Effectiveness of solids removal from liquid swine and dairy manures using biomaterial filtration

Abstract

Recently, the livestock industry in the United States has been under scrutiny of environmental policymakers and the general public in regards to the industry's impact on the environment. This has forced the livestock industry to be more conscious in the handling, treatment, and disposal of manures produced by confinement animals. The management of animal waste typically involves several steps, but due to low production profit margins and the demand for technological simplicity, animal manures tend to have less treatment than human wastes. Liquidsolid separation using biomaterials, like com stover, offers a possible cheap and technologically simple alternative for waste processing, in some cases. Separation allows for the recovery of one or both components (liquid or solid fraction) as a useful by-product or to enhance the overall waste treatment process. The primary objective of this investigation was to examine the effect of biomaterial filtration on dairy and swine manure using two readily available biomaterials (com stover and wood shavings). The effects of filter density and influent manure total solids (TS) mass were also investigated. Filter performance primarily depended on manure type and to lesser extent on influent TS concentration and filter media density. TS mass removal ranged from 53 to 80% and from 35 to 56% for dairy and swine manures, respectively. Biomaterials, like com stover, offer some promise as filter materials for liquid-solid separation of animal manures.