Study on the raw fish oil purification from PCDD/F and dl-PCB-industrial tests

The results of tests for the purification of fish oils with activated carbon for industrial use are presented. The optimum parameters for the process of purification (granulation of the activated carbon, its dosage, the oil temperature, and the duration of mixing the oil with activated carbon) were previously established for the laboratory scale. The optimization of the process consisted of selecting purification parameters that would allow for maximum reduction of the toxic polychlorinated dibenzo-para-dioxins and polychlorinated dibenzofurans (PCDD/Fs) content, while retaining the favorable high fatty acid content [C20:5 n-3, eicosapentaenoic acid (EPA) and C22:6 n-3, docosahexaenoic acid (DHA)]. The use of that optimum parameters in industrial conditions confirmed the satisfactory results obtained in laboratory tests. Five types of oil derived from various Baltic fish were purified. Reduction in the PCDD/Fs content was 77.0-93.6% on average, whereas in the dioxin-like polychlorinated biphenyls (dl-PCBs)-it was 42.7-50.5% on average, with insignificant changes in the total amount of EPA and DHA content. Furthermore, a significant reduction in the content of arsenic was noted (by about 62% on average), with insignificant changes in the content of organochlorine pesticides (OCPs), and marker polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), cadmium, lead, and mercury. Purification provided fish oil having standardized parameters that allow for its use as feed additives, whilst retaining its favorable fatty acid content.