pH 及蒙脱石投加量对其吸附沼液中碳氮磷和重金属的影响

以蒙脱石为吸附材料,研究了蒙脱石投加量、pH对其吸附沼液中COD、TN、TP、NH_4~+-N、Zn、Cu、Cr、As、Mn、Ni的影响,并阐述了吸附过程中沼液理化性质与重金属之间的关系。结果表明:蒙脱石投加量为0～50g/L时,COD、TN、NH_4~+-N、TP、Zn、Cu的吸附量随投加量增加逐渐降低,去除率先增加后趋于平衡,投加量为30g/L时吸附效果较好,为适宜投加量。pH为6.5～9.5时,蒙脱石对沼液中TP、Zn、Cu吸附作用较显著,最大去除率可达84.3%、86.8%、94.5%,但对TN、NH_4~+-N、Cr的吸附作用较差,综合吸附量和去除率,7.5～8.5是蒙脱石吸附沼液的适宜pH。Zata电位与电导率、COD、TP、TN、NH_4~+-N、Zn、Cu、Ni之间呈显著负相关,Zn与Cu和Cr与pH呈显著正相关,Cr与TP呈显著负相关,Cr与As不相关。

Effects of pH and dosages of montmorillonite on the carbon, nitrogen, phosphorus and heavy metals adsorption from biogas slurry

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.