利用锆改性沸石控制地表水体底泥氮磷释放研究

发布时间：2018-06-17 08:16

本文选题：锆改性沸石 + 螺蛳壳和鱼骨混合物　；参考：《上海海洋大学》2015年硕士论文

【摘要】：大量含氮(N)、磷(P)等污染物废水未经处理直接排放是引起地表水体污染的主要原因,同时底泥中氮、磷等污染物向上覆水释放给水质带来的巨大影响亦不容忽视。控制底泥中氮磷等污染物向上覆水的释放对于地表水环境污染防治是非常必要的。底泥原位改良技术和活性覆盖技术是两种极具应用前景的底泥氮磷释放控制技术。成功应用这两种技术的一个关键问题是寻找合适的吸附剂材料。天然沸石成本低廉且容易获得,利用其较高的阳离子交换性能,可以有效吸附去除水中氨氮。但是天然沸石对水中磷酸盐的吸附能力却较差。将锆氧化物负载到天然沸石表面上,所制备得到的锆改性沸石预计可以有效吸附去除水中的氨氮和磷酸盐,将锆改性沸石作为底泥改良剂或底泥活性覆盖材料预计可以有效控制底泥氮磷的释放。本文首先制备了锆改性沸石,对锆改性沸石的结构进行了表征,考察了锆改性沸石对水中磷酸盐的吸附作用,对比分析了锆改性沸石和铝改性沸石对太湖底泥-水系统中溶解性磷酸盐的固定作用,考察了不同条件下锆改性沸石改良太湖底泥对水中磷酸盐的吸附作用,考察了不同条件下锆改性沸石添加对太湖底泥磷释放的控制效果,考察了锆改性沸石活性覆盖控制重污染河道底泥氮磷释放的效果,并考察了螺蛳壳和鱼骨混合物对水中磷酸盐的吸附作用,以期为应用锆改性沸石作为底泥改良剂和活性覆盖材料控制底泥氮磷释放提供帮助。研究了锆改性沸石对水中磷酸盐的固定作用。结果表明,锆改性沸石对水中磷酸盐具备很好的吸附能力。锆改性沸石对水中磷酸盐的单位吸附量随吸附剂投加量的增加而降低,水中残留的磷酸盐浓度亦随着吸附剂投加量的增加而降低。锆改性沸石对水中磷酸盐的吸附能力随着p H的逐渐增加而逐渐降低。锆改性沸石对水中磷酸盐的吸附符合准二级动力学模型。Langmuir等温吸附模型可以很好地用于描述锆改性沸石对水中磷酸盐的吸附平衡数据,锆改性沸石对磷酸盐的最大单位吸附量为10.2 mg P/g(p H 7和25oC)。锆改性沸石所吸附的磷主要以Na OH提取态磷(Na OH-r P)和残渣态(Res-P)形态存在,通常p H(5~9)和厌氧条件下不容易被重新释放出来。对比分析了铝改性沸石和锆改性沸石对太湖底泥-水系统中溶解性磷酸盐的固定作用。结果表明,太湖底泥和改性沸石改良太湖底泥对水中较高浓度磷的吸附平衡数据可以采用Langmuir和Freundlich等温吸附模型加以描述,吸附动力学过程可以采用准二级动力学模型加以描述。太湖底泥、铝改性沸石改良及锆改性沸石改良太湖底泥的最大磷吸附量分别为395、613和1009 mg/kg.铝改性沸石改良太湖底泥所吸附的磷主要以Na OH-P形态存在,锆改性沸石改良太湖底泥所吸附的磷主要以Na OH-P和Res-P形态存在。当水中初始磷浓度很低时,太湖底泥和改性沸石改良太湖底泥均释放出磷,且后者的释磷量低于前者。改性沸石改良太湖底泥中生物有效磷(BAP)含量低于太湖底泥,前者的弱吸附态磷(NH4Cl-P)含量明显低于后者。铝改性沸石改良太湖底泥的氧化还原敏感态磷(BD-P)含量与太湖底泥相比差异不显著,而锆改性沸石改良太湖底泥的BD-P含量明显低于太湖底泥。可见,铝和锆改性沸石均可以用于控制太湖底泥磷的释放,锆改性沸石比铝改性沸石更适合用于控制太湖底泥磷的释放。研究了不同条件下锆改性沸石改良太湖底泥对水中磷的吸附作用。结果表明,当水中初始磷浓度为1~12 mg P/L时,未改良太湖底泥和锆改性沸石改良太湖底泥对磷酸盐的吸附平衡数据可以采用Langmuir和Freundlich模型加以描述。未改良太湖底泥和锆改性沸石改良太湖底泥对磷酸盐的吸附动力学过程可以采用准二级动力学模型进行拟合,该吸附过程属于吸热反应,并且是自发进行的。当p H值由2逐渐增加到4时,未改良太湖底泥和锆改性沸石改良太湖底泥对磷酸盐的吸附能力逐渐下降;当p H值由5增加到8时,未改良太湖底泥和锆改性沸石改良太湖底泥对磷酸盐的吸附能力变化很小;当p H值由8增加到10时,未改良太湖底泥和锆改性沸石改良太湖底泥对磷酸盐的吸附能力急剧下降。溶液中共存的Cl-和SO42-对未改良太湖底泥和锆改性沸石改良太湖底泥吸附水中的磷酸盐无负面影响,而溶液中共存的HCO3-和Si O32-会抑制未改良太湖底泥和锆改性沸石改良太湖底泥对水中磷酸盐的吸附。锆改性沸石改良太湖底泥的磷吸附-解吸平衡浓度(EPC0)低于未改良太湖底泥。锆改性沸石改良太湖底泥对水中磷酸盐的吸附能力高于未改良太湖底泥。被改良底泥中锆改性沸石所吸附的磷酸盐中大部分(约76%)以较稳定形态磷存在,通常p H(5~9)和厌氧条件下它们不容易被重新释放出来。研究了不同条件下锆改性沸石添加对太湖底泥磷释放的控制效果。结果表明,向太湖底泥中添加锆改性沸石可以有效降低底泥中无机磷的活性,可以促进底泥中BD-P向Na OH-P和Res-P转化。向太湖底泥中添加锆改性沸石后,底泥中的水溶性磷(WSP)、Na HCO3可提取态磷(Olsen-P)和藻类可利用磷(AAP)等生物有效态磷的含量降低,从而增加了底泥中磷的稳定性。不同的p H值、离子强度、Si O32-浓度和底泥有机质(OM)含量等条件下,向底泥中添加锆改性沸石可以有效的降低底泥中磷向上覆水中磷的释放通量。厌氧条件下,向底泥中添加锆改性沸石亦可以有效降低底泥中磷向上覆水的释放通量。研究了锆改性沸石活性覆盖控制重污染河道底泥氮磷释放的效果。通过实验首先考察了锆改性沸石对水中磷酸盐和铵的吸附去除作用,再考察了锆改性沸石活性覆盖控制底泥溶解性磷酸盐和铵释放的效率。结果表明,锆改性沸石对水中磷酸盐的吸附能力随p H的增加而降低。当p H由4增加到5时,锆改性沸石对水中铵的吸附能力增加;当p H 5~8时,对铵的吸附能力较高;当p H由8增加到10时,对铵的吸附能力下降。锆改性沸石对水中磷酸盐和铵的吸附动力学满足准二级动力学模型,并且对磷酸盐和铵的吸附速率比较快。Langmuir和Freundlich等温吸附模型可以用于描述锆改性沸石对水中磷酸盐和铵的吸附平衡数据。根据Langmuir模型计算得到的锆改性沸石对水中磷酸盐和铵的最大吸附量分别为7.75和9.59 mg/g(p H 7和25°C)。锆改性沸石对水中磷酸盐和铵的去除率随锆改性沸石投加量的增加而增加。锆改性沸石吸附水中磷酸盐的主要机制是配位体交换,吸附水中铵的主要机制是阳离子交换。被锆改性沸石所吸附的磷酸盐大部分(82.5%)以较为稳定形态磷(Na OH-P)存在,低溶解氧条件下不容易重新被释放出来。吸附磷酸盐后锆改性沸石中水溶性磷(WSP)、易解吸磷(RDP)和Na HCO3可提取态磷(Olsen-P)含量非常低,藻类可利用磷(AAP)含量仅占总磷含量的29%左右。低溶解氧条件下,重污染河道底泥会释放出大量的溶解性磷酸盐和铵;锆改性沸石活性覆盖则不仅可以使上覆水中的溶解性磷酸盐浓度控制到很低的水平,而且可以明显降低铵由底泥向上覆水迁移的速率。上述实验结果表明,锆改性沸石适合作为一种活性覆盖材料用于控制底泥溶解性磷酸盐和铵的释放。研究了螺蛳壳和鱼骨混合物对水中磷的固定作用。结果表明,螺蛳壳和鱼骨混合物可以有效去除水中的磷酸盐,并且它的去除能力明显优于单独螺蛳壳和单独鱼骨。螺蛳壳和鱼骨混合物对水中磷酸盐的去除动力学过程可以较好地采用准二级动力学模型加以描述。螺蛳壳和鱼骨混合物对水中磷酸盐的单位去除量随初始磷酸盐浓度的增加而增加。p H对螺蛳壳和鱼骨混合物去除水中磷酸盐的影响较小。水中共存的Cl-和SO42-对螺蛳壳和鱼骨混合物去除水中磷酸盐的影响较小,而水中共存的HCO3-会抑制螺蛳壳和鱼骨混合物对水中磷酸盐的去除。水中共存的Na+、K+和Mg2+等阳离子对螺蛳壳和鱼骨混合物去除水中磷酸盐几乎没有影响,而水中共存的Ca2+会促进螺蛳壳和鱼骨混合物对水中磷酸盐的去除。螺蛳壳和鱼骨混合物对水中磷酸盐的主要去除机制包括螺蛳壳和鱼骨对磷酸盐的表面吸附作用,以及钙磷化合物沉淀作用。鱼骨可以为钙磷化合物沉淀的异质成核提供核心,促进钙磷化合物沉淀的生成。螺蛳壳和鱼骨所释放出来的钙离子可以为钙磷化合物沉淀的形成提供钙源。上述结果表明,利用锆改性沸石作为底泥改良剂可以有效控制底泥磷的释放;利用锆改性沸石作为底泥活性覆盖材料可以有效控制污染底泥氮磷的释放。
