An apparatus and methods to eliminate PFAS from wastewater biosolids through fluidized bed gasification. The gasifier decomposes the PFAS in the biosolids at temperatures of 900-1800° F. Synthesis gas (syngas) exits the gasifier which is coupled to a thermal oxidizer and is combusted at temperatures of 1600-2600° F. This decomposes PFAS in the syngas and creates flue gas. Heat can be recovered from the flue gas by cooling the flue gas to temperatures of 400-1200° F. in a heat exchanger that is coupled with the thermal oxidizer. Cooled flue gas is mixed with hydrated lime, enhancing PFAS decomposition, with the spent lime filtered from the cooled flue gas using a filter system that may incorporate catalyst impregnated filter elements. The apparatus and methods thereby eliminate PFAS from wastewater biosolids and control emissions in the resulting flue gas.