Effect of 15 Year Application of Municipal Solid Waste Composts on the Heavy Metals Accumulation in Soil.

The environmental and safety usage of the compost as an organic fertilizer depends on the quality of the solid waste and the quality of the produced compost. In order to investigate the impact of the compost to be produced from the compost plant in Syria, a study was made in the Faculty of Agriculture, Damascus University. This study investigated the 15 year usage of the compost produced from compost plant of Damascus on the soil in Rural Damascus.A randomized block (RB) design was made. Five pairs of similar fields were located. In each pair, one field was randomly assigned to receive compost from the Damascus compost plant, set about 15 cm deep (the treatment) , and the other received no compost (the control). Three subsamples were taken from depths down to 30 cm from each of the ten Fields. Each soil sample was analyzed in order to determine its chemical composition.The results of the analysis showed that the soil in which compost was used has a higher concentration of heavy metals like , Pb, Cu, Fe, Zn…etc.Content of Zinc element in soil has ranged between 18.19 mg/kg in field No.(5) and 4.22 mg/kg in control field No. (3) .The content of Fe in the soil ranged between about 17.10 mg/kg in the treatment field No. (2) and 8.92 mg/kg in th econtrol field No. (3).The values of Mn in the studied soil have ranged between 15.7 and 8.30 mg/kg in the treatment field No.(5) and control field No.(5) respectively.The values of Pb in the studied soil have ranged between 29.41 and 9.53 mg/kg in the treatment field No.(5) and control field No.(3) respectively.The values of Cd in the studied soil have ranged between 4.71 and 2.00 mg/kg in the treatment field No.(1) and control field No.(5) respectively.Statistical analysis showed significant treatment effect for all five pairs combined and also for most pairs individually.The study recommends continuing the research to establish a standard for the quantitative and qualitative content of heavy metals in the compost used for fertilizer.