Prepare for the American Water Works Water Treatment Plant Operator Test. Study with multiple choice questions, each with hints and explanations. Get ready to excel!

Multiple Choice

What device is used to apply dry chlorine gas to sewage when water under pressure is not available?

When chlorine gas is used without a supply of pressurized water to carry and dissolve it, you need a device that can meter and inject the gas directly into the sewer flow. A dry feed gas chlorinator is designed for this purpose: it precisely doses a measured amount of chlorine gas into the wastewater without relying on water pressure to dissolve it. The system typically attaches to a chlorine cylinder with a regulator, but its essential function is the chlorinator that controls the amount of gas fed into the line. A chlorine cylinder with regulator alone only provides gas; it doesn’t provide the metering/injection mechanism. A hypochlorite dosing system uses a liquid chemical, not dry chlorine gas. A gas diffusion scrubber is used to remove chlorine gas from exhaust streams, not to dose it into sewage.

When chlorine gas is used without a supply of pressurized water to carry and dissolve it, you need a device that can meter and inject the gas directly into the sewer flow. A dry feed gas chlorinator is designed for this purpose: it precisely doses a measured amount of chlorine gas into the wastewater without relying on water pressure to dissolve it. The system typically attaches to a chlorine cylinder with a regulator, but its essential function is the chlorinator that controls the amount of gas fed into the line.

A chlorine cylinder with regulator alone only provides gas; it doesn’t provide the metering/injection mechanism. A hypochlorite dosing system uses a liquid chemical, not dry chlorine gas. A gas diffusion scrubber is used to remove chlorine gas from exhaust streams, not to dose it into sewage.