[Abstract]:A large number of wastewater containing nitrogen (N), phosphorus (P) and other pollutants untreated directly is the main cause of surface water pollution. At the same time, the great influence of the release of nitrogen, phosphorus and other pollutants from the sediment to the water quality can not be ignored. It is often necessary. In situ improvement technology and active covering technology are two promising technology for the release control of nitrogen and phosphorus. The key problem for the successful application of these two technologies is to find suitable adsorbents. Natural zeolite is cheap and easy to obtain, and can be effectively adsorbed by its higher cation exchange properties. The adsorption capacity of natural zeolite to water phosphate is poor. The zirconium modified zeolite can be effectively adsorbed to remove ammonia and phosphate in water by loading zirconium oxide on the surface of natural zeolite. The zirconium modified zeolite is expected to be used as a base mud modifier or a sediment active cover material. The structure of zirconium modified zeolite was first prepared. The structure of zirconium modified zeolite was characterized. The adsorption of zirconium modified zeolite to phosphate in water was investigated. The immobilization effect of zirconium modified zeolite and aluminum modified zeolite on the soluble phosphate in the sediment water system of Taihu was compared and analyzed. The Zr modified zeolite improved the adsorption of phosphate in water from the bottom mud of Taihu. The control effect of Zr modified zeolite on the release of phosphorus in the sediment of Taihu was investigated under different conditions. The effect of Zr modified zeolite activity coverage on the release of nitrogen and phosphorus from the sediment of heavy polluted river was investigated, and the phosphoric acid of the mixture of snail shell and fish bone was examined in the water. The adsorption of salt is helpful for the use of zirconium modified zeolite as a remodifier and active covering material to control the release of nitrogen and phosphorus in the sediment. The immobilized effect of zirconium modified zeolite on phosphate in water has been studied. The results show that zirconium modified zeolite has a good adsorption capacity for phosphate in water. The adsorption capacity of the phosphate in water decreased with the increase of the dosage of adsorbent. The adsorption capacity of zirconium modified zeolite to water phosphate gradually decreased with the increase of P H. The adsorption of phosphate by zirconium modified zeolite conformed to the quasi two stage kinetic model.Langmuir The isothermal adsorption model can be well used to describe the adsorption equilibrium data of phosphate in water by zirconium modified zeolite. The maximum unit adsorption capacity of zirconium modified zeolite to phosphate is 10.2 mg P/g (P H 7 and 25oC). The phosphorus adsorbed by zirconium modified zeolite mainly exists in the form of Na OH extraction