Research On The Influence Of Inorganic Carbon (IC) And Vanadium (V(?)) On The Denitrification Characteristics Of Marine Anammox Bacteria

Marine anammox bacteria?MAB?,as a special branch of anammox bacteria,has a good tolerance to high salinity and low temperature.As a result,it possesses great potential to treat nitrogen-rich saline wastewater under low temperature.The effect of inorganic carbon?IC?and pentavalent vanadium?V????on MAB treating nitrogen-rich saline wastewater was analyzed and studied,respectively.Besides,the kinetic analysis was performed to study nitrogen removal characteristics of MAB with different IC and V???concentrations,and achieved some results:An anaerobic sequencing batch reactor?ASBR?was used to study the effect on MAB nitrogen removal performance in nitrogen-rich saline wastewater treatment with different IC addition.The KHCO₃ was added as the inorganic carbon source.Nitrogen removal processes in typical operations were described by the remodified Logistic model,modified Boltzmann model and modified Gompertz model.Ammonium removal efficiency?ARE?was above 99%at 108–3600 mg/L IC,which indicated that MAB had a good tolerance to high IC dose.When IC was 108–1200 mg/L,ARE reached 90%within 2.5 h.MAB activity was greatly promoted by providing adequate IC.Besides,the maximal substrate conversion rate?3.4 kg/?m³·d??was achieved at 180 mg/L IC.Both the remodified Logistic model and modified Boltzmann model were appropriate to describe nitrogen removal of MAB at low IC doses,while the modified Gompertz model was more accurate at high IC doses.Calcium carbonate crystal was formed on the surface of MAB granule at high IC doses,which resulted in a significant deterioration of nitrogen removal performance.An ASBR was used to study the effect of MAB nitrogen removal performance treating nitrogen-rich saline wastewater with different V???addition.The NaVO₃ was added as pentavalent vanadium source.Besides,the effect of V???on MAB nitrogen removal process was analyzed.Still,kinetic analysis was performed to study nitrogen removal characteristics of MAB with V???addition.Experimental results showed that nitrogen removal performance of MAB in treating nitrogen-rich saline wastewater was enhanced by adding 0.25–20 mg/L V???.V???dose of 1 mg/L was the optimal concentration.At this V???level,NO₂^--N concentration in effluent was the lowest and NH₄⁺-N could be removed completely within 160 minutes.When V???was no more than 10 mg/L,the substrate conversion rate of MAB was enhanced and maintained high level for longer period.However,nitrogen removal of MAB was deteriorated as MAB bioactivity inhibited at high V???concentration?>20 mg/L?.In addition,V???was perhaps used to instead of NO₂^-as the electron acceptor by MAB in anammox process,viz.Vammox.When V???was no more than 20 mg/L,the remodified Logistic model,modified Boltzmann model and modified Gompertz model could simulate the nitrogen removal process of MAB well in the typical operation.The R² values were high and TNRE_max could also be predicted well.Nevertheless,TNRE_max,as well as other kinetic parameters,predicted by remodified Logistic model was the most accurate and the standard error was only 0.0222.Thus,the remodified Logistic model was the most suitable model.