Comparative study of the characteristics of three types of sludge from wastewater treatment plants

摘要

whatever the adopted treatment system, the w astew aler treatment is accompanied by prod net ion of large amounts of sludge which must be disposed. Several pathways exist for the disposal of sewage sludge, but the choice must depend on the cost of installation, the result as an added value of the product and the possible impact of the chain retained on the environment To justify the choice of sludge recycling in agriculture, we will have to estimate the fertilizer value of sludge through the anuhsisof plnsico-chemical and microbiological parameters coniphing with regulations. Considering these parameters will determine the worth of sludge, the environmental impact and precautions for use. for this purpose, we have to compare the sludge characteristics from three wastewater treatment plants (WIP) in the wilaya of Mascara (west of Algeria). Mascara. Tizi and Ghriss. The results show that our overall sludge is rich in nutrients (N. P. K) but contains a hight concentrations in Nickel (Ni) of about 8.6 mg / kg prooabK due to industrial waste. To enhance the fertilizing power of the sludge in an agricultural lield we recommend an additional treatment