state phosphorus (Na OH-r P) and residue state (Res-P). The immobilized effect of aluminum modified zeolite and zirconium modified zeolite to the dissolved phosphate in the sediment water system of Taihu was compared and analyzed. The results showed that the adsorption equilibrium number of the high concentration of phosphorus in the water of the Taihu sediment and modified zeolite modified by the modified zeolite of Taihu could be absorbed by Langmuir and Freundlich isothermal absorption. The adsorption kinetic process can be described by the quasi two order kinetic model. The bottom mud of Taihu, the modification of aluminum modified zeolite and the modified zeolite of zirconium modified zeolite, the maximum phosphorus adsorption capacity of the Taihu sediment is 395613 and 1009 mg/kg. aluminum modified zeolite improved in the form of Na OH-P and zirconium modification. The phosphorus adsorbed by the zeolite improved mainly in the form of Na OH-P and Res-P. When the initial phosphorus concentration in the water is very low, the sediment of the sediment and the modified zeolite in Taihu all release phosphorus, and the latter is lower than the former. The modified zeolite improved the content of the bioavailable phosphorus (BAP) in the bottom mud of Taihu and the weak absorption of the former, the weak absorption of the former in the Taihu mud. The content of NH4Cl-P was significantly lower than that of the latter. The redox sensitive phosphorus (BD-P) content of the modified Taihu sludge was not significantly different from that of Taihu sediment, while the BD-P content of the modified zeolite modified by zirconium modified zeolite was significantly lower than that of Taihu sediment. Therefore, aluminum and zirconium modified zeolite can be used to control the release of phosphorus in the sediment of Taihu. Zirconium modified zeolite is more suitable for controlling the release of phosphorus in Taihu sediment than aluminum modified zeolite. The adsorption of phosphorus on water in Taihu under different conditions of zirconium modified zeolite under different conditions is studied. The results show that when the initial concentration of phosphorus in the water is 1~12 mg P/L, the modified Taihu sediment and zirconium modified zeolite improve the adsorption of phosphate on the base mud of Taihu. The equilibrium data can be described by Langmuir and Freundlich models. The adsorption kinetics of phosphate in Taihu sediment without improved sediment and zirconium modified zeolite in Taihu can be fitted by a quasi two stage kinetic model. The adsorption process belongs to the endothermic reaction and is spontaneous. When the P H value increases from 2 to 4, The adsorption capacity of Taihu sediment on phosphate was gradually reduced without improved sediment and zirconium modified zeolite in Taihu. When the value of P H increased from 5 to 8, the change in the adsorption capacity of Taihu sediment on the base mud of Taihu and zirconium modified zeolite improved little. When the value of P H increased from 8 to 10, the improvement of the modified zeolite and zirconium modified zeolite was too much to be improved. The adsorption capacity of lake bottom mud to phosphate decreased rapidly. The coexisting Cl- and SO42- in