【作者】 马静；

【导师】 邱立平；

【作者基本信息】 济南大学 ， 市政工程， 2012， 硕士

【摘要】 磷是造成水体富营养化的主要原因之一，又是一种不可再生的资源。水环境中磷污染主要来源于污水排放，所以，必须加强对污水厂排水中磷的控制。由于污水生物脱氮除磷过程中经常出现碳源不足的问题，因此，研究探讨对化粪池废水进行强化除磷等源控制技术，不仅可以有效去除和回收污水中的磷资源，还可以减少和控制进入污水厂的氮磷量，解决污水处理厂进水碳源比例过低等问题。磷酸铵镁结晶法（MagnesiumAmmonium Phosphate，MAP）是一种既可除磷又能回收磷的有效方法，所以，本文拟对磷酸铵镁结晶法去除和回收化粪池废水中的磷开展深入研究，以期探索一种基于源控制（化粪池）的废水除磷技术。本文对模拟化粪池废水为研究对象，考察了反应物摩尔比、初始pH值、反应时间、反应动力条件、陈化时间、初始磷浓度对磷酸铵镁结晶反应的影响作用规律，探讨了MAP结晶反应动力学特性；以钢渣、矿渣、钢渣基复合滤料、矿渣基复合滤料和石英砂为晶种，研究了晶种对磷酸铵镁结晶法除磷效能的影响作用规律，分析了晶种对结晶反应的作用机理，为磷酸铵镁结晶法晶种的选择提供了依据；以晶种滤池处理模拟化粪池废水为研究对象，研究了废水中COD和氨氮对磷酸铵镁结晶除磷效果的影响，系统考察了晶种滤池处理模拟化粪池废水的运行效果及反应器运行条件对磷酸铵镁结晶除磷效果的影响；考察了晶种滤池处理实际化粪池废水的运行效果，并利用XRD对结晶除磷反应产物进行了表征，讨论了结晶产物的回收价值。研究结果表明，提高初始pH值有利于提高除磷率，一定程度的增大反应物摩尔比、反应时间、反应动力条件、陈化时间有利于提高结晶除磷效果，对于初始磷浓度较高的含磷废水，磷酸铵镁结晶除磷效果优于初始磷浓度低的含磷废水的结晶除磷效果。但是，当反应时间超过30min、搅拌速度超过80r/min、陈化时间超过30min，都会使结晶除磷效果下降。通过对比研究晶种对磷酸铵镁结晶除磷的影响规律，发现钢渣和钢渣基复合滤料作为晶种可以有效提高磷酸铵镁结晶除磷效能，矿渣基复合滤料和矿渣次之，石英砂最差。当晶种表面含有类似磷酸铵镁成分时，有利于提高磷酸铵镁结晶除磷效果。对晶种进行成分分析发现，当晶种含有可以拓宽介稳区宽度的成分时，会导致结晶反应诱导期变长，降低磷酸铵镁结晶除磷效果。在本试验条件下，磷酸铵镁结晶除磷效果不受COD变化的影响。当初始磷浓度越低时，化粪池废水中氨氮对磷酸铵镁结晶反应的影响较大。当氨氮是结晶反应的限制因子时，会影响结晶除磷效果；当化粪池废水中的含磷浓度很高时，氨氮不是结晶反应的限制因子，对结晶反应除磷效果没有影响。晶种滤池处理模拟含磷废水试验结果表明，废水初始磷浓度越低，结晶除磷效果越好，剩余磷浓度越低。当废水初始磷浓度较高时，氨氮、COD、HRT对高磷废水结晶除磷的影响大小为：HRT>COD>氨氮，处理低初始磷浓度含磷废水，影响结晶除磷效果的大小为：氨氮>COD>HRT。晶种滤池的除磷率随着反应pH和HRT的增加而升高。在相同pH条件下，初始磷浓度越低，磷酸铵镁结晶反应除磷效果越好。HRT越高，剩余磷浓度越低，磷酸铵镁结晶反应除磷效果越好。在相同HRT条件下，初始磷浓度越低，磷酸铵镁结晶反应除磷效果越好。XRD表征结果表明，不同初始磷浓度条件下得到的结晶产物的晶化程度都很好。晶种滤池处理实际化粪池废水的试验结果表明，晶种滤池可以实现长期有效的除磷，当进水磷浓度为75mg/L，氨氮浓度为186mg/L，COD为324mg/L，镁为20mg/L，SS为100NTU时，出水剩余磷浓度维持在1mg/L以下。通过对结晶产物进行XRD表征，得到的磷酸铵镁晶体晶化程度很好，有很高的回收价值。更多还原

