Green waste, also known as "biological waste", is any
organic waste that can be
compost
Compost is a mixture of ingredients used as plant fertilizer and to improve soil's physical, chemical and biological properties. It is commonly prepared by decomposing plant, food waste, recycling organic materials and manure. The resulting m ...
ed. It is most usually composed of refuse from gardens such as grass clippings or leaves, and domestic or industrial kitchen wastes. Green waste does not include things such as dried leaves, pine straw, or hay. Such materials are rich in
carbon
Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent
In chemistry, the valence (US spelling) or valency (British spelling) of an element is the measure of its combining capacity with o ...
and considered "
brown waste
Brown waste is any biodegradable waste that is predominantly carbon based. The term includes such items as grass cuttings, dry leaves, twigs, hay, paper, sawdust, corn cobs, cardboard, pine needles or cones, etc.
Carbon is necessary to compostin ...
s," while green wastes contain high in concentrations of
nitrogen
Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...
. Green waste can be used to increase the efficiency of many composting operations and can be added to soil to sustain local
nutrient cycling.
Collection of green waste
Green waste can be collected via
municipal
A municipality is usually a single administrative division having corporate status and powers of self-government or jurisdiction as granted by national and regional laws to which it is subordinate.
The term ''municipality'' may also mean the go ...
curbside collection
Kerbside collection or curbside collection is a service provided to households, typically in urban and suburban areas, of collecting and disposing of household waste and recyclables. It is usually accomplished by personnel using specially built ...
schemes or through private
waste management
Waste management or waste disposal includes the processes and actions required to manage waste from its inception to its final disposal.
This includes the collection, transport, treatment and disposal of waste, together with monitoring ...
businesses. Many communities, especially in the United Kingdom, have initiated green waste
recycling and collection programs in order to decrease the amount of
biodegradable materials in landfills.
Communities are provided with, or can provide their own, compost receptacles that they fill with plant and food remains, which are then emptied on a regular basis. Programs such as this allow communities to be an active part of composting their green waste which allows them to play an active role in decreasing the amount of food being dumped into local and
regional landfills.
Uses
Green waste can be used to improve the quality and sustainability of industrially
manufactured topsoils and the sanitariness and efficiency of
sewage disposal.
Manufactured topsoils
Green waste is an integral part of many
manufactured topsoils, as it provides both nutrients for growing plants and increases the volume of manufactured topsoils.
Its woody components do not decompose quickly, so they provide the bulk that is necessary for supplementary topsoils.
Mixing industrial wastes such as
fly ash or
coal dust Coal dust is a fine powdered form of which is created by the crushing, grinding, or pulverizing of coal. Because of the brittle nature of coal, coal dust can be created during mining, transportation, or by mechanically handling coal. It is a form ...
with green waste to create artificial topsoil not only facilitates the
repurposing
Repurposing is the process by which an object with one use value is transformed or redeployed as an object with an alternative use value.
Description
Repurposing is as old as human civilization, with many contemporary scholars investigating t ...
of industrial debris and keeps it out of landfills, but it also allows the nutrients in green waste materials to be cycled back into the environment. By utilizing fly ash in conjunction with green waste, manufactured soils are able to increase their water holding capacity while simultaneously recycling refuse materials that might otherwise take up space in a landfill.
This allows fly ash and green waste to increase local soil nutrient levels and promotes natural nutrient cycling processes.
Sewage disposal
Green waste can also be mixed with
sewage wastes and composted, providing a safe, environmentally sustainable option for sewage disposal.
Co-composting green and sewage wastes eliminates the risk that
pathogen
In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...
s and
pollutant
A pollutant or novel entity is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like oi ...
s contained in sewage wastes might pose to the environment.
Utilization of green waste to dispose of sewage wastes not only decreases the amount of sewage
incinerated and dumped each year, it also facilitates the cycling of organic wastes back into the environment. The co-composted remains of these organic wastes can be safely employed for use in
agriculture
Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to ...
.
