The stainless steel robotic pig developed by Thermo-Systems in Germany specialize in drying sewage plant sludge by constantly giving it a stir thereby accelerating the drying process -- it even helps prevent rotting to boot. Why dry it? Well, since sludge is mostly water, you can remove 90 to 95 percent of its mass by drying it which simplifies its removal not to mention the savings in fossil fuels associated with the transport. The resulting product also becomes an ideal fertilizer since the strong odor has been removed and it’s virtually free of bacteria.