#TITLE_ALTERNATIVE#

• Main Author: EKA DIYANTI (NIM: 25312050), IMANIA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/28007
• Institution: Institut Teknologi Bandung

<p align= "justify">Besides its biochemical and biological aspect, the physical/hydraulic aspect of an oxidation ditch also has a significant influence on the treatment result, of which have not been studied thoroughly yet. Thus, in this research, a lab-scale oxidation ditch reactor was modeled using 2D-based Computational Fluid Dynamics (CFD) program to assess its velocity distribution pattern and to investigate dead zones within the reactor. The outcome served as a basis to determine modifications required in the ditch configuration in order to optimize its hydrodynamical characteristics through dead zones reduction. There had been no aeration mechanism involved in the model system yet since the focus of this study lied on how the nature of the basin’s form will affect velocity distribution and flow mixing within itself, as of the optimization could be emphasized on the physical aspects modification in form of influent flowrate and baffles variation. Total length, width, and depth measurements of the ditch are 3.2 m, 1.9 m, and 58.5 cm respectively. Velocity profile acquired from the preliminary simulation was considered as laminar flow and dead zones were scattered along the inner side of the ditch reactor as well as part of the outer bank. Influent discharge variation of 4 lpm, 8 lpm, and 12 lpm were introduced afterwards and the most minimum dead zones percentage of 45.07% were obtained on 12 lpm flowrate. A graph drawn later between influent flowrate and dead zones percentage of 5 data points shows that dead zones depletion until 50% area left could be reached by 7.7 lpm, whereas optimum discharge was obtained to be 12 lpm. On the other hand, baffles configurated in this study could not reduce the dead zones percentage. COD removal had been investigated as well. It was obtained to be 85.31% for two weeks operation.<p align= "justify">