Degermination methods Hypochlorite

Hypochlorite-solutions:

Chlorination with hypochlorite-solutions is feasible beside chlorination of water with chloric gas. Especially in cases of proportionally small water-amounts without the need of large equiptional effort.

In these procedures hypochlorite (sodium-, calciumhypochlorite, chlorinated lime amongst others) is solved or added in solid form to the water that needs to be treated.

A hypochlorite-solution (chlorine bleach liquor) has the advantage of a smaller safety risk compared to chloric gas. But the disadvantages are higher costs in chemicals, higher chemical volume and therefore more efforts in transport and storage.

Use:

Contrary to chloric gas, sodium-hypochlorite-solutions are used preferably in small waterworks with low water delivery, low specific chlorine-addition, lacking technical supervision due to own specialized staff, irregular utility-occupancy with operational staff (e.g. at night), close constructing housing in the area of the waterwork (chloric gas cloud, security risk), etc.

As opposed to liquid sodium-hypochlorite, calcium-hypochlorite are in the form of tablets or granulate material. Calcium-hypochlorite is not suitable for continuous disinfection of drinking-water because opposite to chloric gas, the price for active chlorine is ten times higher. Calcium-hypochlorite is preferred as an emergency-reserve in cases of malfunctions (better durability and shelf life contrary to sodium-hypochlorite).

Hypochlorite-solutions react alkalescent and contain 150 – 170 g chlorine per liter. A chlorine-portion can be reduced through exposure of light and storage (warmth). Even contamination, for example traces of heavy metal, can enforce degradation.

Critical:

In recent times hypochlorite hit the headlines as a disinfectant. Newest scientific insight link the use of all chlorine compounds with creating objectionable byproducts, for example trihalomethanes. These byproducts are under suspicion in being carcinogenic.