Sewage sludge is the residual, semi-solid material, produced as a by-product during sewage treatment of industrial or municipal wastewater. The term "septage" refers to sludge from simple wastewater treatment but is connected to simple on-site sanitation systems, such as septic tanks; when fresh sewage or wastewater enters a primary settling tank 50% of the suspended solid matter will settle out in an hour and a half. This collection of solids is known as raw sludge or primary solids and is said to be "fresh" before anaerobic processes become active; the sludge will become putrescent in a short time once anaerobic bacteria take over, must be removed from the sedimentation tank before this happens. This is accomplished in one of two ways. In an Imhoff tank, fresh sludge is passed through a slot to the lower story or digestion chamber where it is decomposed by anaerobic bacteria, resulting in liquefaction and reduced volume of the sludge. After digesting for an extended period, the result is called "digested" sludge and may be disposed of by drying and landfilling.
More with domestic sewage, the fresh sludge is continuously extracted from the tank mechanically and passed to separate sludge digestion tanks that operate at higher temperatures than the lower story of the Imhoff tank and, as a result, digest much more and efficiently. "Biosolids" is a term used in conjunction with reuse of sewage solids after sewage sludge treatment. Biosolids can be defined as organic wastewater solids that can be reused after stabilization processes such as anaerobic digestion and composting. Opponents of sewage sludge reuse reject this term as a public relations term. Class A sludge is dried and pasteurized, is known as "exceptional" quality. Class B includes all sludge not classified as Class A. Class B sludge is "undigested" and is volatile. Both classes of sludge may still contain pharmaceutical wastes; the amount of sewage sludge produced is proportional to the amount and concentration of wastewater treated, it depends on the type of wastewater treatment process used.
It can be expressed as kg dry solids per cubic metre of wastewater treated. The total sludge production from a wastewater treatment process is the sum of sludge from primary settling tanks plus excess sludge from the biological treatment step. For example, primary sedimentation produces about 110–170 kg/ML of so-called primary sludge, with a value of 150 kg/ML regarded as being typical for municipal wastewater in the U. S. or Europe. The sludge production is expressed as kg of dry solids produced per ML of wastewater treated. Of the biological treatment processes, the activated sludge process produces about 70–100 kg/ML of waste activated sludge, a trickling filter process produces less sludge from the biological part of the process: 60–100 kg/ML; this means that the total sludge production of an activated sludge process that uses primary sedimentation tanks is in the range of 180–270 kg/ML, being the sum of primary sludge and waste activated sludge. United States municipal wastewater treatment plants in 1997 produced about 7.7 million dry tons of sewage sludge, about 6.8 million dry tons in 1998 according to EPA estimates.
As of 2004, about 60% of all sewage sludge was applied to land as a soil amendment and fertilizer for growing crops. Production of sewage sludge can be reduced by conversion from flush toilets to dry toilets such urine-diverting dry toilets and composting toilets. Bacteria in Class A sludge products can regrow under certain environmental conditions. Pathogens could remain undetected in untreated sewage sludge. Pathogens are not a significant health issue if sewage sludge is properly treated and site-specific management practices are followed. Micro-pollutants can become concentrated in sewage sludge; each of these disposal options comes with myriad potential — and in some cases proven — human health and environment impacts. Sterols and other hormones have been detected. One of the main concerns in the treated sludge is the concentrated metals content. Leaching methods can be used to meet the regulatory limit. In 2009 the EPA released the Targeted National Sewage Sludge Study, which reports on the level of metals, chemicals and other materials present in a statistical sample of sewage sludges.
