TABLE OF CONTENTS (1) A rapid current of the tides. (2) A channel bringing water to or from a waterwheel or a turbine.
A bar screen, often a coarse screen.
A technique used to clean the inside of a water main prior to rehabilitation. It involves cleaning the pipe with a metal flay on the end of rods which are rotated by the driving rig that pushes the boring flay through the pipe. The turburculations are scraped from the pipe and flushed away with water.
The unit of absorbed dose of radiation. One hundred rad equals one Gray.
A pump with the water moving away from the axis of rotation, as in the centrifugal pump.
(Figure R.1) A circular sedimentation tank with the water or wastewater entering at the centre through an upward flow pipe into a vertical walled drum. The drum distributes the water or wastewater through its bottom and sides. Effluent flows out over a perimeter weir. The flow velocity is greatest at the centre and there is also an upward flow effect. Rotating sludge scrapers (either fixed bridge scrapers or rotating bridge scrapers) sweep the sludge into a central sludge hopper. Scraper speeds should not exceed 25 mm/s, to avoid breaking up the sludge. Radial flow tanks may be used for primary sedimentation or
