[Objectives]This study aimed to optimize the chelation process for complex microelement iron supplement derived from pig blood by response surface methodology.[Methods]On the basis of single-factor test,p H value,conc...[Objectives]This study aimed to optimize the chelation process for complex microelement iron supplement derived from pig blood by response surface methodology.[Methods]On the basis of single-factor test,p H value,concentration of polypeptide solution and volume ratio of polypeptide solution to FeCl_2 solution were selected as influencing factors with Fe(II)chelation rate as the indicator for Box-Behnken central composite experimental design with three factors and three levels.The effects of three factors on the response value were analyzed by response surface methodology.[Results]The optimized chelation process for complex microelement iron supplement derived from pig blood by response surface methodology was as follows:pH 5.40,polypeptide solution concentration 2.27%,volume ratio of polypeptide solution to FeCl_2 solution 2.16∶1.Under this condition,the predictive Fe(II)chelation rate of iron supplement was 79.37%,while the actual value was 79.41%.[Conclusions]The optimized process may provide new thoughts for the development and utilization of complex microelement iron supplement derived from pig blood.展开更多
A self-synthesized bi-pyridine chelating resin(PAPY)could separate Cu(Ⅱ)/Ni(Ⅱ)/Fe(Ⅱ)sequentially from strong-acidic pickling wastewater by a two-stage p H-adjusted process,in which Cu(Ⅱ),Ni(Ⅱ),and Fe(Ⅱ)were succ...A self-synthesized bi-pyridine chelating resin(PAPY)could separate Cu(Ⅱ)/Ni(Ⅱ)/Fe(Ⅱ)sequentially from strong-acidic pickling wastewater by a two-stage p H-adjusted process,in which Cu(Ⅱ),Ni(Ⅱ),and Fe(Ⅱ)were successively preferred by PAPY.In the first stage(p H 1.0),the separation factor of Cu(Ⅱ)over Ni(Ⅱ)reached 61.43 in Cu(Ⅱ)-Ni(Ⅱ)-Fe(Ⅱ)systems.In the second stage(p H 2.0),the separation factor of Ni(Ⅱ)over Fe(Ⅱ)reached 92.82 in Ni(Ⅱ)-Fe(Ⅱ)systems.Emphasis was placed on the selective separation of Cu(Ⅱ)and Ni(Ⅱ)in the first-stage.The adsorption amounts of Cu(Ⅱ)onto PAPY were 1.2 mmol/g in the first stage,while those of Ni(Ⅱ)and Fe(Ⅱ)were lower than 0.3 mmol/g.Cu(Ⅱ)adsorption was hardly affected by Ni(Ⅱ)with the presence of dense Fe(Ⅱ),but Cu(Ⅱ)inhibited Ni(Ⅱ)adsorption strongly.Part of preloaded Ni(Ⅱ)could be replaced by Cu(Ⅱ)based on the replacement effect.Compared with the absence of Fe(Ⅱ),dense Fe(Ⅱ)could obviously enhance the separation of Cu(Ⅱ)-Ni(Ⅱ).More than 95.0%of Cu(Ⅱ)could be removed in the former 240 BV(BV for bed volume of the adsorbent)in the fixed-bed adsorption column process with the flow rate of 2.5 BV/h.As proved by X-ray photoelectron spectrometry(XPS)and density functional theory(DFT)analyses,Cu(Ⅱ)exerted a much stronger deprotonation and chelation ability toward PAPY than Ni(Ⅱ)and Fe(Ⅱ).Thus,the work shows a great potential in the separation and purification of heavy metal resources from strong-acidic pickling wastewaters.展开更多
文摘适用p H范围窄是限制亚铁/过一硫酸盐(Fe(Ⅱ)/PMS)体系进一步推广应用的关键因素之一,亟需开发拓宽Fe(Ⅱ)/PMS体系适用p H范围的策略。该文旨在探究含氮络合剂1,10-邻菲罗啉(phen)和2,2'-联吡啶(bipy)对Fe(Ⅱ)/PMS体系降解有机污染物效能和机制的影响。结果表明,引入phen和bipy可显著促进Fe(Ⅱ)/PMS体系对富含供电子基团的有机污染物苯酚和双氯芬酸的降解。当phen/Fe(Ⅱ)和bipy/Fe(Ⅱ)的摩尔比分别为3.0和4.5时,phen/Fe(Ⅱ)/PMS和bipy/Fe(Ⅱ)/PMS体系对苯酚的去除效果最佳。phen/Fe(Ⅱ)/PMS和bipy/Fe(Ⅱ)/PMS体系在p H 3.0~9.0条件下均能有效降解苯酚。化学探针、电子顺磁共振和淬灭剂实验结果表明,phen/Fe(Ⅱ)/PMS和bipy/Fe(Ⅱ)/PMS体系产生的活性氧化剂包括^(1)O_(2)和Fe(Ⅳ),且^(1)O_(2)对这2个体系中苯酚的降解起主要作用。
