STUDIES REGARDING THE EFFECTS OF SETTLING TANKS SLUDGE RECYCLING ON ORGANIC MATTER CONCENTRATION FROM TREATED WATER

摘要

Paper objective was to search the effect of settling tank sludge recycling on organic matters concentration in treated water. The recycling of settling tank sludge has a beneficial effect on treated water turbidity. The value of COD-Mn indicator decreases with coagulant dose increasing, in all cases. The effect of higher sludge doses recycling is beneficial for the water treated turbidity, but in the case of organic matter concentration this favourable effect is reduced or may be unfavourable with sludge dose increasing. In the case of sludge recycling exists an optimum sludge dose that may be added in the water treatment process. At this dose the parameters of coagulation-settling process are improved (COD-Mn indicator included).