Research On Biodegradation Characteristics Of Dianilino Dithiophosphoric Acid

Aniline aerofloat (dianilino dithiophosphoric acid), with its molecular formula (C₆H₅NH) 2PSSH, is an organic flotation reagent used frequently in lead sulfide mineral (PbS) flotation .This paper first studied domesticating and screening highly-effective-aniline aerofloat-degradation strains from flotation wastewater of refined lead mineral which containing aniline aerofloat, and we studied the characteristics in structure and appearance of the strains. Then we examined the optimization of biodegradation conditions and explore the mechanism of aniline float biodegradation by strain l^#.The conditions include pH value, temperature, oxygen, quantity of bacterial consortium, concentration of substrate ,heavy mental ,etc. At last we studied the effect of biodegradation on actual wastewater by the strains. This paper provides academic sustains on biodegrading flotation wastewater for Nanjing Xinyang Mine Company.Three bacterial strains ( 1^# , 2^#, 3^# ) were isolated from flotation wastewater ,which could grow with aniline aerofloat as the sole source of carbon and energy. Among those bacterial consortium, the colony of 1^# is peachblow on the solid culture medium of beef extract, and is gram -negative, globular and non-flagella, 0.5 μ m in diameter;while 2^# is ivory , and deepen as the culturing time goes, also gram-negative, globular and non-flagella, 0.8μm in diameter;and 3^# is light yellow while deepen as the culturing time goes, gram-negative, rod and about 1.0 μm in length. According to the analysis about the shape characteristics of colony or individual and other morphological characters, we guessed the three strains all belong to pseudomonas.Among the three strains ,strain 1^# was the most active in degrading aniline aerofloat, therefore, further studies focused on this strain, and also studied the mixed consortium of the three strains in this paper. For the strain 1^#, the optimum pH is 9.0, temperature is 30°C, under the shaking speed 125r/min, 20mL is the best quantity in the cone bottle whose capacity is 250mL, and the bacterial consortium is 10%(volume percent), and when the concentration of aniline aerofloat is 300mg/L, 64.5% of CODcr were removed, and while 100 mg/L, 77.8% of CODcr, 84% of aniline aerofloat were removed. The results showed that the ions of Pb²⁺, Ag⁺ and Zn²⁺ allrestrained the biodegradation on aniline aerofloat, and the latter stronger.. Adding the glucose at the concentration of 0.2g/L could greatly enhance degrading efficiency. No matter to simulated wastewater or actual wastewater, the mixed consortium of the three strains is better to biodegrade.Ultraviolet spectrophotometry and CODcr determination showed that strains biodegraded aniline aerofloat to new CODcr substances.