LEVELS OF PERSISTENT ORGANOCHLORINE COMPOUNDS IN SEWAGE SLUDGE FROM WASTEWATER TREATMENT PLANTS
AgroLife Scientific Journal
The use of sewage sludge as fertilizer in agricultural soils is considered an economical way to use the high amounts produced by wastewater treatment plants. Besides the benefit, meaning high content of organic matter and nutrients, sewage sludge can have a negative impact on environment because it can contain persistent organic pollutants or heavy metals. The aim of this study is to establish the level of polychlorinated biphenyls (PCBs) and organochlorine insecticides in sewage sludge
... wage sludge collected from 10 wastewater treatment plants. The PCB IUPAC no. 28, 52, 101, 118, 138, 153, 180 and ten organochlorines were extracted with organic solvents, purified with copper and silicagel and analysed by gas chromatography/time of flight mass spectrometry. The concentration of total PCBs ranged from 3ng/g to 59.2ng/g dry weight, levels below the upper limit for land application according to Romanian legislation law for agricultural use. The predominant congeners found in sewage sludge were PCB 28, PCB 52 and PCB 138. PCB homologue profiles are dominated by Tri-CBs and Tetra-CBs. The contamination of sewage sludge samples with organochlorine insecticides refers only to the presence of DDE and dieldrin. The other insecticides (aldrin, HCH, ppDDT and ppDDD) are undetectable.