Liu Hai-wei, Liu Yun, Wang Hai-yun, Dong Yuan-hua
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
Huan Jing Ke Xue. 2010 Aug;31(8):1884-9.
Batch equilibrium experiments were carried out to study ammonia adsorptions from aqueous solution by strawberry (Fragaia ananassa Duchesne) stem powder. The effects of pH, coexisting cations, initial ammonia concentration and temperature were investigated as well. The results showed that the equilibrium data fitted well to the Langmuir model and Freundlich model, and the maximum adsorption capacities were 3.05, 4.24 and 4.79 mg x g(-1) at 15, 25 and 35 degrees C respectively. The increase of temperature was favorable to ammonia adsorption. The optimal pH of ammonia adsorption was in the range of 4-8. The NH4+ content decreased at higher pH and the negative charges decreased at lower pH, resulting in the decrease of ammonia adsorption at both higher and lower pH. The pH changes after adsorption buffered both effects. K+, Na+, Ca2+ and Mg2+ had no effect on ammonia adsorption by strawberry stem, but Zn2+ and Al3+ decreased the adsorption for their hydrolyzation. The ammonia adsorption by strawberry stem powder could be applied in a large pH range and could not be affected by usual metal cations in wastewater, therefore the strawberry stem powder not only could be a suitable ammonia adsorbent, but also had advantages comparing with most mineral materials.
进行了批量平衡实验，以研究草莓（Fragaia ananassa Duchesne）茎粉对水溶液中氨的吸附作用。同时考察了pH值、共存阳离子、初始氨浓度和温度的影响。结果表明，平衡数据与Langmuir模型和Freundlich模型拟合良好，在15、25和35℃时最大吸附容量分别为3.05、4.24和4.79 mg x g(-1)。温度升高有利于氨的吸附。氨吸附的最佳pH值范围为4-8。较高pH值下NH4+含量降低，较低pH值下负电荷减少，导致在较高和较低pH值下氨吸附均降低。吸附后pH值的变化缓冲了这两种影响。K+、Na+、Ca2+和Mg2+对草莓茎对氨的吸附没有影响，但Zn2+和Al3+因其水解作用而降低了吸附。草莓茎粉对氨的吸附可在较大的pH范围内应用，且不受废水中常见金属阳离子的影响，因此草莓茎粉不仅可以是一种合适的氨吸附剂，而且与大多数矿物材料相比具有优势。
