Study Of Wasterwater Treatment Using Anaerobic Microorganism Technology Enhanced By Ferrous Ion

Iron is the key element for the microorganism to maintain metabolism and enzymatic activity during anaerobic reaction.The anaerobic collaborative system of ferrous ion and microorganism continue low energy consumption,strong treatment effect and other advantages from anaerobic biological treatment technology.At the same time,ferrous ion can greatly promote the processing efficiency of anaerobic technology and the activity of microorganism.Therefore,it is of great importance to study the effect of ferrous ion on anaerobic treatment.This paper explores the process of anaerobic biological treatment under the synergistic effect of ferrous ion and microorganism.In the first stage,based on the UASB plant's testing sucrose wastewater treatment test in the laboratory,this paper studies the concentration of inflow sucrose,the concentration of ferrous ion and the influence of hydraulic retention time on the effect of anaerobic treatment,and detects the concentration of outflow COD when the reactor is continuously operated.The results show that in the certain concentration range,the increase of ferrous ion has a great promotion to remove COD;under the condition of short hydraulic retention time and fast up-flow velocity,low water load can remove COD better,while under the condition of long hydraulic retention time,high water load can remove COD better.After detecting EPS in different condition,it is found that the growth of sucrose can greatly increase the protein content in EPS and contribute to the stability of anaerobic system;meanwhile,the growing concentration of ferrous ion has more coenzyme F420 detected in EPS,the gas deliverability of UASB reactor is improved,and the process of sludge granulation is also promoted.Moreover,this research detects reactor the concentration of ion element in reactor outflow,and studies the influence of sludge granulation by the microscope.The results show that the increasing ferrous ion makes more ion element in the sludge,which accelerates the formation of sludge granulation,at the same time,strengthens the utilization of anaerobe to ion element.After Box-Behnken model designed by response surface methodology further optimized the operation parameters of the reactor,the best operation parameters of the UASB reactor are obtained:the inflow sucrose concentration:2500mg/L,Fe²⁺concentration:13.93 mg/L,and the hydraulic retention time:16.35 h.In the second stage,based on the intermittent experiment equipment and high-throughput sequencing,the strengthening function and effect of ferrous ion on anaerobic biological treatment are analyzed from the perspective of microbiology of water treatment microbiology.Main conclusions are as follows:the intermittent experiment results show that the input of ferrous ion has a promoting effect to remove the fermented liquid COD.Subtracting out the impact of flocculation,appropriate ferrous ion can make the key enzymes in the process of anaerobic digestion reaction have stronger activity.High-throughput sequencing results show that the growing concentration of ferrous ion can change the dominant population in the anaerobic system,Clostridium replaces Longilinea to become the bacterial genus with absolute advantage;the abundance of Methanolinea,Methanobacterium,Candidatus Methanoregula is significantly improved.All of them are the key bacterial genera to produce methane.And it suggests that the improving concentration of ferrous ion reinforce the capacity of UASB reactor to generate methane,which is consistent with the content changes of coenzyme F₄₂₀ showed in study above.This shows that the increase of ferrous ion in the certain range promotes the synthesis of the active enzymes of methanogens.In conclusion,the anaerobic treatment system with ferrous ion and microorganism has obtained good treatment effect,which has research value and feasibility.In the experiment,the ferrous ion has a positive effect on improving anaerobic environment,improving the stability of the reactor,promoting the activity of microorganisms and key enzymes,and changing the structure of microbial community structures.