Toxic metals such as Cu, Ni, Cr, and Pb were not of significant concentrations to inhibit anaerobic processes of a feces waste stream. However, the high concentrations of sulfide reported have the potential to exhibit toxicity to methanogenic bacteria Speece, ; this will only occur when high levels of sulfate are entering digesters along with sulfate reducing bacteria.
Relatively high levels of sulfate 1. Therefore, ammonia toxicity resulting from urea toxicity is likely to be problematic when feces and urine are treated as a combined waste stream and significant dilution could be necessary. Toxicity from the urine fraction could have negative impacts on biological systems as relatively large volumes of urine are collected in relation to feces daily urine:feces ratio on a weight basis of Accordingly it is suggested that smaller household systems that treat a combined feces and urine waste stream need to especially consider such issues and may be enhanced through inclusion of source separation.
Source separation could be carried out through the use of urine diverting toilets in which the feces and urine fractions are collected separately within the toilet bowl. There are numerous different types of separating technologies; however, the majority are likely to be predominantly influenced by variation in the solids content, physical form, as well as levels of protein and fat in feces.
For technologies based on separation the lack of a standard feces shape, structure, and water content may be one of the greatest challenges. This could impact bound water removal from different stool types and also the different particle sizes that make up feces. This uncertainty could be problematic when selecting process types and optimization operating conditions. In addition to this feces show a low proportion of fixed to volatile solids which could make dewatering challenging and require the addition of increasing amounts of chemicals or conditioning agents in order to gain adequate separation without pretreatment.
Layers of protein that form on the outside of particles could lead to clogging and its deposition and adhesion to membrane surfaces may cause fouling Chan and Chen, Nevertheless, shock loads due to variation in the fat content of feces may be large enough to cause the clogging of pores and impact dewatering properties. Information regarding the physical structure immediately after voiding provides an indication as to how the structure of feces may change over short time periods, for example, in the Bristol Stool Form scale a number of 1 or 2 would suggest a feces structure that holds its shape to a much greater extent than others in the scale.
This lack of data regarding the change in physical structure over time is limiting current ability to fully understand technology needs. Importantly, the time required to lose the initial consolidated identity of the fresh fecal material is required to understand the potential virtue of utilizing fast separation processes that could benefit from the initial cohesion of the solid material.
However, such development must also take into account looser fecal material that will also enter such systems and is likely to be significantly less effectively removed by physical processes. Accordingly, understanding the kinetics of the structural change in fecal material during the initial periods after generation remains a critical area for future research activity that could inform novel low cost technology development.
Chemical treatment processes can be wide ranging and are dependent on the end use and initial purpose of treatment and include processes such as chemical precipitation, disinfection, oxidation, neutralization, and stabilization. Efficient thermal technologies have been the focus of much development because of their potential for energy saving and cost recovery.
However, although there is great potential for energy production there is the negative aspect of the loss of nutrients present within feces and urine as the majority are made unavailable for agriculture use. The cost efficiency of the process is primarily dependent on the water content of excreta and its calorific value. The TS content and its variation will determine the financial viability of thermal processes and whether it can be a viable feedstock.
This is important as it highlights that when feces are voided the material is already at the level of de-watered sludge if it could avoid being diluted. This could therefore mean that thermal treatment technologies could potentially be used without prior dewatering processes and this factor could promote collection practices that involve less dilution of the waste stream highlighting again the need to understand the time related change in fecal identity that occurs during the initial periods after being voided.
Diet was the predominant cause for variation in water content predominantly fiber intake in healthy subjects, however, in unhealthy subjects this range can further increase due to the prevalence of diarrhea. Chronic and acute diarrhea within populations could have a significant impact on treatment technology as feces of those with diarrhea showed increases in water content and a change in physical structure. Global averages of diarrhea prevalence are significant in developed countries; therefore, this should be accounted for and amplified for technologies aimed at low income regions where both the chronic and acute diarrhea prevalence rates are likely to be significantly greater.
In contrast to diarrhea, constipation decreases the water content of feces and is equally prevalent in the developed world. Scales relating to the physical form of feces also provides a further estimation of the solids composition by providing approximate estimations of the TS content of feces across large sectors of populations.
