Cheap electricity could recycle animal waste, recover valuable chemicals

Talk about a crappy problem. Every year the world’s livestock farms generate more than 3 billion tons of animal waste, equivalent to more than 9000 Empire State Buildings. All that manure pollutes bodies of water and releases noxious fumes and greenhouse gases. But a new recycling technique could reduce those burdens while turning a profit. Researchers have shown that they can use electricity to break down organic nutrients in animal waste , all while recovering valuable chemicals. Initial projections—reported this month in Nature Sustainability —suggest that in most cases the value of these chemicals would be higher than the costs of the technique, making it profitable for farmers to pursue it. The approach could work well in rural, agricultural areas, which are awash in both manure and cheap, renewable electricity from wind and solar farms, says Taeyoung Kim, a chemist at Clarkson University who was not involved in the study. Many livestock operations already attempt to recycle animal waste by flushing it into ponds known as manure lagoons. Ammonia-rich solids settling to the bottom can be dredged up and spread back on farmland as fertilizer. Microbes can be used to break down much of the remaining organic compounds into methane, which can be gathered and burned to generate electricity. But even with such treatments, vast amounts of ammonia and other compounds are released into the environment, triggering algal blooms and fish die...
Source: ScienceNOW - Category: Science Source Type: news