摘要
为达到利用人工湿地处理高氨氮污水的目的,采用天然沸石作为人工湿地基质,对比研究了天然沸石对NH4Cl溶液和猪场厌氧发酵液中氨氮的等温吸附特征、吸附动力学过程,考察了吸附时间、氨氮初始浓度、沸石用量对沸石吸附氨氮的影响。结果表明,Freundlich方程较Langmuir方程能更为准确地描述天然沸石对两种水质中氨氮的等温吸附特征;在两种水质中,单分子层饱和吸附量分别为16.20mg·g-1和3.85mg·g-1。天然沸石对氨氮的吸附作用受吸附时间、氨氮初始浓度及沸石用量影响较大,在两种水质中,沸石对氨氮的吸附过程在0～8h内均随时间显著上升,到48h时达到吸附平衡;当采用NH4Cl溶液时,初始氨氮的浓度由10mg·L-1增加到500mg·L-1时,平衡吸附量由0.19mg·g-1增加到5.91mg·g-1;当采用猪场厌氧发酵液时,初始氨氮的浓度由39.4mg·L-1增加到502.9mg·L-1时,平衡吸附量由0.63mg·g-1增加到3.20mg·g-1;增加沸石用量,可以提高氨氮的去除率,但单位质量沸石的氨氮吸附量随之降低。准二级动力学可以很好地描述天然沸石吸附两种水质中氨氮的动力学过程;由模型得出的天然沸石对氨氮的平衡吸附量与试验所得最大吸附量偏差范围分别为5%～11%和2.9%～5.4%。
In order to enhance the ammonium removal in constructed wetland,the adsorption performances of the natural zeolite were studied in batch experiments with ammonium chloride solution and effluent from pig manure biogas plant（EPMBP）.It was indicated that the characteristics of isothermal adsorption of ammonium with natural zeolite could be well described by both the Langmuir and Freundlich equations,however,the results fit the Freundlich equation better than the Langmuir.Saturation adsorption capacities of natural zeolite in ammonium chloride solution and EPMBP were 16.20 mg·g-1 and 3.85 mg·g-1 respectively.The adsorption capacity was affected by adsorption time,initial ammonium concentration and quality of zeolite.The adsorption proceeded linearly in the first 8 hours and the adsorption equilibrium was reached 40 hours later.The zeolite adsorption capacity in ammonium chloride solution increased from 0.19 mg·g-1 to 5.91 mg·g-1 when the initial ammonia nitrogen concentration increased from 10 mg·L-1 to 500 mg·L-1,while the adsorption capacity in EPMBP increased from 0.63 mg·g-1 to 3.20 mg·g-1 when the initial ammonia nitrogen concentration increased from 39.4 mg·L-1 to 502.9 mg·L-1.The ammonia nitrogen removal rate could be improved with the increase of zeoite dosage.However,the ammonium adsorption amount of zeolite per gram will be lower.The adsorption process in ammonium chloride solution and EPMBP could also be described by the pseudo-second order kinetics model.Accordingly,the amount of equilibrium adsorption of ammonia nitrogen in ammonium chloride solution and EPMBP varied in the range of 5%～11% and 2.9%～5.4%,respectively.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2011年第10期2130-2135,共6页
Journal of Agro-Environment Science
基金
"十一五"国家科技支撑计划资助项目(2008BADC4B17)
关键词
天然沸石
氨氮吸附
NH4Cl溶液
猪场厌氧发酵液
准二级动力学模型
zeolite
ammonium adsorption
ammonium chloride solution
effluent from pig manure biogas plant
adsorption kinetics
