Whitewater clarification using a dual flocculation/ultrasonic method

As a novel approach to solids removal, a dual chemical flocculation/ultraso nic method to clarify a whitewater stream was investigated. The technology first considers the use of flocculants to create larger particles or flocs. Then, an ultrasonic field is applied to the flocs to obtain a clarified wa ter stream and a stream of concentrated flocs. A laboratory ultrasonic sepa ration system was used to demonstrate the clarification concept. Experiment s at different flow rates, ultrasonic frequencies and acoustic intensity le vels were made. Best results were observed using the flocculant system poly (ethylene oxide)/phenolic formaldehyde resin (PEO/PFR). A clean stream with less than 100 ppm of solids and a clarification efficiency close to 80% of the maximum achievable efficiency in the experimental setup were obtained. A preliminary economic assessment of the technology was performed.