the solution had no negative effect on the modified Taihu sediment and zirconium modified zeolite to improve the phosphate in the sediment of Taihu, while the HCO3- and Si O32- in the solution could inhibit the improvement of the phosphate of Taihu sediment by the modified Taihu mud and the zirconium modified zeolite. The adsorption and desorption equilibrium concentration (EPC0) of Taihu sediment was lower than that of unmodified Taihu sediment. The adsorption capacity of phosphate in water by zirconium modified zeolite improved by zirconium modified zeolite was higher than that of unmodified Taihu sediment. Most of the phosphates adsorbed by zirconium modified zeolite in the modified sediment (about 76%) (about 76%) were more stable form phosphorus. They are not easy to be released under the conditions of P H (5~9) and anaerobic conditions. The control effect of zirconium modified zeolite on the release of phosphorus in the sediment of Taihu under different conditions is studied. The results show that the addition of zirconium modified zeolite to the sediment of Taihu can effectively reduce the activity of inorganic phosphorus in the sediment and promote the BD-P to Na OH-P and Re in the sediment. S-P conversion. After adding zirconium modified zeolite to the sediment of Taihu, the content of water soluble phosphorus (WSP), Na HCO3 extractable phosphorus (Olsen-P) and algae can be used as bioavailable phosphorus (AAP) and so on, thus increasing the stability of phosphorus in the sediment. Different P H values, ionic strength, Si O32- concentration and sediment organic matter (OM) content Adding zirconium modified zeolite to the sediment can effectively reduce the release flux of phosphorus from the phosphorus to the overlying water. Under anaerobic conditions, adding zirconium modified zeolite to the sediment can effectively reduce the release flux of phosphorus from the sediment to the overlying water. The effect of zirconium modified zeolite on the adsorption and removal of phosphate and ammonium in water was first investigated. The efficiency of Zr modified zeolite activity coverage to control the release of dissolved phosphate and ammonium was investigated. The results showed that the adsorption capacity of zirconium modified zeolite decreased with the increase of P H. When the P H increased from 4 to 5, the zirconium modified zeolite had a modified boiling. The adsorption capacity of ammonium in water is increased; when p H 5~8, the adsorption capacity of ammonium is higher. When p H increases from 8 to 10, the adsorption capacity of ammonium is decreased. The adsorption kinetics of phosphate and ammonium in water satisfies the quasi two kinetic model, and the adsorption rate of phosphate and ammonium is faster.Langmuir and Freundlich isothermal absorption. The attached model can be used to describe the adsorption equilibrium data of phosphate and ammonium in water by zirconium modified zeolite. The maximum adsorption of phosphate and ammonium in water by zirconium modified zeolite based on Langmuir model is 7.75 and 9.59 mg/g respectively (P H 7 and 25 degree C). The removal rate of phosphate and ammonium in water with zirconium modified zeolite with zirconium modified zeolite The main mechanism for the adsorption