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===Types of composting=== | ===Types of composting=== | ||
Nearly all methods stem from the famous Indore method developed by Sir Albert Howard. Basic needs are air, moisture, energy food (carbon) and protein food (nitrogen) in the right proportion, and warmth. As long as all of these basic requirements are taken care of, other improvising can be done. | |||
Most composting systems are aerobic, so they require adequate air to be available throughout the pile. Most common is to turn the pile at regular intervals. More frequent the turning, the faster the decomposition. There are creative ways to introduce air into static piles and avoid having to turn so frequently. For example, burying perforated drainpipe at intervals within the pile. Natural convection is sufficient to circulate air throughout a pile. | |||
You want your compost to be about as damp as a moist sponge. No moisture should come out when squeezing a handful. But if not moist enough, it will slow down the decomposition and prevents the pile from heating up. Steamy environment for microorganisms. Select a site that drains easily for humid climates so the compost never sits in a pool of water. The turning process releases moisture. If the pile is soggy, more absorbent materials should be added (e.g. leaves or dried grass clippings). | |||
Carbon is for energy and nitrogen for growth. Ideal C/N ratio is between 25:1 and 30:1, carbon being the higher number. If there is too much nitrogen to carbon, it will be lost as ammonia, detected by the smell. Generally only lasts for a day or two. | |||
When the temperature drops below 55 degF, bacteria become dormant. Insulation is great way to keep temperatures up. Optimum temperatures are 140 degF or 60 degC. Pile must be at least 3 feet in each dimension to provide for necessary critical mass. For best heating, a heap 4 or 5 feet square rising up 4 feet is good. Temperature decreases toward the outside of the pile. When turning, it is a good idea to shovel undigested materials from the outside into the middle of the pile. | |||
The more diverse the compost materials, the more likely there is a good balance of bacteria. Sprinkling a thin coating of good topsoil or finished compost from a previous batch over each layer of new materials is the best way to inoculate your pile with the right cultures. | |||
When choosing a method, factors that need to be taken into account are space and construction available, total need for compost in terms of the area under cultivation and the rate of use, time to be given to the project, the human and mechanical energy available, the equipment owned or obtainable, the materials at hand or easily procurable, and special crop needs. Methods vary from quick, hot composting that requires effort and attention, to slow, cool techniques that are less trouble. Time needed for a quick compost is generally less than 8 weeks and as little as 2. Speed is achieved by keeping aeration levels high. Monitoring temperature is helpful, turning it as soon as temperature drops. A drawback is that the whole pile must be built at once. Scraps must be stored up until you’re ready to start a new pile. | |||
Appropriate materials for composting are garden debris, manures, vegetable trimmings, unprinted paper and cardboard, and various absorbent materials. Useful way to assure adequate ratio of carbon to nitrogen is doing alternating layers of “browns” and “greens”. Phosphorus is also required, and is found in plant debris and manures. Ideal pH level for most microorganisms is 7.0 or neutral. Adding lime to the compost can keep the pile from becoming too acidic, but it can promote the loss of nitrogen. Minimum dimensions for bin should be 3x3 ft and height at 4-6 ft. One side should be removable, so that compost can be reached. Height of pile should not exceed 6 ft. Compost should be fluffed. | |||
<ref name=Example></ref> | |||
====Type 1==== | ====Type 1==== | ||
Aerated (turned) Windrow Composting: Suited for large volumes, such as those generated by entire communities. Involves forming organic waste into rows of long piles called “windrows” and periodically aerating them by turning the piles. Ideal pile height is 4-8 ft tall and 14-16 ft wide. This size is large enough to generate enough heat and maintain temperatures, but small enough to allow oxygen flow to the core. Suitable for diverse waste such as yard trimmings, grease, liquids, and animal byproducts (such as fish and poultry wastes). Often requires large tracts of land, sturdy equipment, a continual supply of labor to maintain and operate the facility, and patience to experiment with various materials mixtures and turning frequencies. In rainy seasons, shapes of the piles can be adjusted so that water runs off the top of the piles rather than absorbed. Leachate is a liquid released during the process, it can contaminate local ground and surface water. It should be collected and treated. <ref>This is a third example of a plain footnote.</ref> | |||
====Type 2==== | ====Type 2==== | ||
Aerated Static Pile Composting: Produces compost relatively quickly (3-6 months). Suitable for a relatively homogenous mix of organic waste and works well for larger quantities. Does not work well for animal byproducts or grease. Organic waste is mixed in a large pile, and layers of loosely piled bulking agents (e.g., wood chips, shredded newspaper) are added so that air can pass from the bottom to the top of the pile. Requires careful monitoring to ensure that the outside of the pile heats up as much as the core. May require significant cost and technical assistance. | |||
<ref name=Example/> | |||
====Type 3==== | ====Type 3==== | ||
