Characteristics Of Sulfate Reducing Ammonium Oxidation

With the progress and development of industrialization,a large number of high-concentration sulfates and ammonia nitrogen in the sewage discharged by many industries,resulting in pollution that affects human health.Under the action of microorganisms,the sulfate reducing ammonium oxidation technology has the advantages of no secondary pollution,no consumption of additional carbon sources,and low sludge production.However,continuous research on sulfate reducing ammonium oxidation.This thesis mainly focuses on the following four aspects:the initiation process of sulfate reducing ammonium oxidation reaction and the performance of water treatment;The effect of different N/S on the reaction process and the study of the reaction performance of nitrate and nitrite,the analysis of experimental phenomena of sulfate reducing ammonium oxidation reaction,reaction process,environmental conditions,while using high-throughput indicators Means analyze the microbial structure of sludge,and provide theoretical support for subsequent related research.Simultaneous reduction of ammonium and sulfate was achieved in a self-designed reactor,the removal efficiencies of NH₄⁺-N and SO₄^2--S were up to 92.0%and 30.5%,respectively,and the minimum concentrations achieved in the effluent were 8.4 mg·L^-1 and67.3 mg·L^-1,respectively.The products of NO₂^-and NO₃^-could be observed in the effluent at the average concentrations of 4.5 mg·L^-1 and 9.6 mg·L^-1,respectively.Two forms of alkalinity were added to the reactor,and the research results showed that N/S[n?NH₄⁺-N?/n(SO₄^2--S)]conversion rates during the experiment had not been unified.The increase of NO₃^-production and HCO₃^-removal in the effluent indicated the occurrence of the new interaction between N-C.NH₄⁺was converted to NO₂^-and NO₃^-.These results showed that nitrogen was converted by the partial nitrifying process,the denitrification process,and the traditional anammox process simultaneously with the SRAO process.In contrast with these two situations,when the N/S of the influent was improved,the NH₄⁺-N of the conversion ratio was higher and the NO₂^-formation was higher.Approximately 12.4%of the denitrifying bacteria,ammonium-oxidizing bacteria,anaerobic ammonium-oxidation bacteria were found in sludge.Proteobacteria was the main functional bacteria in the reactor.The process of sulfate reducing ammonium oxidation was accompanied by nitrification-denitrification.In the presence of 30 mg·L^-1 of nitrite,the oxidation efficiency of ammonia nitrogen and the reduction efficiency of sulfate were improved.Proteobacteria,Nitrospirae,Bacteroidetes,Chloroflexi,Chlorobi were detected in the anaerobic cycle growth reactor.NH₄⁺was converted to NO₂ and other intermediates,for which the electron acceptor was SO₄^2-.Injections of a certain amounts of nitrate had positive effects on the SRAO process performance;the sulfate removal efficiency was 85%,and approximately no NH₄⁺-N was detected in the effluent.Compared with the blank group,nitrifying bacteria and traditional anammox activity were positively impacted,and nitrification-denitrification and anammox occurred simultaneously with SRAO after the reactor ran for 97 days.Sulfur-based autotrophic denitritation and denitrification occurring in the reactor were caused by nitrite and nitrate.The oxidation process of ammonia nitrogen and the reduction process of sulfate are divided into three steps.According to the above research results,it is believed that the final product depends on the ratio of the element N and the element S that enter the water in the experiment.The high-throughput 16SrRNA gene sequencing results clearly show that nitrite is an intermediate product of ammonia nitrogen oxidation.Partial nitrification process,denitrification process and traditional anaerobic ammonia oxidation process and sulfate reducing ammonium oxidation process participate in the conversion of ammonia nitrogen at the same time.