Extremes in solids composition may cancel each other out in an averaging effect; however, thermal systems would have to be capable of dealing with this wide range and potential fluctuations in water content. The calorific value can be used as a metric of potential energy that can be produced during combustion of excreta. Human feces therefore could present an economically viable option for energy creation through combustion. However, humans will consume a much more varied diet then animals, leading to greater deviation from median values than would be seen in manure feedstock.
For example, although there is variation in the calorific value of swine manure from different sites e. This variation is predominantly caused by the varying presence of unavailable carbohydrates in the diet, the larger the quantity of unavailable carbohydrates the higher the energy value of feces voided. This has significance, as in lower income countries foodstuffs may often have more unavailable carbohydrates, therefore, feces of subjects in lower income countries may have fecal energy values higher than the values presented in this study suggest.
The high TS concentration of feces gives a good case for the source separation of feces and urine as the addition of urine could add the further problem of dewatering and could resultantly increase costs of thermal treatment processes. Other factors that may be significant for thermal process regard the potential emissions from any thermal treatment process.
This review aimed to characterize feces and urine and determine the extent and causes of variation seen and its subsequent impact on technologies treating feces and urine as a fresh waste stream. The generation rate of feces and urine shows significant variation across a wide range of studies presenting difficulties assigning standard design values for treatment technology processes. The values presented are based upon a large database of values from studies worldwide. The largest factor leading to variability in fecal mass is the indigestible fiber content of dietary intake; this explains the reason why fecal wet mass values were increased by a factor of 2 in low income countries.
A urine generation rate of 1. Variation in the chemical and physical composition of feces and urine was widespread throughout the study; this means that technology developments must be robust and flexible in order to deal with this uncertainty. It can be concluded however that the composition of feces and urine is highly dependent on the dietary intake of subjects. The predominant factor leading to variation in key parameters in feces was the dietary intake of non-degradable fiber which was shown to impact production rate, stool frequency, TS, fat, protein, and the energy value of feces.
In the urine fraction, protein intake was one of the key factors leading to variation in urea concentration as well as impacting concentrations of P, K, and Ca in urine. Biological treatment processes are likely to be effective at treating feces as a waste stream and a large proportion of the feces are likely to digest readily. However, high non-degradable fiber content of feces may reduce digestibility and with a combined waste stream of feces and urine the anaerobic digestion process may be limited with potential problems such as ammonia toxicity.
Technologies based on separation will predominantly be impacted by the variation in TS concentration as well as fluctuating levels of protein and fat found within the feces. Chemical processes will be largely influenced by variation in the diet consumed by subjects, leading to fluctuations in nitrogen and phosphorus loads which could be influential on pH levels, precipitation, and nutrient recovery. Thermal treatment processes will similarly be most influenced by variation in TS as well as the energy content of these solids, once again the intake of fiber proved most influential in predicting these factors.
The source separation of feces and urine could prove beneficial for biological treatment such as anaerobic digestion where large urea concentrations in the urine stream could prove problematic and cause ammonia toxicity. Similarly, the separation of the two streams could increase the efficiency of the dewatering process and make thermal processes increasingly attractive. In addition to this the largest proportion of nutrients e. It is therefore evident that source separation could be beneficial to many treatment technologies. This study has illustrated that there is significant variation in both the production values as well as the physicochemical composition of feces and urine.
Therefore, there are limitations in using standard design values in the development of treatment technology. Consequently it is important that treatment technology is robust and flexible enough to deal with the variation exposed. It is however possible to make more appropriate decisions about values of production and composition through the assessment of a target population's diet.
Through this a range of dietary factors can be assessed in order to make more informed decisions about design values that specifically target individual populations. Additional data, especially information regarding how the structure of feces changes over time, would be of further benefit to technology development but there is nevertheless no shortage of data regarding the production and composition of feces and urine.
National Center for Biotechnology Information , U. Critical Reviews in Environmental Science and Technology. Crit Rev Environ Sci Technol. Published online May Rose , a A. Jefferson , a and E. Cartmell a. Author information Copyright and License information Disclaimer. Address correspondence to A. E-mail: ku. Rose, A. Parker, B. Jefferson, E. The moral rights of the named author s have been asserted.
This article has been cited by other articles in PMC. Abstract The safe disposal of human excreta is of paramount importance for the health and welfare of populations living in low income countries as well as the prevention of pollution to the surrounding environment. Table 1 Measured variables for feces and urine. Open in a separate window. Table 2 The geographical location and human development index ranking of studies used in statistical analysis.
