Human waste is a messy, and unfortunately necessary part of everyday life for people all around the world. However, as cultures and governments have evolved, this reality has become a great deal more real and pressing. In cities with millions of people, there must be a way for human waste to be collected, and moved to a more central location so that the waste can be dealt with. In America, this is the sewage system, where all disposal facilities, including public and private toilets, connect to a central treatment facility. This is done by flushing human waste through pipes with the aid of water.
Once the human waste has been collected as a treatment plant, it goes through stages. The incoming waste is first put through physical filters which weed out substances that shouldn't be in the stream. Toilet paper that hasn't disintegrated, tampons, condoms, and other objects. Once the waste has been moved along and "purified" so that only human waste is present, the treatments begin. Processes which involve radiation, heat, chemical additives, and other options then begin, all with the goal to make this human waste safe, and to separate it from the fresh water used to move it through the sewage system in the first place.
The main result of this disposal is that the water is separated, and human waste is kept away from areas it can contaminate. Most waste is broken down into material components through chemical and radiation treatments and then expelled into designated areas, but other options are also available. One option for example is that human waste is treated, but the naturally occurring amounts of nitrogen, phosphorous, and other organic matter is left intact. This waste is then turned into fertilizer and sold or outright given to farmers. With the popularity of green technologies and recycling methods, treatment options like this one may become a great deal more common.