Suchergebnisse

AbstractThis study was carried out to evaluate the use of viscosity measurements as a method of assessing the optimum use of organic polymers as conditioning agents in sludge dewatering. The study focused on sludge from the clarifiers of a water‐treatment works. In addition to viscosity measurements, the programme included an appraisal of other techniques for specifying dewater‐ability, e.g. the specific resistance to filtration, the capillary suction time and the electrical charge status via streaming‐current measurements.

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.