Sanitation

From Wikipedia, the free encyclopedia

The sanitation system: collection, transport, treatment, disposal or reuse.

 

Sanitation refers to public health conditions related to clean drinking water and adequate treatment and disposal of human wastes and sewage. Preventing human contact with feces is part of sanitation, as is hand washing with soap. Sanitation systems aim to protect human health by providing a clean environment that will stop the transmission of disease, especially through the fecal–oral route. For example, diarrhea, a main cause of malnutrition and stunted growth in children, can be reduced through sanitation. There are many other diseases which are easily transmitted in communities that have low levels of sanitation, such as ascariasis (a type of intestinal worm infection or helminthiasis), cholera, hepatitis, polio, schistosomiasis, trachoma, to name just a few. 

A range of sanitation technologies and approaches exists. Some examples are community-led total sanitation, container-based sanitation, ecological sanitation, emergency sanitation, environmental sanitation, onsite sanitation and sustainable sanitation. A sanitation system includes the capture, storage, transport, treatment and disposal or reuse of human excreta and wastewater. Reuse activities within the sanitation system may focus on the nutrients, water, energy or organic matter contained in excreta and wastewater. This is referred to as the "sanitation value chain" or "sanitation economy".

Several sanitation "levels" are being used to compare sanitation service levels within countries or across countries. The sanitation ladder defined by the Joint Monitoring Programme in 2016 starts at open defecation and moves upwards using the terms "unimproved", "limited", "basic", with the highest level being "safely managed". This is particularly applicable to developing countries. 

The Human Right to Water and Sanitation was recognized by the United Nations (UN) General Assembly in 2010. Sanitation is a global development priority and the subject of Sustainable Development Goal 6. The estimate in 2017 by JMP states that 4.5 billion people currently do not have safely managed sanitation. Lack of access to sanitation has an impact not only on public health but also on human dignity and personal safety.

Definition

The World Health Organization defines the term "sanitation" as follows:

"Sanitation generally refers to the provision of facilities and services for the safe disposal of human urine and feces. The word 'sanitation' also refers to the maintenance of hygienic conditions, through services such as garbage collection and wastewater disposal."

Sanitation includes all four of these engineering infrastructure items (even though often only the first one is strongly associated with the term "sanitation"): Excreta management systems, wastewater management systems (included here are wastewater treatment plants), solid waste management systems, drainage systems for rainwater, also called stormwater drainage.

There are some variations on the use of the term "sanitation" between countries. For example, hygiene promotion is seen by some as an integral part of sanitation. For this reason, the Water Supply and Sanitation Collaborative Council defines sanitation as "The collection, transport, treatment and disposal or reuse of human excreta, domestic wastewater and solid waste, and associated hygiene promotion."

Despite the fact that sanitation includes wastewater treatment, the two terms are often used side by side as "sanitation and wastewater management".

Purposes

The overall purposes of sanitation are to provide a healthy living environment for everyone, to protect the natural resources (such as surface water, groundwater, soil), and to provide safety, security and dignity for people when they defecate or urinate. 

The Human Right to Water and Sanitation was recognized by the United Nations (UN) General Assembly in 2010. It has been recognized in international law through human rights treaties, declarations and other standards. It is derived from the human right to an adequate standard of living.

Effective sanitation systems provide barriers between excreta and humans in such a way as to break the disease transmission cycle (for example in the case of fecal-borne diseases). This aspect is visualised with the F-diagram where all major routes of fecal-oral disease transmission begin with the letter F: feces, fingers, flies, fields, fluids, food.

One of the main challenges is to provide sustainable sanitation, especially in developing countries. Maintaining and sustaining sanitation has aspects that are technological, institutional and social in nature. Sanitation infrastructure has to be adapted to several specific contexts including consumers' expectations and local resources available.

Sanitation technologies may involve centralized civil engineering structures like sewer systems, sewage treatment, surface runoff treatment and solid waste landfills. These structures are designed to treat wastewater and municipal solid waste. Sanitation technologies may also take the form of relatively simple onsite sanitation systems. This can in some cases consist of a simple pit latrine or other type of non-flush toilet for the excreta management part. 

Providing sanitation to people requires attention to the entire system, not just focusing on technical aspects such as the toilet, fecal sludge management or the wastewater treatment plant. The "sanitation chain" involves the experience of the user, excreta and wastewater collection methods, transporting and treatment of waste, and reuse or disposal. All need to be thoroughly considered.

Types and terms

Percentage of population served by different types of sanitation systems

 

Example of sanitation infrastructure: Shower, double-vault urine-diverting dry toilet (UDDT) and waterless urinal in Lima, Peru

 

The term sanitation is connected with various descriptors or adjectives to signify certain types of sanitation systems (which may deal only with human excreta management or with the entire sanitation system, i.e. also greywater, stormwater and solid waste management) – in alphabetical order:

Basic sanitation

In 2017, JMP defined a new term: "basic sanitation service". This is defined as the use of improved sanitation facilities that are not shared with other households. A lower level of service is now called "limited sanitation service" which refers to use of improved sanitation facilities that are shared between two or more households.

Container-based sanitation

Container-based sanitation (CBS) refers to a sanitation system where human excreta is collected in sealable, removable containers (or cartridges) that are transported to treatment facilities. Container-based sanitation is usually provided as a service involving provision of certain types of portable toilets, and collection of excreta at a cost borne by the users. With suitable development, support and functioning partnerships, CBS can be used to provide low-income urban populations with safe collection, transport and treatment of excrement at a lower cost than installing and maintaining sewers. In most cases, CBS is based on the use of urine-diverting dry toilets.

Community-led total sanitation

Community-Led Total Sanitation (CLTS) is an approach to achieve behavior change in mainly rural people by a process of "triggering", leading to spontaneous and long-term abandonment of open defecation practices. CLTS takes an approach to rural sanitation that works without hardware subsidies and that facilitates communities to recognize the problem of open defecation and take collective action to clean up and become "open defecation free".

Dry sanitation

The term "dry sanitation" is not in widespread use and is not very well defined. It usually refers to a system that uses a type of dry toilet and no sewers to transport excreta. Often when people speak of "dry sanitation" they mean a sanitation system that uses urine-diverting dry toilet (UDDTs).

Ecological sanitation

Ecological sanitation, which is commonly abbreviated to ecosan, is an approach, rather than a technology or a device which is characterized by a desire to "close the loop" (mainly for the nutrients and organic matter) between sanitation and agriculture in a safe manner. Put in other words: "Ecosan systems safely recycle excreta resources (plant nutrients and organic matter) to crop production in such a way that the use of non-renewable resources is minimised". When properly designed and operated, ecosan systems provide a hygienically safe, economical, and closed-loop system to convert human excreta into nutrients to be returned to the soil, and water to be returned to the land. Ecosan is also called resource-oriented sanitation.

