The following points highlight the top three methods adopted for purification of water. The methods are: 1. Sedimentation 2. Filtration 3. Disinfection. Method # 1. Sedimentation: Sedimentation is done when water consists of large sized organic materials such as leaves, and gravels which have run off from the soil. Suspended particles settle down depending on their size and weight and [...]
Physicochemical properties of soil include soil texture, water, air, inorganic chemicals, and organic matter. The biological factors of soil are soil flora and fauna. Mechanical composition (texture) of soil is determined on the basis of size of soil particles i.e. sand, silt and clay particles (Table 30.1). However, the ratio of soil particles governs the porosity (pore size of soil), [...]
Microorganisms which live in soil are algae, bacteria, actinomycetes, bacteriophages, protozoa, nematodes and fungi (Fig. 30.2). A brief description of soil microorganisms has been given below: 1. Soil Algae: Soil algae (both prokaryotes and eukaryotes) luxuriantly grow where adequate amount of moisture and light are present. They play a variety of roles in soil. One of the important role of [...]