Wastewater: Difference between revisions
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In less-developed or rural regions, sewage may drain directly into major [[drainage basin|watersheds]] with minimal or no treatment. This usually has serious impacts on the quality of an environment and on human health. [[Pathogen]]s can cause a variety of illnesses. Some chemicals pose risks even at very low concentrations and can remain a threat for long periods of time because of [[bioaccumulation]] in animal or human tissue. |
In less-developed or rural regions, sewage may drain directly into major [[drainage basin|watersheds]] with minimal or no treatment. This usually has serious impacts on the quality of an environment and on human health. [[Pathogen]]s can cause a variety of illnesses. Some chemicals pose risks even at very low concentrations and can remain a threat for long periods of time because of [[bioaccumulation]] in animal or human tissue. |
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=== Treatment === |
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=== Reuse === |
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{{Excerpt|Reclaimed water|paragraphs=1-3|file=no}} |
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=== Disposal === |
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== Legislation == |
== Legislation == |
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Revision as of 06:48, 17 June 2021
 | It has been suggested that this article be merged into wastewater treatment. (Discuss) Proposed since June 2021. |
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Wastewater is any water that has been contaminated by human use. Wastewater is "used water from any combination of domestic, industrial, commercial or agricultural activities, surface runoff or stormwater, and any sewer inflow or sewer infiltration".[1] Types of wastewater include: domestic wastewater from households, municipal wastewater from communities (also called sewage) and industrial wastewater. Wastewater can contain physical, chemical and biological pollutants. Its characteristics vary depending on the source.
Management of wastewater includes its collection, treatment, reuse or disposal. Wastewater that is produced by activities within a municipality is usually collected and transported in a sanitary sewer or in a combined sewer that conveys stormwater runoff, sewage and pre-treated industrial wastewater. After treatment at a wastewater treatment plant, treated wastewater (also called effluent) is discharged to a receiving water body. The terms "wastewater reuse" and "water reclamation" apply if the treated wastewater is used for another purpose. Wastewater that is discharged to the environment without suitable treatment can cause water pollution.
Sources
Sources of wastewater include households, municipalities, industries, urban runoff and agriculture.
When the source is from households, the wastewater is called sewage. It can come from the following domestic or household activities:
- Human excreta (feces, urine, blood and other bodily fluids) often mixed with used toilet paper or wet wipes; this is known as blackwater if it is collected from flush toilets
- Washing water (personal hygiene, clothes, floors, dishes, cars, etc.), also known as greywater or sullage
- Surplus manufactured liquids from domestic sources (drinks, cooking oil, pesticides, lubricating oil, paint, cleaning detergents, etc.)
Activities producing industrial wastewater include:
- Industrial site drainage (silt, sand, alkali, oil, chemical residues);
- Industrial cooling waters (biocides, heat, slimes, silt)
- Industrial processing waters
- Organic or biodegradable waste including waste from hospitals, abattoirs, creameries, and food factories.
- Organic or non bio-degradable waste that is difficult-to-treat from pharmaceutical[2] or pesticide manufacturing
- Extreme pH waste from acid and alkali manufacturing
- Toxic waste from metal plating, cyanide production, pesticide manufacturing, etc.
- Solids and emulsions from paper mills, factories producing lubricants or hydraulic oils, foodstuffs, etc.
- Water used in hydraulic fracturing
- Produced water from oil & natural gas production
Other related activities or events:
- Urban runoff from highways, roads, railway tracks, car parks, roofs, pavements (contains oils, animal feces/manure, food waste, litter, petrol, diesel or rubber residues from tyres, soapscum, metals from vehicle exhausts, de-icing agents, herbicides and pesticides from gardens, etc.)
- Agricultural pollution, direct and diffuse
Dilution and mixing
Wastewater can be diluted or mixed with other types of water through the following mechanisms:
- Seawater ingress (high volumes of salt and microbes)
- Direct ingress of river water
- Rainfall collected on roofs, yards, hard-standings, etc. (generally clean with traces of oils and fuel)
- Groundwater infiltrated into sewage
- Mixing with other types of wastewater or fecal sludge
Pollutants
The composition of wastewater varies widely. This is a partial list of pollutants that may be contained in wastewater:
Chemical or physical pollutants
- Heavy metals, including mercury, lead, and chromium
- Organic particles such as feces, hairs, food waste, vomit, paper fibers, plant material, humus, etc.;
- Soluble organic material such as urea, fruit sugars, soluble proteins, drugs, pharmaceuticals, etc.;
- Inorganic particles such as sand, grit, metal particles, rubber residues from tires, ceramics, etc.;
- Soluble inorganic material such as ammonia, road-salt, sea-salt, cyanide, hydrogen sulfide, thiocyanates, thiosulfates, etc.;
- Macro-solids such as sanitary napkins, nappies/diapers, condoms, needles, children's toys, dead animals or plants, etc.;
- Gases such as hydrogen sulfide, carbon dioxide, methane, etc.;
- Emulsions such as paints, adhesives, mayonnaise, hair colorants, emulsified oils, etc.;
- Toxins such as pesticides, poisons, herbicides, etc.
