POLYMERS IN ALUM SLUDGE DEWATERING: DEVELOPMENTS AND CONTROL
In: Water and environment journal, Volume 17, Issue 2, p. 106-110
ISSN: 1747-6593
ABSTRACTThe paper (a) discusses the use of polymers for conditioning alum sludge derived from the coagulation of low turbidity coloured waters, and (b) reviews the factors which control the optimum dosage vis a vis individual test methods such as specific resistance to filtration and capillary suction time. It was demonstrated that good estimates of the solids feed could be obtained via the suspended‐solids concentration in the flocculators. An algorithm based on water‐quality parameters was recommended for planning purposes. Difficulties arising from variations in the solids delivery to the thickeners were shown to influence the separation efficiency. The paper also includes a survey of polymer routeing within a water‐treatment plant in which there was multiple polymer use and extensive recycling; this identified a number of quality‐control issues and demonstrated the value of polymer measurement.