Table 3 Daily wet and dry mass produced by humans from low and high income populations. Table 4 The effect of diet type on fecal characteristics. Table 5 Daily loadings and concentrations of elements in feces wet weight. Figure 1. Outliers represent the upper value of the 75th percentile multiplied by the outlier coefficient 1. Factors Affecting Fecal Mass The major factors leading to variation in fecal generation rate are total food intake, body weight, and diet.
Figure 2. Values from 22 studies where fiber intake was recorded. Three large outliers were recorded, however, no reason could be found to exclude these results from the study. Stool Frequency Defecation frequency provides an indication for design parameters relating to treatability as it provides an indication of how often a facility may be used.
Figure 3. Ranges of individuals within these studies varied from 0. Composition Feces are composed of water, protein, undigested fats, polysaccharides, bacterial biomass, ash, and undigested food residues. Figure 4. Daily per capita weights of organic fractions excreted in feces. Lipids Fats contribute between 2. Chemical Nature Fecal pH is neutral with a median value of pH 6. Figure 5. Physical Form For the development of onsite treatment technologies an understanding of the physical form of feces is important; this characterization can be done through the use of visual scales or prevalence rates of diarrhea and constipation.
Visual Scale Within the medical literature a number of linear scales have been used to characterize feces e. Figure 6. Stool types 3 and 4 make up the most common stool type in both studies, however all types of stool are recorded in both studies.
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Diarrhea Diarrhea has an impact on stool production, structure, form, and composition. Table 7 Diarrhea prevalence in a selection of six countries. Constipation Constipation has prevalence rates that can range from 1. Urine In contrast to feces, the characteristics of urine have been studied extensively Diem and Lentner, ; Kirchmann and Pettersson, ; Karak and Bhattacharyya, Liquid Generation Human urine is a liquid that is secreted by the kidneys, collected within the bladder and excreted through the urethra.
Composition Urine composition varies due to differences in physical exercise, environmental conditions, as well as water, salt, and high protein intakes. Chemical Nature The pH of fresh urine is largely neutral with a median of pH 6. Table 9 Concentration of key components in fresh urine. Table 10 Components and generation rate of human excreta waste streams and possible additional inputs. Table 11 Classifications of broad treatment pathways in wastewater treatment. Biological Processes The predominant factors likely to impact biological processes to the greatest extent are solids loading, energy content, protein, and fat concentration in the feces and the high urea concentrations in urine.
Physical Separators There are numerous different types of separating technologies; however, the majority are likely to be predominantly influenced by variation in the solids content, physical form, as well as levels of protein and fat in feces. Chemical Processes Chemical treatment processes can be wide ranging and are dependent on the end use and initial purpose of treatment and include processes such as chemical precipitation, disinfection, oxidation, neutralization, and stabilization.
Thermal Processes Efficient thermal technologies have been the focus of much development because of their potential for energy saving and cost recovery. Table 12 Summary table of feces and urine characteristics providing on-site sanitation design criteria. Nancey S. Moussata D. Graber I. Messing B. Flourie B. Faecal bacterial mass and energetic losses in healthy humans and patients with a short bowel syndrome.
European Journal of Clinical Nutrition. Cofie O. Urine as an alternative fertilizer in agriculture: Effects in amaranths Amaranthus caudatus production. Renewable Agriculture and Food Systems. Behzad E. Pirzadeh S. Mohseni M. Bowel habit reference values and abnormalities in young Iranian healthy adults. Digestive Diseases and Sciences. Tao W. Forsberg B. Diarrheal diseases in low- and middle-income countries: Incidence, prevention and management.
The Open Infectious Diseases Journal. Wenzl H. Ana C. Porter J. Schiller L. Fordtran J. A comparison of stool characteristics from normal and constipated people. Butler D. Friedler E. At-source domestic wastewater quality. Urban Water. Park F. Lof J. Quigley E. An examination of the reliability of reported stool frequency in the diagnosis of idiopathic constipation.
The American Journal of Gastroenterology. Vora R. Kokai G. Investigations of chronic diarrhoea. Paediatrics and Child Health. Lax H. Hirche H. Winkler P. Zon R.
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Janhsen E. Renson C. Gool J. Self-reported urinary incontinence, voiding frequency, voided volume and pad-test results: Variables in a prospective study in children. BJU International. Wang X. Nitrogen-retaining property of compost in an aerobic thermophilic composting reactor for the sanitary disposal of human feces. International conference on environmental, biomedical and biotechnology, 3, 19—21 August, Shanghai pp. Study on dynamics model of biodegration of organic matter in aerobic mesophilic composting reactor for sanitary disposal of human feces.