Vermicomposting: Redworms in bins that feed on food scraps, yard trimmings, and other organic matter. The materials broken down by the worms is produced into high quality compost called castings. A pound of mature worms, which is approximately 800-1,000 worms, can eat up to a half a pound of organic material per day. Usually takes about three to fourth months for usable castings. The worms can also produce what is called “worm tea” which is a high-quality liquid fertilizer. The best temperatures for vermicomposting range from 55-77 degree F, and avoidance of direct sunlight. Most common and preferred choice for composting. Worms produce castings that have lower nitrogen compared to other composting methods. Do not house in metal containers, copper can leech out and become toxic. Need to be connected to the ground so nutrients can go right into soil. Need to be kept out of sun, frost, and rain. Also not too cold. Worms are temperamental and will leave if not happy. | |||
====Type 4==== | |||
The University of California Method: Aims for more heat and faster decomposition. A minimum volume of 1 cubic yard, but a greater volume may be required in cold weather. Bin constructed from wood and hardware cloth, wood alone, or concrete. Materials should be reduced to pieces of 6-8 inches. Turning is essential. Recommended turning schedule every 3 days. | |||
====Type 5==== | |||
Raised-Bin Method: Open-hearth-bottom bin sitting on cement slab. A grill made from pipe sits above the slab. Allowing air into the center of the heap. As the pile heats up, it pulls the cooler air from the ground, aerating throughout the pile. | |||
====Type 6==== | |||
Open Air Composting (Bay composting): Usually a pile of green and brown matter. Generally considered a hot composting method. A bay is constructed using anything handy, such as wire cages or bins. Requires monitoring, watering, turning, and spreading. Attracts worms, but will not stay if conditions are not perfect. Temperature and pH are very important. Nitrogen and carbon ratio are very important. 2-3 bays are optimal for the process time. Worm friendly food only. If not the right mix, it can smell. Takes a long time and turning to aerate is essential. Ideal for a farmer with lots of green waste. | |||
===Designing interpretive materials=== | ===Designing interpretive materials=== | ||
Revision as of 03:50, 17 February 2020
Background
The Campus Center for Appropriate Technology (CCAT) was established at Humboldt State University (HSU) in Arcata, California, USA in 1978. Since then CCAT has evolved into a living laboratory of sustainability that incorporates appropriate technology as a core operating philosophy. CCAT recently added a composting system into their facility where students, campus dining facilities, and community members can bring their compostable food waste. CCAT currently takes in over 50 lbs of community food waste a week to be composted. However, the current composting system has some specific issues such as: 1) lack of clarity/instructions for users 2) inefficient three-phase system and 3) rodent intrusion. These three aspects will be the primary focuses for our upgrade. It is our team goal to create a well-signed point-positive and user-friendly composting system that can be effectively utilized by anyone with or without a CCAT employee’s assistance. This project is set to be completed by the end of spring semester 2020.
- Before Photos of Composting System
-
This is the front of the current compost system at CCAT.
-
Here is the top view of the current composting system at CCAT.
-
This is the newly built compost signage holder made by CCAT.
Problem statement
The objective of this project is to update the current CCAT composting system. The current CCAT composting system is not user-friendly, rodent-resistant, or well-signed to guide composters through proper utilization. We plan to renovate the system so the community can add to and use the CCAT’s composting system with ease. Our hope is that after the renovations, using the system will be clearer and protected from rodents, leading to a more efficient and beneficial compost.
Additional Information
For more information or to learn more about Humboldt State University's CCAT, click the following link:
For basic information on composting, click the following link:
This is a review of the available literature pertinent to the a specific project.
Literature Review
This is a review of the available literature pertinent to the a specific project.
Composting basics
Paragraph on the basics. [1]
Composting concerns
Short paragraph on the concerns.[2]
Types of composting
Nearly all methods stem from the famous Indore method developed by Sir Albert Howard. Basic needs are air, moisture, energy food (carbon) and protein food (nitrogen) in the right proportion, and warmth. As long as all of these basic requirements are taken care of, other improvising can be done. Most composting systems are aerobic, so they require adequate air to be available throughout the pile. Most common is to turn the pile at regular intervals. More frequent the turning, the faster the decomposition. There are creative ways to introduce air into static piles and avoid having to turn so frequently. For example, burying perforated drainpipe at intervals within the pile. Natural convection is sufficient to circulate air throughout a pile. You want your compost to be about as damp as a moist sponge. No moisture should come out when squeezing a handful. But if not moist enough, it will slow down the decomposition and prevents the pile from heating up. Steamy environment for microorganisms. Select a site that drains easily for humid climates so the compost never sits in a pool of water. The turning process releases moisture. If the pile is soggy, more absorbent materials should be added (e.g. leaves or dried grass clippings). Carbon is for energy and nitrogen for growth. Ideal C/N ratio is between 25:1 and 30:1, carbon being the higher number. If there is too much nitrogen to carbon, it will be lost as ammonia, detected by the smell. Generally only lasts for a day or two. When the temperature drops below 55 degF, bacteria become dormant. Insulation is great way to keep temperatures up. Optimum temperatures are 140 degF or 60 degC. Pile must