Valentín Pando Fernández

Influence on Polychlorinated Biphenyls Content Using Three Types of Biowastes As Fertilizers In Agricultural Soils

A 4-year field study was carried out to investigate the effects of three types of biowastes application on PCB accumulation in agricultural soils. This study was based on the experiments designed for four soils in two areas of Palencia province (Spain) (Cerrato and Tierra de Campos) for non irrigated and irrigated land after applying biowaste. The amounts of the three different types of biowastes added were determined according to the fertilization needs of nitrogen for the crop. The concentrations of PCBs in soils were determined before and after biowaste application. The three biowaste treatments raise the concentration of PCBs in the soil, sewage sludge compost (SC) treatment produced the main increase in PCBs concentration, followed by municipal solid waste compost (MC) treatment and the dehydrated sewage sludge (SD) treatment. The values of biowaste treated areas were 3.7-11.5 times higher than the respective values of the non treated areas. Changes observed in the congener distribution also suggest the influence of the biowaste on the soil. The biowaste used had an average PCBs concentration of 63.16 ng g−1 with a range from 34.08 ng g−1 to 118.93 ng g−1, which are values below the EEC recommended limit (800 ng g−1). In the soils without treatment was found an average concentration 0.206 ng g−1 of PCBs, typical of areas with low levels of environmental pollution.