Adsorption of phosphate from water on lake sediments amended with zirconium-modified zeolites in batch mode
Adsorption of phosphate from water on lake sediments amended with zirconium-modified zeolites in batch mode
复制标题
DOI：
10.1016/j.ecoleng.2014.07.035
复制
发表时间：
2014-10
影响因子：
3.8
通讯作者：
Yang Meng-juan;Jianwei Lin;Yanhui Zhan;Hong-hua Zhang
中科院分区：
文献类型：
--
作者：
Yang Meng-juan;Jianwei Lin;Yanhui Zhan;Hong-hua Zhang
锆改性沸石（ZrMZ）可能是一个湖泊修复工具，旨在控制内部磷（P）负荷从沉积物。通过批实验研究了吸附剂投加量对磷酸盐在ZrMZ上吸附的影响，以及磷酸盐在原沉积物和添加ZrMZ的沉积物上的吸附特性。采用连续萃取法研究了磷酸盐吸附的ZrMZ中磷的形态。ZrMZ对水中的磷酸盐有较好的去除效果。在实验室条件下从磷酸盐吸附的ZrMZ中连续提取P表明，约6%的ZrMZ结合的P是释放敏感的，而约94%的结合P在还原和普通pH（5-9）条件下不可能被释放。在初始磷浓度为1-12 mg/L范围内，沉积物对磷的吸附符合Langmuir和Freundlich吸附等温式。磷酸盐在原沉积物和添加ZrMZ的沉积物上的吸附动力学均符合准二级动力学模型，吸附过程是自发的吸热过程。Cl−或SO 42 −的存在对磷酸盐在原始沉积物和ZrMZ改良沉积物上的吸附没有竞争作用，而HCO 3 −或SiO 32 −的存在抑制了磷酸盐的吸附。零平衡磷浓度（EPC 0）的ZrMZ修正的沉积物是远远低于原沉积物。添加ZrMZ的底泥对磷酸盐的吸附量远高于未添加ZrMZ的底泥。研究结果表明，添加ZrMZ可以降低湖泊沉积物中磷的释放潜力，同时增加沉积物对磷的吸附能力。
Zirconium-modified zeolite (ZrMZ) may be a lake remediation tool designed to control the internal phosphorus (P) loading from sediments. Batch experiments were conducted to investigate the effect of adsorbent dosage on the adsorption of phosphate on ZrMZ, as well as the adsorption characteristics of phosphate on the raw and ZrMZ-amended sediments. The sequential extraction methods were used to investigate the forms of P in the phosphate-adsorbed ZrMZ. The ZrMZ was effective for the removal of phosphate from water. The sequential extraction of P from the phosphate-adsorbed ZrMZ under laboratory conditions suggested that about 6% of P bound by ZrMZ was release-sensitive, while about 94% of bound P was unlikely to be released under reducing and common pH (5–9) conditions. The equilibrium adsorption data of phosphate on the raw and ZrMZ-amended sediments at initial P concentrations of 1–12 mg/L could be described by the Langmuir and Freundlich isotherm models. The adsorption kinetics of phosphate on the raw and ZrMZ-amended sediments followed a pseudo-second-order model, and the adsorption process was spontaneous and endothermic in nature. The presence of Cl−or SO42−showed no competing effect on the adsorption of phosphate on the raw and ZrMZ-amended sediments, while the presence of HCO3−or SiO32−inhibited the adsorption of phosphate. The zero-equilibrium P concentration (EPC0) for the ZrMZ-amended sediment was much lower than that for the raw sediment. The phosphate adsorption capacity for the ZrMZ-amended sediment was much higher than that for the raw sediment. Results of this work indicate that the addition of ZrMZ into the lake sediment can reduce the potential of phosphate–P release from the sediment as well as can increase the phosphate–P adsorption capacity of the sediment.