【作者】 赵桂瑜；

【导师】 周琪；

【作者基本信息】 同济大学 ， 环境科学， 2007， 博士

【摘要】 通过等温吸附试验，研究了沸石、干渣、页岩陶粒、砾石、白云石和钢渣六种人工湿地基质材料对溶液中磷的吸附去除特征，考察了溶液浓度、基质粒度、pH值、铵根离子、有机质和无机阴离子等多种因素对基质吸附除磷作用的影响；通过吸附动力学试验，考察了六种基质对溶液中磷的吸附动力学特征，分析了温度、基质粒度和溶液浓度对基质吸附除磷动力学过程的影响；通过动态吸附试验，进一步考察了基质的吸附除磷能力。在此基础上，筛选出适宜的人工湿地基质材料，考察其饱和吸附磷后的解吸释磷情况。对于除磷能力较差的基质，通过改性试验，提高了它们的除磷能力。最后，从吸附热力学、平均吸附能、饱和基质磷形态分析等角度探讨了基质的吸附除磷机理。 等温吸附实验表明，Langmuir方程与Freundlich方程均能很好地描述沸石、干渣、砾石和页岩陶粒四种基质对磷的吸附等温特征：Langmuir方程能够比Freundlich方程更好地描述白云石对磷的吸附等温特征；钢渣对磷的吸附等温特征符合Langmuir吸附等温模型，但不符合Freundlich模型。六种基质相比较，钢渣对磷的理论饱和吸附量最大，为3.55×10⁴mg／kg，其次是干渣、页岩陶粒、砾石和沸石，白云石对磷的理论饱和吸附量最小，仅为14.51mg／kg。 pH值对基质吸附除磷作用的影响较大：随着pH值的增加，页岩陶粒对磷的吸附量显著降低。对钢渣和干渣而言，pH值＜9时，磷吸附量随pH值的增大而减小，pH值在9左右，磷吸附量达到最小，pH值＞9时，磷吸附量显著增加。白云石、沸石和砾石三种基质的吸附除磷作用受pH值影响较小。 吸附动力学实验表明：准二级动力学模型对六种基质吸附除磷动力学过程的描述最为准确，一级动力学模型次之，Elovich方程和双常数方程略差。应用准二级动力学模型计算出相同条件下，六种基质对磷的最大吸附速率v_max，依次为：钢渣＞干渣＞沸石＞页岩陶粒≥白云石＞砾石。 吸附热力学研究表明：基质吸附除磷过程中，系统的ΔG⁰＜0，ΔH⁰＞0，即基质对磷的吸附作用是一个自发的、吸热过程。更多还原

【Abstract】 Phosphates are very important basic materials in agricultural and other industrial applications. Phosphorus is often present in wastewater, almost solely in the form of organic and inorganic phosphates. The removal of phosphates from surface waters is generally necessary to avoid problems, such as eutrophication. The usual methods of treatment are either biological or physicochemical by sedimentation. This thesis studies the removal of phosphorus by adsorption onto some natural adsorbents.Phosphorus adsorption isotherm and its kinetics were examined and effects of initial phosphorus concentration, adsorbent particle size, adsorbent dose, pH, organic materials, temperature and ion strengths were investigated to understand the characteristics of phosphorus adsorption onto zeolite, blast furnace slags, shale, gravel, dolomite and steel converter slags. In addition, Phosphorus adsorption mechanisms on different substrates were explored by the means of adsorption theromdynamics, the mean adsorption energy and the phosphorus fractionation of substrates saturated with phosphorus. Based on the obtained results, suitable substrates were selected and applied in concstructed wetlands. Unsuitable substrates were modified to improve their phosphorus adsorption capacity.Both Langmuir and Freundich isotherm were observed to fit the adsorption characteristics of zeolite, blast furnace slags, gravel and shale. Langmuir isotherm was more suitable to describe the phosphorus adsorption onto dolomite than Freundlich isotherm. The phosphorus adsorption onto steel converter slags can be described by Langmuir isotherm, but not by Freundlich isotherm. Two industrial by-products including steel converter slags and blast furnace slags had higher phosphorus adsorption capacities of 3.55 × 10~4 and 769.23mg/kg, respectively. Followed are shale, gravel and zeolite with phosphorus adsorption capacities of 232.56, 112.36 and 87.72mg/kg. The dolomite had the least phosphorus adsorption更多还原