Qualitative and Quantitative Analysis of Volatile Constituents from Latrines

Abstract

More than 2.5 billion people defecate in the open. The increased commitment of private and public organizations to improving this situation is driving the research and development of new technologies for toilets and latrines. Although key technical aspects are considered by researchers when designing new technologies for developing countries, the basic aspect of offending malodors from human waste is often neglected. With the objective of contributing to technical solutions that are acceptable to global consumers, we investigated the chemical composition of latrine malodors sampled in Africa and India. Field latrines in four countries were evaluated olfactively and the odors qualitatively and quantitatively characterized with three analytical techniques. Sulfur compounds including H2S, methyl mercaptan, and dimethyl-mono-(di;tri) sulfide are important in sewage-like odors of pit latrines under anaerobic conditions. Under aerobic conditions, in Nairobi for example, paracresol and indole reached concentrations of 89 and 65 μg/g, respectively, which, along with short chain fatty acids such as butyric acid (13 mg/g) explained the strong rancid, manure and farm yard odor. This work represents the first qualitative and quantitative study of volatile compounds sampled from seven pit latrines in a variety of geographic, technical, and economic contexts in addition to three single stools from India and a pit latrine model system.

Urban groundwater quality in sub-Saharan Africa: current status and implications for water security and public health

“…Sorensen et al (2015c) provided the first assessment of groundwater contamination for a broad range of compounds (n > 1,000) including pharmaceuticals, personal care products and industrial breakdown products within urban groundwater in Africa. Lin et al (2013) recently characterised a broad range of volatile organic compounds from pit latrines in Africa, an important source of groundwater contamination in this region (Graham and Polizzotto 2013). Olujimi et al (2010) review the presence of phthalates and other endocrine disruption chemicals in the South African environment.…”

Quantitative Headspace Analysis of Selected Odorants from Latrines in Africa and India

“…1 GC−MS coupled to an olfaction port showed the importance of di(tri)-methyl disulfide, guaiacol, and other aromatic compounds such as alkyl phenols, also described previously. 1 However, NEM derivatives were also present; therefore, these organic extracts were used only for quantification, and no intensive GC-O was performed. The organic extract of the acidified water showed the occurrence of branched short chain fatty acids, phenyl acetic acid, and phenyl propionic acid.…”

“…During a previous part of our project, we analyzed the sludge of a pit latrine. 1 The sludge was diluted in water, loaded on a solid-phase cartridge to capture the hydrophobic molecules, and shipped back to our laboratories. The volatiles were then extracted with an organic solvent and analyzed by gas chromatography−mass spectrometry-olfaction (GC−MS-O).…”

Sustainable sanitation, improved use of composting latrines through mixing and moisturizing: case study in Paraguay

“…There are issues related to the use (Clasen et al 2012), acceptance (Nayono et al 2010), and diffusion (Jenkins and Cairncross 2010) of latrines in developing countries, influence of latrines on water quality in sandy aquifers (Knappett et al 2012), degree of improvement realized (Exley et al 2015), methane (Reid et al 2014), and volatile compound (Lin et al 2013) emissions, microbial fuel cells for latrines (Castro et al 2014), and the spread of fecal matter from latrine floors (Pickering et al 2012) that are also important, but beyond the scope of this work.…”