Analytical modeling of sedimentation phenomena in swine waste slurries

The purpose of this research was to develop an analytical relationship that would describe the sedimentation phenomena associated with swine slurries, A mathematical model was derived which described sedimentation of particles in suspension for discrete, flocculant, and zone settling. The data of flush swine waste from a laboratory settling column, which simulated the ideal assumptions of the mathematical model, were used to develop empirical relationships from which the coefficients of the model were determined. Each coefficient was related to specific growth characteristics of the particles in wastewater and the dimensions of the sedimentation system. The resultant general equation was verified by the conventional graphical procedures. This general sedimenta tion equation was used to establish design criteria for a prototype sedimentation basin of a field system. The remaining compoents (aera tion unit, final clarifier, and solids pad) were designed from existing technology. Field data compared favorably with the values predicted from the model, which proved to be an additional verification that the model could be used to replace the laborious graphical method in the design of sedimentation basins. The settling basin in the treatment system successfully reduced solids and chemical oxygen demand for the influent, and should be considered a usefvil alternative in a swine waste management system.