| Coexisting substances in water are an important factor that affects the adsorption effect.Current researches have focused on the effect of coexisting ions like SO42-or Clon adsorption,but identification of the effect on phosphorus adsorption removal by nitrogen form is still a scientific problem to be solved urgently.This paper based on the real wastewater and chose ammonia,nitrate and serval kinds of organic nitrogen as the solvable nitrogen in secondary effluent.Furthermore,new kinds of actinium and lanthanide nanocomposite materials and classic material like activated carbon and ionexchange resin were used as phosphorus removal adsorbent and the research was launched to explore the effect of resolved nitrogen on phosphorus removal perspective and mechanism.Firstly,the influence perspective and mechanism of inorganic nitrogen on phosphorus removal by four adsorbents were explored.The result shows that the absorption to phosphorus by activated carbon is depended on van der Waals force and that as a result the removal rate is stable when facing various inorganic nitrogen.The phosphorus removal is affected by NO3-and NO2-mainly through direct competition of ion exchange sites in D201,HZO-201 and HLO-201,indirectly promoting the adsorption of metal oxides in HZO-201 and HLO-201.With the increase of NO3-/P from 0 to 5,the phosphorus adsorption capacity of HZO-201 and HLO-201 contributed by metal sites increased from 6.39 and 10.04 to 13.08 and 22.79(unit mg/g),respectively.These three kinds of inorganic nitrogen can affect the p H through ion exchange and dissociation equilibrium,in which NH4+ has a significant effect on preventing the increase of the p H in the nanocomposite adsorption system.In the nanocomposite system with the multiphase comixed nitrogen,the initial phosphorus concentration affects the binding ratio of phosphorus at the two sites,and the form of the depending nitrogen will change accordingly.After that,the structure-activity relationship between the effect perspective on phosphorus adsorption removal by serval organic nitrogen and molecular characteristics was studied using common biochemical metabolism molecules as entry point.The result shows that negative charged structure on the amino acids competed with phosphates for the positive charged group on the resin skeleton,and that the positive charged structure increased the phosphorus adsorption capacity by 1.37 mg/g at most through electrostatic attraction and stabilized p H of the system.Hydrophobic amino acids had no obvious interference to phosphorus removal by adsorption.The middle and large-scale organic nitrogen mainly inhibits the adsorption of phosphorus.The influence mechanism was confirmed by XPS,XRD and N2 adsorption-desorption to be related to pores clogging,electrostatic interaction,coordination which interacts metal sites and crystal conversion.Exhausted D201,HZO-201,HLO-201 can be regenerated by Na OH-Na Cl mixed solution.The adsorption capacity of HLO-201 decreased with the increase of the cycle number due to the coexisting of middle and macromolecular organic nitrogen,whose loss was up to 21.1% after 6 cycles.D201,HZO-201 repeatedly used for cycles without capacity loss when all kinds of nitrogen coexisted.Finally,the effect of coexisting nitrogen on nanocomposite material fixed bed adsorption was explored,confirming that static experiment showed remarkable reference to fixed bed adsorption,where the HZO-201 showed the best corresponding.Besides,the effluent statistic was fitted by mathematical simulation.Thomas model showed the best fitting degree to the breakthrough curves of HZO-201.The data of simulated and actual effluent treated by fixed bed with the same concentration of nitrogen and phosphorus shows great similarity,which preliminarily confirms the guiding significance of experiment research to engineering in effluent treatment. |
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