Investigation of some properties of North-Isfahan sewage sludge for application on agricultural land –Isfahan.

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 waste water plans as a fertilizer in agricultural lands. Samples were collected from North Isfahan WWTPs1 in 2012, seasonally.Micro-biochemical parameters were measured for this site. 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 ratiosranged from 8.7-9. 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 4.6-7.5.It may contribute to soil salinization in long term.Seasonal variations showed the maximum nitrogen andphosphor was in winter. Minimum and maximum of potassium, calcium and magnesium were recorded in summer in sludge of North Isfahan. 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.