Emergency pit lining kits by Evenproducts

Emergency sanitation

Emergency sanitation is required in situations including natural disasters and relief for refugees and Internally Displaced Persons (IDPs). There are three phases: Immediate, short term and long term. In the immediate phase, the focus is on managing open defecation, and toilet technologies might include very basic latrines, pit latrines, bucket toilets, container-based toilets, chemical toilets. The short term phase might also involve technologies such as urine-diverting dry toilets, septic tanks, decentralized wastewater systems. Providing handwashing facilities and management of fecal sludge are also part of emergency sanitation. The Sphere Project handbook provides protection principles and core standards for sanitation to put in place after a disaster or conflict.

Environmental sanitation

Environmental sanitation encompasses the control of environmental factors that are connected to disease transmission. Subsets of this category are solid waste management, water and wastewater treatment, industrial waste treatment and noise and pollution control.

Improved and unimproved sanitation

Improved sanitation and unimproved sanitation refers to the management of human feces at the household level. This terminology is the indicator used to describe the target of the Millennium Development Goal on sanitation, by the WHO/UNICEF Joint Monitoring Programme for Water Supply and Sanitation.

Lack of sanitation

Lack of sanitation refers to the absence of sanitation. In practical terms it usually means lack of toilets or lack of hygienic toilets that anybody would want to use voluntarily. The result of lack of sanitation is usually open defecation (and open urination but this is of less concern) with associated serious public health issues. It is estimated that 2.4 billion people still lacked improved sanitation facilities as of 2015.

Onsite sanitation

Onsite sanitation (or on-site sanitation) is defined as "a sanitation system in which excreta and wastewater are collected and stored or treated on the plot where they are generated". The degree of treatment may be variable, from none to advanced. Examples are pit latrines (no treatment) and septic tanks (primary treatment of wastewater). On-site sanitation systems are often connected to fecal sludge management systems where the fecal sludge that is generated onsite is treated at an offsite location. Wastewater (sewage) is only generated when piped water supply is available within the buildings or close to them. 

A related term is a decentralized wastewater system which refers in particular to the wastewater part of on-site sanitation. Similarly, an onsite sewage facility can treat the wastewater generated locally.

Safely managed sanitation

A relatively high level of sanitation service is now called "safely managed sanitation" by the JMP definition. This is basic sanitation service where in addition excreta are safely disposed of in situ or transported and treated offsite.

Sustainable sanitation

Sustainable sanitation considers the entire "sanitation value chain", from the experience of the user, excreta and wastewater collection methods, transportation or conveyance of waste, treatment, and reuse or disposal. The term is widely used since about 2009. In 2007 the Sustainable Sanitation Alliance defined five sustainability criteria to compare the sustainability of sanitation systems. In order to be sustainable, a sanitation system has to be economically viable, socially acceptable, technically and institutionally appropriate, and it should also protect the environment and the natural resources.

Other

Other terms used to describe certain types of sanitation include:

• Community-based sanitation (often related to decentralized wastewater treatment or DEWATS)

Health aspects

The "F-diagram" (feces, fingers, flies, fields, fluids, food), showing pathways of fecal-oral disease transmission. The vertical blue lines show barriers: toilets, safe water, hygiene and handwashing.

 

For any social and economic development, adequate sanitation in conjunction with good hygiene and safe water are essential to good health. Lack of proper sanitation causes diseases. Most of the diseases resulting from sanitation have a direct relation to poverty. The lack of clean water and poor sanitation causes many diseases and the spread of diseases. It is estimated that inadequate sanitation is responsible for 4.0 percent of deaths and 5.7 percent of disease burden worldwide.

Lack of sanitation is a serious issue that is affecting most developing countries and countries in transition. The importance of the isolation of excreta and waste lies in an effort to prevent diseases which can be transmitted through human waste, which afflict both developed countries as well as developing countries to differing degrees.

This situation presents substantial public health risks as the waste could contaminate drinking water and cause life-threatening forms of diarrhea to infants. Improved sanitation, including hand washing and water purification, could save the lives of 1.5 million children who die from diarrheal diseases each year.

It is estimated that up to 5 million people die each year from preventable waterborne diseases, as a result of inadequate sanitation and hygiene practices. The effects of sanitation has impacted the society of people throughout history. Sanitation is a necessity for a healthy life.

Diarrhea

Diarrhea plays a significant role: Deaths resulting from diarrhea are estimated to be between 1.6 and 2.5 million deaths every year. Most of the affected are young children below the ages of five. Children suffering from diarrhea are more vulnerable to become underweight (due to stunted growth) which makes them more vulnerable to other diseases such as acute respiratory infections and malaria. Diarrhoea is primarily transmitted through faecal-oral routes. 

Numerous studies have shown that improvements in drinking water and sanitation (WASH) lead to decreased risks of diarrhoea. Such improvements might include for example use of water filters, provision of high-quality piped water and sewer connections.

Open defecation – or lack of sanitation – is a major factor in causing various diseases, most notably diarrhea and intestinal worm infections. For example, infectious diarrhea resulted in about 0.7 million deaths in children under five years old in 2011 and 250 million lost school days. It can also lead to malnutrition and stunted growth in children. Open defecation is a leading cause of diarrheal death; 2,000 children under the age of five die every day, one every 40 seconds, from diarrhea.

Malnutrition and stunting

A child receiving malnutrition treatment in Northern Kenya

 

The combination of direct and indirect deaths from malnutrition caused by unsafe water, sanitation and hygiene (WASH) practices is estimated by the World Health Organisation to lead to 860,000 deaths per year in children under five years of age. The multiple interdependencies between malnutrition and infectious diseases make it very difficult to quantify the portion of malnutrition that is caused by infectious diseases which are in turn caused by unsafe WASH practices. Based on expert opinions and a literature survey, researchers at WHO arrived at the conclusion that approximately half of all cases of malnutrition (which often leads to stunting) in children under five is associated with repeated diarrhoea or intestinal worm infections as a result of unsafe water, inadequate sanitation or insufficient hygiene.