This process decreases the amount of trash being dumped into landfills and other trash repositories and allows for the complete
cycling of organic nutrients through the environment.
Renewable energy
Biogas
Biogas is a mixture of gases, primarily consisting of methane, carbon dioxide and hydrogen sulphide, produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste and food waste. It is a ...
captured from biodegradable green waste can be used as
biofuel
Biofuel is a fuel that is produced over a short time span from biomass, rather than by the very slow natural processes involved in the formation of fossil fuels, such as oil. According to the United States Energy Information Administration (E ...
. Green waste can be composed of
non-food crop
A nonfood crop, also known as industrial crop, is a crop grown to produce goods for manufacturing, for example fibre for clothing, rather than food for consumption.
Purpose
Industrial crops is a designation given to an enterprise that attempts ...
s, which decompose to produce
cellulosic ethanol
Cellulosic ethanol is ethanol (ethyl alcohol) produced from cellulose (the stringy fiber of a plant) rather than from the plant's seeds or fruit. It can be produced from grasses, wood, algae, or other plants. It is generally discussed for use as a ...
. It can also help reduce the necessity of petroleum gases, which produce large amounts of
greenhouse gas
A greenhouse gas (GHG or GhG) is a gas that Absorption (electromagnetic radiation), absorbs and Emission (electromagnetic radiation), emits radiant energy within the thermal infrared range, causing the greenhouse effect. The primary greenhouse ...
es, such as
carbon dioxide
Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...
, when burned.
Soil health
Green waste composting has also been linked to suppression of soil borne diseases such as
damping off
Damping off (or damping-off) is a horticultural disease or condition, caused by several different pathogens that kill or weaken seeds or seedlings before or after they germinate. It is most prevalent in wet and cool conditions.
Symptoms
There ar ...
and
root rot
Root rot is a condition in which anoxic conditions in the soil or potting media around the roots of a plant cause them to rot. This occurs due to excessive standing water around the roots. It is found in both indoor and outdoor plants, although ...
s that affect large agricultural and horticultural ventures like
greenhouse
A greenhouse (also called a glasshouse, or, if with sufficient heating, a hothouse) is a structure with walls and roof made chiefly of Transparent ceramics, transparent material, such as glass, in which plants requiring regulated climatic condit ...
s and
large-scale farms.
This disease suppressive quality has positive implications for lesser-developed nations that do not have the technology or resources to purchase expensive
fertilizer
A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...
s.
Addition of composts that contain residues and particles of
heavy metals
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Heavy metals are generally defined as ...
to soil can raise the soil's heavy metal content and increase the probability of these metals to transfer into crop plants.
When biological, or green waste is added to these soil samples, plant uptake of heavy metal has been shown to decrease crop uptake of metals compared to other types of compost composed of things such as sewage sludge.
This can protect consumers and the environment from
biomagnification
Biomagnification, also known as bioamplification or biological magnification, is any concentration of a toxin, such as pesticides, in the tissues of tolerant organisms at successively higher levels in a food chain. This increase can occur as a ...
caused by long-term
accumulation
Accumulation may refer to:
Finance
* Accumulation function, a mathematical function defined in terms of the ratio future value to present value
* Capital accumulation, the gathering of objects of value
Science and engineering
* Accumulate (hi ...
of heavy metal particles within the soil and plant life of an area.
See also
*
Garden waste dumping
*
Biomass
Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms bi ...
*
Biomass to liquid
Biomass to liquid (BtL or BMtL) is a multi-step process of producing synthetic hydrocarbon fuels made from biomass via a thermochemical route.
Main processes
According to a study done by the U.S. Department of Agriculture and the Department of En ...
*
Biomass heating system
Biomass heating systems generate heat from biomass.
The systems fall under the categories of:
*direct combustion,
*gasification,
*combined heat and power (CHP),
*anaerobic digestion,
*aerobic digestion.
Benefits of biomass heating
The use of bio ...
References
{{Waste
Biodegradable waste management
Waste