Sludge and water mixture is homogeneous or heterogeneous mixture?

It is a heterogeneous mixture

Explanation:

A mixture is a substance that is formed by several components (two or more), which do not lose their properties and characteristics due to the mixing because there is no chemical reaction between them.

Homogeneous mixtures: Those mixtures whose components cannot be distinguished with the naked eye. The homogeneous mixtures of liquids are known as solutions and consist of a solute and a solvent, the first being the one in smaller proportion and also usually the liquid. For example, water mixed with mineral salts or sugar, water would be the solvent and sugar the solute.

Heterogeneous Mixtures: A heterogeneous mixture is one that has a non-uniform composition in which its components can be distinguished with the naked eye and is formed by two or more substances, physically different, unevenly distributed. The parts of a heterogeneous mixture can be separated mechanically. For example, water and sand, water and sludge, water and oil