With the popular trend towards using bamboo and bamboo-derived products, one expects significant waste production (old utensils, broken items, and “offcuts”). Like most waste, leftover and broken bamboo products usually end up in landfills. But should it end up here, or is there a better solution? Most importantly, is bamboo biodegradable?
Bamboo, in its natural state, is 100% biodegradable, thanks to its organic composition. However, it takes longer to decompose or entirely stops when it’s processed or mixed with certain other materials and compounds. Several additional factors influence bamboo’s decomposition rate.
Like all plants, bamboo degrades over time, thanks to its composition and the work of microorganisms. What is interesting is understanding what speeds up/slows down the decomposition rate, what inhibits decomposition, and whether bamboo can be recycled.
Bamboo: The Ultimate Green Product
“Bamboo” refers to a collection of grass plants (Poaceae) belonging to the Bambusoideae subfamily. These plants are globally distributed in tropical, subtropical, and mildly temperate regions.
Most species (and the highest biomass) occur in Asia (East and Southeast) and the surrounding areas.
Bamboo has a long-standing relationship with humans due to its widespread occurrence and versatility as a resource.
Humans use bamboo for various industries, including:
- Biocomposites
- Fabric
- Food
- Fuel
- Shelter (construction)
Thanks to the plethora of uses, bamboo is frequently manufactured into various products. However, with wide-scale use, as much as 50% of bamboo timber is discarded as residues (sawdust and small fragments).
While bamboo decomposes easily in its natural state, it undergoes several transformations when converted into a product, influencing the decomposition rate.
What Makes Bamboo Biodegradable?
Bamboo is biodegradable thanks to its susceptibility to decomposer organisms and the process of “leaching.”
It’s is a naturally occurring product made of carbon, nitrogen, hydrogen, oxygen, and many other compounds at a cellular level, which bond to form various plant parts.
- 74% cellulose
- 13% hemicellulose
- 10% lignin
- 3% other minor components
Once bamboo dies, organisms and natural processes begin the decomposition process.
Fragmentation starts the process, where large pieces are broken into smaller pieces. Dead bamboo is eaten by insects, stepped on by large animals, crushed when it falls over, etc. The resultant smaller pieces include sawdust and wood pulp.
Earthworms and other soil biota further fragment the pieces when it’s in the soil.
Once fragmented (and during the process), microorganisms (specifically bacteria and fungi) take over and play a fundamental role in this decomposition (without them, it would not be possible).
Thanks to how bamboo grows and assimilates nutrients, microorganisms easily break these bonds, releasing the stored nutrients as carbon dioxide and other minerals. Some of these they absorb, while the rest move into the soil.
Water moving through the soil (mostly from rain) transports the nutrients. Water also aids in decomposition by “leaching” nutrients from plant material (washing nutrients out of the plant’s parts).
Does Bamboo Breakdown Completely?
In its natural state, bamboo is completely biodegradable. The nutrients locked inside the tree are in an accessible format for fungi and bacteria to process (particularly during and after fragmentation).
Under What Situations Is Bamboo Not Biodegradable?
Bamboo may become non-biodegradable once processed and subjected to various chemical treatments.
The most obvious instance of this transformation is when bamboo is shredded, and the fibers are mixed with an adhesive glue (as a biocomposite).
This practice is frequently used in the construction industry, where strand woven bamboo is manufactured for flooring. Thanks to the process, bamboo becomes almost impervious to water and decomposition.
The most commonly used adhesives usually contain urea formaldehyde, a hazardous chemical poisonous to humans and animals. This chemical also prevents decomposers from processing the bamboo.
How Quickly Does Bamboo Decompose?
Although biodegradable, bamboo takes time to decompose thanks to its hardy characteristics and physical traits.
The age of the plant, the size of the parts, the plant parts, the degree of fragmentation, and the species play are significant to decomposition rates.
- Mature plants that are substantially lignified take more time to decompose than saplings.
- Bamboo species that are more “woody” decompose slower.
- Culms take a longer time when compared to leaves, and whole plants have a slower decomposition rate than cut pieces.
According to a study, bamboo leaf litter took 8 months to undergo 50% decomposition but 2.8 years to decompose to 95%.
Bamboo culms in their entire (whole) state may take between 4 and 8 years to decompose when left alone.
Several other extrinsic factors influence decomposition rates, including the following.
Environmental Factors Which Influence Bamboo Decomposition Rate
The table below demonstrates that decomposition is a product of complex environmental interactions.
|
Factor |
Affect |
|
Temperature |
|
|
Moisture |
|
|
Oxygen |
|
|
Microorganisms |
|
The table assumes the bamboo is left naturally (without harmful chemicals or special treatments).
The Processing Bamboo Undergoes Influences Its Decomposition Rate
Thanks to its versatility, bamboo is a popular material used in various industries. These industries process bamboo in different ways.
For example, bamboo is frequently treated with chemicals to prevent decomposition/to slow the decomposition rate. These chemicals include lysine-based diisocyanate, formaldehyde, borax, and boric acid.
These chemicals prevent microorganism activities by creating unfit conditions (usually toxic). Additionally, bamboo is often treated with resin (when it is decorative). Resin seals the wood, preventing moisture and microorganism activity delaying and preventing decomposition.
However, bamboo processing may also speed up decomposition. When milled for animal fodder or used as fuel, bamboo is converted into a form more easily processed by microorganisms.
Bamboo packaging, cups, and plates generally decompose quicker (if untreated and not mixed with other products like melanin) because of the increased surface area and broken fibers.
Bamboo packaging takes roughly 8 weeks to decompose. Decomposing takes roughly 45 to 180 days when bamboo is intensively and actively composted.
Can Bamboo Be Recycled?
Bamboo is a truly wondrous product. It is biodegradable and can be recycled, thanks to its inherent toughness/durability, provided it is in a usable state.
Unfortunately, not all bamboo products are recyclable. Many states (and countries) won’t accept bamboo for recycling if it’s been treated with chemicals, covered in resins, or mixed with synthetic products (including melanin- as is common practice when making bamboo crockery).
Before taking your old bamboo products to a recycling station, call ahead to ensure they take them and inquire about what they don’t accept.
Bamboo Compost
As a minor technicality, allowing bamboo to decompose in a compost heap and adding it to the soil is a form of recycling (although it is nutrient recycling, allowing you to grow other plants). Thanks to this characteristic, no natural (untreated) piece of this plant can ever truly go to waste.
Bamboo is frequently mixed with other organic materials to create usable compost. Bamboo charcoal is also used for compost as it contains phosphorus, nitrogen, and potassium in a readily available form.
Bamboo’s widespread distribution, incredible growth rate, biodegradable nature, and the option to recycle products make it one of the best sustainable resources available.
Conclusion
Like all other plants, bamboo is biodegradable. Thanks to its molecular structure, microorganisms can access the stored nutrients, breaking them down into usable nutrients released into the soil during decomposition. However, when harmful chemicals are added to bamboo, decomposition is slowed or hindered, making it unsuitable for recycling. Natural bamboo makes adequate compost, particularly when mixed with other organic matter.