Some highlights include: Silver is present to the degree of 20 mg/kg of sludge, on average, a near economically recoverable level, while some sludges of exceptionally high quality have up to 200 milligrams of silver per kilogram of sludge. Barium is present at the rate of 500 mg/kg. Lead, arsenic and cadmium are estimated by the EPA to be present in detectable quantities in 100% of national sewage sludges in the US, while thallium is only estimated to be present in 94.1% of sludges. Sewage treatment plants receive various forms of hazardous waste from hospitals, nursing homes and households. Low levels of constituents such as PCBs, brominated flame retardants, may remain in treated sludge. There are thousands other components of sludge that remain untested/undetected disposed of from modern society that end up in sludge which have been proven to be hazardous to both human and ecological health. In 2013 in South Carolina PCBs were discovered in high levels in wastewater sludge; the problem was not discovered until thou
John Derbyshire is a British-American computer programmer, writer and political commentator. He wrote a column in National Review before moving to a staff position at the white supremacist website VDARE, where he continues to work, he has written for the New English Review. His columns cover a broad range of political-cultural topics, including immigration, history and race. Derbyshire's 1996 novel Seeing Calvin Coolidge in a Dream was a New York Times "Notable Book of the Year", his 2004 non-fiction book Prime Obsession won the Mathematical Association of America's inaugural Euler Book Prize. A political book, We Are Doomed: Reclaiming Conservative Pessimism, was released in September 2009. Derbyshire has been described as a figure within the alt-right movement, considers himself to be part of it. Derbyshire attended the Northampton School for Boys and graduated from University College London, of the University of London, where he studied mathematics. Before turning to writing full-time, he worked on Wall Street as a computer programmer.
Derbyshire worked as a writer at National Review until he was terminated in 2012 because of an article published in Taki's Magazine in which Derbyshire wrote about the dangers posed by African-Americans to whites. Derbyshire worked at VDARE. Derbyshire's book Prime Obsession: Bernhard Riemann and the Greatest Unsolved Problem in Mathematics was first published in hardcover in 2003 and paperback in 2004, it focuses on one of the Millennium Problems. The book is aimed, as Derbyshire puts it in his prologue, "at the intelligent and curious but nonmathematical reader..." Prime Obsession explores such topics as complex numbers, field theory, the prime number theorem, the zeta function, the harmonic series, others. The biographical sections give relevant information about the lives of mathematicians who worked in these areas, including Euler, Lejeune Dirichlet, Chebyshev, Vallée-Poussin, Hadamard, as well as Riemann himself. In 2006, Joseph Henry Press published another Derbyshire book of popular mathematics: Unknown Quantity: A Real And Imaginary History of Algebra.
Derbyshire writes in general from a small government conservative perspective. He notably ridiculed George W. Bush's "itty-bitty tax cut, paid for by dumping a slew of federal debt on your children and grandchildren," derided Bush as too sure of his religious convictions and for his "rich-kid-ness", he has noted that small-government conservatism is unlikely to take hold in the United States, called for immediate U. S. withdrawal from Iraq, opposed market reforms or any other changes in Social Security, supported legal access to abortion, supported euthanasia in a wide range of circumstances, suggested that he might vote for Hillary Clinton as president. Derbyshire wrote about American schooling in his book We Are Doomed, "Education is a vast sea of lies, corruption, crackpot theorizing, careerist log-rolling." He further argued. Derbyshire once argued. In 2005, in a monthly column containing a series of miscellaneous musings, he controversially stated that women's physical attractiveness peaks between ages 15 and 20.
In an August 2012 article, Derbyshire summed up his view of American society by saying that it is "slipping into totalitarianism: into a state of affairs where to hold certain opinions is to be excluded from normal society, to be unemployable." He stated that "given enough advance warning, I can get my own wife and kids out to the comparative sanity and freedom of China." He wrote: The thought came upon me, as it has done quite a lot this past few years, that I shall end up in a labor camp. I can't keep my mouth shut. In the world we are fast heading into, that makes me camp fodder for sure. In April 2012, Derbyshire wrote an article for Taki's Magazine titled "The Talk: Nonblack Version." The article was a response to reports in the news media about "talks" given by African-American parents to their children warning them to be careful with police and to avoid arousing suspicion. The article, which he presented in terms of advice he had given his own children on interacting with African-Americans, made the point that members of any race could theoretically warn their children about the dangers posed by other ethnic groups.
