竹炭对水溶液中氨氮的吸附特性研究

Adsorption characteristic of bamboo charcoal for ammonia-nitrogen in water solution

研究了竹炭对水溶液中的氨氮的吸附特性,测定了不同竹炭粒径、溶液初始氨氮浓度、pH值、吸附时间对吸附效果的影响。结果表明:在酸性条件下,pH值增大吸附量增加较快,pH值为7时吸附效果最佳;在不同氨氮初始浓度下,竹炭吸附量随着浓度增大而急剧增加;吸附时间越长,吸附量越大,6h时达到吸附平衡,竹炭饱和吸附量最高达到0.21mg/g;竹炭颗粒粒径越小,吸附效果越显著。竹炭对氨氮的等温吸附符合Freundlich吸附等温方程式;用NaOH溶液进行再生,再生次数越多吸附量显著下降,4次再生后达到原吸附量的64%。

The adsorption characteristic of bamboo charcoal for ammonia-nitrogen in water solution was studied, and the effects of granular diameter of bamboo charcoal, initial ammonia-nitrogen concentration of the solution, pH value and adsorption time on the adsorption performance were determined. The results showed that： under acidic condition, the adsorption quantity increased fast with the increasing of the pH value, the best adsorption effect was obtained when the pH value was 7; under different initial ammonia-nitrogen concentrations, the adsorption quantity of bamboo charcoal rapidly increased with the increasing of the concentration; and it also increased along with the increasing of the adsorption time, the adsorption equilibrium was reached in 6 h; the highest saturated adsorption quantity of bamboo charcoal was 0.21 mg/g; the smaller the granular diameter of bamboo charcoal was, the more prominent the adsorption effect would be. The isothermal adsorption of ammonia-nitrogen by bamboo charcoal fit the Freundlich adsorption isothermal equation; the bamboo charcoal could be regenerated by NaOH solution, with the increasing of the regeneration times, its adsorption quantity decreased notably, and was 64% of the original adsorption quantity after be regenerated 4 times.