Study On Isolation Of A Bacterial Strain Capable Of Typical PPCPs And Its Degradation Characteristics

In recent years, people started to pay attention to impact of trace contaminants-Pharmaceuticals and Personal care Products (PPCPs) on the environment, which was developd into global hot spots. Studies showed that some PPCPs had toxicological effect on humans and other organisms or had carcinogenic potential.China, as the world's largest user of PPCPs of the countries, controlling PPCPs from sewage was particularly important.This paper were conducted to investigate the removal property of two typical PPCPs.Two bacterial strains capable of typical PPCPs were isolated from aerobic activated sludge, then according to the morphological character and 16S rDNA gene sequencing analysis, the strains were identified.On the base of previous research, temperture, pH and initial concentration were examined to research the biodegradation characteristics of the two strains. Furthermore, the adsorption characteristics of trace typical PPCPs by the sludge in the SBR reactors were investigated.Firstly, a quantitative analysis method has been developed for determination of typical PPCPs in aqueous environment by using Solid-phase Extraction Coupled to High Performance Liquid Chromatography (HPLC). The optimal chromatographic condition of EE2 was described:The mobile phase was acetonitrile:water= (60:40, V/V), the column temperature was 30℃, current velocity 1.0 mL/min and detection wavelength was 280nm on the basis of the peaks appearance time. The optimal chromatographic condition of AHTN was described:The mobile phase was acetonitrile:water= (50:50, V/V), the column temperature was 30℃, current velocity 1.0 mL/min and detection wavelength was 242nm on the basis of the peaks appearance time.Then, a ethinyloestradiol degrading bacterial strain and a tonalid degrading bacterial strain were isolated from aerobic activated sludge, the two strains were named DE7 and DA5 respectively. According to the morphological character and 16S rDNA gene sequencing analysis, the strain DE7 was identified as genus Cupriavidus and the strain DA5 was identified as genus Alcaligenes. In order to research the biodegradation characteristics of the two strains, temperture, pH and initial concentration were examined. The results showed that when temperture was 30℃, pH was between 6.5 to 7.0, rotation speed was 160r/min, initial concentration was 25mg/L,about 82% EE2 was degraded by DE7. And when temperture was between 25℃to 30℃, pH was 7.0, rotation speed was 160r/min, initial concentration was 6mg/L,about 52% EE2 was degraded by DA5.At last lab-scale experiments were conducted to investigate the removal efficiency of typical PPCPs by SBR process. When the water input temperature was room temperature, pH was between 6.8 to 7.2, DO was 5mg/L, the average removal efficiency of conventional pollution and typical PPCPs inscreased with the increase of HRT and decreased with the increase of C/N. When the HRT was 10,C/N was 5,the removal efficiency of COD and NH4-N was best,the removal rate was 88% and 77.6% respectively. The removal efficiency of the typical PPCPs was obvious increased in the NO.2 SBR reactor, which was added the efficient strains. The best removal rate of ethinyloestradiol and tonalid was 92% and 64%.