Isolation,Growth Characteristics And High-salt Wastewater Treatment Of Salt-tolerant Photosynthetic Bacteria ES1

With the rise of industry,many industrial sectors generate high-salt wastewater in the production process.Based on the process characteristics,these wastewaters not only has extremely high salinity,but also has other high organic matter or refractory substances.Discharge directly of those poorly treated high-salt wastewater into the water environment can have a fatal impact on the ecosystem.Compared with other methods,the biological treatment of high salt wastewater has always been concerned because of its high performance cost ratio and low energy consumption,among which the research focus is on the selection and exploration of salt-tolerant microorganisms.The wastewater treatment technology based on photosynthetic bacteria has become a new wastewater treatment scheme because of its high adaptability,more effective solid-liquid separation and nutrient recovery.At the same time,more and more high salt tolerance photosynthetic bacteria have been found in the high-salt natural environment.But due to the low pertinence of the separation and screening technology,there were few tentative applications.In this study,the targeted separation of salt-tolerant photosynthetic bacteria was achieved by adjusting the separation medium components and operation,and one strain Ectothiorhodospira sp.(ES1)was successfully isolated from the photosynthetic tank in the sewage system of a pharmaceutical factory in Zhejiang province.Taking them as the research objects,the growth characteristics of the bacteria were preliminarily explored,including basic physiological and biochemical characteristics and some important environmental factors,such as metabolism,salinity tolerance range,p H,light intensity and so on.It was found that the bacteria grew rapidly in the optimized medium and had a high tolerance to carbon,nitrogen,sulfur and other substances,and maintained good growth under the conditions of COD up to 10 g/L,sodium nitrite up to 1g/L or sulfide concentration up to 5mmol/L.It also has a maximum salinity tolerance of 9%.All results indicated the bacteria can survive in more demanding environments.In addition,the feasibility of applying this strain to high-salt wastewater was preliminarily explored,and the results showed that the light-aerobic condition,as a special environmental condition,could promote the metabolic capacity of ES1 and improve the wastewater treatment effect.Adding the bacterial solution to the ordinary activated sludge system can effectively improve the system's resistance to salinity impact.