Study On The Removal Efficiency Of Heavy Metal-Cr(Ⅵ) In Sewage Using The Micro-aerated Strengthen Ecological Floating Bed

In recent years,The rapid development of chromium pollution industry in our country (such as electroplating, dyeing and metal pickling leather) makes a large number of chromium-contained wastewater discharg into the environment, causing a serious pollution of the environment. Chromium is easily to be absorbed and accumulated in the body, and easily to cause cancer. Therefore, the governance of natural water body which has been polluted by chromium is an important and urgent environmental problem that our country is facing. High concentrations of chromium containing wastewater usually use chemical precipitation method and electrolysis. Low concentration concentrations of chromium containing wastewater usually use ion exchange resin. They are all face of the high cost of disposal problems. In recent years,the ecological floating bed technology has a good development in the field of pollutant.It use the absorption, enrichment and assimilation of the plant process the pollutants in the environment, which has a good purification effect.Appling this management method which close to nature in heavy metal chromium pollution control has the advantage of low cost in control investment, simple operation process, convenient in management and good treatment effect, etc. In addition, after checking relevant information, there is neither related experimental research nor engineering practice on hexavalent chromium waste water by ecological floating bed system at home and abroad, this belongs to the research for the first time.Therefore, the ecological floating bed technology in control of chromium pollution wastewater has high theoretical research value and good application prospects.In this paper, the whole experiment process is accomplished by ecological floating bed, after a series of experimental comparison research, it finally determined that the micro aeration strengthening ecological floating bed as the best experimental platform.This paper studying the removal effect and accumulation pattern of heavy metal Cr6+ in sewage in the whole ecological floating bed system,which will be conducive to understand the principle of purifying water quality in micro aeration strengthening ecological floating bed, which will provide a strong theoretical support for the application in practice of micro aeration strengthening ecological floating bed.The whole experiment process last for 3 months, under this experimental condition, I mainly draw the following conclusion:(1) The ability to remove the Cr6+ in the sewage:micro aeration strengthening ecological floating bed> micro aeration strengthening ecological floating bed> traditional ecological floating bed; The final removal rate of the three kinds of ecological floating bed respectively reached67.32%,62.70% and 48.65%. And the presence of Cr6+ on the system would have a certain inhibitory effect on the removal of CODCr, NH3-N and TP.(2) Different aeration rate micro aeration strengthening ecological floating bed all have a certain ability to remove the Cr6+ in the sewage:7.5 L min-1>10 L min-1>5 Lmin-1>2.5 L·min-1>0 L min-1. At the end of the experiment, the final removal rate of the 0 L·min-1,2.5 L·min-1,5 L min-1,7.5 Lmin-1 and 10 L·min-1 of ecological floating bed respectively reached 61.28%,68.24%,74.58%,78.52% and 75.68%. The quantity of accumulation in the packing was less, and the accumulation of Cr6+ in the packing has nothing to do with the aeration rate.(3)Different packing micro aeration strengthening ecological floating bed all have a certain ability to remove the Cr6+ in the sewage:combined packing> mixed packing> elastic solid packing. The final removal rate of the three kinds of ecological floating bed respectively reached 73.64%,69.84% and 47.42%.The combined packing micro aeration strengthening ecological floating bed system had the best plant growth condition, and it also had the best capability of accumulation for Cr6+. The accumulation of Cr6+ in the packing shows correlation with the packing type. The combined packing system accumulated the most Cr6+ in plants.