超声改性沸石去除微污染原水中氨氮的研究

Ultrasonically Modified Zeolite for Removing Ammonia Nitrogen from Micro-polluted Raw Water

采用超声强化NaCl对天然沸石进行改性,考察了改性沸石对氨氮的吸附去除特性。结果表明,在超声功率为560 W、改性时间为40 min、NaCl浓度为0.8 mol/L的条件下制备的改性沸石对氨氮的去除效果最佳;在氨氮初始浓度为10 mg/L、改性沸石投加量为5 g/L的条件下,吸附40 min后改性沸石对氨氮的去除率可达到86.9%,120 min后达到吸附平衡,此时对氨氮的去除率为91.11%,相比天然沸石提高了86.3%;准二级反应动力学模型可以较好地描述改性沸石的吸附行为,R2=0.991;改性沸石对氨氮的吸附符合Langmuir模型(R2=0.961 2),其最大吸附量可达到12.56 mg/g。

Ultrasonic and NaC1 were applied to modify natural zeolite, with investigating the influ- ence of different modification conditions on ammonia nitrogen adsorption. The results showed that the op- timal ammonia nitrogen removal efficiency was achieved by zeolite modified under the conditions of ultra- sonic power 560 W, modification time 40 min and 0.8 mol/L NaC1. The modified zeolite had ammonia nitrogen removal rate of 86.9% with the conditions of initial ammonia nitrogen concentration 10 mg/L, modified zeolite dosage 5 g/L and adsorption time 40 rain, and there was adsorption equilibrium after 120 min. The removal rate of ammonia nitrogen was 91.11%, with an increase of 86.3% compared with nat- ural zeolite. Second order reaction kinetics model could describe the adsorption behavior of modified zeo- lite exactly with R2 of 0. 991. The Langmuir model with R2 of 0.961 adsorption capacity of modified zeolite for ammonia nitrogen was fit for 2 and the maximum adsorption capacity could reach 12.56 mg/g.