Derbyshire presented multiple statistics regarding disparities in IQ test scores and rates of violent crime between blacks and whites, described "about five percent" of black people as being "ferociously hostile" to whites, relying on personal anecdotal experience to make the latter claim. He advised his readers to avoid settling in black neighborhoods, avoid events that draw large numbers of black people, refrain from helping black people who appear to be in distress, he advised white readers to scrutinize black politicians more than white ones, to cultivate friendships with the minority of "intelligent and well socialized blacks" for reasons of both "ordinary pleasures of friendship" and for "gain an amulet against career-destroying accusations of prejudice."A 2012 statement by him on VDARE attracted more media attention: Leaving aside the intended malice, I think "White Supremacist" is not bad semantically. White supremacy, in the sense of a society in which key decisions are made by white Europeans, is one of the better arrangements History has
Polecat is a common name for mammals in the order Carnivora and subfamilies Galictinae and Mustelinae. Polecats do not form a single taxonomic rank. In the United States, the term polecat is sometimes applied to the black-footed ferret, a native member of the Mustelinae, to skunks, which are only distantly related. Despite the name, being various caniform mustelids, are more related to dogs than cats, why they belong to the suborder Caniformia. In Canada, the term polecat is sometimes applied to electric utility linemen. According to the most recent taxonomic scheme proposing eight subfamilies within Mustelidae, the polecats are classified as: Subfamily Galictinae Genus Ictonyx Striped polecat, I. striatus, Saharan striped polecat, I. libycus Genus Vormela Marbled polecat, V. peregusna Subfamily Mustelinae Genus Mustela Steppe polecat, M. eversmannii American polecat M. nigripes European polecat, M. putorius
Greywater or sullage is all wastewater generated in households or office buildings from streams without fecal contamination, i.e. all streams except for the wastewater from toilets. Sources of greywater include, showers, clothes washing machines or dish washers; as greywater contains fewer pathogens than domestic wastewater, it is safer to handle and easier to treat and reuse onsite for toilet flushing, landscape or crop irrigation, other non-potable uses. The application of greywater reuse in urban water systems provides substantial benefits for both the water supply subsystem by reducing the demand for fresh clean water as well as the wastewater subsystems by reducing the amount of wastewater required to be conveyed and treated. Treated greywater has many uses, for irrigation. Greywater contains some traces of excreta and is therefore not free of pathogens; the excreta comes from washing a person's anal area from the laundry. The quality of greywater can deteriorate during storage because it is warm and contains some nutrients and organic matter, as well as pathogens.
Stored greywater leads to odour nuisances for the same reason. In households with conventional flush toilets, greywater makes up about 65% of the total wastewater produced by that household, it may be a good source of water for reuse, because there is a close relationship between the production of greywater and the potential demand for toilet flushing water. Misconnections of pipes can cause greywater tanks to contain a percentage of blackwater; the small traces of feces that enter the greywater stream via effluent from the shower, sink, or washing machine do not pose practical hazards under normal conditions, as long as the greywater is used correctly. In Hong Kong regional usage, an alternative term for blackwater is "foul water"; the separate treatment of greywater falls under the concept of source separation, one principle applied in ecological sanitation approaches. The main advantage of keeping greywater separate from toilet wastewater is that the pathogen load is much reduced and the greywater is therefore easier to treat and reuse.
When greywater is mixed with toilet wastewater, it is called sewage or blackwater and should be treated in sewage treatment plants or onsite sewage facility, a septic system. When it is kept separate, it may open up interesting decentralized reuse options. Greywater from kitchen sinks contains fats and grease and high loads of organic matter, it should undergo preliminary treatment to remove these substances before discharge into a grey water tank. If this is difficult to apply, it could be directed to the blackwater system or to an existing sewer. Most greywater is easier to treat and recycle than blackwater, because of lower levels of contaminants. If collected using a separate plumbing system from blackwater, domestic greywater can be recycled directly within the home, garden or company and used either or processed and stored. If stored, it must be used within a short time or it will begin to putrefy due to the organic solids in the water. Recycled greywater of this kind is never safe to drink, but a number of treatment steps can be used to provide water for washing or flushing toilets.