Diseases caused by lack of sanitation

Relevant diseases and conditions caused by lack of sanitation and hygiene include:

• Waterborne diseases, which can contaminate drinking water
• Diseases transmitted by the fecal-oral route
  • Infections with intestinal helminths (worms) - approximately two billion people are infected with soil-transmitted helminths worldwide; they are transmitted by eggs present in human faeces which in turn contaminate soil in areas where sanitation is poor.
• Stunted growth in children
• Malnutrition, particularly in children

The list of diseases that could be reduced with proper access to sanitation and hygiene practices is very long. For example, in India, 15 diseases have been listed which could be stamped out by improving sanitation:

1. Anaemia, malnutrition
2. Ascariasis (a type of intestinal worm infection)
3. Campylobacteriosis
4. Cholera
5. Cyanobacteria toxins
6. Dengue
7. Hepatitis
8. Japanese encephalitis (JE)
9. Leptospirosis
10. Malaria
11. Ringworm or Tinea (actually a fungal infection)
12. Scabies
13. Schistosomiasis
14. Trachoma
15. Typhoid and paratyphoid enteric fevers
16. Shigellosis

Polio is another disease which is related to improper sanitation and hygiene.

Hygiene promotion

Hygiene education (on proper handwashing) in Afghanistan

 

In many settings, provision of sanitation facilities alone does not guarantee good health of the population. Studies have suggested that the impact of hygiene practices have as great an impact on sanitation related diseases as the actual provision of sanitation facilities. Hygiene promotion is therefore an important part of sanitation and is usually key in maintaining good health.

Hygiene promotion is a planned approach of enabling people to act and change their behaviour in an order to reduce and/or prevent incidences of water, sanitation and hygiene (WASH) related diseases. It usually involves a participatory approach of engaging people to take responsibility of WASH services and infrastructure including its operation and maintenance. The three key elements of promoting hygiene are; mutual sharing of information and knowledge, the mobilisation of affected communities and the provision of essential material and facilities.

Environmental aspects

Indicator organisms

When analysing environmental samples, various types of indicator organisms are used to check for fecal pollution of the sample. Commonly used indicators for bacteriological water analysis include the bacterium Escherichia coli (abbreviated as E. coli) and non-specific fecal coliforms. With regards to samples of soil, sewage sludge, biosolids or fecal matter from dry toilets, helminth eggs are a commonly used indicator. With helminth egg analysis, eggs are extracted from the sample after which a viability test is done to distinguish between viable and non viable eggs. The viable fraction of the helminth eggs in the sample is then counted.

Wastewater and stormwater management

Sewage treatment plant, Australia.

 

Wastewater management consists of collection, wastewater treatment (be it municipal or industrial wastewater), disposal or reuse of treated wastewater. The latter is also referred to as water reclamation. 

Sanitation systems in urban areas of developed countries usually consist of the collection of wastewater in gravity driven sewers, its treatment in wastewater treatment plants for reuse or disposal in rivers, lakes or the sea. Sewers are either combined with storm drains or separated from them as sanitary sewers. Combined sewers are usually found in the central, older parts or urban areas. Heavy rainfall and inadequate maintenance can lead to combined sewer overflows or sanitary sewer overflows, i.e., more or less diluted raw sewage being discharged into the environment. Industries often discharge wastewater into municipal sewers, which can complicate wastewater treatment unless industries pre-treat their discharges.

In developing countries most wastewater is still discharged untreated into the environment. Alternatives to centralized sewer systems include onsite sanitation, decentralized wastewater systems, dry toilets connected to fecal sludge management.

Solid waste disposal

Hiriya Landfill, Israel.

 

Disposal of solid waste is most commonly conducted in landfills, but incineration, recycling, composting and conversion to biofuels are also avenues. In the case of landfills, advanced countries typically have rigid protocols for daily cover with topsoil, where underdeveloped countries customarily rely upon less stringent protocols. The importance of daily cover lies in the reduction of vector contact and spreading of pathogens. Daily cover also minimises odor emissions and reduces windblown litter. Likewise, developed countries typically have requirements for perimeter sealing of the landfill with clay-type soils to minimize migration of leachate that could contaminate groundwater (and hence jeopardize some drinking water supplies). 

For incineration options, the release of air pollutants, including certain toxic components is an attendant adverse outcome. Recycling and biofuel conversion are the sustainable options that generally have superior lifecycle costs, particularly when total ecological consequences are considered. Composting value will ultimately be limited by the market demand for compost product.

Other industries

Food industry

Modern restaurant food preparation area.

Sanitation within the food industry means the adequate treatment of food-contact surfaces by a process that is effective in destroying vegetative cells of microorganisms of public health significance, and in substantially reducing numbers of other undesirable microorganisms, but without adversely affecting the food or its safety for the consumer (U.S. Food and Drug Administration, Code of Federal Regulations, 21CFR110, USA). Sanitation Standard Operating Procedures are mandatory for food industries in United States. Similarly, in Japan, food hygiene has to be achieved through compliance with food sanitation law.

In the food and biopharmaceutical industries, the term "sanitary equipment" means equipment that is fully cleanable using clean-in-place (CIP) and sterilization-in-place (SIP) procedures: that is fully drainable from cleaning solutions and other liquids. The design should have a minimum amount of deadleg, or areas where the turbulence during cleaning is insufficient to remove product deposits. In general, to improve cleanability, this equipment is made from Stainless Steel 316L, (an alloy containing small amounts of molybdenum). The surface is usually electropolished to an effective surface roughness of less than 0.5 micrometre to reduce the possibility of bacterial adhesion.

Developing countries

Modified logo of International Year of Sanitation, used in the UN Drive to 2015 campaign logo

 

In December 2006, the United Nations General Assembly declared 2008 "The International Year of Sanitation", in recognition of the slow progress being made towards the MDGs sanitation target. The year aimed to develop awareness and more actions to meet the target.

Sustainable Development Goal Number 6 (from 2016 onwards)

In the year 2016, the Sustainable Development Goals replaced the Millennium Development Goals. Sanitation is a global development priority and the subject of Sustainable Development Goal 6 (SDG 6). The target is to ensure everyone everywhere has access to toilets by 2030.

One indicator for the sanitation target is the "Proportion of population using safely managed sanitation services, including a hand-washing facility with soap and water". The current value in the 2017 baseline estimate by JMP is that 4.5 billion people currently do not have safely managed sanitation. JMP is the Joint Monitoring Programme by UNICEF and WHO to monitor SDG6 progress.

Millennium Development Goal Number 7 until 2015

Example for lack of sanitation: Unhygienic pit latrine with ring slab in Kalibari community in Mymensingh, Bangladesh

 

The United Nations, during the Millennium Summit in New York in 2000 and the 2002 World Summit on Sustainable Development in Johannesburg, developed the Millennium Development Goals (MDGs) aimed at poverty eradication and sustainable development. The specific goal for the year 2015 was to reduce by half the number of people who had no access to potable water and sanitation in the baseline year of 1990. As the JMP and the United Nations Development Programme (UNDP) Human Development Report in 2006 has shown, progress meeting the MDG sanitation target is slow, with a large gap between the target coverage and the current reality.

