Study On Biodegradation Of Persistent Organic Pollutant Pentachlorophenol (PCP)

Pentachlorophenol (PCP) is one of persistent organic pollutants; it is existed broadly in the waters. Firstly, it is used to timber antiseptic, and then it is popular applied as insecticides and herbicides together with other chloroprene. The use of PCP lead to a broad polluted. The studies on degradation of PCP are signaled.Firstly, the toxicity of pentachlorophenol (PCP) with protozoan community as target organism was studied. In the 12h-cute toxicity testing, the maximal tolerance and minimal all lethal are investigated, the half lethal concentration was 2.40mg/L. Secondly, four bacteria that could live in the high concentration of PCP had been cultivated and domesticated; they are Klebsiella terrigena,Uncultured bacterium,Bacterium SV26II,Pseudomonas migulae. The fittest vegetal conditions of the four predominant bacteria had been listed by studying these growth lines. Under the fittest condition, intermits experiments of degradation had been researched, and the curves of degradation had been investigated. Thirdly, the processes of producing chlorine and other production during metabolizing had been detected.The adsorption of PCP by immobilized granules had been studied carefully. The adsorbed balance time is 24 hours and the adsorbed equations had been calculated. When the immobilized granules were PVA and diatomite, the adsorbed equations were as same as Freundlich adsorbed equation. The orthogonal experiments were designed, in order to know the optimized conditions. Under the optimized condition, curves of intermit degradation of PCP by immobilized bacteria had been described. Compared with the results of degradation by bacteria in solution, the method of immobilized bacteria is better. The results of degradation by immobile mixed bacteria were also known. The results proved that the velocity of degradation could be enhanced. Especially, the immobile bacteria mixed with B, C and D is the best compounding. Cometabolic degradation of pentachlorophenol (PCP) was also researched. The effect of PCP degradation with glucose, glycerol, phenol or butanedioic acid as growth substrate was compared.