Influence Factor Research On Monosodium Glutamate Wastewater Treatment By Simultaneous Nitrification-Denitrification In SBBR

The Sequencing batch biofilm reactor?SBBR?is a new kind of Hybrid Biological Reactor combined with the activated sludge process and biofilm process.Monosodium glutamate?MSG?wastewater was used as the water resource and the Built-in suspension ball packing was used as the biofilm carrier.The startup process of training biofilm,simultaneous nitrification-gentrification?SND?phenomenon and factors affecting the SND of SBBR process were investigated in this research,and the mechanism of SND by SBBR system processing MSG wastewater was further explored.After 29 days of intermittent operation,the Sequencing batch biofilm reactor was started up successfully by training the biofilm.On the biofilm formation stage,COD,NH₄+-N and TN removal rate increased gradually,and eventually stabilized at 90%,95%and 77%or so;the Sludge Volumetric Index?SVI?also stabilized gradually,and ultimately maintained at 100 mL/g or so with good sludge settling characteristics.Domesticating of the biofilm on the packing media was the key stage of the reactor starting and it was mainly related with the environmental factors,microbial properties and carrier surface properties.By tracking analysis of DO,pH,COD,NH₄+-N,NO₂--N,N0₃--N and TN for lots of cycles in SBBR,obvious simultaneous nitrification and denitrification was found in the aeration reaction stage,which was the main denitrification form by this process.The factors affecting simultaneous nitrification and denitrification had been researched and the main conclusions were as follows:when the air flux was 0.5³/h?the average DO concentration was 2.4mg/L?,the phenomenon of SND was obvious and the denitrification effect was optimal with the average TN removal rate of 79.62%;shortcut nitrification-denitrification could be realized throughout the process under air fluxes of 0.4?0.5m³/h.To control C/N ratio between 3 to 8,when C/N ratio was increased,the effect of SND would be better.When C/N ratio was increased further,TN removal rate began to decline,and would result in nitrifying function incompletely.In the conditions when the influent NH₄/-N volumetric loading was less than 0.09kg/?m³·d?,the more complete SND reaction would take place and higher denitrification performance would obtain.pH value was a important factor to SND.According to the experimental result,the efficiency of SND was the best when pH value was in the scope of 7.5?8.5.By analyzing the reaction process of SND,the main mechanism of SND in sequencing batch-biofilm reactor is the theory of anoxic microenvironment.The pilot-scale experiment was also carried out.The study showed that SBBR system processing MSG wastewater had certain advantages,and using this process to transform the existing SBR process was feasible.