为满足不断提高的污水处理排放标准要求,化学除磷工艺被越来越广泛地应用,其中同步化学除磷(Simultaneous chemical phosphorus removal,SCPR)是运行较为简单、投资较少的工艺。以两座采用SCPR工艺的污水处理厂为研究对象,进行了系统性...为满足不断提高的污水处理排放标准要求,化学除磷工艺被越来越广泛地应用,其中同步化学除磷(Simultaneous chemical phosphorus removal,SCPR)是运行较为简单、投资较少的工艺。以两座采用SCPR工艺的污水处理厂为研究对象,进行了系统性的水质检测与分析,探究了SCPR对生物除磷的影响及其机理。研究结果表明,协同除磷时,除磷药剂的过量投加导致外回流污泥含有大量的残余除磷药剂。当外部条件满足聚磷菌释磷环境时,回流污泥中的残余除磷药剂对厌氧释磷过程无明显影响。但回流污泥中的残余除磷药剂可瞬间与进水TP及聚磷菌在厌氧期释放的磷反应,使得进入好氧区的TP浓度较低,好氧吸磷作用不能发挥或作用降低,同时除磷药剂的过量投加导致运行费增加。建议设置精准加药系统,根据好氧出水实时TP浓度确定除磷药剂投加量,既可减少药耗,又可同时发挥生物除磷最大潜力,有利于SCPR工艺的高效运行。展开更多
In this study,the ZIF-8 membrane(ZIF-8/PP-g-MAH)is prepared by in situ synthesis of ZIF-8 on irradiation-pretreated polymer substrates to improve the uranium adsorption performance and address the recycling problems o...In this study,the ZIF-8 membrane(ZIF-8/PP-g-MAH)is prepared by in situ synthesis of ZIF-8 on irradiation-pretreated polymer substrates to improve the uranium adsorption performance and address the recycling problems of ZIF-8 powder.The effects of pH,contact time,and uranium concentration on the adsorption of ZIF-8/PP-g-MAH were investigated.Adsorption isotherm and kinetics analysis show that ZIF-8/PP-g-MAH has a high adsorption capacity of 478.5 mg/g,which is 1.26 times higher than that of ZIF-8,and a rapid adsorption equilibrium of 120 min,which is shortened to one-third of that required for ZIF-8(360 min).The adsorption process of ZIF-8/PP-g-MAH is consistent with that of the Langmuir isotherm and pseudo-second-order dynamic model.ZIF-8/PP-g-MAH also exhibits good selectivity for uranium in simulated seawater.The high adsorption performance of ZIF-8/PP-g-MAH is attributed to its membrane structure,which improves the utilization of coordination sites,including Zn-OH,C-N,and C=N.This study provides an efficient adsorption material for rapid uranium extraction,thus promoting the development of uranium extraction technologies.展开更多
文摘为满足不断提高的污水处理排放标准要求,化学除磷工艺被越来越广泛地应用,其中同步化学除磷(Simultaneous chemical phosphorus removal,SCPR)是运行较为简单、投资较少的工艺。以两座采用SCPR工艺的污水处理厂为研究对象,进行了系统性的水质检测与分析,探究了SCPR对生物除磷的影响及其机理。研究结果表明,协同除磷时,除磷药剂的过量投加导致外回流污泥含有大量的残余除磷药剂。当外部条件满足聚磷菌释磷环境时,回流污泥中的残余除磷药剂对厌氧释磷过程无明显影响。但回流污泥中的残余除磷药剂可瞬间与进水TP及聚磷菌在厌氧期释放的磷反应,使得进入好氧区的TP浓度较低,好氧吸磷作用不能发挥或作用降低,同时除磷药剂的过量投加导致运行费增加。建议设置精准加药系统,根据好氧出水实时TP浓度确定除磷药剂投加量,既可减少药耗,又可同时发挥生物除磷最大潜力,有利于SCPR工艺的高效运行。
文摘In this study,the ZIF-8 membrane(ZIF-8/PP-g-MAH)is prepared by in situ synthesis of ZIF-8 on irradiation-pretreated polymer substrates to improve the uranium adsorption performance and address the recycling problems of ZIF-8 powder.The effects of pH,contact time,and uranium concentration on the adsorption of ZIF-8/PP-g-MAH were investigated.Adsorption isotherm and kinetics analysis show that ZIF-8/PP-g-MAH has a high adsorption capacity of 478.5 mg/g,which is 1.26 times higher than that of ZIF-8,and a rapid adsorption equilibrium of 120 min,which is shortened to one-third of that required for ZIF-8(360 min).The adsorption process of ZIF-8/PP-g-MAH is consistent with that of the Langmuir isotherm and pseudo-second-order dynamic model.ZIF-8/PP-g-MAH also exhibits good selectivity for uranium in simulated seawater.The high adsorption performance of ZIF-8/PP-g-MAH is attributed to its membrane structure,which improves the utilization of coordination sites,including Zn-OH,C-N,and C=N.This study provides an efficient adsorption material for rapid uranium extraction,thus promoting the development of uranium extraction technologies.
