Mieke Van Bavel, Kristel Van den Broeck, Nausikaä Van Hoornick, Jan Van Hoeymissen, IMEC, Leuven, Belgium & Robert de Boer, DHV Water BV, The Netherlands
The development of a sustainable technology for the treatment of HF containing wastewater is an important issue for the semiconductor industry. This paper presents a method that allows treating HF wastewater without waste production. The method uses the Crystalactor® technology and is based on the crystallization of CaF2 on sand particles in a fluidized bed reactor. Optimal working conditions were determined for the treatment of real wastewater originating from a semiconductor prototyping line. Depending on the operating conditions, the treated water can have a fluoride concentration as low as 10 ppm, and exhibits a low turbidity. In addition, a post-treatment process for the further removal (< 10 ppm) of fluoride in the effluent is presented.