Dave G. Laboratory studies on recovery of n and p from human urine through struvite crystallisation and zeolite adsorption. Environmental Technology. Allar A. Bayram S. Nitrogen recovery from source-separated human urine using clinoptilolite and preliminary results of its use as fertilizer. Water Science and Technology. Akkaymak E. Cinar S. Removal of ammonium from human urine through ion exchange with clinoptilolite and its recovery for further reuse.
Bender A. Nutrition; a reference handbook. Flynn M.
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Effects of high- and low-fiber diets on human feces. Journal of the American Dietetic Association. Muris J. Knottnerus J. Hoes A. De Wit N. Systematic review: The role of different types of fibre in the treatment of irritable bowel syndrome. Muir J. Phillips J. Jones G. Resistant starch lowers fecal concentrations of ammonia and phenols in humans. American Journal of Clinical Nutrition.
Sur R. Miller O. Pak C. Preminger G. Kolon T. Urinary reference values for stone risk factors in children. Journal of Urology. Foxon K. Broukaert C. Rodda N. Nwaneri C. Balboni E. Couderc A. Magagna D. Scientific support for the design and operation of Ventilated Improved Pit latrines VIPs and the efficacy of pit latrine additives. Pretoria: Water Research Commission; WRC Project No. Morley D. Walker A. Dietary fibre in under-and overnutrition in childhood. Archives of Disease in Childhood.
Painter N. Effect of dietary fibre on stools and transit-times, and its role in the causation of disease. The Lancet. Nixon G. Foy C. Harris N. Standardisation of data from real-time quantitative PCR methods—evaluation of outliers and comparison of calibration curves. BMC Biotechnology. Feachem R.
Environmental health engineering in the tropics: An introductory text. Chichester: Wiley; Vila A. Carrera M. Nieto J. Long-term effects of cyclosporine A in Alport's syndrome. Kidney International. Kretsch M. Protein and energy utilization in men given a rural Guatemalan diet and egg formulas with and without added oat bran.
The American Journal of Clinical Nutrition. Margen S. Variation in endogenous nitrogen excretion and dietary nitrogen utilization as determinants of human protein requirement. The Journal of Nutrition. Goldner B. Lutwack R. Research on applied bioelectrochemistry; First quarterly progress report. Hunt P. Uchimiya M. Novak J. Impact of pyrolysis temperature and manure source on physicochemical characteristics of biochar.
Bioresource Technology. Chappell M. Mao J. Chemical structures of swine-manure chars produced under different carbonization conditions investigated by advanced solid-state 13C Nuclear Magnetic Resonance NMR spectroscopy. Trevisan A. Bartolucci G. Adjustment to concentration-dilution of spot urine samples: Correlation between specific gravity and creatinine. International Archives of Occupational and Environmental Health. Sustainable environmental protection using modified pit-latrines.
Sanders W. Lettinga G. Demonstration of anaerobic stabilization of black water in accumulation systems under tropical conditions. Chen V. Characterization of protein fouling on membranes: Opportunities and challenges. Journal of Membrane Science. Chaudhury S. Dettmar P. Sykes J. Shaw A. Davies G. Effect of ispaghula husk on the faecal output of bile acids in healthy volunteers.
Cheng H. Liu Y. Liu S. Supplementation of konjac glucomannan into a low-fiber Chinese diet promoted bowel movement and improved colonic ecology in constipated adults: A placebo-controlled, diet-controlled trial. Journal of the American College of Nutrition. Haack V. Janecky C. Vollendorf N. Marlett J. Mechanisms by which wheat bran and oat bran increase stool weight in humans. Phua K. Normal bowel habits and prevalence of functional bowel disorders in Singaporean adults-findings from a community based study in Bishan.
Singapore Medical Journal. Eum Y. Gil K. High strength nitrogen removal from nightsoil and piggery wastes. The response of the colon to eating. Conroy R. Spelman K. The diuretic effect in human subjects of an extract of Taraxacum officinale folium over a single day. The Journal of Alternative and Complementary Medicine. Sontrop J. Macnab J. Suri R. Moist L. Salvadori M. Garg A. Urine volume and change in estimated GFR in a community-based cohort study. Clinical Journal of the American Society of Nephrology.