There are numerous reasons for this gap. A major one is that sanitation is rarely given political attention received by other topics despite its key importance. Sanitation is not high on the international development agenda, and projects such as those relating to water supply projects are emphasised.

The Joint Monitoring Programme for Water Supply and Sanitation of WHO and UNICEF (JMP) has been publishing reports of updated estimates every two years on the use of various types of drinking-water sources and sanitation facilities at the national, regional and global levels. The JMP report for 2015 stated that:

• Between 1990 and 2015, open defecation rates have decreased from 38% to 25% globally. Just under one billion people (946 million) still practise open defecation worldwide in 2015.
• 82% of the global urban population, and 51% of the rural population is using improved sanitation facilities in 2015, as per the JMP definition of "improved sanitation".

Economic benefits

The benefits to society of managing human excreta are considerable, for public health as well as for the environment. For every US$1 spent on sanitation, the estimated return to society is US$5.50.

Various initiatives

In 2011 the Bill & Melinda Gates Foundation launched the Reinvent the Toilet Challenge to promote safer, more effective ways to treat human waste. The program is aimed at developing technologies that might help bridge the global sanitation gap.

The treatment components of the Nano Membrane Toilet from the BMGF "Reinvent the toilet challenge"

History

Major human settlements could initially develop only where fresh surface water was plentiful, such as near rivers or natural springs. Throughout history people have devised systems to get water into their communities and households, and to dispose (and later also treat) wastewater. The focus of sewage treatment at that time was on conveying raw sewage to a natural body of water, e.g. a river or ocean, where it would be diluted and dissipated.

The Sanitation in the Indus Valley Civilization in Asia is an example of public water supply and sanitation during the Bronze Age (3300–1300 BCE). 

Sanitation in ancient Rome was quite extensive. These systems consisted of stone and wooden drains to collect and remove wastewater from populated areas—see for instance the Cloaca Maxima into the River Tiber in Rome. It is estimated that the first sewers of ancient Rome were built between 800 and 735 BCE. Nevertheless, there was widespread presence of several helminth types (intestinal worms) that caused dysentery.

There is little record of other sanitation in most of Europe until the High Middle Ages. Unsanitary conditions and overcrowding were widespread throughout Europe and Asia during the Middle Ages. This resulted in pandemics such as the Plague of Justinian (541–542) and the Black Death (1347–1351), which killed tens of millions of people. Very high infant and child mortality prevailed in Europe throughout medieval times, due partly to deficiencies in sanitation.

Modern history

The modern technology has improved sanitation greatly. Research has done to reuse human waste. In space, astronauts recycle their urine, because of the limited supplies on the International Space Station.

Nature-based solutions

From Wikipedia, the free encyclopedia

 

Multiple rows of trees and shrubs, as well as a native grass strip, combine in a riparian buffer to protect Bear Creek in Story County, Iowa, United States.

 

Nature-based solutions (NBS) refers to the sustainable management and use of nature for tackling socio-environmental challenges. The challenges include issues such as climate change, water security, water pollution, food security, human health, and disaster risk management. 

A definition by the European Union states that these solutions are "inspired and supported by nature, which are cost-effective, simultaneously provide environmental, social and economic benefits and help build resilience. The Nature-based Solutions Initiative meanwhile defines them as "actions that work with and enhance nature so as to help people adapt to change and disasters". Such solutions bring more, and more diverse, nature and natural features and processes into cities, landscapes and seascapes, through locally adapted, resource-efficient and systemic interventions". With NBS, healthy, resilient and diverse ecosystems (whether natural, managed or newly created) can provide solutions for the benefit of societies and overall biodiversity. 

For instance, the restoration or protection of mangroves along coastlines utilizes a nature-based solution to accomplish several things. Mangroves moderate the impact of waves and wind on coastal settlements or cities and sequester CO_2. . They also provide safe nurseries for marine life that can be the basis for sustaining populations of fish that local populations may depend on. Additionally, the mangrove forests can help control coastal erosion resulting from sea level rise. Similarly, in cities green roofs or walls are nature-based solutions that can be used to moderate the impact of high temperatures, capture storm water, abate pollution, and act as carbon sinks, while enhancing biodiversity. 

Conservation approaches and environment management initiatives have been carried out for decades. What is new is that the benefits of such nature-based solutions to human well-being have been articulated well more recently. Even if the term itself is still being framed, examples of nature-based solutions can be found all over the world, and imitated. Nature-based solutions are on their way to being mainstreamed in national and international policies and programmes (e.g. climate change policy, law, infrastructure investment and financing mechanisms). For example, the theme for World Water Day 2018 was "Nature for water" and by UN-Water's accompanying UN World Water Development Report had the title "Nature-based Solutions for Water".

Background

Chicago City Hall green roof

 

Construction sample of a green roof system

 

Mangroves protect coastlines against erosion (Cape Coral, Florida, United States)

 

Coastal habitat protection at Morro Strand State Beach in San Luis Obispo County, California

 

Constructed wetland for wastewater treatment at an ecological housing estate in Flintenbreite, Germany

 

Societies increasingly face challenges such as climate change, urbanization, jeopardized food security and water resource provision, and disaster risk. One approach to answer these challenges is to singularly rely on technological strategies. An alternative approach is to manage the (socio-)ecological systems in a comprehensive way in order to sustain and potentially increase the delivery of ecosystem services to humans. In this context, nature-based solutions (NBS) have recently been put forward by practitioners and quickly thereafter by policymakers. These solutions stress the sustainable use of nature in solving coupled environmental-social-economic challenges.

While ecosystem services are often valued in terms of immediate benefits to human well-being and economy, NBS focus on the benefits to people and the environment itself, to allow for sustainable solutions that are able to respond to environmental change and hazards in the long-term. NBS go beyond the traditional biodiversity conservation and management principles by "re-focusing" the debate on humans and specifically integrating societal factors such as human well-being and poverty reduction, socio-economic development, and governance principles.

With respect to water issues, NBS can achieve the following, according to the World Water Development Report 2018 by UN-Water:

• Use natural processes to enhance water availability (e.g., soil moisture retention, groundwater recharge),
• Improve water quality (e.g., natural wetlands and constructed wetlands to treat wastewater, riparian buffer strips), and
• Reduce risks associated with water‐related disasters and climate change (e.g., floodplain restoration, green roofs).

