Laboratory Investigation of sewage microbial pollutant transmission from sewage sludge as organic fertilizers in two different soils

Surplus and incorrect use of the organic manure cause some pollutants in manures enter to the drained runoff of irrigation water and, therefore, by entering to drainage network cause the pollution of groundwater. Microbial pathogen are important factors which can be transmitted in soils and develop the pollutions. Sewage sludge is one of organic fertilizers which are used by farmers. Various criteria are used to predict the presence of microbial factors. The most of them is to count number of coli forms which enable us to indicate the quantity and possibility of transmission of pollutions. In order to determine the transmitted rate of pollutions; a set-up of plastic circular barrel lysimeters are used in laboratory. Sewage sludge as organic manure are used on top of the soils by 35 tone/ha. Three samples of drained water after irrigating the soils obtained from each lysimeter by 10-1dilution based on pore volume. Taking sample was done for three times irrigation in total. The interval time was one week from each other. Then fermentation 15 -tubes standard method tests are carried out. The result is presented in tabular form. Result showed that the transmitted pollution rate (coliform) due to applying sewage sludge as fertilizer in loam soil is more than silt loam. Furthermore, pollution rate in first week was less than third week for both. In other word, increase in pollution is increased by time.

کلیدواژه ها:

Coliform ، Organic Manure ، Sewage Sludge ، Silt Loam ، Soil Pollution ، Water Pollution