Study Of Fibrous Filters For Oily Wastewater Treatment

The deep bed filtration is the last procedure in oily water treatment, and nowadays allkinds of filters are available in the market for different demands. This study tried toinvestigate a agricultural fiber filter, that is, utilizing agricultural fibers as filter medium. Plantfibers were mainly by-products of agriculture and forestry, even as wastes. Due to low costs,excellent absorbency and biodegradation, plant fibers have huge potential value. So plantfibers were chosen, and compared to other kinds of filters, natural plant fiber filter had manyadvantages, such as low cost, easier treating technique.The effect of packing height and ratio on the performance of six kinds of natural plantbed filter were evaluated. Oily water was first prepared by online emulsifying machine andfilter medium was prepared using mechanical method. For better investigatation, an oily watertreatment experimental facility was established. The experimental restults showed that wheatstraw was chosen with the best filtration performance, which was related to Spiral cavitystructure itself. In the single filter bed test, three bed heights were set for wheat straw and20cm was proved to be the best. In double beds test, small particles were lay down and bigparticles up. Through comparison testing, the ratio3:1of big and small particles was decided.Three temperatures and three types of oils were investigated then. The oil removal rate did notchange much at different conditions, however, the head loss differed greately. The head lossrose with increase of temperature. At40℃, the head loss increased exponentially. The headloss exhibited trend of decrease with increase of viscosity, but maybe other properties of oilsled this.At last a new fibrous filter was designed, in which back wash part was not involved. Sothe outer structure got simplification with less tubes and valves, which enhanced itspracticability and operability.