Related concepts

In 2015, the European network BiodivERsA highlighted how NBS relate to concepts like ecosystem approaches and ecological engineering. NBS are strongly connected to ideas such as natural systems agriculture, natural solutions, ecosystem-based approaches, adaptation services, natural infrastructure, green infrastructure and ecological engineering. For instance, ecosystem-based approaches are increasingly promoted for climate change adaptation and mitigation by organisations like United Nations Environment Programme and non-governmental organisations such as The Nature Conservancy. These organisations refer to "policies and measures that take into account the role of ecosystem services in reducing the vulnerability of society to climate change, in a multi-sectoral and multi-scale approach".

Likewise, natural infrastructure is defined as a "strategically planned and managed network of natural lands, such as forests and wetlands, working landscapes, and other open spaces that conserves or enhances ecosystem values and functions and provides associated benefits to human populations"; and green infrastructure refers to an "interconnected network of green spaces that conserves natural systems and provides assorted benefits to human populations".

Similarly, the concept of ecological engineering generally refers to "protecting, restoring (i.e. ecosystem restoration) or modifying ecological systems to increase the quantity, quality and sustainability of particular services they provide, or to build new ecological systems that provide services that would otherwise be provided through more conventional engineering, based on non-renewable resources".

Definitions

The International Union for the Conservation of Nature (IUCN) defines NBS as actions to protect, sustainably manage, and restore natural or modified ecosystems, that address societal challenges effectively and adaptively, simultaneously providing human well-being and biodiversity benefits,^[15] with climate change, food security, disaster risks, water security, social and economic development as well as human health being the common societal challenges.

Categories

IUCN proposes to consider NBS as an umbrella concept. Categories and examples of NBS approaches according to IUCN include:

Category of NBS approaches	Examples
Ecosystem restoration approaches	Ecological restoration; Ecological engineering; Forest landscape restoration
Issue-specific ecosystem-related approaches	Ecosystem-based adaptation; Ecosystem-based mitigation; Climate adaptation services; Ecosystem-based disaster risk reduction
Infrastructure-related approaches	Natural infrastructure; Green infrastructure
Ecosystem-based management approaches	Integrated coastal zone management; Integrated water resources management
Ecosystem protection approaches	Area-based conservation approaches including protected area management

Objectives and framing

The general objective of NBS is clear, namely the sustainable management and use of nature for tackling societal challenges. However, different stakeholders view NBS from other perspectives. For instance, IUCN defines NBS as "actions to protect, sustainably manage and restore natural or modified ecosystems, which address societal challenges effectively and adaptively, while simultaneously providing human well-being and biodiversity benefits". This framing puts the need for well-managed and restored ecosystems at the heart of NBS, with the overarching goal of "Supporting the achievement of society's development goals and safeguard human well-being in ways that reflect cultural and societal values and enhance the resilience of ecosystems, their capacity for renewal and the provision of services". 

In the context of the ongoing political debate on jobs and growth (main drivers of the current EU policy agenda), the European Commission underlines that NBS can transform environmental and societal challenges into innovation opportunities, by turning natural capital into a source for green growth and sustainable development. In their view, NBS to societal challenges are "solutions that are inspired and supported by nature, which are cost-effective, simultaneously provide environmental, social and economic benefits and help build resilience. Such solutions bring more, and more diverse, nature and natural features and processes into cities, landscapes and seascapes, through locally adapted, resource-efficient and systemic interventions."

This framing is somewhat broader, and puts economy and social assets at the heart of NBS as importantly as sustaining environmental conditions. It shares similarities with the definition proposed by Maes and Jacobs (2015) defining NBS as "any transition to a use of ES with decreased input of non-renewable natural capital and increased investment in renewable natural processes". In their view, development and evaluation of NBS spans three basic requirements: (1) decrease of fossil fuel input per produced unit; (2) lowering of systemic trade-offs and increasing synergies between ES; and (3) increasing labor input and jobs. Here, nature is seen as a tool to inspire more systemic solutions to societal problems. 

Whatever definition used, promoting sustainability and the increased role of natural, self-sustained processes relying on biodiversity, are inherent to NBS. They constitute actions easily seen as positive for a wide range of stakeholders, as they bring about benefits at environmental, economic and social levels. As a consequence, the concept of NBS is gaining acceptance outside the conservation community (e.g. urban planning) and is now on its way to be mainstreamed into policies and programmes (climate change policy, law, infrastructure investment and financing mechanisms).

Types

Schematic presentation of the NBS typology.

 

In 2014-2015, the European network BiodivERsA mobilized a range of scientists, research donors and stakeholders and proposed a typology characterizing NBS along two gradients. 1. "how much engineering of biodiversity and ecosystems is involved in NBS", and 2. "how many ecosystem services and stakeholder groups are targeted by a given NBS". The typology highlights that NBS can involve very different actions on ecosystems (from protection to management and even creation of new ecosystems) and is based on the assumption that the higher the number of services and stakeholder groups targeted, the lower the capacity to maximize the delivery of each service and simultaneously fulfil the specific needs of all stakeholder groups. As such, three types of NBS are distinguished (Figure 2):

Type 1 – Minimal intervention in ecosystems

Type 1 NBS consists of no or minimal intervention in ecosystems, with the objectives of maintaining or improving the delivery of a range of ES both inside and outside of these conserved ecosystems. Examples include the protection of mangroves in coastal areas to limit risks associated to extreme weather conditions and provide benefits and opportunities to local populations; and the establishment of marine protected areas to conserve biodiversity within these areas while exporting biomass into fishing grounds. This type of NBS is connected to, for example, the concept of biosphere reserves which incorporates core protected areas for nature conservation and buffer zones and transition areas where people live and work in a sustainable way.

Type 2 – Some interventions in ecosystems and landscapes

Type 2 NBS corresponds to management approaches that develop sustainable and multifunctional ecosystems and landscapes (extensively or intensively managed). These types improve the delivery of selected ES compared to what would be obtained with a more conventional intervention. Examples include innovative planning of agricultural landscapes to increase their multi-functionality; and approaches for enhancing tree species and genetic diversity to increase forest resilience to extreme events. This type of NBS is strongly connected to concepts like natural systems agriculture, agro-ecology, and evolutionary-orientated forestry.

Type 3 – Managing ecosystems in extensive ways

Type 3 NBS consists of managing ecosystems in very extensive ways or even creating new ecosystems (e.g., artificial ecosystems with new assemblages of organisms for green roofs and walls to mitigate city warming and clean polluted air). Type 3 is linked to concepts like green and blue infrastructures and objectives like restoration of heavily degraded or polluted areas and greening cities. 

