Environmental and chemical study of the applying treated sewage on irrigating urban forested areas

Abstract

Using treated sewage for irrigation can be a good source of food for plants and enriching agricultural lands due to the presence of fertilizing materials in treated sewage in addition to saving in water consumption. Nitrogen, phosphor and potassium are some of the essential nutrients for the growth and reproduction of plants. This research aims to evaluate the effect of irrigation with urban treated sewage on the chemical characteristics of soil and on the growth of three plant species namely Sempervirns, Buxus Cupressus Arizonica and Pinus Nigra used in green spaces and also on the aggregation of nutritional elements in different parts of plant species in the urban green space of Ghods Town in Tehran. In order to conduct the research, the green space area of Ghods Town in Tehran was selected as the sample area a part of which is irrigated with well water and another part irrigated with waste water. After the precise determination of the geographical and topographical characteristics of the control and experimental areas in this research, three 20x20 cm plots were implemented in a random systematical way. Three sample pieces were selected in each sample with a random systematical transmission. About 70 to 80 sample leaves as well as well water and waste water samples were collected in four repetitions for analysis. The results of this research show that irrigating green spaces with waste water causes a significant increase in some elements (N, P, K) in the leaf and in the growth of trees in green space.