The Feasibility Study Of Anammox Process To Treat The High Salnity Wastwater Containing Nickel And Nitrogen

Anaerobic ammonium oxidation?anammox?technology has some advantages of high nitrogen removal rates,low operational costs,and small footprints,and has been successfully implied to treat high-strength ammonium wastewater.However,very little is known about the synthetic toxicity of anammox technogy performances and microorganism diversity from divalent nickel and salinity.1?In the present study,we revealed the short-and long-term influences of divalent nickel on anammox in an upflow anaerobic sludge blanket?UASB?reactor.The results showed that the half maximal inhibitory concentration(IC₅₀)of Ni???on anammox biomass was 14.64 mg L^-1 in short-term exposure.The continuous-flow experiment was observed during the 150 days,and illustrated that after domestication,nitrogen removal efficiency was up to 93±0.03%under the addition of 10 mg·Ni²⁺·L^-1.The settling velocity,SAA and content of EPS were decreased as the increase of the concentration of Ni???roughly,nevertheless,the content of heme c increased when the concentration of Ni???raised.It was implied that short-term exposure to Ni???had an adverse impact on anammox biomass,yet the anammox system could tolerate Ni???stress to 10 mg·L^-1after acclimation during the continuous-flow operation for 150 days.High-throughput sequencing results indicated that the presence of Ni???had an impact on the microbial community composition in the anammox reactor,especially Candidatus Kuenenia.At Ni???concentrations of 0-10 mg·L^-1,the relative abundance of Candidatus Kuenenia decreased from 36.23%to 28.46%.2?Effects of the continuous addition of a high-concentration of salinity and Ni???on the characteristics of anammox as well as on the variety and recovery of their ability removing nitrogen in an upflow anaerobic sludge blanket reactor?UASB?.This is the first study to examine the changes in quantity and composition of the extracellular polymeric substances?EPS?in an anammox-UASB system with different treatment.The operation performance and the sludge characteristics was also investigated.The results showed that after a 170-day acclimation to the addition of 0.2 mg·Ni²⁺·L^-1 and 20g·NaCl·L^-1,the ability to remove nitrogen was mainly recovered,and NRE and NRR were reached to 77.08%and 1.18 kg·N·m³·d^-1.Through 3D-EEM and FT-IR spectroscopy analysis,the introduced salinity and Ni???made a great change in the quantity and composition of the EPS in anammox granule.We used the mathematic model to simulate the behavior of anammox system in different phases,and investigated16S rRNA gene of bacteria using the high throughput sequencing technology in a laboratory-scale up-flow anaerobic sludge blanket?UASB?bioreactor.Stover–Kincannon model,the First order model,the Second order model used to simulate the seven stages.The outcomes were revealed,?1?Planctomycetes Ca.Kuenenia is the dominant microorganism in all samples;?2?the abundance of Ca.Kuenenia only decreased by 18.08%as anammox activity reduced by 98%.