be at least 3 feet in each dimension to provide for necessary critical mass. For best heating, a heap 4 or 5 feet square rising up 4 feet is good. Temperature decreases toward the outside of the pile. When turning, it is a good idea to shovel undigested materials from the outside into the middle of the pile. The more diverse the compost materials, the more likely there is a good balance of bacteria. Sprinkling a thin coating of good topsoil or finished compost from a previous batch over each layer of new materials is the best way to inoculate your pile with the right cultures. When choosing a method, factors that need to be taken into account are space and construction available, total need for compost in terms of the area under cultivation and the rate of use, time to be given to the project, the human and mechanical energy available, the equipment owned or obtainable, the materials at hand or easily procurable, and special crop needs. Methods vary from quick, hot composting that requires effort and attention, to slow, cool techniques that are less trouble. Time needed for a quick compost is generally less than 8 weeks and as little as 2. Speed is achieved by keeping aeration levels high. Monitoring temperature is helpful, turning it as soon as temperature drops. A drawback is that the whole pile must be built at once. Scraps must be stored up until you’re ready to start a new pile. Appropriate materials for composting are garden debris, manures, vegetable trimmings, unprinted paper and cardboard, and various absorbent materials. Useful way to assure adequate ratio of carbon to nitrogen is doing alternating layers of “browns” and “greens”. Phosphorus is also required, and is found in plant debris and manures. Ideal pH level for most microorganisms is 7.0 or neutral. Adding lime to the compost can keep the pile from becoming too acidic, but it can promote the loss of nitrogen. Minimum dimensions for bin should be 3x3 ft and height at 4-6 ft. One side should be removable, so that compost can be reached. Height of pile should not exceed 6 ft. Compost should be fluffed. [3]
Type 1
Aerated (turned) Windrow Composting: Suited for large volumes, such as those generated by entire communities. Involves forming organic waste into rows of long piles called “windrows” and periodically aerating them by turning the piles. Ideal pile height is 4-8 ft tall and 14-16 ft wide. This size is large enough to generate enough heat and maintain temperatures, but small enough to allow oxygen flow to the core. Suitable for diverse waste such as yard trimmings, grease, liquids, and animal byproducts (such as fish and poultry wastes). Often requires large tracts of land, sturdy equipment, a continual supply of labor to maintain and operate the facility, and patience to experiment with various materials mixtures and turning frequencies. In rainy seasons, shapes of the piles can be adjusted so that water runs off the top of the piles rather than absorbed. Leachate is a liquid released during the process, it can contaminate local ground and surface water. It should be collected and treated. [4]
Type 2
Aerated Static Pile Composting: Produces compost relatively quickly (3-6 months). Suitable for a relatively homogenous mix of organic waste and works well for larger quantities. Does not work well for animal byproducts or grease. Organic waste is mixed in a large pile, and layers of loosely piled bulking agents (e.g., wood chips, shredded newspaper) are added so that air can pass from the bottom to the top of the pile. Requires careful monitoring to ensure that the outside of the pile heats up as much as the core. May require significant cost and technical assistance. [3]
Type 3
Vermicomposting: Redworms in bins that feed on food scraps, yard trimmings, and other organic matter. The materials broken down by the worms is produced into high quality compost called castings. A pound of mature worms, which is approximately 800-1,000 worms, can eat up to a half a pound of organic material per day. Usually takes about three to fourth months for usable castings. The worms can also produce what is called “worm tea” which is a high-quality liquid fertilizer. The best temperatures for vermicomposting range from 55-77 degree F, and avoidance of direct sunlight. Most common and preferred choice for composting. Worms produce castings that have lower nitrogen compared to other composting methods. Do not house in metal containers, copper can leech out and become toxic. Need to be connected to the ground so nutrients can go right into soil. Need to be kept out of sun, frost, and rain. Also not too cold. Worms are temperamental and will leave if not happy.
Type 4
The University of California Method: Aims for more heat and faster decomposition. A minimum volume of 1 cubic yard, but a greater volume may be required in cold weather. Bin constructed from wood and hardware cloth, wood alone, or concrete. Materials should be reduced to pieces of 6-8 inches. Turning is essential. Recommended turning schedule every 3 days.
Type 5
Raised-Bin Method: Open-hearth-bottom bin sitting on cement slab. A grill made from pipe sits above the slab. Allowing air into the center of the heap. As the pile heats up, it pulls the cooler air from the ground, aerating throughout the pile.
Type 6
Open Air Composting (Bay composting): Usually a pile of green and brown matter. Generally considered a hot composting method. A bay is constructed using anything handy, such as wire cages or bins. Requires monitoring, watering, turning, and spreading. Attracts worms, but will not stay if conditions are not perfect. Temperature and pH are very important. Nitrogen and carbon ratio are very important. 2-3 bays are optimal for the process time. Worm friendly food only. If not the right mix, it can smell. Takes a long time and turning to aerate is essential. Ideal for a farmer with lots of green waste.
Designing interpretive materials
According to ______ interpretive materials for composting should include....