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Published in Jill L. Baker, Technology of the Ancient Near East, 2018
However, much earlier, in Mesopotamia, the Babylonians applied their knowledge of chemistry to create cleaning substances. Artifactual evidence for soap dates to ca. 2800 bce from a vessel containing a soapy substance, and from textual evidence dating to ca. 2200 bce. A recipe found on a tablet describes a soap formula consisting of water, alkali, and cassia oil. Chemists boiled these together to produce a residue with which people washed themselves and their clothing. They also mixed animal fats (e.g. goat) and/or vegetable oil and/or olive oil and/or coconut oil with wood ash (e.g. beechwood) and water. Alkali can be derived from burnt plant ashes soaked in a pot of water, also known as potash. Alkali can also be mined as a mineral and heated with calcium hydroxide (slaked lime), which results in caustic potash or potassium hydroxide. Caustic potash, combined with fats or oils (plant or animal), produces soap, and when combined with other fruits and vegetables, can be beneficial to one’s skin and hair. The soap was pressed into balls or blocks, much like we do today. The chemical reaction of the alkali (or lye) breaks down the triglycerides found in oils, and it is through saponification, the reaction between fatty acids and lye, that the soap is produced (Cable 2017). Soap allows otherwise insoluble particles like grease to become soluble in water so they can wash away (James and Thorpe 1995:261–263).
Pretreatment Limits for Fats, Oil and GreasE
Published in John M. Bell, Proceedings of the 43rd Industrial Waste Conference May 10, 11, 12, 1988, 1989
Peter V. Cavagnaro, Kenneth E. Kaszubowski
When alkali is mixed with food oil and fats the glycerol is liberated. The fatty acids and alkali react to form salts of fatty acids termed soaps, by a process known as saponification. Common soaps are formed by the saponification of fats with sodium hydroxide, and are soluble in water. In the presence of hardness, the sodium salts are converted to calcium and magnesium salts, which are insoluble and precipitate. The implication is significant for industries that use caustic cleaners for cleaning process equipment. As the rinse waters mix with fats and oils the free floating material will become emulsified. The subsequent saponification and precipitation could account for high effluent solids concentrations even after pretreatment. This is justification for pH neutralization as soon in the treatment process as is practical.
Water Pollutants and Water Pollution
Published in Stanley E. Manahan, Environmental Chemistry, 2022
Soaps are salts of higher fatty acids, such as sodium stearate, C17H35COO−Na+ . The cleaning action of soap results largely from its emulsifying power and its ability to lower the surface tension of water. This concept may be understood by considering the dual nature of the soap anion. An examination of its structure shows that the stearate ion consists of an ionic carboxyl “head” and a long hydrocarbon “tail”:
Efficacy of detergent-based cleaning methods against coronavirus MHV-A59 on porous and non-porous surfaces
Published in Journal of Occupational and Environmental Hygiene, 2022
Rachael L. Hardison, Sarah W. Nelson, Daniela Barriga, Jessica M. Ghere, Gabrielle A. Fenton, Ryan R. James, Michael J. Stewart, Sang Don Lee, M. Worth Calfee, Shawn P. Ryan, Megan W. Howard
Surface cleaning combines surfactant-based (e.g., detergents, soaps) or abrasive cleaners with physical removal to remove foreign material from surfaces (e.g., dirt, dust, or other organic debris [including microbes]); the physical removal (wiping or scrubbing) is a key component of this process. Residual non-microbial material (or soil) on surfaces can interfere with the antimicrobial activity of some chemical disinfectants by acting as a physical barrier or forming a chemical-soil complex with reduced antimicrobial activity (Lewis and Arens 1995; Muscarella 1995; Wyrzykowska-Ceradini et al. 2019). For this reason, disinfection strategies often incorporate surfactant-based cleaning prior to registered disinfection product application. Real-world cleaning methods vary by chosen product, but typically consist of wiping- or scrubbing- generated friction (by cloth, wipe, mop, or sponge) in addition to applying the cleaning solution.
Effect of zeolitic nano-catalyst on biodiesel yield and biochar formation during the pyrolysis of tallow
Published in Biofuels, 2021
Lawrence I. Obidike, Kelvin O. Yoro
The transformation of animals into meat in a slaughterhouse produces a significant amount of wastes, comprising mainly of fats. Furthermore, cattle produce about 31 kg of solid wastes from their rumen content, manure, skins, horns, hooves, and bones [31]. Also, about 820 L/day of liquid wastes comprising blood, bile, urine, and water is usually discharged as animal wastes from abattoirs [32]. Most slaughterhouses in developing countries dispose off the aforementioned animal wastes using methods such as incineration, spraying, and burial which are environmentally unfriendly [33]. Some of these animal wastes find their way into nearby streams and lakes; thereby rendering such disposal methods unhygienic and dangerous to environmental health. The indiscriminate disposal of animal wastes into water bodies contributes to the high organic nutrient loads in streams, leading to eutrophication and the impairment of aquatic life [34]. Furthermore, some slaughterhouses have developed substandard ways to dispose off animal fats. For instance, some slaughterhouses pre-treat bulk animal wastes with sodium hydroxide in an inadvertent saponification process to produce a soap-like mass which is usually disposed into streams. This “soap-like” mass slowly dissolves in water bodies as it moves along and is harmful to aquatic life. Also, the sodium hydroxide used in pretreating these wastes is not cheap, and the costs of contracting a waste processing company is high, thereby making the total expenses for the disposal of these animal wastes unaffordable. Therefore, there is an urgent need to promote the development of green alternative fuels through the beneficiation and valorization of animal wastes to meet growing global energy demand as well as reduce CO2 emissions. In response to this need, Obidike [12] studied the Karan Beef abattoir in Johannesburg South Africa which slaughters about 1200 cattle per day. Waste fats (tallow) from these slaughtered cattle could produce about 1.6 MWh of electricity, and which could take care of 554.75 households monthly in Diepsloot which is a township in Johannesburg with a population of about 350,000 people and 87,500 households. About 158 abattoirs the size of Karan Beef would supply the electricity need of Diepsloot and this is feasible since there are 479 registered abattoirs in South Africa. Obidike [12] also established that it is possible to produce biodiesel on a large scale in South Africa. A process flow diagram describing the unit operations to produce biodiesel is presented in Figure 2.