- Pharmaceuticals, endocrine disrupting compounds, hormones, perfluorinated compounds, siloxanes, drugs of abuse and other hazardous substances [3][4][5]
- Microplastics such as polyethylene and polypropylene beads, polyester and polyamide [6]
- Thermal pollution from power stations and industrial manufacturers
Biological pollutants
If the wastewater contains human feces, as is the case for sewage, then it may also contain pathogens of one of the four types:[7][8]
- Bacteria (for example Salmonella, Shigella, Campylobacter, Vibrio cholerae),
- Viruses (for example hepatitis A, rotavirus, enteroviruses, coronaviruses),
- Protozoa (for example Entamoeba histolytica, Giardia lamblia, Cryptosporidium parvum) and
- Parasites such as helminths and their eggs (e.g. Ascaris (roundworm), Ancylostoma (hookworm) and Trichuris (whipworm));
It can also contain non-pathogenic bacteria and animals such as insects, arthropods and small fish.
Quality indicators
Wastewater quality indicators are laboratory test methodologies to assess suitability of wastewater for disposal, treatment or reuse. The main parameters in sewage that are measured to assess the sewage strength or quality as well as treatment options include: solids, indicators of organic matter, nitrogen, phosphorus, indicators of fecal contamination.[9]: 33 Tests selected vary with the intended use or discharge location. Tests can measure physical, chemical, and biological characteristics of the wastewater. Physical characteristics include temperature and solids. Chemical characteristics include pH value, dissolved oxygen concentrations, biochemical oxygen demand (BOD) and chemical oxygen demand (COD), nitrogen, phosphorus, chlorine. Biological characteristics are determined with bioassays and aquatic toxicology tests.
Both the BOD and COD tests are a measure of the relative oxygen-depletion effect of a waste contaminant. Both have been widely adopted as a measure of pollution effect. Any oxidizable material present in an aerobic natural waterway or in an industrial wastewater will be oxidized both by biochemical (bacterial) or chemical processes. The result is that the oxygen content of the water will be decreased.Management
Management of wastewater includes its collection, treatment, reuse or disposal. It is part of the broad term sanitation which includes not only the management of wastewater but also the management of human excreta, solid waste and stormwater.
Collection
Wastewater from factories, power plants and other industrial activities is extensively regulated in developed nations, and treatment is required before discharge to surface waters. (See Industrial wastewater treatment.)
In many cities, municipal wastewater is carried together with stormwater, in a combined sewer system, to a sewage treatment plant. In some urban areas, municipal wastewater is carried separately in sanitary sewers and runoff from streets is carried in storm drains. Access to these systems, for maintenance purposes, is typically through a manhole.
During high precipitation periods a combined sewer system may experience a combined sewer overflow event, which forces untreated sewage to flow directly to receiving waters. This can pose a serious threat to public health and the surrounding environment.
In less-developed or rural regions, sewage may drain directly into major watersheds with minimal or no treatment. This usually has serious impacts on the quality of an environment and on human health. Pathogens can cause a variety of illnesses. Some chemicals pose risks even at very low concentrations and can remain a threat for long periods of time because of bioaccumulation in animal or human tissue.
Legislation
See also
- Fecal sludge management
- List of waste-water treatment technologies
- Reuse of excreta
- Water management
References
- ^ Tilley, E., Ulrich, L., Lüthi, C., Reymond, Ph., Zurbrügg, C. (2014). Compendium of Sanitation Systems and Technologies – (2nd Revised ed.). Swiss Federal Institute of Aquatic Science and Technology (Eawag), Duebendorf, Switzerland. p. 175. ISBN 978-3-906484-57-0. Archived from the original on 8 April 2016.
{{cite book}}: CS1 maint: multiple names: authors list (link) - ^ Naddeo, V.; Meriç, S.; Kassinos, D.; Belgiorno, V.; Guida, M. (September 2009). "Fate of pharmaceuticals in contaminated urban wastewater effluent under ultrasonic irradiation". Water Research. 43 (16): 4019–4027. doi:10.1016/j.watres.2009.05.027. PMID 19589554.
- ^ Arvaniti and Stasinakis, 2015. Review on the occurrence, fate and removal of perfluorinated compounds during wastewater treatment. Science of the Total Environment vol. 524-525, August 2015, p. 81-92. Arvaniti and Stasinakis, 2015
- ^ Bletsou et al., 2013. Mass loading and fate of linear and cyclic siloxanes in a wastewater treatment plant in Greece. Environmental Science and Technology vol. 47, January 2015, p. 1824-1832. Bletsou et al., 2013
- ^ Gatidou et al., 2016. Drugs of abuse and alcohol consumption among different groups of population on the Greek island of Lesvos through sewage-based epidemiology. Science of the Total Environment vol. 563-564, September 2016, p. 633-640. Gatidou et al., 2016
- ^ Gatidou et al. 2019. Review on the occurrence and fate of microplastics in Sewage Treatment Plants. Journal of Hazardous Materials, vol. 367, April 2019, p. 504-512. Gatidou et al., 2019
- ^ World Health Organization (2006). Guidelines for the safe use of wastewater, excreta, and greywater. World Health Organization. p. 31. ISBN 978-9241546850. OCLC 71253096.
- ^ Andersson, K., Rosemarin, A., Lamizana, B., Kvarnström, E., McConville, J., Seidu, R., Dickin, S. and Trimmer, C. (2016). Sanitation, Wastewater Management and Sustainability: from Waste Disposal to Resource Recovery Archived 1 June 2017 at the Wayback Machine. Nairobi and Stockholm: United Nations Environment Programme and Stockholm Environment Institute. ISBN 978-92-807-3488-1, p. 56
- ^ Von Sperling, M. (2007). "Wastewater Characteristics, Treatment and Disposal". Water Intelligence Online. 6: 9781780402086. doi:10.2166/9781780402086. ISSN 1476-1777. Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License