The treatment processes that can be used are in principle the same as those used for sewage treatment, except that they are installed on a smaller scale at household or building level: Biological systems such as constructed wetlands or living walls and bioreactors or more compact systems such as membrane bioreactors which are a variation of the activated sludge process and is used to treat sewage. Mechanical systems In constructed wetlands, the plants use contaminants of greywater, such as food particles, as nutrients in their growth; however and soap residues can be toxic to microbial and plant life alike, but can be absorbed and degraded through constructed wetlands and aquatic plants such as sedges and grasses. The global water resources are worsening. According to a report from United Nations states that 2.7 billion people will face the problem of water shortage by 2025, which means 1/2-1/3 of the total population of the world will be affected by this problem. Reusing the wastewater has become a good way to solve this problem, wastewater reuse is called recycled or reclaimed water.
Demand on conventional water supplies and pressure on sewage treatment systems is reduced by the use of greywater. Re-using greywater reduces the volume of sewage effluent entering watercourses which can be ecologically beneficial. In times of drought in urban areas, greywater use in gardens or toilet systems helps to achieve some of the goals of ecologically sustainable development; the potential ecological benefits of greywater recycling include Reduced freshwater extraction from rivers and aquifers Less impact from septic tank and treatment plant infrastructure Reduced energy use and chemical pollution from treatment Groundwater recharge Reclamation of nutrients Greater quality of surface and ground water when preserved by the natural purification in the top layers of soil than generated water treatment processesIn the U. S. Southwest and the Middle East where available water supplies are limited in view of a growing population, a strong imperative exists for adoption of alternative water technologies.
The potential economic benefits of greywater recycling include Can reduc
Sewage is a type of wastewater, produced by a community of people. It is characterized by volume or rate of flow, physical condition and toxic constituents, its bacteriologic status, it consists of greywater, blackwater. Sewage travels from a building's plumbing either into a sewer, which will carry it elsewhere, or into an onsite sewage facility. Whether it is combined with surface runoff in the sewer depends on the sewer design; the reality is, that most wastewater produced globally remains untreated causing widespread water pollution in low-income countries: A global estimate by UNDP and UN-Habitat is that 90% of all wastewater generated is released into the environment untreated. In many developing countries the bulk of domestic and industrial wastewater is discharged without any treatment or after primary treatment only; the term sewage is nowadays regarded as an older term and is being more and more replaced by "wastewater". In general American English usage, the terms "sewage" and "sewerage" mean the same thing.
In common British usage, in American technical and professional English usage, "sewerage" refers to the infrastructure that conveys sewage. Before the 20th century, sewers discharged into a body of water such as a stream, lake, bay, or ocean. There was no treatment, so the breakdown of the human waste was left to the ecosystem. Today, the goal is that sewers route their contents to a wastewater treatment plant rather than directly to a body of water. In many countries, this is the norm. Current approaches to sewage management may include handling surface runoff separately from sewage, handling greywater separately from blackwater, coping better with abnormal events. Proper collection and safe, nuisance-free disposal of the liquid wastes of a community are recognized as a necessity in an urbanized, industrialized society; the wastewater from residences and institutions, carrying bodily wastes, washing water, food preparation wastes, laundry wastes, other waste products of normal living, are classed as domestic or sanitary sewage.
Liquid-carried wastes from stores and service establishments serving the immediate community, termed commercial wastes, are included in the sanitary or domestic sewage category if their characteristics are similar to household flows. Wastes that result from industrial processes such as the production or manufacture of goods are classed as industrial wastewater, not as sewage. Surface runoff known as storm flow or overland flow, is that portion of precipitation that runs over the ground surface to a defined channel. Precipitation absorbs gases and particulates from the atmosphere and leaches materials from vegetation and soil, suspends matter from the land, washes spills and debris from urban streets and highways, carries all these pollutants as wastes in its flow to a collection point. Sewage is a complex mixture of chemicals, with many distinctive chemical characteristics; these include high concentrations of ammonium, nitrogen, high conductivity, high alkalinity, with pH ranging between 7 and 8.
