The Study Of Determination And Microbial Degradation Of Five Kinds Of Phthalate Esters In Chaohu Lake

Phthalic acid esters (PAEs) are a class of refractory organic compounds widelyused plastcizers in polyvinyl chloride plastics. They are among the most commonlyused industrial chemicals and have become widespread in the environment; theyhave been found in sediments, natural waters, soils, and aquatic organism. As a resultof both the large quantities produced and their widespread distribution , PAEs havebecome one of the most prevalent contaminants or the second PCBs pollutants. Theavailable literatures suggest that the routs of environmental degradation of PAEs arehydrolyze, photodegradation and biodegradation, microorganisms are responsible forthe complete destruction of PAEs in the environment. The detection and evaluationof five kinds of PAEs(DMP,DEP,DBP,DEHP,DOP)in part of Chaohu lake havebeen studied in this paper. Bacterial strains which could decompose the five kinds ofPAEs are isolated from a batch culture with PAEs as carbon source and the sedimentsamples from Chaohu lake After degradation bacterial in the enrichment culture areisolated, purified, and dominant bacterial colonies are identified with biology GNSystem. This paper mainly studies degradation ability to the five kinds of PAEs whenpresent simultaneously and individually, the primary study of microbial controllingpollution of PAEs in Chaohu lake has been carried out. The main results of study areas follows: After the comparision of effect of alumina cleanup and oil vitriol cleanup,amethod for the determination of five kinds of PAEs in water have been developed ,which is extracted with methylene chloride .After oil vitriol cleanup of the sample ofextracting is analyzed by gas chromatography with electron capture detection(GC/ECD). This paper develops the program of safety evaluation of the organismpollutants that is suggested by EPA. The effect of PAEs is estimated by the method inChaohu lake,we find that PAEs in Chaohu lake have effected natural environmentand healths of people. Twenty-one bacterial strains which could decompose PAEs are isolated from abatch culture with PAEs as carbon source and the sediment samples from Chaohulake After determining the rest quantity of PAEs with gas chromatography, threestrains from sediment of Chaohu, two strains from sludge of a local wastewatertreatment plant and two strains from sludge of a local industrial wastewater ,namedD1,D3,D5,W1,W5,G1and G5. The dominant strain of Chaohu lake are identifieddominant bacterial colonies with biology GN System,named Burkholderia P. Theenvironmental facts are manipulated to investigate their effects during degradationbacterial colonies of incubation. The effects of time, temperature, acid andconcentration of biomass on growth of the three strains have been studied. The biodegradation dynamics of the five kinds of PAEs when presentsimultaneously by Burkholderia P are as follows: (1).Effects of different concentration of PAEs to degradation show thatBurkholderia P has obvious degradation ability to PAEs. With concentration of PAEsincrease, the degradation rates of PAEs decrease. PAEs degradation dynamics arestudied by Burkholderia P, degradation kinetics follow the first order kinetic:Ct = C0.e?kt . (2).Burkholderia P degrades lower molecular weight phthalates of DMP and DEPeasily, and finds the high molecular weight DEHP and DOP more difficult to degrade.The study confirmed that a correlation exists between increasing length of the esterside-chain and decreasing biodegradability. There are correlations between catalysisrate constants (Kow) and biodegradation rate constants (K): relation equation isLogK=-0.3774LogKow-1.7866. (3).In the simultaneous presence of Burkholderia P and D3, degradation rates ofPAEs are also enhanced. In the simultaneous presence of Burkholderia P, D3 and D5,degradation abilities of PAEs have been better than the simultaneous presence ofBurkholderia Pand D3. (4)Three facts of temperature, pH, oncentration of PAEs c have effect on PAEsbiodegradation and follow the sequence :temperature > PAEs concentration > pH.The optical condition of PAEs biodegr...