Phytoremediation Of Pentachlorophenol Contaminated Soil By Aquatic Macrophytes

Pentachlorophenol is broadly applied in the work agriculture produce as timber antisepsis, herbicide and the prevention and control schistosomiasis, PCP-Na salt is main medicine that annihilates the Oncomelania hupensis Gredler in the disease prevention and control. PCP is one of persistent organic pollutants (POPs), it can enter the human body through food chain, store in liver, kidney and fats. PCP not only has direct harm to the human body but also poses genetic toxicity. American EPA listed it as the priority pollutants as early as 1976. At the late 1980s ,the Chinese EPA took PCP into the Chinese environment priority pollutants" blacklist" according to the pollution status of our country. A lot of physical and chemical methods can be applied in dealing with PCP in environment, including Fenton'e reagent, oxidation by metal compounds, photochemical reaction, the electricity chemical reaction, ozone oxidation, ultrasonication and combination of different types of treatments. But all those methods are tedious and costy, and unable to apply in situ. In contrast, phytoremediation is more suitable for remediation of PCP contaminated soil in the environment.Phytoremediation of sediments rely on macrophytes. The macrophytes is similar to Land higher plants which having the ability to adsorb, accumulate, degrade the toxic pollutants and is easy to be harvested. Phytoremediation technique is supposed to be applied in removal of toxic pollutants in aquatic environment. This research investigate the common macrophytes (particularly development root system of emergent plant) Fhragmites communis Trin, Typha orientalis, Scirpus Validus Vahl and Vetiveria zizanioides to study ability of resistance and accumulation capacity to PCP, aiming to lay foundation for PCP remediation in water by native macrophytes of our country. Among them Vetiveria zizanioides is alien species, according to the related report, has good purifying effects of dirty water, development root system and broad adaptability, so it is a research object here.Initial concentration of 2 mg/ kg PCP was set to soil for imitating the open country ecosystem experiment. The results showed that, under this concentration, PCP has certain incitement to the height of plant, chlorophyll concentration, the root activity and the antioxidant enzyme system activity, which underwent increasing to some degree compared to unplanted group. PCP also showed certain inhibiting eifects on rhizosphere microorganisms; The concentration of PCP in the soil reduces continuously, after eight month PCP in plant and soil in all is as low as PCP determination limit. the variety of plant physiology (height of plant, chlorophyll concentration, the root activity and the antioxidant enzyme system activity(SOD,POD,CAT)) correlate with PCP residual in soil and plant.. This Explain that Fhragmites communis Trin, Typha orientalis, Scirpus Validus Vahl have favorable ability to accumulate and remediate the PCP in the soil and are suitable for remediating the PCP contaminative soil in the environment. The peroxidases and superoxides dismutase played an main role in defending and reducing the toxicity and harm of PCP to the plant in the process of remediation.