REMOVAL OF MN AND SIMULTANEOUS REMOVAL OF NH3, FE AND MN FROM POTABLEWATER USING A TRICKLING FILTER

Manganese removal using a biological trickling filter was investigated . Manganese removal was found to be caused by both biological and chem ical manganese oxidation. The extent of each oxidation type was assess ed. The performance of the trickling filter was tested under both cont inuous and sequencing batch reactor operation. The effectiveness and t hroughput for each operational mode were determined as a function of r etention time and the advantages of each operational mode were investi gated. It was found that the continuous operational mode leads to high er percentage of manganese removal but lower throughput rates when com pared with a sequencing batch reactor operation with the same feed con centration and retention time. A series of experiments was also perfor med in order to investigate the interactions between ammonia, iron and manganese removal when simultaneously present in a biological filter. For low ammonia concentrations there is no serious inhibition of mang anese removal. For higher ammonia concentrations inhibition of mangane se removal becomes substantial. The presence of iron affects both ammo nia and manganese removal negatively, while ammonia and manganese do n ot significantly affect iron removal. (C) 1998 Elsevier Science Ltd. A ll rights reserved.