The organic matter of sewage is measured by determining its biological oxygen demand or the chemical oxygen demand. Sewage contains human feces, therefore contains pathogens of one of the four types: Bacteria, Viruses and Parasites such as helminths and their eggs Sewage can be monitored for both disease-causing and benign organisms with a variety of techniques. Traditional techniques involve filtering and examining samples under a microscope. Much more sensitive and specific testing can be accomplished with DNA sequencing, such as when looking for rare organisms, attempting eradication, testing for drug-resistant strains, or discovering new species. Sequencing DNA from an environmental sample is known as metagenomics. Sewage contains environmental persistent pharmaceutical pollutants. Trihalomethanes can be present as a result of past disinfection. Sewage has been analyzed to determine relative rates of use of prescription and illegal drugs among municipal populations. All categories of sewage are to carry pathogenic organisms that can transmit disease to humans and animals.
Sewage contains organic matter that can cause odor and attract flies. Sewage contains nutrients. A system of sewer pipes takes it for treatment or disposal; the system of sewers is called sewerage or sewerage system in British English and sewage system in American English. Where a main sewerage system has not been provided, sewage may be collected from homes by pipes into septic tanks or cesspits, where it may be treated or collected in vehicles and taken for treatment or disposal. Properly functioning septic tanks require emptying every 2–
A sanitary sewer or foul sewer is an underground pipe or tunnel system for transporting sewage from houses and commercial buildings to treatment facilities or disposal. Sanitary sewers are part of an overall system called sewerage. Sewage may be treated to control water pollution before discharge to surface waters. Sanitary sewers serving industrial areas carry industrial wastewater. Separate sanitary sewer systems are designed to transport sewage alone. In municipalities served by sanitary sewers, separate storm drains may convey surface runoff directly to surface waters. Sanitary sewers are distinguished from combined sewers, which combine sewage with stormwater runoff in one pipe. Sanitary sewer systems are beneficial. Sewage treatment is less effective when sanitary waste is diluted with stormwater, combined sewer overflows occur when runoff from heavy rainfall or snowmelt exceeds the hydraulic capacity of sewage treatment plants. To overcome these disadvantages, some cities built separate sanitary sewers to collect only municipal wastewater and exclude stormwater runoff collected in separate storm drains.
The decision between a combined sewer system or two separate systems is based on need for sewage treatment and cost of providing treatment during heavy rain events. Many cities with combined sewer systems built prior to installing sewage treatment have not replaced those sewer systems. In the developed world, sewers are pipes from buildings to one or more levels of larger underground trunk mains, which transport the sewage to sewage treatment facilities. Vertical pipes made of precast concrete, called manholes, connect the mains to the surface. Depending upon site application and use, these vertical pipes can be cylindrical, eccentric, or concentric; the manholes are used for access to the sewer pipes for inspection and maintenance, as a means to vent sewer gases. They facilitate vertical and horizontal angles in otherwise straight pipelines. Pipes conveying sewage from an individual building to a common gravity sewer line are called laterals. Branch sewers run under streets receiving laterals from buildings along that street and discharge by gravity into trunk sewers at manholes.
Larger cities may have sewers called interceptors. Design and sizing of sanitary sewers considers the population to be served over the anticipated life of the sewer, per capita wastewater production, flow peaking from timing of daily routines. Minimum sewer diameters are specified to prevent blockage by solid materials flushed down toilets. Commercial and industrial wastewater flows are considered, but diversion of surface runoff to storm drains eliminates wet weather flow peaks of inefficient combined sewers. Pumps may be necessary where gravity sewers serve areas at lower elevations than the sewage treatment plant, or distant areas at similar elevations. A lift station is a sewer sump; the pump may discharge to another gravity sewer at that location or may discharge through a pressurized force main to some distant location. Effluent sewer systems called septic tank effluent drainage or solids-free sewer systems, have septic tanks that collect sewage from residences and businesses, the effluent that comes out of the tank is sent to either a centralized sewage treatment plant or a distributed treatment system for further treatment.
