Douglas W. Hamilton Oklahoma state University

Publish Date: June 18, 2013

You may have heard it is impossible to digest swine manure. This is not true. Swine farmers can enjoy all the benefits provided by anaerobic digestion. They just have to work a little harder than other livestock producers to get them. The problem is hog farmers like to handle pig manure as a liquid. The extra water added to manure means digesters on swine farms are larger than those on other farms such as dairies. We can overcome this challenge by using specially designed digesters, scraping rather than flushing manure, or adding a high-energy co-digestion product to the waste stream.

Publish Date: June 3, 2006

A solids separator removes solids from mixtures of solids and liquids. It is appropriate to think of a solids separator as a device that breaks an incoming waste stream into two separate flows: one with a solids content lower than the original waste stream, the other with a solids content higher than the original waste stream (Figure 1). Depending on the type of separator used, the lower-solids content waste stream may be called effluent, separated liquids, or liquor. Likewise, the higher-solids stream might be called sludge, grit, separated solids, or cake. Individual manufacturers may use different terms to describe the same stream. To keep things simple, in this paper we will call the stream entering a solids separator influent, the low solids stream leaving the separator liquor, and the high solids stream cake. Devices remove solids by a number of methods: settling material to the bottom of a waste stream, screening larger particles out of the stream, and floating light material to the top of the stream, to name a few. Some devices may perform more than one type of removal and create three or more waste streams, the idea of a solids separator is to create at least one stream of low-solids liquor.

Publish Date: June 3, 2006

Recirculation systems involve the addition of varying amounts of dilution water in order to improve the removal of manure from the animal area. The two types of recirculation systems used in pork production facilities are underslat flushing and pit recharge systems. Both systems use a shallow gutter that is flushed or drained periodically to remove waste from the building to the lagoon or storage basin. Open gutter systems have been used in the past but are no longer recommended because of concerns with disease transmission.

Publish Date: June 3, 2006

Research has shown and field experience has verified that corrosive and odorous gas production increases with storage time and storage temperature. Manure can be removed from a swine barn by: (1) manual or mechanical scraping, (2) gravity draining, (3) flushing with dump tanks, siphons or pumping systems with automatic or manually controlled valves, or (4)…