| With the severe eutrophication problem occurred, sewage treatment must be taken into account not only phosphorus removal, but also nitrogen removal. We put biological membrane in the denitrifying pool of the original continuous flow process, at the same time join some tamed nitrosation denitrifying phosphorus accumulating bacteria (NDPAOs), form double sludge bio-film nitrosation denitrifying phosphorus removal technology, then research on the effect of bio-film reactor on denitrifying phosphorus removal with dispose the synthetic rural domestic sewage. Experiments were carried out in the double sludge bio-film reactor system to study the removal efficiency for the low COD/TN domestic sewage as well as the key effect factors, such as different carbon source, system sludge concentration, rear aeration pool hydraulic retention time, transcend sludge recycle ratio sludge ratio. Meanwhile, we have been separated some denitrifying phosphorus removing bacteria the anaerobic pool of the system, In this research we studies the growth and the absorption and release of phosphorus of the denitrifying phosphorus removing bacteria.Domestication nitrosation bacteria with a SBR reactor. The early domestication, we have a low nitrification rate and ammonia nitrogen removal rate, at the 7th day, the nitrosation rate increased obviously, at the same time there is a small number of sludge appear floating phenomenon, account for that a certain amount of nitrosation bacteria has been demonstrated in sludge contains. Between 8-25 days, we got a high nitrification rate and ammonia nitrogen removal rate, the average is around 80%. At the 73th day, nitrosation rate is above 80%. Starting from the 75th day, in addition to the volatility of individual points, the nitrification rate remained at 70%-100%, ammonia nitrogen removal rate was between 80%-100%, description that nitrosation bacteria have got a enrichment, and nitrosation sludge domesticated mature basically. Domestication NDPAOs by three phase method. The first phase, we determined whether PAO has domestication mature through a result of release/aerobic phosphorus absorption. The second stage, we determined whether DPAOs or NDPAOs has become a advantage bacterium group through a result of the system and the accumulation of nitrite. The third stage, we determined whether the NDPAOs domestication mature by detecting water nitrite concentration and phosphate concentration.The self-made anaerobic, anoxic device have been used in this experiment to research the effect of carbon source and MLSS on double sludge bio-film nitrosation denitrifying phosphorus removal system. With different carbon sources, the order of COD removal rate in six systems is sludge hydrolysis acidification liquid, sodium acetate, sodium propionate, starch, glucose, methanol. The nitrification denitrification rate of methanol is 0.19mgNO2--N/(gMLSS·h), the nitrification denitrification rate of starch is 0.15mgNO2--N/(gMLSS-h), the nitrification denitrification rate of glucose is 0.26mgNO2--N/(gMLSS·h), the nitrification denitrification rate of sodium acetate is 0.49mgNO2--N/(gMLSS·h), the nitrification denitrification rate of sodium propionate is 0.31mgNO2--N/(gMLSS·h), the nitrification denitrification rate of liquid sludge hydrolysis acidification is 0.32mgNO2--N/(gMLSS·h). The order of the effect of phosphorus release from good to bad is sodium acetate, sodium propionate, sludge hydrolysis acidification liquid, methanol, glucose, starch. By changing the aeration tank outlet location, nutrients, phosphorus and COD removal in two-sludge bio-film process of different HRT conditions were discussed. Within the higher MLSS in the system, the greater the COD removal rate, the higher anaerobic phosphorus release rate and anoxic phosphorus absorption rate, the unit sludge on phosphorus absorption speed was the first to increase then fall down, the anaerobic phosphorus release amount and anoxic nitrosation denitrifying phosphorus uptake of the system increases, the reaction time reduced. By comparing, we can learned that the dephosphorization and denitrification effect are the best when MLSS is about 5200mg/L. By changing the aeration tank outlet method to adjust the position of aeration tank after HRT, research the biological denitrification and phosphorus removal performance of two-sludge membrane technology and the change of COD removal rate under the conditions of different HRT. When HRT was 2.4h, the system average COD removal rate was 66.68%, the COD value of effluent water can meet the discharge standards. The average ammonia nitrogen removal rate is 88.41%, the average ammonia nitrogen concentration of effluent water is 6.26mg/L, and most over removed in the the forepart, denitrification effect is stable. The average phosphate removal rate is around 94.88%, anaerobic phosphorus release rate steady at around 45.24%, anoxic phosphorus absorption rate are larger, and steady at 54.59%, the phosphorus removal effect is best. Based on artificial wastewater treatment object of this test, double slime bio-film nitrification and denitrosation denitrifying phosphorus removal technology of sludge ratio were studied. The affect of beyond sludge ratio on COD removal efficiency is small, and the affect of beyond sludge on ammonia nitrogen and phosphate removal effect are very big. When the beyond sludge ratio were 0.21,0.6, 0.9, in two-sludge process, the average COD removal rate were 74.99%,78.42% and 78.96%, respectively. The average ammonia nitrogen removal rate are 76.24%,75.46% and 76.24%, respectively. The average phosphate removal rate were 61.11%,66.65% and 40.74%, respectively. When the beyond sludge ratio is 0.6, COD and nitrogen removal efficiency are comparatively good. When the beyond sludge ratio is, the water quality of phosphate concentration is minimal.11 strains of bacteria were separated from double sludge bio-film system. The order to the effect of nitrification and denitrification and phosphorus absorption of the bacteria from good to bad is Vei., Sta., Bac., Ent., Bac., Edw., Lac., Par., Nei., Mor., Bra.. The strain bacteria phosphorus content of bacteria Vei., Edw., Sta., Nei., are all above 10%, and they are highest of all. The maximum value of maximum phosphorus absorption rate is 5.30mg/(L·h), and the minimum value of maximum phosphorus absorption rate is 0.767mg/(L·h). To compound with NDPAOs single strain and remove the antagonism relationship strains we got 16 strains of compound bacteria. The adjustment time of all the compound bacteria are between 0-3h, is shorter than any single bacteria strains. Z8 has the strongest ability to adapt to the new environment. The slope of growth curve in logarithmic phase of Z3, Z9, Z1 are least. The duration time in stable phase of Z5 is between 144-168h and shorter than other strains. The duration time in stable phase of Z11 is between 144-216h and longer than other strains. The curve trend of Z13, Z15 are similar, it's logarithmic phase between 6-75h, then enter the duration time, they have a slow-growth tendency until two maximum value attained at the time 105h and 116 h. Z1 has the shortest logarithmic phase and a longest stable phase.The temperature test shown that the optimum growth temperature of Z4, Z5, Z11 is 28,28, 25?, respectively. The inoculum size test shown that the optimal quantity inoculum size of Z1, Z3, Z4, Z8, Z11, Z12, Z14, Z16 is 1%,7%-10%,7%, 1%-2%,1%,2%,2%,2%-2%, respectively. The salt resistance test shown that the optimum growth salt resistance of Zl, Z8, Z12 is 5%,4%,5%, respectively. In the pH value test, the optimal growth pH of Z4 is 8.0, and the phosphorus removal rate is over 88%. The optimal growth pH of Z5 is 7.5, and the phosphorus removal rate is increasing at this time, the amount of bacteria increased. The optimal growth pH of Z11 is 8.0, it has a best phosphorus removal effect and a stable microbial. |
PDF Full Text Request