NaOH浓度对树脂基HFO复合吸附剂的结构及除磷影响  

Effect of NaOH concentration on structure and phosphate adsorption of polymer-based hydrated ferric oxide composite adsorbents

作　　者：孙健 尚依依 徐兆郢 薛崇灏 赵平歌[1] 张格红[1] SUN Jian;SHANG Yiyi;XU Zhaoying;XUE Chonghao;ZHAO Pingge;ZHANG Gehong(School of Civil&Architecture Engineering,Xi’an Technological University,Xi’an 710021,China;Xi’an Key Laboratory of Civil Engineering Testing and Destruction Analysis on Military-Civil Dual Use Technology,Xi’an 710021,China;Xi’an Thermal Power Research Institute CO.,LTD.,Xi’an 710054,China)

机构地区：[1]西安工业大学建筑工程学院,西安710021 [2]西安市军民两用土木工程测试技术与毁损分析重点实验室,西安710021 [3]西安热工研究院有限公司,西安710054

出　　处：《复合材料学报》2022年第12期5678-5687,共10页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51908439);陕西省教育厅专项科学研究计划项目(19JK0395);陕西省自然科学基础研究计划资助项目(2021JM-424)。

摘　　要：树脂基水合氧化铁(Hydrated ferric oxide,HFO)复合吸附剂以磷吸附容量大、吸附速率快、洗脱率高等特点,受到广泛关注,但不同NaOH浓度制备的复合吸附剂结构和吸附性能是否一样尚不清楚。通过考察NaOH浓度对树脂基HFO复合吸附剂的结构和除磷性能影响,为优化D213-HFO复合吸附剂制备提供依据。结果表明,NaOH浓度从1 mol·L^(−1)增加至6 mol·L^(−1),复合吸附剂的HFO负载量(约为16wt%,以Fe质量分数计)和晶体结构无显著差异,但复合吸附剂负载纳米HFO颗粒团聚程度降低,分布更均匀。此外,随着NaOH浓度增加,复合吸附剂的磷吸附容量先增加后稳定(18 mg·g^(−1))。另外,复合吸附剂吸附磷的平衡时间为240 min,更符合准一级动力学模型(R^(2)>0.99),最佳吸附pH为6~8,相同浓度时共存离子对磷吸附影响程度为SO_(4)^(2−)>Cl−>NO_(3)^(−)。在连续5个吸附洗脱周期内,复合吸附剂的磷洗脱率均接近100%。实验表明,随NaOH浓度增加,复合吸附剂负载HFO颗粒分布更均匀,磷吸附容量先增加后稳定,但晶体结构、吸附平衡时间、最佳pH范围、共存离子影响趋势及洗脱效果均无显著差异。Polymer-based hydrated ferric oxide(HFO)composite adsorbents had attracted extensive attention because of large phosphate adsorption capacity,rapid adsorption rate and high regeneration efficiency.Nevertheless,whether the same structure and phosphate adsorption could be performed by composite adsorbents prepared at different NaOH concentration was still unclear.In order to provide evidence for optimization of polymer-based hydrated ferric oxide composite adsorbents preparation,the structure and phosphate adsorption of composite adsorbents prepared by regulating NaOH concentration were studied.The results show that when NaOH concentration increases from 1 mol·L^(−1) to 6 mol·L^(−1),there are no significantly effect on the HFO loadings(approximately 16wt%,mass fraction in Fe)and crystal structure of composite adsorbents.However,the considerable selfagglomerate of HFO nanoparticles decrease,and HFO nanoparticles distribute evenly.Moreover,phosphate adsorption capacity is increased with NaOH concentration and then remains the same(18 mg·g^(−1)).Additionally,adsorption equilibrium times are 240 min,and the adsorption kinetic curves are fitted well with pseudo-first order kinetic model(R^(2)>0.99).The optimal pH value for phosphate adsorption is 6-8,and the influence degree of phosphate adsorption by co-existing ions is SO_(4)^(2−)>Cl−>NO_(3)^(−)under the same concentration.The regeneration efficiencies of composite adsorbents approach 100%during 5 continuous adsorption regeneration cycles.The experiments show that the HFO nanoparticles distribute evenly with the increase of NaOH concentration,and the phosphate adsorption capacity of composite adsorbents is increased and then remains the same,while there is no significant difference in crystal structure,adsorption equilibrium time,optimal pH,effect of coexisting anions,and elution effect.

关 键 词：氢氧化钠 水合氧化铁 阴离子交换树脂 复合吸附剂 磷酸盐 

分 类 号：TQ424[化学工程] X703[环境科学与工程—环境工程]