DISTRIBUTION OF ALUMINUM FROM ALUM SLUDGE IN WATER AND SEDIMENT

Aluminium sulfate is generally used as a primary coagulant in most mun icipal water treatment plants. The sludge produced is often discharged back into the river. Depending on the physicochemical properties of t he river water, aluminium from the sludge will become soluble and form various species that may be toxic to aquatic life. This study is an a ttempt to look at the effect of alum sludge dumping on the distributio n of various aluminium species in the Linggi River of Negeri Sembilan, Malaysia, which is used as source of raw water for the Linggi Water T reatment Plant. The result showed that the total aluminium concentrati ons in the five sampling stations located upstream and downstream of t he dumping point along the river were 0.48-1.14 mg L(-1), of which lab ile aluminium was 0.37-0.56 mg L(-1) and non-labile aluminium was 0.12 -0.58 mg L(-1). Statistical analysis indicated that there was no signi ficant difference in aluminium concentration in the water along the ri ver. However, total aluminium concentration in the sediments increased significantly downstream from the water plant, indicating that alumin ium from the sludge dumping may accumulate in the sediment.