FLOCCULATION REACTOR

Operation:

The flow of the "fine-tuned", treated effluent leaves the neutralization reactor and flows to the DMP flocculation module. At this point, a polyelectrolyte coagulant, or polymer, is introduced into the effluent to aid in the flocculation of the contaminants.

The feed rate and delivery is controlled by the operator interface located in the DMP Control Center. Through a simple set of keystrokes, the operator will input the amount of polymer to be delivered in gallons per hour. The Control Center will take input from the chemical feed pump to maintain the preset amount of flow of polymer to the flocculator. If the chemical feed pump cannot maintain the preset amount of flow, an alarm will alert the operator to check the chemical feed delivery system for any closed valves, blockages, etc.

The concentration and amount of polymer introduced into the treated effluent is based on preliminary testing and evaluation of samples during start-up. It will also be "fine tuned" based on visual appearance of the wastewater in the flocculator. When polymer (DMP 73-111) is added to treated and neutralized water, the precipitated metal hydroxides congeal to form larger particles that will become obvious when looking in the flocculator. The size of the particles varies greatly depending on the type of treatment. The proper formation of the "floc" is governed by pH and thorough mixing of the polymer with the treated water.

The extreme pH range for the operation of DMP 73-111 is 5.5 to 12.0; the optimum range is 7.5 to 9.0. Even though flocculation will occur out of the optimum range, the stability of the "floc" particles is adversely affected.

Jar Testing:

DMP has devised a relatively simple test for proper "floc" development. It consists of collecting two samples from the flocculator tank into a clear container (approximately 250 - 500 ml in size). Rapidly stir one of the containers with a scoop or spoon for a few seconds. Then allow the sample to settle for a brief time. The "floc" should re-form to approximately the consistency of the other container.

If the "floc" formation does not re-form, try adding more polymer and re-stirring. If settling is improved, increase the amount of polymer added to the flocculation tank.