有机改性沸石覆盖抑制底泥氮磷释放的效果  

Efficiency of Barrier with Modified Zeolite to Control Nitrogen and Phosphorus Release from Sediments

作　　者：林建伟[1] 朱志良[1] 赵建夫[1] 马红梅[1] 

机构地区：[1]同济大学环境科学与工程学院

出　　处：《同济大学学报（自然科学版）》2007年第12期1651-1655,共5页Journal of Tongji University:Natural Science

基　　金：科技部小城镇科技发展重大资助项目(2003BA808A17);国家自然科学基金资助项目(50478103);上海水产大学博士启动基金资助项目(6750306327);上海高校优秀青年教师科研专项基金资助项目(677030701801)

摘　　要：制备了十六烷基三甲基铵(HDTMA)有机改性沸石,研究了该改性沸石覆盖底泥对底泥中氮磷释放的影响及机理,结果表明:①当HDTMA负载量为沸石外部阳离子交换容量(ECEC)的207%时,有机改性沸石吸附磷酸盐的效果最佳;最佳负载量条件下的有机改性沸石,对磷酸盐的吸附能较好地符合Langmuir等温吸附方程,饱和吸附量为0.644 mg.g-1,常数K为0.295 L.mg-1;pH值对有机改性沸石吸附磷酸盐的性能有显著影响,随着pH值的增加对磷酸盐的吸附能力逐渐增强;共存阴离子(NO3-,HCO3-和SO42-)的存在会抑制有机改性沸石对磷酸盐的吸附.②最佳HDTMA负载量条件下有机改性沸石对氨氮的吸附作用符合Langmuir等温吸附方程,饱和吸附量为13.0 mg.g-1,常数K为0.011 9 L.mg-1,且与天然沸石相比单位质量改性沸石的吸附量降低了20%左右.③有机改性沸石覆盖可以有效地抑制底泥氨氮的释放,但有效抑制底泥氨氮释放的持续时间与天然沸石相比缩短了1/5;有机改性沸石覆盖抑制底泥磷释放的效率与天然沸石相比大大加强,且投加的有机改性沸石越多,对底泥磷释放的抑制效果越好.Hexadecyl-trimethyl-ammonium（HDTMA） modified zeolite was prepared and applied to controlling nitrogen and phosphorus release from sediments. An investigation is carried out on the efficiency and mechanism of this HDTMA modified zeolite as barriers to controlling nitrogen and phosphorus release. The results show, when HDTMA loading is less than 207% of external cation exchange capacity （ECEC） of the zeolite, the efficiency of phosphate sorption onto the modified zeolite increases with the increment of HDTMA loading amount. When HDTMA loading amount is more than 207% of ECEC of the zeolite, phosphate sorption efficiency doesn＇t increase obviously with the increment of the loading amount. The phosphate sorption on the modified zeolite accords with the Langmuir sorption isotherm, and the saturation sorption capacity is 0. 644 mg· g^- 1 and /g is 0. 295 mg· g^- 1.The coexistence anions such as NO3^-, HCO3^- and SO3^- have a negative effect on the phosphate sorption under the given experimental conditions. The phosphate sorption on the modified zeolite is also affected by pH value of the solution. The sorption of ammonia on the modified zeolite is described by the Langmuir sorption isotherm, and the saturation sorption capacity is 13.0 mg·g^-1 and K is 0.011 9 L· mg^-1. In comparison with the natural zeolite, the ammonium sorption amount of the modified zeolite is about 20% less for each unit weight of materials. It is demonstrated that the barrier of HDTMA modified zeolite can control phosphorus release from sediments more efficiently than that of the natural zeolite. The HDTMA modified zeolite barrier can also control ammonia release from sediments. However, comparing with the natural zeolite barrier, the duration of ammonia release control from sediments is shortened to four-fifths for the HDTMA modified zeolite.

关 键 词：底泥 十六烷基三甲基铵改性沸石 氮磷 释放 覆盖 

分 类 号：X524[环境科学与工程—环境工程]