Hydraulic Modelling and Optimization of a Wastewater Treatment System for Developing Nations Using Computational Fluid Dynamics

Waste stabilization pond (WSP) is globally one of the most popular wastewater treatment options because of its high efficiency and low cost. However, no rigorous assessment of WSPs that account for cost in addition to hydrodynamics and treatment efficiency has been performed. A study was conducted that utilized Computational Fluid Dynamics (CFD) coupled with an optimization program to optimize the selection of the best WSP configuration based on cost and treatment efficiency. Several designs generated by the CFD/optimization model showed that both shorter and longer baffles, alternative depths, and reactor length to width ratios could improve the hydraulic efficiency of the ponds at a reduced overall construction cost. In addition, a study was conducted on the optimized WSP which consisted of an anaerobic, facultative, and a maturation stage whose baffle orientation, length to width ratio, was specified by a CFD model prediction and was compared with a three stage WSP designed according to literature suggested reactor geometric configurations. Experimental tests were performed on a pilot scale version of the threestage WSP where the removal performance was based on a number of parameters (Faecal coliform, pH, TDS, and Conductivity). Results showed that the significantly lower cost design based on the optimized CFD simulations displayed slightly better removal performance compared to the standard WSP design developed from literature data. The results of this study clearly showed that unit treatment process designs based on rigorous numerical optimization can aid in producing cost effective designs that make it more possible for developing nations to incorporate adequate and effective sanitation

Optimization of Waste Stabilization Pond Design for Developing Nations using Computational Fluid Dynamics

Waste stabilization ponds (WSPs) have been used extensively to provide wastewater treatment throughout the world. However, no rigorous assessment of WSPs that account for cost in addition to hydrodynamics and treatment efficiency has been performed. A study was conducted that utilized computational fluid dynamics (CFD) coupled with an optimization program to optimize the selection of the best WSP configuration based on cost and treatment efficiency. The results of monitoring the fecal coliform concentration at the reactor outlet showed that the conventional 70% pond-width baffle pond design is not consistently the best pond configuration as previously reported in the literature. The target effluent log reduction can be achieved by reducing the amount of construction material and tolerating some degree of fluid mixing within the pond. As expected, the multi-objective genetic algorithm optimization did produce a lower-cost WSP design compared to a SIMPLEX optimization algorithm, however, with only a marginal increase in the effluent microbial log reduction. Several other designs generated by the CFD/optimization model showed that both shorter and longer baffles, alternative depths, and reactor length to width ratios could improve the hydraulic efficiency of the ponds at a reduced overall construction cost. In addition, a study was conducted to validate a computational fluid dynamics (CFD) model of an optimized WSP configuration based on minimum cost and maximum treatment efficiency. In this study, the optimized WSP consisted of an anaerobic, facultative, and a maturation stage whose baffle orientation, length to width ratio, was specified by a CFD model prediction and was compared with a three stage WSP designed according to literature suggested reactor geometric configurations. Experimental tests were performed on a pilot scale version of the three-stage WSP where the removal performance was based on a number of parameters (Faecal coliform, pH, TDS, and Conductivity). Results showed that the significantly lower cost design based on the optimized CFD simulations displayed slightly better removal performance compared to the standard WSP design developed from literature data. The results of this study clearly showed that unit treatment process designs based on rigorous numerical optimization can aid in producing cost effective designs that make it more possible for developing nations to incorporate adequate and effective sanitation

Creating Water, Sanitation And Hygiene (WASH) Program Awareness In Schools: A Tool Towards The Success Of Community Wash Program

The prov1s1on of safe water, sanitation and hygiene (WaSH) in schools has been established to improve health, boost educational achievement, and promote gender equity which has a positive impact on the society. However, in an earlier study conducted, with public secondary schools as the focus group, it was discovered that students· knowledge and perceptions about the importance of WaSH are very low. Moreover, there is wide disparity between the WaSH programs being instituted at these schools and the schools' facilities, thus making it difficult to impress the importance of this program in students. The previous study provides background data and insights on the practice levels and the need to apply suitable strategies to increase the effectiveness and success of the WaSH program in the future. One way to increase the effectiveness of the WaSH program is to stimulate students' interest in science and technology that could build their capacity in combating WaSH challenges. The main goal of this paper is to propose an idea on how to motivate students about WaSH issues while increasing their interest in Science Technology Engineering and Math (STEM). The presentation will propose STEM educational tools that can motivate and educate young men and women about water and sanitation. In addition, the presentation will show how to create awareness that would help integrate WaSH global standards into Nigeria's national programs and set specific targets at local level in order to ensure sustainability. The aftermath of the implementation of this idea is expected to create increased awareness of students in secondary schools and other higher levels on WaSH services. This would engender access to, and practice of safe drinking water, sanitation, and hygiene knowledge to all the people in the community and key-stakeholders for long-term sustainabilit