Abstract
Effects of mixing operations of jar test on the turbidity removal by polymeric flocculant were studied experimentaly. The significance of the operating conditions such as the duration of flocculant injection, the stirrer speed, the mixing time and the combination of rapid and slow mixing operations.
The conclusions are summarized as follows :
1. The condition of flocculant injection such as the injection position and the duration of injection should be clearly defined so as to secure the reproducibility of the test.
2. As the jar test is affected greatly by either the mixing intensity or the mixing time the results of the test should be interpreted in terms of not only the amount of energy input but also the scheme of mixing operation.
3. Under the condition of the equal amount of energy input the rapid and slow mixing operations should be in order.
4. Under the above condition there exists an optimal time distribution to the rapid and slow mixing operations.
