Returning human waste to the land is nothing new, nor is the composting of human waste. Cities across North America have been spreading human waste effluent on farm land for decades, serving the needs of farmers for fertilizer and City administrators for a cost-effective way of disposing of sewage sludge.
However, there are downsides to spreading sewage biosolids onto farmlands, including the fact that sewage treatment plants do not remove heavy metals and industrial chemicals found in abundance in city sewage, prior to spreading the waste.
A composting toilet system, using little or no water, is designed to aerobically treat human excrement by allowing it to decompose naturally. This is typically a faster way to treat human waste when compared to the wastewater methods, such as the septic systems used in most urban areas. The most important attribute, however, may be the saving of thousands of gallons of water annually.
Nutrients salvaged from composted human waste matter are returned to the land in a safe, cost-effective and ‘green’ way. Whereas raw sewage releases chemicals and pathogens onto the farmer’s land, the composted matter is free from industrial chemicals and pathogens have been destroyed through the natural process of aerobic decomposition long before the nutrient-rich material is returned to the land.
How a Composting Toilet Works
While there are many varieties of composting toilets available and they are used all around the world, all composting systems rely on a basic process involving the collection of human excreta into a composter chamber where a bulking agent (such as sawdust or peat moss) is added to create air pockets for maximum aerobic processing and where decomposition will occur as a result of bacteria breaking down the waste into its various components. The bacteria consume some of the waste during breakdown, reducing the volume of the matter and eliminating pathogens in the process. The one essential in all composting systems is proper ventilation.
Read more at Suite101: Green Living with Composting Toilets: Environmentally Friendly Human Waste Management http://water-conservation.suite101.com/article.cfm/green-living-with-composting-toilets#ixzz0ixcU6Lle