Definitions & Origins

Cow Dung

As a waste resource from cows, cow dung can be defined as the undigested residue of consumed food.

It is rich in minerals such as potassium, magnesium, and phosphorus, which have good binding properties. Cow dung also typically contains undigested plant fiber.

Origins

In traditional earthen buildings in various Asian and African countries, such as India, Burkina Faso, Swaziland, and Botswana, cow dung is used in combination with clay as a plaster compound or covering layer for its water-repellent properties.

In India, in particular, traditional clay plasters contain high amounts of cow dung. This technique is still used today, alongside industrialized products that utilize waste cow dung from Indian farms.

Water Resistance

The reason cow dung has waterproofing properties is small microbial aggregates (SSMA), which consist of clay-sized, negatively charged particles rich in fatty acids. SSMA make up about one-third of the mass of cow dung.

Due to their shape, water droplets tend to slide down the SSMA. As they dry, the particles adhere to each other, increasing their surface area. Therefore, dried cow dung is less suitable for use than fresh cow dung.

One of the dominant fatty acids present, called octadecanoic acid, is also used in the production of superhydrophobic coatings.

Source: Kulshreshtha et al., 2022