The Inputs of POPs into Soils by Sewage Sludge and Dredged Sediments Application

Abstract

The use of sewage sludge and dredged sediments in agriculture belong to the most important ways of possible pollutants inputs into agricultural soils in many countries including Czech Republic. The application of sewage sludge on agricultural soils is connected with following facts: increasing amounts of sewage sludge thanks to intensive waste water treatment the characteristic of sludge as the material with increased content of organic matter and nutrients The application of sludge into soil could lead to an increase of the contents of organic matter or macro elements, but the contamination by potentially risky elements and persistent organic pollutants could be relevant also. The problems connecting with increased persistent organic pollutants (POPs) contents in sewage sludge were confirmed by many authors (Markard, 1988; Melcer et al., 1988; Starke, 1992; Oleszczuk, 2007; Clarke et al., 2008; Natal-da-Luz et al., 2009). The load of soil by POPs after sludge application can influence their transfer into food chains (Passuello et al., 2010). Increased contents of polycyclic aromatic hydrocarbons (PAHs) limit not only direct application of sewage sludge on the soil but also the use of sludge in composting processes for example (Rosik-Dulewska et al., 2009). The inputs of POPs into agricultural soils by biosolids use in agriculture plays an important role. This problematic is documented on the example of following study realised in the Czech Republic where the contents of POPs in the soil and plants after sewage sludge and sediments application were observed. The number of waste water factories increased after implementation of Czech Republic into European Union when the obligation of waste water factory existence in every settlement over 10 000 inhabitants till 2010 year had to be fulfilled. The necessity of legislative regulation existence controlling this process was obvious since the beginning of ninetieth years and the Directive No. 382/2001 was the first version of legislative adaptation. The Directive was modified under the No. 504/2004 Sb. in 2004 year. The directive of Czech Ministry of Environment No. 504/2004 Sb. regulates the application of the sludge on agricultural soils. The directive determines the conditions of sludge application on agricultural soils, including limit values of potentially risk elements and some persistent organic pollutants (sum of halogenated organically bound substances AOX, sum of six congeners of polychlorinated biphenyls PCB6) in sludge. The directive 86/278/EEC regulates the sludge application in EU legislation. Only the contents of 6