Биоразлагаемые отходы

Биоразлагаемые отходы в себя любое органическое вещество в отходах , которое можно разбить на углекислый газ , воду , метан , компост , гумус и простые органические молекулы микроорганизмами включают и другими живыми существами путем компостирования , аэробного расщепления , анаэробного расщепления или аналогичных процессов. В основном он включает в себя кухонные отходы (испорченные пищу, отделки, несъедобные детали), пепел, почву, навоз и другие растительные вещества. В управлении отходами он также включает в себя некоторые неорганические материалы, которые могут быть разложены бактериями. Такие материалы включают в себя гипс и его продукты, такие как гипсовая доска и другие простые сульфаты , которые могут быть разложены с помощью сульфатов, восстанавливающих бактерии с получением серо водорода в анаэробных условиях заполнения земли.

При сборе бытовых отходов объем биоразлагаемых отходов могут быть сужены, чтобы включать только те разлагаемые отходы, способные обрабатывать в местных объектах обработки отходов. Чтобы решить эту проблему, многие местные районы управления отходами интегрируют программы, связанные с сортировкой биоразлагаемых отходов для компостирования или других стратегий царизации отходов , где биоразлагаемые отходы повторно используются для других продуктов, таких как использование сельскохозяйственных отходов для производства волокна или биочара .

Biodegradable waste when not handled properly can have an outsized impact on climate change, especially through methane emissions from anaerobic fermentation that produces landfill gas. Other approaches to reducing the impact include reducing the amount of waste produced, such as through reducing food waste.

Sources

Biodegradable waste can be found in municipal solid waste (sometimes called biodegradable municipal waste, or as green waste, food waste, paper waste and biodegradable plastics). Other biodegradable wastes include human waste, manure, sewage, sewage sludge and slaughterhouse waste. In the absence of oxygen, much of this waste will decay to methane by anaerobic digestion.

In the UK, 7.4 million tonnes of biodegradable waste was sent to landfill in 2018 having reduced from 7.8 million tonnes in 2017.

Collection and processing

In many parts of the developed world, biodegradable waste is separated from the rest of the waste stream, either by separate curb-side collection or by waste sorting after collection. At the point of collection such waste is often referred to as green waste. Removing such waste from the rest of the waste stream substantially reduces waste volumes for disposal and also allows biodegradable waste to be composted.

Biodegradable waste can be used for composting or a resource for heat, electricity and fuel by means of incineration or anaerobic digestion. Swiss Kompogas and the Danish AIKAN process are examples of anaerobic digestion of biodegradable waste. While incineration can recover the most energy, anaerobic digestion plants retain nutrients and make compost for soil amendment and still recover some of the contained energy in the form of biogas. Kompogas produced 27 million Kwh of electricity and biogas in 2009. The oldest of the company's lorries has achieved 1,000,000 kilometers driven with biogas from household waste in the last 15 years.

Valorization

Crop residue

This section is an excerpt from Waste valorization § Crop residue.[edit]

Crop residue, such as corncob, and other residues from the food processing industry, such as residues from biorefineries, have high potential for use in further processes, such as producing biofuel, bioplastics, and other biomaterials for industrial processes.

Food waste

This section is an excerpt from Waste valorization § Food waste.[edit]

One of the more fruitful fields of work is food waste—when deposited in landfills, food waste produces the greenhouse gas methane and other toxic compounds that can be dangerous to humans and local ecosystems. Landfill gas utilization and municipal composting can capture and use the organic nutrients. Food waste collected from non-industrial sources is harder to use, because it often has much greater diversity than other sources of waste—different locations and different windows of time produce very different compositions of material, making it hard to use for industrial processes.

Transforming food waste to either food products, feed products, or converting it to or extracting food or feed ingredients is termed as food waste valorisation. Valorisation of food waste offers an economical and environmental opportunity, which can reduce the problems of its conventional disposal. Food wastes have been demonstrated to be valuable bioresources that can be utilised to obtain a number of useful products, including biofertilizers, bioplastics, biofuels, chemicals, and nutraceuticals. There is much potential to recycle food wastes by conversion to insect protein.

Human excreta

This section is an excerpt from Reuse of human excreta.[edit]

Harvest of capsicum grown with compost made from human excreta at an experimental garden in Haiti

Reuse of human excreta is the safe, beneficial use of treated human excreta after applying suitable treatment steps and risk management approaches that are customized for the intended reuse application. Beneficial uses of the treated excreta may focus on using the plant-available nutrients (mainly nitrogen, phosphorus and potassium) that are contained in the treated excreta. They may also make use of the organic matter and energy contained in the excreta. To a lesser extent, reuse of the excreta's water content might also take place, although this is better known as water reclamation from municipal wastewater. The intended reuse applications for the nutrient content may include: soil conditioner or fertilizer in agriculture or horticultural activities. Other reuse applications, which focus more on the organic matter content of the excreta, include use as a fuel source or as an energy source in the form of biogas.

