New Treatment System Decolorizes, Recovers Phosphorus, and Disinfects Livestock Wastewater All at Once

Left: before treatment, right: after treatment
Copyright National Agriculture and Food Research Organization

Japan's Institute of Livestock and Grassland Science at the National Agriculture and Food Research Organization (NARO), the Chiba Prefectural Livestock Research Center, Taiheiyo Cement Corp., and Onoda Chemical Industry Co. announced on June 6, 2012, that they have developed an advanced system for treating wastewater discharged from livestock-raising facilities. The system can simultaneously decolorize, recover phosphorus, and disinfect wastewater discharged from livestock houses such as pigpens.

The system uses a newly developed substance, amorphous calcium silicate hydrate (CSH), produced from silica and lime. CSH is a porous particle with a high adsorption capacity. After being used, CSH particles can be recovered through a simple filtration process.

Results of a verification test in which 0.5 to 1.5 kilograms of CSH per ton of livestock-derived wastewater was added after an ordinary treatment process and allowed to react for two to six hours assured a more than 90 percent removal of phosphorous as phosphate, a more than 99 percent removal of coliform bacteria, and a 40 to 80 percent reduction in chromaticity value. Besides phosphorous, recovered CSH particles also contain such fertilizer ingredients as calcium, magnesium, and silica, and can be used as fertilizer.

Recovering phosphorous is an effective way to control water pollution and save resources. Lowered chromaticity of final effluent and improved sanitation are also important challenges for livestock farmers to overcome in order to run their production businesses without impacting their local communities. NARO and the other entities intend to make efforts to reduce the system's cost and promote its widespread use.

Posted: 2012/09/14 06:00:15 AM