Sherif, A.E. A. A.R. Rabie Maha.,F.M. Ismaile El-Atrash E.N.( 2014). Impact of long-term application of treated Waste effulnts on nutration status and heavy Metals accumulation in irigated soil and some Growing woody tree species.J.Soil Sci. and Agric. Eng., Mansoura Univ., Vol. 5 (12): 1675 - 1690, 2014
Abstract: Egypt is an arid country, which covers an area of about one million Km2 of
which only 4% is occupied by its population. The population has tripled during last 50 years from 19 million in 1947 to about 83.5 million in 2012.of whom about 99% are concentrated in the Nile valley and Delta. The population is estimated to be about 100 million by the year 2025. One of the important issue in the future is to redistribute the population over a large area. To reach this objective, it is essential to reclaim new lands in order to provide the required food for the new communities. The current study was conducted at Egyptian& China Friendship Forest (El- Sadat City, Minufiya Governorate, about 100 Km North West of Cairo), to asses the suitability of the sewage effluent treated through stabilization ponds from the stand point of the Egyptian Code (501/2005). In addition the impact of long-term use of that effluent on the nutrition status and heavy metal accumulation in irrigated sandy soil as
well as some growing forest tree species. i.e. Cupressus sempervirens, Pinus
halepensis., Corymbia citriodora and Eucalyptus camaldulensis. The results of
chemical analyses of the waste effluents and tissue of tree organs indicated that:
1-There is no great seasonal variation in the most wastewater constituents
along the study year, and fall in category B in the code, with which no problem could be expected upon utilization for irrigation, especially in the light soil with deep ground water.
2-Utilization that effluents for irrigation along 12 years improved nutrition status of the sand soil and increased the level of heavy contents compared with that of the virgin one. That increases differed among the different elements, being due to the concentration of each in the effluent, its physic-chemical properties and the growing plant species. However, some nutrients in the effluents fail to produce the growing plants with its recommended value with which other nutrient sources is required. On the other hand the level of all heavy metal in the soil being below the maximum permissible limit.
3-The rate of heavy metals accumulation in the growing plants differed more or
less according to the growing plant species and their organs as well as sort of the element itself. The results of this study draw the attention of the benefit of using such sources of water in forest trees irrigating.
4-The study proved that the application of the principles and standards of the
Egyptian Code 501/2005 can be used successfully sewage waste to irrigate woody trees in desert areas and cities surrounded by desert without an environmental or health problems.
Keywords: (Reuse wastewater- heavy metals- contaminated soil- hyper accumulation trees.)
