镁镧复合材料及其与过硫酸氢钾联用对水体内源磷释放的控制效果与机制  

Efficiency and mechanism of magnesium/lanthanum composite material and its combination with potassium hydrogen persulfate for the control of phosphorus release from sediment

作　　者：陈秋哲 周俪瑾 龚以菲 李欣洁 魏青 詹艳慧 林建伟 CHEN Qiuzhe;ZHOU Lijin;GONG Yifei;LI Xinjie;WEI Qing;ZHAN Yanhui;LIN Jianwei(College of Marine Ecology and Environment,Shanghai Ocean University,Shanghai,201306,China)

机构地区：[1]上海海洋大学海洋生态与环境学院,上海201306

出　　处：《环境化学》2021年第9期2841-2853,共13页Environmental Chemistry

基　　金：山东省重大科技创新工程项目(2018YFJH0902);国家自然科学基金(51408354);上海市自然科学基金(15ZR1420700);上海市科学技术委员会项目(10230502900);大学生创新创业训练计划项目资助。

摘　　要：本文采用共沉淀法制备了氢氧化镁/氢氧化镧复合材料(Mg/La复合材料),通过批量吸附实验考察了Mg/La复合材料对水中磷酸盐的吸附特性,采用X射线光电子能谱探索了相关的吸磷机理,再通过底泥培养实验考察了Mg/La复合材料覆盖、过硫酸氢钾(PMS)添加及联用对水体底泥磷释放的控制效果,并探讨了相关的控磷机制.结果发现,Langmuir和Freundlich等温吸附模型均可描述Mg/La复合材料对水中磷酸盐的等温吸附.与准一级动力学模型相比,准二级和Elovich动力学模型更适合于Mg/La复合材料对水中磷酸盐的吸附动力学过程. Mg/La复合材料对水中磷酸盐的吸附去除具有较为广阔的pH适应性.溶液共存Ca^(2+)极大地促进了Mg/La复合材料对水中磷酸盐的吸附,而共存的Na^(+)、K^(+)、Mg^(2+)、Cl^(-)、HCO_(3)^(-)和SO_4^(2-)的影响可忽略不计. Mg/La复合材料吸附水中磷酸盐的机理为La(OH)_(3)与磷酸盐之间的配位体交换作用和Mg(OH)_(2)与磷酸盐之间的化学反应作用. Mg/La复合材料单独覆盖及联合或单独使用PMS添加均可以有效抑制缺氧条件下水体底泥内源磷的释放,使得上覆水体中溶解态活性磷(SPR)浓度处于很低水平,并且它们的控磷效果均优于单独添加PMS.绝大多数被Mg/La复合材料覆盖层所吸附的磷以盐酸提取态磷(HCl-P)和残渣态磷(Res-P)形式存在,在缺氧且pH(5—9)条件下难以被重新释放. Mg/La复合材料是一种有希望用于控制缺氧条件下水体底泥磷释放的活性覆盖材料.In this study,a composite material of magnesium hydroxide and lanthanum hydroxide(Mg/La composite material)was prepared,and the characteristics and mechanism of phosphate adsorption onto Mg/La composite material from water were investigated through batch adsorption experiments and X-ray photoelectron spectroscopy(XPS).The efficiencies of Mg/La composite material capping,potassium hydrogen persulfate(PMS)injection,and their combined use for the control of the release of phosphorus(P)from sediment were investigated through sediment culture experiment,and the related controlling mechanisms were also explored.It was found that the Langmuir and Freundlich isotherm models both are suitable to describe the adsorption isotherm data of phosphate from water on Mg/La composite material.The adsorption kinetics of phosphate from water on Mg/La composite materials better followed the pseudo-second-order and Elovich kinetic models than the pseudo-first-order kinetic model.The phosphate adsorption onto Mg/La composite material had a wide effective pH range.The uptake of phosphate from water by Mg/La composite material was greatly promoted by the coexistence of Ca^(2+),but the presence of Na^(+),K^(+),Mg^(2+),Cl^(-),HCO_(3)^(-)Under anoxic condition,Mg/La composite material capping could effectively control the release of P from sediment into the overlying water,making the SPR(soluble reactive P)concentration in the overlying water at a very low level.The combined use of Mg/La composite material capping and PMS injection also could effectively control the release of P from sediment into the overlying water under anoxic condition.The controlling efficiency of Mg/La composite material capping had no significant difference to that of Mg/La composite material capping combined with PMS injection.However,the controlling efficiencies of Mg/La composite material capping and its combination with PMS injection both were much higher than that of PMS injection.The vast majority of P bound by the Mg/La composite material-based capping layer e

关 键 词：镁镧复合材料覆盖 过硫酸氢钾添加 联用 底泥 内源磷 释放控制 

分 类 号：X52[环境科学与工程—环境工程]