Description

Process Description

What is Perchlorate?

• Perchlorate is a naturally occurring and man-made anion that consists of one chlorine atom bonded to four oxygen atoms (ClO₄^–) .
• Perchlorate is an emerging environmental contaminant of concern and a known endocrine disruptor that affects thyroid activity.
• The Perchlorate anion is very water soluble, highly inert and stable.

Perchlorate may occur naturally, particularly in arid regions.  Manufactured forms of perchlorate include perchloric acid and salts such as ammonium perchlorate, sodium perchlorate and potassium perchlorate. Perchlorate is found as a natural impurity in nitrate salts , and are sometimes used to produce nitrate fertilizers and other products. Perchlorate is commonly used as an oxidizer in solid propellants, munitions, fireworks, airbag initiators for vehicles, matches and signal flares . It is also used in some electroplating operations and found in some disinfectants and herbicides.

What are perchlorate’s health effects?

• Perchlorate is highly soluble in water and  migrates quickly from soil to groundwater.
• Primary pathways for human exposure include ingestion of contaminated food and drinking water.
• Short-term exposure to high doses may cause eye and skin irritation,coughing, nausea, vomiting and diarrhoea.
• Perchlorate is a known endocrine disruptor that affects thyroid activity

What are the treatment methods for Perchlorate in water?

Common treatment technologies include ion exchange, bioreactors and in situ bioremediation.

Ion Exchange is a preferred means of perchlorate removal for the following reasons:

•  Ion exchange is an established technology for drinking water (e.g. softening, nitrate removal, tannin removal)
•  Non-detect levels for perchlorate can be achieved in the treated water (e.g. <1 ppb)
• Resins utilised are ANSI / NSF-61 Certified for municipal applications
• Setup and operation is fast and simple – shortest lead time; minimum operator attention
• Other coincident contaminants (e.g. nitrate, uranium, chrome-6) can be simultaneously removed.
• Ion exchange technology is particularly cost effective for removing trace levels of perchlorate in parts per billion range typically found in drinking water.

Our automatic backwashing filters are equipped with automated backwash control heads to backwash the media  at preset intervals. Whilst the filter media is  not regenerated,  the backwash serves to reclassify the media bed.

Automatic Backwashing Valves

Fleck Control Valve:

• Simple mechanical design is easy to use
  

  

• Two valve body designs: one for downflow regeneration and one for upflow (covers every valve in the 5600 family – quick access to all internal components)
• Injector/drain modules containing the brine valve, flow controls, and injector are removable from the valve’s exterior
• Ruggedly-built timer is designed with heavy-duty 3/8″ wide plastic gears
• 5600 controls are user-friendly and easily programmable
• Non-corrosive, UV-resistant, fiber-reinforced polymer valve body
• Choice of 7- or 12- day clock or demand regeneration with a mechanical meter
• Economical – small annual power consumption; keeps the time and activates the piston/valve mechanics with a single motor
• Designed with double backwash

Clack Control Valve:

• Solid state microprocessor with easy access front panel settings
• Double backwash feature offers efficiency and optimum regeneration and cleaning ability
• Days between regeneration feature: 1-99 days standard; 7-day optional
• Down flow regeneration
• 10 selectable pre-programmed regeneration cycles
• Stores system configuration and operation data in a non-volatile memory
• 12-volt transformer provides safe and easy installation
• Control valve design provides optimum service and backwash rates
• Treated water regenerant refill

 Filtration Media Description

LSC 106 Anion Resin

LSC 106 Anion exchange resins exhibit very strong affinities to the perchlorate ion.

It’s special matrix and tributylamine function group makes it highly selective for perchlorate.

In commercial applications, LSI 106 shows good mechanical strength and excellent mechanical strength to osmotic and thermal shock.

They can be used on a disposable or a regenerable basis. Type 1 or type 2 strong base anion resins have a higher affinity for the perchlorate ion than the nitrate or sulphate ions. This can lead to a long service run for perchlorate removal, but in cases where there is also nitrate present, the potential for nitrate dumping exists.

The standard SBA resins can be expected to remove perchlorates with capacities of between 2,000 to 10,000 bed volumes.

Selective Resins

“Targeted treatment” by the use of selective anion resins have helped to lower the overall treatment cost of perchlorate removal.A fair number of selective anion resins have been synthesised, but only two are available commercially, the tributylamine and triethylamine types. Each of the two types of selective resins has its own advantages, depending on the application. They both show very low affinities for sulphate and therefore practically eliminate the potential for nitrate dumping by sulphate. The triethlyamine structure, because of its smaller size, yields a resin with a higher operating capacity than the tributylamine (TBA) type. However, the TBA may provide lower chemical operating costs in large systems when regenerant use is minimised through brine reclamation schemes. The TBA resin shows the best promise as a selective resin for perchlorate removal.The TBA resin has shown throughput capacities more than two orders of magnitude higher than the standard anion resin. For point-of-use, this could result in a cartridge-type installation that would only need changing out once or twice a year.