Abstract
The transparent demonstration plant is a good platform to perform flocculation experiments on, due to its manageable size and close approximation of an actual AguaClara water treatment plant. Experiments were done to investigate how more uniform shear in the flocculator - created by obstacles inserted in the vertical sections between bends - improves flocculation. Initial results showed that more uniform shear at the beginning of the flocculator caused effluent turbidity to decrease. Yet when the plant was modified to make it more robust and to make the results more repeatable, those initial results could not be replicated. Certain systematic errors in the initial experiments were eliminated and new errors were introduced. Subsequently, the plant was automated using Process Controller to make it more time-efficient, and the desktop turbidity meter was replaced by an inline turbidity meter to eliminate unintended bias in readings. However, the results still showed that the performance of the flocculator did not improve by making shear more uniform. It is probable that the performance of the unmodified plant is already at the theoretical limit, and that improving flocculation at the beginning of the plant cannot decrease the turbidity of the effluent any further.
Keywords: demonstration plant, uniform shear, obstacles, improve flocculation
History
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