There is a large and growing number of treatment options to make excreta safe and manageable for the intended reuse option. Options include urine diversion and dehydration of feces (urine-diverting dry toilets), composting (composting toilets or external composting processes), sewage sludge treatment technologies and a range of fecal sludge treatment processes. They all achieve various degrees of pathogen removal and reduction in water content for easier handling. Pathogens of concern are enteric bacteria, virus, protozoa, and helminth eggs in feces. As the helminth eggs are the pathogens that are the most difficult to destroy with treatment processes, they are commonly used as an indicator organism in reuse schemes. Other health risks and environmental pollution aspects that need to be considered include spreading micropollutants, pharmaceutical residues and nitrate in the environment which could cause groundwater pollution and thus potentially affect drinking water quality.

Climate change impacts

Landfill gas

This section is an excerpt from Landfill gas.[edit]

A gas flare produced by a landfill in Lake County, Ohio

Landfill gas is a mix of different gases created by the action of microorganisms within a landfill as they decompose organic waste, including for example, food waste and paper waste. Landfill gas is approximately forty to sixty percent methane, with the remainder being mostly carbon dioxide. Trace amounts of other volatile organic compounds (VOCs) comprise the remainder (<1%). These trace gases include a large array of species, mainly simple hydrocarbons.

Landfill gases have an influence on climate change. The major components are CO₂ and methane, both of which are greenhouse gases. Methane in the atmosphere is a far more potent greenhouse gas, with each molecule having twenty-five times the effect of a molecule of carbon dioxide. Methane itself however accounts for less composition of the atmosphere than does carbon dioxide. Landfills are the third-largest source of methane in the US.

Because of the significant negative effects of these gases, regulatory regimes have been set up to monitor landfill gas, reduce the amount of biodegradable content in municipal waste, and to create landfill gas utilization strategies, which include gas flaring or capture for electricity generation.

Food waste

This section is an excerpt from Food loss and waste.[edit]

Fruit and vegetables in a dumpster, discarded uneaten

Food recovered by food waste critic Robin Greenfield in Madison, Wisconsin, from two days of recovery from dumpsters

Food loss and waste is food that is not eaten. The causes of food waste or loss are numerous and occur throughout the food system, during production, processing, distribution, retail and food service sales, and consumption. Overall, about one-third of the world's food is thrown away. A similar amount is lost on top of that by feeding human-edible food to farm animals (the net effect wastes an estimated 1144 kcal/person/day). A 2021 meta-analysis, that did not include food lost during production, by the United Nations Environment Programme found that food waste was a challenge in all countries at all levels of economic development. The analysis estimated that global food waste was 931 million tonnes of food waste (about 121 kg per capita) across three sectors: 61 percent from households, 26 percent from food service and 13 percent from retail.

Food loss and waste is a major part of the impact of agriculture on climate change (it amounts to 3.3 billion tons of CO₂e emissions annually) and other environmental issues, such as land use, water use and loss of biodiversity. Prevention of food waste is the highest priority, and when prevention is not possible, the food waste hierarchy ranks the food waste treatment options from preferred to least preferred based on their negative environmental impacts. Reuse pathways of surplus food intended for human consumption, such as food donation, is the next best strategy after prevention, followed by animal feed, recycling of nutrients and energy followed by the least preferred option, landfill, which is a major source of the greenhouse gas methane. Other considerations include unreclaimed phosphorus in food waste leading to further phosphate mining. Moreover, reducing food waste in all parts of the food system is an important part of reducing the environmental impact of agriculture, by reducing the total amount of water, land, and other resources used.

The UN's Sustainable Development Goal Target 12.3 seeks to "halve global per capita food waste at the retail and consumer levels and reduce food losses along production and supply chains, including post-harvest losses" by 2030. Climate change mitigation strategies prominently feature reducing food waste. In the 2022 United Nations Biodiversity Conference nations agree to reduce food waste by 50% by the year 2030.

See also

• Biodegradability prediction
• Biodegradable bags
• Biodegradation
• Biodrying
• Compost
• Brown waste
• Green waste
• Landfarming
• Landfill diversion
• List of waste types
• Miniwaste
• Sewage treatment