ABSTRACT
Water is the most abundant and almost omnipresent substance on the earth. Driven by solar energy, the water remains in a state of continuous circulation, changing its form along its pathways. The global ecosystem comprises numerous smaller ecosystems interacting with each other in various ways. Ecosystems are nature’s functional units composed of dynamically interacting and interdependent community of plants, animals and micro-organisms, together with their non-living environment. Ecosystems differ from each other in the suite of plant and animal communities which comprise them under the given climatic, geomorphic and edaphic conditions. The human use of water is complicated by a large number of factors. First and foremost, the earth’s water resources are highly unevenly distributed — both spatially and temporally — and at the same time, they vary also in their quality. The problem of degradation of the quality of water is however not restricted to the direct disposal of untreated or partly treated wastewater.
