Because water is not an unlimitedresource, everyone from governmentagencies to individuals is lookingfor ways to conserve water and reducecosts associated with water treatmentto make it reusable. Alternative toilets,such as composting toilets, requireminimal to no water to carry the wasteaway and require no water as part ofthe waste treatment process.

What is a Composting Toilet?

Composting toilet systems (sometimes called biological toilets, dry toilets and waterless toilets) contain and control the composting of excrement, toilet paper, carbon additive, and, optionally, food wastes.

The average American uses 7,665 gallons of water each year just flushing the toilet.

Presented by O.OlupitanMarch 3, 2010_ ELE 333

What's So Good About Compost?

It is ironically one of the oldest forms of recycling known to humankind.

How fast something composts is affect by environmental factors, the composition and constituents of materials being composted,

the health and number of the organisms which are using the materials as a food source and the management of the process by the operator.

Unlike a septic system a composting toilet system relies on unsaturated conditions (material cannot be fully immersed in water), where aerobic bacteria and fungi break down wastes, just as they do in a yard waste composter

Composting toilets eliminate the need for flush toilets, thereby greatly reducing water-use needs and thus reducing the hydraulic load to a septic system. Composting toilets also allow for the recycling of valuable plant nutrients by producing a soil-like supplement. Composting toilets can be used anywhere a flush toilet can be used.

• Yes, you can still use your favorite brand of toilet tissue. Toilet tissue takes a bit longer for the bacteria to break it down

So what exactly is a composting toilet?

A composting toilet is a system that uses nature's composting process to break down waste into humus, a nutrient rich soil.

The system does not produce odors at all because of the toilet's air flow. Bugs are not a problem at all because the composting process produces carbon dioxide and an environment that repels bugs and other hassles.

The only 'odd' thing you have to do is toss in a half cup of mulch to feed the bacteria after each fecal use. Most of the material the toilet contains is mulch; the composting process reduces waste volume by 90%! This mulch isn't just any old mulch though. special mix

Composting toilets are a bit...different, but they are entirely safe and sanitary. They are even more sanitary for our environment than our current sewer system

They do not require any expensive septic system installation; they are just a combination of nature and technology: clean, simple. safe, and sustainable.

Properly designed and maintained, composting toilet systems should contain, immobilize and/or destroy pathogens -- organisms that cause human disease -- especially in a healthy population.

· Composting toilets use nature's decomposition process to reduce waste by 90% and convert it into nutrient rich compost.

· They do not require water hook ups either which is great for our already stressed water supply. In short, composting toilets are a way to allow waste to decompose safely and without odors.

· Composting toilets use oxygen loving bacteria that is naturally present in human waste to do all the work.

What are Pathogens?

Pathogens, or pathogenic organisms, are responsible for the transmission of communicable diseases. They are generally bacteria, viruses and parasites, such as worms, amoebae or protozoa, that invade the body and cause illness by a variety of means that overwhelm the immune system and damage or destroy living tissue.

Whereas conventional wastewater treatment technologies depend on chemical or thermal disinfection to reduce pathogens, in a composting

toilet it is accomplished by the following:

1. Containment 2. Competition 3. Antagonism 4. Adverse Environmental Factors

Other: Pasteurization

*Typical Pathogen Survival Rates at 20° to 30°C in Various Environments

1. ContainmentPathogens cannot survive for long once they have left the human host. Like all organisms, human pathogens have specific lifetimes. An organism's lifetime is shortened in the hostile environment of an aerobic composter. Human pathogens in a composter don't live for long. Containing the excreta for an extended period of time brings about the death of pathogens and reduces the risk of infecting new hosts through ingestion, the primary pathway for enteric pathogen transmission.

2. CompetitionThe competition among composting organisms for available carbon and other nutrients is intense. Human pathogens become food for the well-adapted aerobic soil organisms that thrive in the composter. When the available nutrients are consumed, the microorganisms begin to consume their own protoplasm to obtain energy for cell maintenance. When these organisms die, their protoplasm and cellular matter is digested by other organisms. The end of this phase results in an end-product that is very stable and safe.

3. Antagonism Some composting organisms produce toxic substances which harm, inhibit or kill other organisms. For example, the actinomycete produces streptomycin, well-know antibiotic. The soil bacteria parasitizes the infamous (E. coli), and multiplies within the host cell, eventually killing it.

4. Adverse Environmental FactorsFactors such as pH, temperature, moisture and ammonia content and retention time also play roles. Note: temperatures above 131°F (55°C) do kill pathogens in a short time, but composting toilet systems do not attain these temperatures unless they are highly heated.

Other: PasteurizationAn even faster and controlled way of killing or reducing pathogens is pasteurization.. Pasteurization can be accomplished by a variety of means, but the most common is by applying sufficient heat from external sources such as electric or propane heaters. In some cases, the use of microwave or solar energy is used.

General Types of Composting Toilet SystemsComposting toilet systems can be classified in several ways:Self-Contained versus Centralized

Composting toilet systems are either self-contained, whereby the toilet seat and a small composting reactor are one unit (typically small cottage models), or centralized or remote, where the toilet connects to a composting reactor that is somewhere else.

Batch (Multiple-Chamber) versus Continuous (Single-Chamber)

Most composting toilet systems use one of two approaches to manage the composting process: either single-chamber continuous composting or multi-chamber batch composting processes

Continuous ComposterFeatures a single chamber into which excrement is added to the top, and the end-product is removed from the bottom.

Batch ComposterUtilizes two or more interchangeable composting reactors. One is filled at a time, then allowed to cure while another reactor fills, just as with two- and three-bin yard composters.

· The main difference is you just toss in compost mix after each fecal use instead of flushing. The air flow inside the toilet pulls all odors up the 'chimney' and out of your home.

· Composting reduces waste volume by 90%; the majority of the material inside the toilet is mulch and not waste. You do not even have to see it with the way most toilets are designed.

* Yes, you do have to empty the lower compost tray periodically, depending on how many people are using the toilet, but it is only compost, soil. There is no waste mixed in the tray.

Important things to know about Composting Toilets1. Aeration the aerobes require free atmospheric or molecular oxygen. If there is an

oxygen deficit they will die, which will slow the process and generate odors and potentially flammable methane gas.

2. Moisture Content microbes in the composter need the right amount of moisture to thrive. Too much water drown them, and create conditions for the growth of odor-producing anaerobic bacteria. When the moisture level drops below 45 percent, it can become too dry for composting.

3. Temperature The ambient temperature for acceptable biological decomposition is 78° to 113°F. Biological zero is 41° F. At this temperature, most microbes cannot metabolize nutrients.

4. Carbon-to-Nitrogen (C:N) Ratio Microorganisms require digestible carbon as an energy source for growth, and nitrogen and other nutrients. Due to the high nitrogen content and low carbon content of human urine has a low C:N ratio is the primary reason then to add carbon material is to create air pockets in the composting material.

5. Process Control How you optimize the composting process by controlling the external variables that affect the composting process

*Motorized and manual mixing*Blowers and fans

*Heaters*Pumps

*Warning indicators and alarms tell the manager when something needs attention.

Installation below the floor requires 30" or more, ground to floor. Minimum clearance for an outside wall installation is 22". Low flush Toilets connect to either your gravity feed or pressure water supply.

Presented by O.OlupitanMarch 3, 2010_ ELE 333

Key references http://www.oikos.com