Hilton C. Irvine G. Lennard-Jones J. Misiewicz J. Variation of bowel habit in two population samples. British Medical Journal. Strauss K. Caplan Y. LoDico C. Bush D. Urine pH: The effects of time and temperature after collection. Journal of Analytical Toxicology. Burkitt D. Diet, bowel behaviour, and disease. Letter: Bowel-transit times and diet. Bingham S. Heaton K. Eastwood M. Fecal weight, colon cancer risk, and dietary intake of nonstarch polysaccharides dietary fiber Gastroenterology.
Branch W. Jenkins D. Southgate D. Houston H. James W. Colonic response to dietary fibre from carrot, cabbage, apple, bran, and guar gum. Beatty E. Kingman S.
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Englyst H. Digestion and physiological properties of resistant starch in the human large bowel. British Journal of Nutrition. Wiggins H. Jivraj T. Drasar B. Hill M. Influence of diets high and low in animal fat on bowel habit, gastrointestinal transit time, fecal microflora, bile acid, and fat excretion. The Journal of Clinical Investigation. Phosphorus and nitrogen in sanitary systems in Kalmar.
Few people know that the first gender-segregated toilets were assembled in a Parisian restaurant for a ball held in The first sociological studies of prostitution were conducted by a Parisian sanitary engineer, but what I call the sex-elimination linkage is under-theorized. Little has been written about the otherwise unisex bidet made famous by sex-workers in France and Italy.
We may never know how many of the racially segregated restrooms in the segregated South were unisex and how African-Americans negotiated the unjust Jim Crow laws. It is also of interest that the first public facilities for women were built in shopping areas so that women could shop for longer periods of time. The bladder functions like a leash, and the availability of accessible toilets demarcates who can go where. It is high time we questioned the silence surrounding the gendered and sexual politics of the toilet because they are not only inaccessible to trans folks and people with physical disabilities, but heterosexist as well.
French philosopher Michel Foucault wrote that preoccupations about sex were literally built into modern architectural design. This is especially true of the modern gender-segregated toilets of today. Even the receptacles seem to mirror human anatomy and heterosexual body politics. Scholars of toilet architectural design like Alexander Kira have noted that urinals resemble enlarged vaginas, whereas the oval pedestal enclosed by stall partitions resembles the anus. Men stand upright in open view while women back into a crouching position in enclosed stalls.
It is as if the receptacles prompt us to assume the missionary position associated with penetrative heterosexual sex. It is perhaps not surprising that people have sex in public facilities despite worries about unwanted pregnancy and misconceptions about toilet seats being havens for sexually transmitted infections. Thanks to the diligent work of safer sex activists, we now have condom machines in public facilities, right beside the perfume and tampon dispensers.
In Queering Bathrooms I sought to understand how restrooms enable us to negotiate sex and gender identity in public. Based on a hundred interviews with GLBT subjects in major Canadian and American cities, I provided an overview of their experiences as relayed. People shared stories of being harassed and denied entry to public toilets because of their gender identity.
It was not uncommon for trans folks to be refused a bathroom at their place of work. One interviewee actually kept a bucket under her desk at a large corporation. An unfortunate few were arrested by police, only to have the charges dropped at the station. There are devastating stories about gay men being arrested in urinals for public indecency. Equally moving are those stories told by interviewees who fondly recall having gay sex for the first time in a public lavatory. Many of those who have sex in toilets stress how much they enjoy the homoeroticism of the bathroom; men, for example, standing side-by-backside in plain open view before the urinal social prohibitions on looking not withstanding , and women peering at each other in hanging mirrors above the sink.
One trans man even recalled stepping up to a urinal almost twice his height to the consternation of an older man at a nearby urinal. The stories told by interviewees about using a bathroom for the first time, post-transition, without trouble or trepidation, are especially moving.
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Who would have thought that the toilet played such a pivotal role in sex and gender politics? The room is a repository for social intolerance and a fount of queer counter-cultural politics. What we do in bathrooms matters. The way we sign gender on doors and negotiate sex in public is of relevance to LGBT communities. Minnesota Public Radio. American Public Media Group. Penske Media Corporation. Hidden Remote. April 26, The New York Times. The New York Times Company. Retrieved 26 June This literature-related list is incomplete ; you can help by expanding it.
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