The Oxidation Ditch Design And Its Use In Wastewater Treatment

The oxidation ditch offers certain advantages over several other methods used for the treatment of wastewater. In the following paragraphs I show the advantages of the oxidation ditch design along with a brief about its construction and working.

The oxidation ditch design is a modified form of the extended aeration wastewater treatment method. Though the solids retention time and the hydraulic retention time are the same as the extended aeration method, the ditch has a closed loop process compared to extended aeration. The loops under the oxidation ditch system are designed and built to be oval in shape. This facilitates the aeration of wastewater. The aerators are horizontally mounted and are either disc aerators, cage aerators or brush aerators. Such a design allows the ditch to handle wastewater volumes more than 10,000 gpd or 0.4 L/s. Since this design is a modified extended aeration process, the advantages and disadvantages of this process are also the same as the extended aeration system. In the oxidation ditch system, the aerators are the most maintenance intensive machinery because they are involved in aerating large volumes of wastewater.

There is another version of this ditch design known as the triple channel. This design has three channels or ditches constructed serially one after another. In this design the two outer ditches are used for sedimentation of wastewater and discharging the treated influent. This process happens alternately. Hence the advantage of using the triple channel system is that there is no need to construct a separate sedimentation tank. This also reduces the cost of construction and operation of the wastewater treatment process.