Application Research Of Bio-filling In High Polluted Riverway Treatment In Suzhou City

The application of hydro-ecology rehabilitation technique such as reestablishment of aquatic organism were seriously restricted by low transparency, low dissolved oxygen and high density of suspended materials in high polluted city riverway. Bio-filling has its characteristic of impregnable by water transparency, suspended materials and unpredictability pollution impact. Based on the previous studies and combined with the national important scientific special item—the projection of water environment improvement and comprehensive demonstration in Suzhou city. The influence to water quality melioration under different conditions of packing types, stuffing rate, air supply and hydraulic loading using water of Miaojia river as experiment water sample; the water contaminate removal ability by the absorption and interception of charcoal filling and the research of the denitrification rate of charcoal filling were discussed in the paper. Furthermore, the activity of the biofilm on savageness and artificialness filling surface in the projection demonstration riverway were also analyses.The following conclusions can be obtained through above studies:(1) High density of different species algae are accumulated on the surface of savageness and artificialness filling in the city riverway. The activity of charcoal filling biofilm were much high than the biofilm of plastic filling and plants root of floating carriers.(2) Charcoal were the propriety material for water treatment in the riverway in Suzhou city. In the condition of 75% stuffing rate, 5.60 m³/m²Â·d hydraulic loading and 5-6mg/L dissolved oxygen, the removal rate to COD, NH₄⁺-N, TN,TP and turbidity are 25%, 74%, 10%, 62%, 77% each by charcoal filling.(3) The charcoal filling has tenuity effect in the improvement of water quality were only by its absorption and interception function. The removal rate to TN can be reached 37% by the charcoal filling after the aerobic- anaerobic- aerobic procession.The nutritive salt such as nitrogen and phosphorus, COD loading can be removed remarkably by charcoal filling. Simultaneity, the transparency and dissolved oxygen increased sharply. Charcoal filling contact oxidation technology is a feasible way to improve the water quality in the high polluted riverway which aquatic organism not adapt to existence and may creating harmonize condition for reestablishment of aquatic animals and plants, furthermore, creating the premise condition for the whole hydro-ecology environment restoration.