Investigation some Properties of Shahin-Shahr Sewage Sludge For Land Application–Isfahan, Iran

Background:Land application of sewage sludge is still one of the most important disposal options in most countries. Although, land application of sludge allows the nutrients of sludge to be used beneficially, but pollutants and pathogenic organisms can raise the health risk.The aim of this study was to investigate the suitability of using dried sewage sludge of Isfahan wastewater plans as a fertilizer in agricultural lands. Methods: Samples were collected from Shahin-Shahr WWTPs1 in 2012, seasonally. Micro-biochemical parameters were measured for each site. Results: Total and fecal coliforms did not classify in any standard ranges. The pH, nitrogen, phosphor, potassium, calcium, total solid, organic matter and moisture were classified in normal ranges except for magnesium. The carbon to nitrogen ratios ranged from 7.41-9.45. It was significantly lower than the normal range.Organic nitrogen composed the highest percentage of the total nitrogen (about 78%) and inorganic nitrogen was in normal ranges. The electrical conductivity ranged from 5-8.8.It may contribute to soil salinization in long term. Seasonal variations showed the maximum nitrogen and phosphor was in winter. Minimum and maximum of potassium, calcium and magnesium were recorded in spring. Conclusion:Application of sewage sludge of Isfahan waste water treatment plans as a fertilizer could be useful regardless to its microbial contents because it provides essential nutrients for plants growth regardless to its fecal and total coliforms.