Zastosowanie separatora Lamella-Johnson do klarowania silnie zanieczyszczonych wód powierzchniowych

Investigated was the clarification of backwashing water with a simultaneous thickening of the sludge which forms during water treatment in a Lamella-Johnson separator equipped with a sludge tank and a sludge scraper. The efficiency of both the clarification and thickening processes was found to be high. The quality of the effluents from the backwash of the dual bed filters (operated in the direct filtration mode at the Waterworks of Kozłowa Góra) was described. The Lamella-Johnson separator under test was a pilot-plant model with a capacity of 3 m[3]/h. The advantages of using a multiplate settling tank were substantiated, and the optimal water flow velocity was determined. Consideration was also given to the rate of sludge thickening in the tank equipped with a scraper. The contribution of flu coagulants and polyelectrolytes to the efficiency of water clarification and sludge thickening was examined, and the optimum doses of relevant reagents were established. The results obtained with the Lamella-Johnson separator model were compared td those achieved with a classical settling tank. Thus, the quality of the clarified water was sufficiently high to make it fit for recirculation. The sludge thickened in the Lamella-Johnson separator had a high solids (40 g/dm[3], on average) and volatile suspended solids (55%) content and could be dewatered mechanically.