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