A Floating Settler for Low Cost Clarification

Abstract

During recent years a very significant level of research activity has been concerned with improving clarification techniques. The basis for much of this work has been classical shallow-tray sedimentation theory. The advantages of this concept have been discussed in the literature for over 65 years. In 1904, Hazen suggested shallow basins with a depth approaching 1 in. (1). Since the vertical travel distance for a settling particle is so small in such a basin the retention time could be a few minutes rather than a few hours. Many attempts have been made to develop a practical technology for implementation of this theory. Two major problems impeded progress: the construction or fabrication cost for installing a large number of shallow trays in a basin, and development of an efficient technique for removal of settled sludge. In addition it was found that very wide shallow trays had insufficient lateral constraints and led to unstable hydraulic conditions. (2).