基金Supported by Youth Fund of National Natural Science Foundation of China(31801673)Talent Development Fund of Anhui Academy of Agricultural Sciences(17F1205)+2 种基金Youth Innovation Fund of President of Anhui Academy of Agricultural Sciences(17B1220)Team Building Project of Anhui Academy of Agricultural Sciences(18C1225)Youth Fund of Natural Science Foundation of Anhui Province(1808085QC94)
文摘[Objectives]This study aimed to optimize the chelation process for complex microelement iron supplement derived from pig blood by response surface methodology.[Methods]On the basis of single-factor test,p H value,concentration of polypeptide solution and volume ratio of polypeptide solution to FeCl_2 solution were selected as influencing factors with Fe(II)chelation rate as the indicator for Box-Behnken central composite experimental design with three factors and three levels.The effects of three factors on the response value were analyzed by response surface methodology.[Results]The optimized chelation process for complex microelement iron supplement derived from pig blood by response surface methodology was as follows:pH 5.40,polypeptide solution concentration 2.27%,volume ratio of polypeptide solution to FeCl_2 solution 2.16∶1.Under this condition,the predictive Fe(II)chelation rate of iron supplement was 79.37%,while the actual value was 79.41%.[Conclusions]The optimized process may provide new thoughts for the development and utilization of complex microelement iron supplement derived from pig blood.
基金supported by the National Natural Science Foundation of China(Nos.51878334,51522805)the Natural Science Foundation of Jiangsu Province,China(No.BK20170647)。
文摘A self-synthesized bi-pyridine chelating resin(PAPY)could separate Cu(Ⅱ)/Ni(Ⅱ)/Fe(Ⅱ)sequentially from strong-acidic pickling wastewater by a two-stage p H-adjusted process,in which Cu(Ⅱ),Ni(Ⅱ),and Fe(Ⅱ)were successively preferred by PAPY.In the first stage(p H 1.0),the separation factor of Cu(Ⅱ)over Ni(Ⅱ)reached 61.43 in Cu(Ⅱ)-Ni(Ⅱ)-Fe(Ⅱ)systems.In the second stage(p H 2.0),the separation factor of Ni(Ⅱ)over Fe(Ⅱ)reached 92.82 in Ni(Ⅱ)-Fe(Ⅱ)systems.Emphasis was placed on the selective separation of Cu(Ⅱ)and Ni(Ⅱ)in the first-stage.The adsorption amounts of Cu(Ⅱ)onto PAPY were 1.2 mmol/g in the first stage,while those of Ni(Ⅱ)and Fe(Ⅱ)were lower than 0.3 mmol/g.Cu(Ⅱ)adsorption was hardly affected by Ni(Ⅱ)with the presence of dense Fe(Ⅱ),but Cu(Ⅱ)inhibited Ni(Ⅱ)adsorption strongly.Part of preloaded Ni(Ⅱ)could be replaced by Cu(Ⅱ)based on the replacement effect.Compared with the absence of Fe(Ⅱ),dense Fe(Ⅱ)could obviously enhance the separation of Cu(Ⅱ)-Ni(Ⅱ).More than 95.0%of Cu(Ⅱ)could be removed in the former 240 BV(BV for bed volume of the adsorbent)in the fixed-bed adsorption column process with the flow rate of 2.5 BV/h.As proved by X-ray photoelectron spectrometry(XPS)and density functional theory(DFT)analyses,Cu(Ⅱ)exerted a much stronger deprotonation and chelation ability toward PAPY than Ni(Ⅱ)and Fe(Ⅱ).Thus,the work shows a great potential in the separation and purification of heavy metal resources from strong-acidic pickling wastewaters.
