design of 20 anionic polyacrylamide gel from Angola
automatic preparation. This type of unit (figure 19) comprises the main tank divided into a series of three tanks with overflow transfer: a first tank A, the preparation tank, receives water at a controlled pressure and flow rate, together with the powder measured out by a screw-type feeder, ensuring that the product drops evenly over the disperser; the polymer begins to swell and to dissolve
treatment programme, the turbidity level in the raw water was in the range of 50 NTU to 1200 NTU. After establishing the optimum polyelectrolyte dose with respect to the various raw water turbidity levels, polyelectrolyte dosing was done accordingly by the metering pump arrangement at the suction of raw water pumps.
