【摘要】 光合细菌球形红假单胞菌经甲醛（ＦＡ）诱变获得高絮凝菌株的最佳反应组合条件是１５ｍＭ的ＦＡ、３５℃的反应温度，５ｍｉｎ反应时间和ｐＨ为７的反应液。经初、复筛后获得高絮凝性能理想菌株Ｐ９４７９，其１００ｍｉｎ自然絮凝沉降效率是出发菌株的２．３４倍。聚合硫酸铁絮凝Ｐ９４７９与出发菌株Ｐ９１００的最佳浓度分别为０．７７‰和２．４‰根据测定的Ｅ～ｔ曲线，在絮凝３０ｍｉｎ的同等条件下，Ｐ９４７９在人工废水中菌液絮凝效率达９０％，比出发菌株高出１７％，而聚合硫酸铁的用量比出发菌株低６８％。在ＣＯＤｃｒ为８７２０ｍｇ／Ｌ味精度水中絮凝Ｐ９４７９的最佳聚铁浓度为２‰，絮凝３０ｍｉｎ的效率达８０％，而出发菌株Ｐ９１００的聚合硫酸铁最佳浓度为４‰，效率仅为５０％。在同等絮凝效果的前提下Ｐ９４７９比Ｐ９１００节约聚合梳酸铁６９％。更多还原

【Abstract】 This research aims to increase the purification rate and decrease the operating cost of the wasl ewater treating process by inducing better floculation of photosynthetic bacteria (PSB ) Rhod op seud omonas sphaeroides.Rhodopseudomonas sphaeroides P9400 was the staring strain in this test, which obtained better flocculating ability after formaldehyde -- induced mutation. The optimal reaction conditions were 15mM formaldehyde, 35℃,pH7 and 5 minutes’reaction time.P9470 was the resulting strain of the primary screening, selected from 9 mutant strains of P9400 i. e. P9410, P9420, P9430, P9440, P9450, P9460, P9470, P9480, P9490. The P (%) value of P9470 cells liquid culture was 13%, which is higher than those of the other eight. P (% ) value indicates the floccultating efficiency of Phod opseudjomonas sphaeroides in artificial wastewater with no addition of inorganic flocculant. p= (Af!’--Ams’)/At!’, in this formula, At!’ means the value of optical density of the liquid culture before sedimentation, while A?:’ means the value after sedimentation of 10 minutes. There was some flocculent biomass occured in P9470 liquid culture. Through microscope it shows that 2 to 5 cells adhered to each other forming bigger clump.P9479 was the ideal strain of the further screening, selected from P9471, P9472, P9473,P9474, P9745, P9476, P9477, P9478 and P9479. The P(%) value of P9479 culture was 8. 6% to 18. 5% during the period of sedimentation from 20 minutes to 100 minutes in a glass column which is 50cm high with a diameter of lcm. There is a significant diference between the two groups of values of P9479 and P9100 judged by the statistical treatment of the data (t =4. 00>t0.05(4). The biggest she of the P9479 clump observed reached over lmm.The most suitable concentrations of polyferric sulfate (PFS) [Fe2(OH)n (SO4)3--n/2]m for improving the floccutating efficiency of P9479 and P9100 cells were 0. 77 ‰and 2. 4 ‰ respectively in another glass column 60 cm height with a 4. 6 cm diameter. Their curves of efficiency vs time show that the E value of P9479 cells can reach the level of 90% in 30 minures in the artifiCial wastewater, which is 17% higher than P9100 and can save 68% polyferric sulfate as sediment equivalent bioass of the two kinds of cells. E (%) means the total floccutating efficiency druing the reaction time with PFS. E =P1 +J.,h./hn. △p:P1 means the flocculating efficiency(%) while the cells are at the first height h1 (cm ) ;hn refers to the other 4 heights except h1; h0 is the total height of the galss column.As P9479 and P9100 are transferred into the monosdium glutamate (MSG ) wastewater with PH 7. 0, and CODcr 8720 mg/L for shakinng culture, the most suitable concentration of polyferric sulfate is 2‰ for P9479 and 4‰ for P9100 to improve their flocculating ability. Their floculating efficiency (E ) is 80% and 50% respectively in 30 minutes in MSG wastewater with polyferric sulfate. As for the sedimentaion of equivalent biomass. P4979 can save 69 % of polyferric sulfate needed by P9100.更多还原