Type 1 and 2 would typically fall within the IUCN NBS framework, whereas Type 2 and moreover Type 3 are often exemplified by EC for turning natural capital into a source for green growth and sustainable development.

Hybrid solutions

Hybrid solutions exist along this gradient both in space and time. For instance, at landscape scale, mixing protected and managed areas could be needed to fulfil multi-functionality and sustainability goals. Similarly, a constructed wetland can be developed as a type 3 but, when well established, may subsequently be preserved and surveyed as a type 1.

Examples

Demonstrating the benefits of nature and healthy ecosystems and showcasing the return on investment they can offer is necessary in order to increase awareness, but also to provide support and guidance on how to implement NBS. A large number of initiatives around the world already highlight the effectiveness of NBS approaches to address a wide range of societal challenges.

India

East Kolkata wetlands

In 2018, The Hindu reported that the East Kolkata wetlands, the world's largest organic sewage treatment facility had been used to clean the sewage of Kolkata in an organic manner by using algae for several decades. In use since the 1930s, the natural system was discovered by Dhrubajyoti Ghosh, an ecologist and a municipal engineer in the 1970s while working in the region. Ghosh worked for decades to protect the wetlands. It had been a practice in Kolkata, one of the five largest cities in India, for the municipal authorities to pump sewage into shallow ponds (bheris). Under the heat of the tropical sun, algae proliferated in them, converting the sewage into clean water, which in turn was used by villagers to grow paddy and vegetables. This system has been in use in the region since the 1930s and treats 750 million litres of wastewater per day, giving livelihood to 100,000 people in the vicinity. For his work, Ghosh was included in the UN Global 500 Roll of Honour in 1990 and received the Luc Hoffmann award in 2016.

Practical implementation

There is currently no accepted basis on which a government agency, municipality or private company can systematically assess the efficiency, effectiveness and sustainability of a particular nature-based solution. However, a series of principles are proposed to guide effective and appropriate implementation, and thus to upscale NBS in practice. For example, NBS embrace and are not meant to replace nature conservation norms. Also, NBS are determined by site-specific natural and cultural contexts that include traditional, local and scientific knowledge. NBS are an integral part of the overall design of policies, and measure or actions, to address a specific challenges. Finally, NBS can be implemented alone or in an integrated manner with other solutions to societal challenges (e.g. technological and engineering solutions) and they are applied at the landscape scale. 

Implementing NBS requires political, economic, and scientific challenges to be tackled. First and foremost, private sector investment is needed, not to replace but to supplement traditional sources of capital such as public funding or philanthropy. The challenge is therefore to provide a robust evidence base for the contribution of nature to economic growth and jobs, and to demonstrate the economic viability of these solutions – compared to technological ones – on a timescale compatible with that of global change. Furthermore, it requires measures like adaptation of economic subsidy schemes, and the creation of opportunities for conservation finance, to name a few. Indeed, such measures will be needed to scale up NBS interventions, and strengthen their impact in mitigating the world's most pressing challenges.

Projects supported by the European Union

Since 2016, the EU is supporting a multi-stakeholder dialogue platform (called ThinkNature) to promote the co-design, testing and deployment of improved and innovative NBS in an integrated way. Creation of such science-policy-business-society interfaces could promote the market uptake of NBS. The project is part of the EU’s Horizon 2020 – Research and Innovation programme, and will last for 3 years. There are a total of 17 international partners involved, including the Technical University of Crete (Project Leader), the University of Helsinki and BiodivERsA. 

In 2017, as part of the Presidency of the Estonian Republic of the Council of the European Union, a conference called “Nature-based Solutions: From Innovation to Common-use” was organized by the Ministry of the Environment of Estonia and the University of Tallinn. This conference aimed to strengthen synergies among various recent initiatives and programs related to NBS launched by the European Commission and by the EU Member States, focusing on policy and governance of NBS, and on research and innovation.

Nature-based Solutions in the Paris Agreement

In recognition of the importance of natural ecosystems for mitigation and adaptation, the Paris Agreement calls on all Parties to acknowledge “the importance of the conservation and enhancement, as appropriate, of sinks and reservoirs of the greenhouse gases” and to “note the importance of ensuring the integrity of all ecosystems, including oceans, and the protection of biodiversity, recognized by some cultures as Mother Earth”. It then includes in its Articles several references to nature-based solutions. For example, Article 5.2 encourages Parties to adopt “…policy approaches and positive incentives for activities relating to reducing emissions from deforestation and forest degradation, and the role of conservation and sustainable management of forests and enhancement of forest carbon stocks in developing countries; and alternative policy approaches, such as joint mitigation and adaptation approaches for the integral and sustainable management of forests, while reaffirming the importance of incentivizing, as appropriate, non-carbon benefits associated with such approaches”. Article 7.1 further encourages Parties to build the resilience of socioeconomic and ecological systems, including through economic diversification and sustainable management of natural resources. In total, the Agreement refers to nature (ecosystems, natural resources, forests) in 13 distinct places. An in-depth analysis of all Nationally Determined Contributions submitted to UNFCCC, revealed that around 130 NDCs or 65% of signatories commit to nature-based solutions in their climate pledges, suggesting broad consensus for the role of nature in helping meet climate change goals. However, high-level commitments rarely translate into robust, measurable actions on-the-ground.

History

The term NBS was put forward by practitioners in the late 2000s (in particular the International Union for the Conservation of Nature and the World Bank) and thereafter by policymakers in Europe (most notably the European Commission).

The term "nature-based solutions" was first used in the late 2000s. It was used in the context of finding new solutions to mitigate and adapt to climate change effects, whilst simultaneously protecting biodiversity and improving sustainable livelihoods. 

The IUCN referred to NBS in a position paper for the United Nations Framework Convention on Climate Change. The term was also adopted by European policymakers, in particular by the European Commission in a report stressing that NBS can offer innovative means to create jobs and growth as part of a green economy. The term started to make appearances in the mainstream media around the time of the Global Climate Action Summit in California in September 2018 

Nutrient cycle

From Wikipedia, the free encyclopedia

Composting within agricultural systems capitalizes upon the natural services of nutrient recycling in ecosystems. Bacteria, fungi, insects, earthworms, bugs, and other creatures dig and digest the compost into fertile soil. The minerals and nutrients in the soil is recycled back into the production of crops.

