Review of synthetic human faeces and faecal sludge for sanitation and wastewater research

Penn, Roni; Ward, Barbara J.; Strande, Linda; Maurer, Max

doi:10.1016/j.watres.2017.12.063

Cited by 120 publications

(67 citation statements)

References 62 publications

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“…Motor dysfunctions that include recto-anal dyssynergia have been shown to reduce intrarectal force / pressure and impair fecal expulsion [8,16]. However, whilst the visual assessment of the consistency of feces is well established as an aid to the diagnosis of abnormalities in bowel function [17], relatively little work has been done on the rheological properties of faeces [12,[18][19][20], which will directly influence their resistance to flow and hamper evacuation.…”

Section: Introductionmentioning

confidence: 99%

Rheology of human faeces and pathophysiology of defaecation

Loubens

Lentle

et al. 2020

Tech Coloproctol

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Background: Rectal evacuation involves multiple mechanisms that are not completely understood. The aim of this study was to quantify the rheologic property, i.e. yield stress, that governs the ease of deformation of a range of faeces of differing consistency and understand its influence on the pathophysiology of defaecation. Methods: Yield stresses of faeces of differing consistencies and Bristol scores were determined by the Vane test. We then explored the effects of this property on ease of defecation using a simple static model of the recto-anal junction based on the laws of flow for yield stress pastes and checked the conclusions by X-ray defaecography experience. Results: The yield stress of faeces increased exponentially with their solid content, from 20 to 8000 Pa. The static model of the recto-anal junction showed that evacuation of faeces of normal consistency and yield stress is possible with moderate dilatation of the anal canal, whilst the evacuation of faeces with higher yield stress requires greater dilatation of the anal canal. X-ray defaecography showed that such increases occurred in vivo. Conclusions: The diameter of the recto-anal junction is increased to enable the passage of feces with high yield stress. The finite limits to such dilation likely contribute to fecal impaction. Hence difficulties in defaecation may result either from unduly high yield stress or pathologies of reflex recto-anal dilatation or a combination of the two.

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Section: Introductionmentioning

confidence: 99%

Rheology of human faeces and pathophysiology of defaecation

Loubens

Lentle

et al. 2020

Tech Coloproctol

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“…The characteristics of faecal sludge in on-site sanitation systems may vary extensively depending on factors such as number of users, toilet use and lifestyle habits of the users, topography, location, urban or rural settlement (Penn et al, 2018;Rose et al, 2015;Zuma et al, 2015). The purpose of this data note is to disseminate the data that was collected through assessing the range of properties that may be encountered, it was proposed that faecal sludge samples are collected and analysed for typical on-site sanitation facilities in the Durban metro area, South Africa.…”

Section: Introductionmentioning

confidence: 99%

Mechanical properties of faecal sludge

2019

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On-site sanitation facilities contribute to the majority of toilet facilities in developing countries as full waterborne sanitation is not feasible or affordable. The characteristics of faecal sludge vary greatly between different locations and types of onsite sanitation facilities and at the same time their understanding is crucial for improvement of the existing faecal sludge management services. The Pollution Research Group (PRG), within the School of Chemical Engineering in the University of Kwa-Zulu Natal have been focussing on the analysis of faecal sludge from different on-site sanitation, such as urine diversion and dehydration toilets, wet and dry ventilated improved pit latrines at household and community levels and unimproved pit latrines. This study was undertaken between 2012 and 2014 and focussed on the characteristics of faecal sludge obtained from different on-site sanitation facilities in the Durban metro area in South Africa. Sampling methods were developed and applied for different depth levels of the pits for each on-site sanitation facility. The analysis followed the PRG standard operation procedures for properties such as: moisture content, total solids, ash content, pH, chemical oxygen demand, density, nutrient contents and thermal properties.

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“…These activities in gut are precisely regulated and thereby location-speci c, which means that the environment condition inside gut is different location by location [23][24][25][26][27]. Accordingly, the chemical and physical composition of feces differ from the GI contents in large intestine [28]. In fact, this work showed that the pH and water content of feces even differed from those of the GI contents in large intestine [29].…”

Section: Discussionmentioning

confidence: 98%

The Regional Diversity of Gut Microbiome Along the GI Tract

Lkhagv

Chung

Hong

et al. 2020

Preprint

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Background: The proliferation and survival of microbial organisms including intestinal microbes are determined by their surrounding environments. Contrary to popular myth, the nutritional and chemical compositions, water contents, O2 contents, temperatures, and pH in the gastrointestinal (GI) tract of human are very different in a location-specific manner, implying heterogeneity of the microbial composition in a location specific manner.Results: We first investigated the environmental conditions at 6 different locations along the along the GI tract and feces of ten weeks’ old male SPF C57BL/6 mice. As previously known, the pH and water contents of the GI contents at the different location of the GI tract were very different from each other in a location-specific manner, and none of which were not even similar to those of feces. After confirming the heterogeneous nature of the GI contents in specific location and feces, we thoroughly analyzed the composition of microbiome of the GI contents and feces. Metagenome sequencing on the GI contents and feces showed presence of 13 different phyla. The abundance of Firmicutes gradually decreased from the stomach to feces while the abundance of Bacteroidetes gradually increased. The taxonomic α-diversities measured by ACE richness, Shannon diversity and Fisher’s alpha all indicated that the diversities of gut microbiota at colon and cecum were much higher than that of feces. The diversities of microbiome compositions were lowest in jejunum and ilium while highest in cecum and colon. Interestingly, the diversities of fecal microbiome were lower than those of cecum and colon. Beta diversity analyses by NMDS plots, PCA, and un-supervised hierarchical clustering all showed that the microbiome compositions were very diverse in location-specific manner. Direct comparison of the fecal microbiome with the microbiome of the whole GI tracts by α-and β-diversities showed that fecal microbiome did not represent the microbiome of the whole GI tractConclusion: The fecal microbiome is different from the whole microbiome of the GI tract, contrary to the baseline assumption in the large majority of contemporary microbiome research work.

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Review of synthetic human faeces and faecal sludge for sanitation and wastewater research

Cited by 120 publications

References 62 publications

Rheology of human faeces and pathophysiology of defaecation

Rheology of human faeces and pathophysiology of defaecation

Mechanical properties of faecal sludge

The Regional Diversity of Gut Microbiome Along the GI Tract

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