of phosphate in water by zirconium modified zeolite is the exchange of ligands. The main mechanism for adsorbing ammonium in water is cation exchange. Most of the phosphate adsorbed by zirconium modified zeolite (82.5%) exists in a more stable form of phosphorus (Na OH-P) and is not easily released under the low dissolved oxygen condition. Adsorption phosphoric acid is not easy to be released. The content of soluble phosphorus (WSP), soluble phosphorus (RDP) and Na HCO3 extractable phosphorus (Olsen-P) in the zirconium modified zeolite after salt is very low, and the content of phosphorus (AAP) in algae is only about 29% of the total phosphorus content. Under the low dissolved oxygen condition, heavy polluted river sediment will release a large amount of dissolved phosphate and ammonium, and the active coverage of zirconium modified zeolite is not only available. In order to control the concentration of dissolved phosphate in the overlying water to a very low level and obviously reduce the rate of migration of ammonium from the bottom mud to the overlying water, the experimental results show that the zirconium modified zeolite is suitable to be used as an active covering material to control the release of dissolved phosphate and ammonium in the sediment. The immobilization of phosphorus in water shows that the mixture of spiral shell and fish bone can effectively remove phosphate in water, and its removal ability is better than that of solitary spiral shell and solitary fish bone. The kinetic process of the removal of phosphate by the mixture of spiral shell and fish bone can be well described by the quasi two stage kinetic model. The removal of phosphate in the snail shell and fish bone mixture with the initial phosphate concentration increases with the increase of the initial phosphate concentration. The effect of.P H on the removal of phosphate in water by the shell of the spiral shell and the fish bone mixture is smaller. The effect of the coexisting Cl- and SO42- on the removal of phosphate in the water by the shell and fish bone mixture in the water is less, and the HCO3- in the water coexisted in the water is suppressed. The coexisting cations such as Na+, K+ and Mg2+ in water have little effect on the removal of phosphate in water by the coexisting cations and fish bone mixtures in water, while the coexisting Ca2+ in water can promote the removal of phosphate from the mixture of spiral shells and fish bone to water. The main removal mechanisms include the adsorption of snail shells and fish bones on the surface of phosphate and the precipitation of calcium and phosphorus compounds. Fish bones can provide the core for the heterogeneous nucleation of calcium and phosphorus compounds and promote the formation of calcium and phosphorus compounds. The calcium ions released by the shell and fish bones can be formed for the formation of calcium and phosphorus compounds. The results show that zirconium modified zeolite can effectively control the release of phosphorus in sediment, and Zr modified zeolite can effectively control the release of nitrogen and phosphorus in contaminated sediment.
【学位授予单位】：上海海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52

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