 

A nutrient cycle (or ecological recycling) is the movement and exchange of organic and inorganic matter back into the production of matter. Energy flow is a unidirectional and noncyclic pathway, whereas the movement of mineral nutrients is cyclic. Mineral cycles include the carbon cycle, sulfur cycle, nitrogen cycle, water cycle, phosphorus cycle, oxygen cycle, among others that continually recycle along with other mineral nutrients into productive ecological nutrition.

Outline

Fallen logs are critical components of the nutrient cycle in terrestrial forests. Nurse logs form habitats for other creatures that decompose the materials and recycle the nutrients back into production.

 

The nutrient cycle is nature's recycling system. All forms of recycling have feedback loops that use energy in the process of putting material resources back into use. Recycling in ecology is regulated to a large extent during the process of decomposition. Ecosystems employ biodiversity in the food webs that recycle natural materials, such as mineral nutrients, which includes water. Recycling in natural systems is one of the many ecosystem services that sustain and contribute to the well-being of human societies.

A nutrient cycle of a typical terrestrial ecosystem.

 

There is much overlap between the terms for the biogeochemical cycle and nutrient cycle. Most textbooks integrate the two and seem to treat them as synonymous terms. However, the terms often appear independently. Nutrient cycle is more often used in direct reference to the idea of an intra-system cycle, where an ecosystem functions as a unit. From a practical point, it does not make sense to assess a terrestrial ecosystem by considering the full column of air above it as well as the great depths of Earth below it. While an ecosystem often has no clear boundary, as a working model it is practical to consider the functional community where the bulk of matter and energy transfer occurs. Nutrient cycling occurs in ecosystems that participate in the "larger biogeochemical cycles of the earth through a system of inputs and outputs."

Complete and closed loop

All systems recycle. The biosphere is a network of continually recycling materials and information in alternating cycles of convergence and divergence. As materials converge or become more concentrated they gain in quality, increasing their potentials to drive useful work in proportion to their concentrations relative to the environment. As their potentials are used, materials diverge, or become more dispersed in the landscape, only to be concentrated again at another time and place.

Ecosystems are capable of complete recycling. Complete recycling means that 100% of the waste material can be reconstituted indefinitely. This idea was captured by Howard T. Odum when he penned that "it is thoroughly demonstrated by ecological systems and geological systems that all the chemical elements and many organic substances can be accumulated by living systems from background crustal or oceanic concentrations without limit as to concentration so long as there is available solar or another source of potential energy" In 1979 Nicholas Georgescu-Roegen proposed the fourth law of entropy stating that complete recycling is impossible. Despite Georgescu-Roegen's extensive intellectual contributions to the science of ecological economics, the fourth law has been rejected in line with observations of ecological recycling. However, some authors state that complete recycling is impossible for technological waste.

A simplified food web illustrating a three-trophic food chain (producers-herbivores-carnivores) linked to decomposers. The movement of mineral nutrients through the food chain, into the mineral nutrient pool, and back into the trophic system illustrates ecological recycling. The movement of energy, in contrast, is unidirectional and noncyclic.

 

Ecosystems execute closed loop recycling where demand for the nutrients that adds to the growth of biomass exceeds supply within that system. There are regional and spatial differences in the rates of growth and exchange of materials, where some ecosystems may be in nutrient debt (sinks) where others will have extra supply (sources). These differences relate to climate, topography, and geological history leaving behind different sources of parent material. In terms of a food web, a cycle or loop is defined as "a directed sequence of one or more links starting from, and ending at, the same species." An example of this is the microbial food web in the ocean, where "bacteria are exploited, and controlled, by protozoa, including heterotrophic microflagellates which are in turn exploited by ciliates. This grazing activity is accompanied by excretion of substances which are in turn used by the bacteria so that the system more or less operates in a closed circuit."

Ecological recycling

A large fraction of the elements composing living matter reside at any instant of time in the world’s biota. Because the earthly pool of these elements is limited and the rates of exchange among the various components of the biota are extremely fast with respect to geological time, it is quite evident that much of the same material is being incorporated again and again into different biological forms. This observation gives rise to the notion that, on the average, matter (and some amounts of energy) are involved in cycles.

An example of ecological recycling occurs in the enzymatic digestion of cellulose. "Cellulose, one of the most abundant organic compounds on Earth, is the major polysaccharide in plants where it is part of the cell walls. Cellulose-degrading enzymes participate in the natural, ecological recycling of plant material." Different ecosystems can vary in their recycling rates of litter, which creates a complex feedback on factors such as the competitive dominance of certain plant species. Different rates and patterns of ecological recycling leaves a legacy of environmental effects with implications for the future evolution of ecosystems.

Ecological recycling is common in organic farming, where nutrient management is fundamentally different compared to agri-business styles of soil management. Organic farms that employ ecosystem recycling to a greater extent support more species (increased levels of biodiversity) and have a different food web structure. Organic agricultural ecosystems rely on the services of biodiversity for the recycling of nutrients through soils instead of relying on the supplementation of synthetic fertilizers. The model for ecological recycling agriculture adheres to the following principals:

• Protection of biodiversity.
• Use of renewable energy.
• Recycling of plant nutrients.

Where produce from an organic farm leaves the farm gate for the market the system becomes an open cycle and nutrients may need to be replaced through alternative methods.

Ecosystem engineers

An illustration of an earthworm casting taken from Charles Darwin's publication on the movement of organic matter in soils through the ecological activities of worms.

 

From the largest to the smallest of creatures, nutrients are recycled by their movement, by their wastes, and by their metabolic activities. This illustration shows an example of the whale pump that cycles nutrients through the layers of the oceanic water column. Whales can migrate to great depths to feed on bottom fish (such as sand lance Ammodytes spp.) and surface to feed on krill and plankton at shallower levels. The whale pump enhances growth and productivity in other parts of the ecosystem.

 

The persistent legacy of environmental feedback that is left behind by or as an extension of the ecological actions of organisms is known as niche construction or ecosystem engineering. Many species leave an effect even after their death, such as coral skeletons or the extensive habitat modifications to a wetland by a beaver, whose components are recycled and re-used by descendants and other species living under a different selective regime through the feedback and agency of these legacy effects. Ecosystem engineers can influence nutrient cycling efficiency rates through their actions. 

Earthworms, for example, passively and mechanically alter the nature of soil environments. Bodies of dead worms passively contribute mineral nutrients to the soil. The worms also mechanically modify the physical structure of the soil as they crawl about (bioturbation), digest on the molds of organic matter they pull from the soil litter. These activities transport nutrients into the mineral layers of soil. Worms discard wastes that create worm castings containing undigested materials where bacteria and other decomposers gain access to the nutrients. The earthworm is employed in this process and the production of the ecosystem depends on their capability to create feedback loops in the recycling process.

