Research On The Mechanism And Effect Of The Denitrification And Phosphorus Removal For Biogas Slurry With The Integrated A/O Biofilm Reactor

In the aspects of pig waste treatment：the large and medium-sized pig farmshave shown the effect of reducing pollutant emissions; For small farms, because ofthe high cost of new waste treatment facilities, they only disposed the manurethrough anaerobic treatment by biogas digesters, and lack of the follow-effectiveaerobic treatment. Eventually, it cannot achieve emission limit value in “Dischargestandard of pollutants for livestock and poultry breeding”(GB18596-2001), and itwould cause serious pollution in water and soil of surrounding environment. However,if they have a integrated device of certain types of aerobic treatment processes andsettling ponds placed directly on flat land without a lot of ground-breaking, so long asto ensure its efficiency, it will play a positive role in promoting for the treatment ofthe small farms manure. Therefore, based on this topic, this paper conducts researchon integrated A/O biofilm reactor dealing directly with farm slurry, the mainconclusions are:(1) About the integrated A/O biofilm reactor startup, using the model of "firstindependently started, after jointly launched", in condition of making C/N ratio ofbiogas slurry increased from1.1~1.6to2-3by adding C6H12O6, removal rate of CODand NH3-N can respectively reach76%and88%, and effluent water quality achievethe standards, then the reaction is started normally.(2) When C/N ratio of slurry inlet is2.6, the integrated A/O biofilm reactor ispreferably remove COD, and the effluent concentration is330~380mg/L; When thereflux ratio of nitrification liquid is200%, the removal efficiency of NH3-N can reach89.4%, and the effluent NH3-N is in64~79mg/L; To achieve high efficiency reactorof phosphorus removal, it needs to keep dissolved oxygen higher in the first aerobiczone than the second aerobic zone.Because of the relatively high water content of TP in integrated A/O biofilmreactor effluent, it still need to be further processed. Based on the conventionalbiological phosphorus removal technology and the understanding of the latestremoval process developments at home and abroad, corresponding basic research can be found from the phosphine which is the only phosphorus-containing gaseouscompounds. Therefore, this paper takes the pig slurry as the research object, and teststhe law of phosphine production in slurry, the results showed as follows：:①Without the microbial involvement, in the condition of acidic, neutral andalkaline environment, the cumulative amount of PH3were respectively7.26,12.92and8.07μg in10h. It means that PH3produce more in the neutral environment.②Without the microbial involvement, at the temperature of25,35,45and55oC,it is more suitable to carry out research on PH3under25oC environment, from theperspective of PH3production and energy efficiency.③With the microbial involvement, it was discussed on microbial biogasproduction of PH3from four factors (the pH value, TP, COD and Cu2+). The resultsshowed: when the pH value is from5to6, PH3accumulation amounted to20.937μgin10h, and the average concentration of PH3production per unit of slurry is0.698μg/L·h, and the average mass containing PH3per unit of gas is349.020μg/m3;TP andPH3production value in water were proportional relationship, and the correlationequation is y(PH3,μg/h)=0.24129+0.03818x(TP,mg/L),R2=0.827;When COD ofbiogas slurry is less than620mg/L, COD concentration and PH3production werepositively correlated relationship; When COD is more than620mg/L, CODconcentration and PH3production were negatively correlated relationship; When Cu2+concentration of the slurry is in1.2~4.0mg/L, the cumulative amount of PH3perhour and Cu2+concentrations were negatively correlated relationship.