Submitted to: Water Environment Federation
Publication Type: Proceedings
Publication Acceptance Date: January 15, 2000
Publication Date: N/A
Technical Abstract: Our approach to animal residuals (manure) has been to enhance the potential for effective and affordable treatment and ecosystem benefit. Modern animal production is a very sophisticated business, and the treatment of its residuals will also have to be sophisticated. Adaption of municipal technologies is likely to be the basis from whence the appropriate technologies can emerge. This process will be most effective if residuals can be used to solve other existing problems. We are addressing an approach that will allow treatment of the animal residuals and mitigation of two significant ecological and agricultural problems - soil productivity and carbon sequestration. Our focus has been on swine and dairy where flush systems generate wastewater. Highly efficient(>90%) solids and nutrient separation from flushed manure has been obtained by flocculation through addition of PAM. Improved solids and liquid separation technologies allow transport to central facilities for efficient processing and marketing. Th residuals can then be blended into balanced and mildly recalcitrant forms and applied subsurface in conservation tillage for accelerated accumulation of soil carbon with its associated enhancements of soil productivity. After the solids are removed, the wastewater must be treated to capture and/or transform the nutrients in the soluble fraction. Biological removal of N can be greatly enhanced with the use of acclimated nitrifying bacteria immobilized in polymer pellets. Constructed wetlands have also shown great promise by removing more than 20 kg N/ha/day, much greater than can be applied to crop or pasture land.