropriate pH of montmorillonite adsorbing biogas slurry
was 7.5~8.5. Zata potential was significantly negatively correlated with COD, TP, TN, NH4
+
-N, Zn, Cu, Ni. The
strongest positive correlation was presented between Zn and Cu, and Cr and pH in biogas slurry. Cr and TP had a
negative remarkably relationship, and Cr and As was not significantly correlated. |