Most of the solids are removed by the septic tanks, so the treatment plant can be much smaller than a typical plant. In addition, because of the vast reduction in solid waste, a pumping system can be used to move the wastewater rather than a gravity system; the pipes have small diameters 1.5 to 4 inches. Because the waste stream is pressurized, they can be laid just below the ground surface along the land's contour. Simplified sanitary sewers consist of small-diameter pipes around 100 millimetres laid at flat gradients. Although the investment cost for simplified sanitary sewers can be about half the cost of conventional sewers, the requirements for operation and maintenance are higher. Simplified sewers are most common in Brazil and are used in a number of other developing countries. In low-lying communities, wastewater is conveyed by vacuum sewer. Pipelines range in size from pipes of 6 inches in diameter to concrete-lined tunnels of up to 30 feet in diameter. A low pressure system uses a small grinder pump located at each point of connection a house or business.
Vacuum sewer systems use differential atmospheric pressure to move the liquid to a central vacuum station. Sanitary sewer overflow can occur due to blocked or broken sewer lines, infiltration of excessive stormwater or malfunction of pumps. In these cases untreated sewage is discharged from a sanitary sewer into the environment prior to reaching sewage treatment facilities. To avoid this, maintenance is required; the maintenance requirements vary with the type of sanitary sewer. In general, all sewers deteriorate with age, but infiltration and inflow are problems unique to sanitary sewers, since both combined sewers and storm drains are sized to carry these contributions. Holding infiltration to acceptable levels requires a higher standard of maintenance than necessary for structural integrity considerations of combined sewers. A comprehensive construction inspection program is required to prevent inappropriate connection of cellar and roof drains to sanitary sewers; the probability of inappropriate connecti
A chamber pot is a portable toilet, meant for nocturnal use in the bedroom. It was common in many cultures before the advent of indoor plumbing. "Chamber" is an older term for bedroom. The chamber pot is known as a Jordan, a jerry, a guzunder, a po, a potty pot, a potty, or a thunder pot, it was known as a chamber utensil or bedroom ware. Chamber pots were used in ancient Greece at least since the 6th century BC and were known under different names: ἀμίς, οὐράνη and οὐρητρίς, σκωραμίς /, χερνίβιον; the introduction of indoor flush toilets started to displace chamber pots, in the 19th century but they remained common until the mid-20th century. The alternative to using the chamber pot was a long cold walk to the outhouse in the middle of the night. Chamber pots continue in use today in areas lacking indoor plumbing, such as rural China. In the Philippines, chamber pots are used as urinals and are known as arinola in most Philippine languages, such as Cebuano and Tagalog. In Korea, chamber pots are referred to as yogang.
They were used by people who did not have indoor plumbing to avoid the cold elements during the winter months and are still used in North Korea to this day. A chamber pot might be disguised in a sort of chair, it might be stored in a cabinet with doors to hide it. For homes without these items of furniture, the chamber pot was stored under the bed; the modern commode toilet and bedpan, used by bedbound or disabled persons, are variants of the chamber pot. The term "potty" is used when discussing the toilet with small children, such as during potty training, it is usually used to refer to the small, toilet-shaped devices made for potty training, which are similar to chamber pots. These "potties" are a large plastic bowl with an ergonomically-designed back and front to protect against splashes, they may have a built-in handle or grasp at the back to allow easy emptying and a non-slip bottom to prevent the child from sliding while in use. Some are given bright colors, others may feature gentle or unoffensive drawings or cartoon characters.
In many cases they are used since it is difficult for children to maneuver themselves up onto the normal toilet. Their size means they can be packed away in a bag for days out or when camping with young children, can be placed near or under beds for sufferers of nocturia or some other form of incontinence. "The Crabfish" is an old tale. Philippine mythology recounts. President Elpidio Quirino, as part of a smear campaign against him, was falsely rumoured to possess a golden arinola. Thomas More in his satire Utopia had chamberpots made out of gold. History of water supply and sanitation