耐冷菌强化去除农田径流污染水体中氮磷的模拟研究

Study on Removal Simulation of Nitrogen and Phosphorus in Water Polluted with Runoff from Farm Land by a Psychrotolerant Bacterium

通过室内模拟实验研究1株土著反硝化菌(Acinetobacter johnsonii DBP-3)对农田径流污染水体中氮磷的低温生物强化去除特征。结果表明:10℃下避光好氧培养时菌株对水样中的硝酸盐氮和溶解性正磷酸盐具有较强的去除能力,培养8d后灭菌水样和原水样中硝酸盐氮的浓度分别下降了78.5%和70.2%,溶解性正磷酸盐的浓度分别下降了82.4%和74.6%,与未投加菌的对照组相比差异显著。菌株在低温模拟系统中具有较强的适应能力,实验周期内能够保持数量上的优势。与10℃相比,培养温度为25℃时,菌株的脱氮除磷能力明显增强,5℃时菌株的氮磷代谢能力明显降低,但与对照相比,菌株对氮磷仍然保持一定的代谢活性。菌株在模拟系统中对盐度具有较强的抗性,当盐度为10%时,其氮磷代谢能力才受到明显的抑制。多菌灵和毒死蜱的浓度分别为80.0,60.0mg/L时才对菌株的生长代谢产生明显的抑制作用,表明菌株对这2种农药的耐性较强。研究结果说明,实验用菌株在低温条件下不仅具有明显的脱氮除磷能力,而且对盐度和常见的农药具有较强的抗性,在面源污染的治理方面具有广阔的应用前景。

The biological enhanced removal of nitrate and dissolved phosphate in the mixture of natural water with runoff from farm land by a denitrifying bacterium Acinetobacter johnsonii DBP-3 was studied in a simulation system.The results showed that the added strain could remove strongly the nitrated and dissolved phosphate in water samples under the cultivation conditions of 10 ℃,and aeration in dark.After 8 days of cultivation,the concentrations of nitrate in sterile and raw water samples significantly decreased 78.5% and 70.2%,respectively;the dissolved phosphate significantly decreased by 82.4% and 74.6%,compared to the controlled treatment of without the strain.The strain showed high adaptability to the simulation system and kept numerical superiority during the whole experimental period.Compared to the temperature of 10 ℃,the cultivation temperature of 25 ℃ significantly increased the ability of strain DBP-3 to removal nitrate and dissolved phosphate and at 5 ℃ the ability decreased significantly;whereas,the strain DBP-3 still kept the metabolic activity even at 5 ℃.The ability of strain DBP-3 to remove nitrate and dissolved phosphate was not inhibited until the salinity reached 10%,indicative of the strong resistance to salinity.Carbendazim and chlorpyrifos significantly inhibited the removal of nitrate and dissolved phosphate at the concentrations of 80.0,60.0 mg/L,respectively,suggesting that the strain was tolerant to the two kinds of pesticide.It is indicated that the strain DBP-3 would have promising future in the treatment of eutrophic water body because of its strong ability to remove nitrate and dissolved phosphate and tolerance to salinity and pesticide.