Variation of Oxygen Transfer along the Rectangular Weir Crest Distance of Wastewater Treatment Pond

Community, instead of industrial factories, has been identified as a big point sources for wastewater in which it also spread out around the Kingdom of Thailand. The government inverted to settle wastewater treatment plants to recover them with a lot of money. Unfortunately, such wastewater treatment systems seemed blur for doing those methodology. To fulfill the wastewater recovery for some desirable water uses, H.M. the King of Thailand has initiated natural purification under the nature by supporting nature processes and simple technology by using aquatic plants, constructed wasteland, and stabilization ponds. One of the very successful projects is “The Laem Phak Bia Environmental Study Research and Development Project under Royal Initiatives Petchburi Province”. Our research is performed on this project area, the rectangular weir was introduced to increase the efficiency by oxygen transfer into wastewater as flowing over the weir crest. The experimental setup for five wastewater depths in meters (0.03, 0.04, 0.05, 0.06 and 0.07) is presented in this work. Results found that 0.03-m depth showed the highest efficiency of oxygen diffusion, and it decreased when water depth increase.