【Abstract】 Phosphorus is the main cause of the eutrophication, and it is a non-renewable resource.The phosphorus pollution mainly comes from sewage disposal. Therefore, it is necessary toremove and recover phosphorus from wastewater treatment plant. Processes for biologicalnitrogen and phosphorus removal from urban wastewater sewage are often short of carbonsources. Therefore, to study the technology of source control, enhanced phosphorus removalto the wastewater from the septic tanks, is an effect way to reduce and control the phosphorusflowed into wastewater treatment plant. In the methods of phosphate removal and recovery,magnesium ammonia phosphate crystallization is an effective method that can remove andrecover phosphate. Therefore, this study was deeply investigated the phosphate removal andrecovery from the wastewater of septic tanks by the magnesium ammonium phosphatecrystallization to explore a technology of phosphorus removal from wastewater based onsource control.Different phosphate wastewater was the object of study. The influence rule of molar ratioof reactants, initial pH value, reaction time, reaction dynamic conditions, assembly time andinitial phosphate concentration on magnesium ammonia phosphate crystallization werestudied. Kinetics of crystallization was also discussed. When steel slag, mineral slag,modified steel slag, modified mineral slag and quartz sand were used as the seed crystal, theinfluence rule of the seed crystal on phosphate removal efficiency were studied. And themechanism of the seed crystal could remove the phospate was discussed. The influences ruleof COD and ammonia nitrogen on magnesium ammonia phosphate crystallization weredetermined. The treatment effection of seed crystal media filter and influence of operationalconditions were determined. The crystallization products were analysed by XRD. And therecycling value of crystallization products was discussed.The results indicated that it was helpful to improve the initial pH value to increasephosphate removal efficiency. Some degrees of increasing the mole ratio of reactants, reactiontime, dynamic conditions and assembly time could increase the phosphate removal efficiency.The phosphate removal efficiency was higher when the initial phosphate concentration washigh than that when the initial phosphate concentration was low. When reaction time≥30min,stirring speed≥80r/min and assembly time≥30min, the phosphate removal efficiency wouldreduce.When the seed crystal used steel slag or modified steel slag, the phosphate removal efficiency was higher than the phosphate removal efficiency when the seed crystal usedmodified mineral slag or mineral slag. When quartz sand was used as seed crystal, thephosphate removal efficiency was the worst of all. If the surface of the seed crystal containssimilar components as magnesium ammonia phosphate, it was in favor of improving thephosphate removal efficiency. When there were the components which could broden thewidth of metastable region and lengthen the induction period, the phosphate removalefficiency would reduce.The results showed that COD had no influence on magnesium ammonia phosphatecrystallization. When the initial phosphate concentration was low, the influence of NH4+-Nwas high. When NH4+-N was the restriction factor, it would influence the phosphate removalefficiency. When the initial phosphate concentration was too high, NH4+-N was not therestriction factor. There would be no influence on the phosphate removal efficiency.Through the orthogonal experiment, the results of experiments with simulationwastewater in seed crystal media filter showed that when the initial phosphate concentrationwas lower, the phosphate removal efficiency was higher. When the initial phosphateconcentration was high, the optimal and worse order to phosphate removal efficiency wasHRT>COD>N. When the initial phosphate concentration was low, the optimal and worseorder to phosphate removal efficiency was N>COD>HRT. On the same pH or the same HRTconditions, the phosphate removal efficiency was higher when initial phosphate concentrationwas low than the phosphate removal efficiency when the initial phosphate concentration washigh. The phosphate removal efficiency would increase with HRT increasing. The results ofXRD showed that the crystallization degrees of products were good. The experiments resultsof seed crystal media filter treating the actual septic tank wastewater showed that thephosphate removal efficiency could below1mg/L for a long time when phosphateconcentration was75mg/L, ammonia nitrogen concentration was186mg/L, COD was324mg/L, magnesium was20mg/L and SS was100NTU. The results of XRD showed that thecrystallization degrees of products were good. It had high recovery value.更多还原