Apply Plant Fiber to Enrich the Microorganism for Degrading the Polycyclic Aromatic Hydrocarbons in Water

Abstract

Application of brown hair fiber, ramie fiber, jute fiber and flax fiber to degrade PAHs in water was studied. The experimental results show that the plant fibers which enrich the microbial has better effect of degradation on PAHs in water,and the degradation effects are highly related with plant fiber’s layout density,HRT and aeration rate. The higher the layout density of jute fiver,HRT and aeration rate,the better the effects of decontamination,which means the water quality of effluent meets the GB5749-2006 standard that the total content of PAHs is less than 2000 ng•L-1. Select No11~No14 Tank plant fiber density,6h HRT and 12h aeration,the effect of degradation of PAHs is the best. This result shows that microbial enriched by plant fiber has a good effect of degrading PAHs in water. Plant fibers provide a space as large as possible for indigenous bacteria attached to the growth in water,and also provide a good micro-environment for their biochemical reaction. The indigenous microorganisms attached to the surface of plant fibers rapidly grow to achieve strengthen the natural degradation of the PAHs in water. Except the biodegradable role of plant fiber enrich the microorganisms to degrade PAHs,in addition,there also exists absorption and evaporation effects. Macrocyclic PAHs ring has a more strong hydrophobicity than the small ring,so that in the process of biodegradation,the small ring is more easily to be absorbed by the plant fiber and biofilm surface,and more easily to be degraded. Therefore,plant fiber enriched microbial to degrade PAHs is the main process,then followed by adsorption and evaporation process.