Chlorination can be done using either a solid or liquid form.
Calcium Hypochlorite Tablets (Solid)
A chlorination system utilizing 3.15 inch diameter calcium hypochlorite tablets (NSF 60 listed), weighing 300 grams, in conjunction with NSF 61 listed patented erosion feeder(s) operating in a non-pressurized manner to deliver controllable, adjustable dosages of chlorine as required for the specific water treatment application.
The Accu-Tabâ„¢ system is a superior alternative to liquid chlorine and potential gas hazards. With no liquid chlorine cylinders to handle, chlorine releases are non-existent. Process safety Management and Risk Management program compliance worries disappear.
Accu-Tabâ„¢ 3" Calcium Hypochlorite Blue Tablets are easy to handle. The chlorinators contain no moving parts or small openings to clog. Maintenance is as easy as cleaning the chlorinator once a year.
The PPG Chlorinator system delivers precisely the level of chlorine you need-automatically. Bleach will lose strength rapidly in storage. Other methods may provide variable chlorine levels. Accu-Tab Blue tablets have a patented controlled erosion agent for continuous, steady chlorination.
Accu-Tabâ„¢ System Registrations and Approvals:
- NSF Standard Listed
- Meets AWWA Standard B-300
- EPA Registration # 748-275 and 748-295
See BI Pure Waterâ€™s Calcium Hypochlorite Accu-Tab Systems
Sodium Hypochlorite Liquid (Bleach)
Sodium hypochlorite (NaOCl) is an unstable salt, common as a disinfecting and bleaching (oxidizing) compound. It is usually sold in solutions containing 5% (pH approximately 11) to 15% sodium hypochlorite in water (pH approximately 13), with 0.25 to 0.35% free alkali (usually NaOH) and 0.5 to 1.5% NaCl. Solutions of up to 50% sodium hypochlorite water are available for commercial purposes. A 12% solution is widely used in waterworks for the chlorination of water. High-test hypochlorite (HTH) is sold for chlorination of swimming pools and contains approximately 30% sodium hypochlorite. Sodium hypochlorite solutions often contain other agents, including sodium hydroxide to maintain a pH-dependent equilibrium between hypochlorite and chlorine. Caustic soda in sodium hypo chlorite causes the pH of the water to rise. When sodium hypo chlorite is mixed into water, hypochlorous acid (HOCl) and hypochlorite ion (OCl-) are formed. A mixture of 1 part bleach to 4 parts water is effective against many bacteria and some viruses, and is often the disinfectant of choice in cleaning surfaces in hospitals. Chlorine is unique in that pathogens cannot build up a resistance to the disinfectant.
Sodium hypochlorite is subject to degradation within the piping and pump system as it releases oxygen gas and results in crystallization of the residual. If the oxygen gas or vapour is allowed to build up within the piping and reagent head in sufficient volume, a typical reciprocating piston metering pump, used for accurately feeding chlorine to the process, will not function properly as gas in the pump head is compressed, minimizing the discharge check valve to open upon discharge stroke of the pump. Consequently, this effect could require that the pump be reprimed for operation.
Conditions that tend to increase gassing in sodium hypochlorite solutions are:
- Elevated temperatures
- High concentrating solution
- Exposure to sunlight or UV rays
- Reduction in pressure
- Poor piping conditions
- Contact with metallic impurities
- Contact with organic impurities
- Age of solution
The use of chlorine-based disinfectants in domestic water, although widespread, has led to some controversy due to the formation of small quantities of harmful byproducts such as trihalomethanes and chloroform.
See BI Pure Waterâ€™s Sodium Hypochlorite Systems