Biosolids are nutrient-rich organic materials resulting from the treatment of sewage at a wastewater treatment facility. Basically, biosolids are our treated poop. Biosolids are recycled and used as fertilizer for farming and gardening. Here is a link to the EPA's FAQ on biosolids.
Currently, there is a discussion over the best way to get rid of biosolids. This article explores the present biosolids situation -- how although using biosolids for fertilizer is an attractive solution, there are environmental concerns as to the chemicals found in biosolids. Further, the article probes if there are more desirable ways to recycle biosolids such as converting it into energy.
Related to the power of biosolids, below are two articles that also explore, well, what do do with our poop. First, this article in the Chicago Reader about a local woman, Nancy Klehm, who started a poop composting project. And this article, which delves into whether disposing of poop in our water is the best practice.