Photophysical and photochemical properties of soil and aquatic humic materials

Occurrence of humic materials (HM’s) in almost every natural water as well as in soils is well known (Choudhry 1981 a). HM’s have also been detected in human feces (Khairy 1981). The organic matter of soil, peat, and water is usually divided into two groups, namely (1) non-humic materials and (2) humic materials (HM’s).