Strengthening Methods Of Halo-tolerant Bacteria Properties And Research

Biological treatment technology is widely used in treatment process of the salinity wastewater because of the strong applicability and high efficiency. Due to the salinity restrain the activity of the microorganism, the construction of microorganism system during the disposal process of the salinity wastewater became very difficult. So COD degradation in the salinity wastewater became very difficult. In order to solve the difficult problems, the feasibility of construction of high-salinity micro-biological disposal system and the effect of betaine, ectoine and their mixture to biological treatment system under high-salt condition were studied in this work.This study is made up of two parts, activated sludge acclimatization; effect of compatible solutes on microbial system.In the sludge culture experiment, with the measure of enhance0.4%(NaCl)salinity of inflow every time to supplying acclimatization concentration, high-salinity micro-biological disposal system which the salinity is1%(NaCl) could be constructed. The results of the experiment are as follows:when the salinity is increasing, the microorganism needs a period to adapt the salinity stock. With normal temperature among27℃, the volumetric loading was1.0kg/(m3-d) and adequate dissolved oxygen, the hydraulic residence time to be24hours and pH value of the inlet water among7.0, the biochemical system should to be acclimated about30days before regular operation. When the concentrations of COD in the inlet water were about400mg/L and2800mg/L, the COD in the effluent water could be reduced to22mg/L and222mg/L, and we could get the removing rate of COD as94.27%and92.09%. The Bio-contact oxidation system also had the ability to handling ammonia. It would get the removing rate of ammonia as70.13%in stable operation period.In the dosing of compatible solute experiment, betaine, ectoine and their mixture is putted into high-salinity micro-biological disposal system which the salinity is1%(NaCl). The results of the experiment are as follows:the betaine, ectoine and their mixture accelerated the cultivation of bacteria in high salinity environment and shortened the construction time of biological system under high-salt condition. And treatment effect of0.5mmol/L betaine concentration was the best of all compatible solutes. When the biochemical system should to be acclimated about5days, the effluent COD was117mg/L, and the removal rate was95.81%. The effluent NH4+-N was8.35mg/L. The removal rate of NH4+-N was87.99%. Treatment effect of0.5mmol/L ectoine concentration was the best of all ectoine concentrations. When the biochemical system should to be acclimated about5days, the effluent COD was221mg/L, and the removal rate was92.09%. The effluent was NH4+-N11.73mg/L, and the removal rate of NH4+-N was83.12%. Treatment effects of0.5mmol/L betaine and0.25mmol/L ectoine concentrations were the best of all mixture concentrations. When the biochemical system should to be acclimated about5days, the effluent COD was163mg/L, and the removal rate was94.18%. The effluent NH4+-N was10.45mg/L, and the removal rate of NH4+-N was85.07%.