25 May 2005
Calibrated Mass Balance. Accurate chemical feed (rate and dosage) can
be measured precisely and adjusted according to mass water balance. Some chemical
delivery systems (pumps) use a calibration column to assure that chemicals are being
fed. A measured volume of chemical is fed relative to makeup water or feedwater, then
balanced by maintaining COC.
Automated Sensor Control. This is a relatively advanced technology that
automatically senses treatment level via an ion-specific electrode, such as might be
used for pH control or spectro-analysis that senses chemical tracers. Chemical feed is
adjusted automatically. The technology is effective as long as the sensing devices are
calibrated and properly maintained. The technology for spectro-analysis control is
relatively expensive. Another automated type of control is based on continuous
monitoring and control of the inhibitor based on fluorescence technology. Chemical
feed pumps are turned on when the continuous real-time measurement of the inhibitor
indicates that the level is below the desired treatment level. Control can be reliably
maintained within 3 ppm of the desired treatment levels in response to continuous real-
time measurement. This type of control can be justified based on the reliability of
proper treatment levels.
SAFETY AND GENERAL INFORMATION. A water treatment program
includes procedures for the feeding, handling, monitoring, storage, and disposal of
treatment chemicals. General trends within the water treatment industry have been: to
minimize or eliminate the physical handling of chemicals for reasons of safety and
manpower; to provide container management systems to eliminate drum disposal
problems; and to reduce or eliminate the need to store stockpiles of treatment
Safety. Chemicals used in water treatment, and in related maintenance
activities, range from being highly toxic to mildly irritating to the persons handling them.
All water treatment and testing chemicals are handled with caution, following any
special instructions prescribed by the manufacturer. Areas where chemicals are
handled or stored are kept clean and free of debris to minimize the chance of accidents.
People who handle these chemicals can attend safety education classes, refer to the
MSDS for additional information, and use proper equipment for respiration and
protection as recommended by the installation environmental or safety engineer.
Handling Acid. When handling acid, avoid splashing the liquid. If acid
does contact the eyes, skin, or even clothing, the affected area must be immediately
flushed with water for 15 minutes. All cases of acid burns, especially to the eyes, are
referred to a doctor. When acid is being diluted, water must never be added to acid
because this may cause a violent reaction or splattering. NOTE: Acid is always poured
into water; water is never poured into acid. When handling acid, goggles, face shield,
rubber gloves, and a rubber apron must be worn. Safety equipment must be of a type
approved by OSHA.