Shellfish are also ecosystem engineers because they: 1) Filter suspended particles from the water column; 2) Remove excess nutrients from coastal bays through denitrification; 3) Serve as natural coastal buffers, absorbing wave energy and reducing erosion from boat wakes, sea level rise and storms; 4) Provide nursery habitat for fish that are valuable to coastal economies.

Fungi contribute to nutrient cycling and nutritionally rearrange patches of ecosystem creating niches for other organisms. In that way fungi in growing dead wood allow xylophages to grow and develop and xylophages, in turn, affect dead wood, contributing to wood decomposition and nutrient cycling in the forest floor.

History

Nutrient cycling has a historical foothold in the writings of Charles Darwin in reference to the decomposition actions of earthworms. Darwin wrote about "the continued Following the Greeks, the idea of a hydrological cycle (water is considered a nutrient) was validated and quantified by Halley in 1687.

Variations in terminology

In 1926 Vernadsky coined the term biogeochemistry as a sub-discipline of geochemistry. However, the term nutrient cycle pre-dates biogeochemistry in a pamphlet on silviculture in 1899: "These demands by no means pass over the fact that at places where sufficient quantities of humus are available and where, in case of continuous decomposition of litter, a stable, nutrient humus is present, considerable quantities of nutrients are also available from the biogenic nutrient cycle for the standing timber. In 1898 there is a reference to the nitrogen cycle in relation to nitrogen fixing microorganisms. Other uses and variations on the terminology relating to the process of nutrient cycling appear throughout history:

• The term mineral cycle appears early in a 1935 in reference to the importance of minerals in plant physiology: "...ash is probably either built up into its permanent structure, or deposited in some way as waste in the cells, and so may not be free to re-enter the mineral cycle."
• The term nutrient recycling appears in a 1964 paper on the food ecology of the wood stork: "While the periodic drying up and reflooding of the marshes creates special survival problems for organisms in the community, the fluctuating water levels favor rapid nutrient recycling and subsequent high rates of primary and secondary production"
• The term natural cycling appears in a 1968 paper on the transportation of leaf litter and its chemical elements for consideration in fisheries management: "Fluvial transport of tree litter from drainage basins is a factor in natural cycling of chemical elements and in degradation of the land."
• The term ecological recycling appears in a 1968 publication on future applications of ecology for the creation of different modules designed for living in extreme environments, such as space or under sea: "For our basic requirement of recycling vital resources, the oceans provide much more frequent ecological recycling than the land area. Fish and other organic populations have higher growth rates, vegetation has less capricious weather problems for sea harvesting."
• The term bio-recycling appears in a 1976 paper on the recycling of organic carbon in oceans: "Following the actualistic assumption, then, that biological activity is responsible for the source of dissolved organic material in the oceans, but is not important for its activities after death of the organisms and subsequent chemical changes which prevent its bio-recycling, we can see no major difference in the behavior of dissolved organic matter between the prebiotic and post-biotic oceans."

Water is also a nutrient. In this context, some authors also refer to precipitation recycling, which "is the contribution of evaporation within a region to precipitation in that same region." These variations on the theme of nutrient cycling continue to be used and all refer to processes that are part of the global biogeochemical cycles. However, authors tend to refer to natural, organic, ecological, or bio-recycling in reference to the work of nature, such as it is used in organic farming or ecological agricultural systems.

Recycling in novel ecosystems

An endless stream of technological waste accumulates in different spatial configurations across the planet and turns into a predator in our soils, our streams, and our oceans. This idea was similarly expressed in 1954 by ecologist Paul Sears: "We do not know whether to cherish the forest as a source of essential raw materials and other benefits or to remove it for the space it occupies. We expect a river to serve as both vein and artery carrying away waste but bringing usable material in the same channel. Nature long ago discarded the nonsense of carrying poisonous wastes and nutrients in the same vessels." Ecologists use population ecology to model contaminants as competitors or predators. Rachel Carson was an ecological pioneer in this area as her book Silent Spring inspired research into biomagification and brought to the worlds attention the unseen pollutants moving into the food chains of the planet.

In contrast to the planets natural ecosystems, technology (or technoecosystems) is not reducing its impact on planetary resources. Only 7% of total plastic waste (adding up to millions upon millions of tons) is being recycled by industrial systems; the 93% that never makes it into the industrial recycling stream is presumably absorbed by natural recycling systems In contrast and over extensive lengths of time (billions of years) ecosystems have maintained a consistent balance with production roughly equaling respiratory consumption rates. The balanced recycling efficiency of nature means that production of decaying waste material has exceeded rates of recyclable consumption into food chains equal to the global stocks of fossilized fuels that escaped the chain of decomposition.

Pesticides soon spread through everything in the ecosphere-both human technosphere and nonhuman biosphere-returning from the 'out there' of natural environments back into plant, animal, and human bodies situated at the 'in here' of artificial environments with unintended, unanticipated, and unwanted effects. By using zoological, toxicological, epidemiological, and ecological insights, Carson generated a new sense of how 'the environment' might be seen.

Microplastics and nanosilver materials flowing and cycling through ecosystems from pollution and discarded technology are among a growing list of emerging ecological concerns. For example, unique assemblages of marine microbes have been found to digest plastic accumulating in the worlds oceans. Discarded technology is absorbed into soils and creates a new class of soils called technosols. Human wastes in the Anthropocene are creating new systems of ecological recycling, novel ecosystems that have to contend with the mercury cycle and other synthetic materials that are streaming into the biodegradation chain. Microorganisms have a significant role in the removal of synthetic organic compounds from the environment empowered by recycling mechanisms that have complex biodegradation pathways. The effect of synthetic materials, such as nanoparticles and microplastics, on ecological recycling systems is listed as one of the major concerns for ecosystem in this century.

Technological recycling

Recycling in human industrial systems (or technoecosystems) differs from ecological recycling in scale, complexity, and organization. Industrial recycling systems do not focus on the employment of ecological food webs to recycle waste back into different kinds of marketable goods, but primarily employ people and technodiversity instead. Some researchers have questioned the premise behind these and other kinds of technological solutions under the banner of 'eco-efficiency' are limited in their capability, harmful to ecological processes, and dangerous in their hyped capabilities. Many technoecosystems are competitive and parasitic toward natural ecosystems. Food web or biologically based "recycling includes metabolic recycling (nutrient recovery, storage, etc.) and ecosystem recycling (leaching and in situ organic matter mineralization, either in the water column, in the sediment surface, or within the sediment."